Minimally invasive procedures for right side infective endocarditis: A targeted literature review

INTRODUCTION

Right-side infective endocarditis (RSIE) is caused by microorganisms and develops into intracardiac and extracardiac complications with high in-hospital and 1-year mortality. Treatments involve antibiotic and surgical intervention. However, those presenting with extremes e.g. heart failure, or septic shock who are not ideal candidates for conventional medical therapy might benefit from minimally invasive procedures.

OBJECTIVE

This review summarizes existing observational studies that reported minimally invasive procedures to debulk vegetation due to infective endocarditis either on valve or cardiac implantable electronic devices.

METHODS

A targeted literature review was conducted to identify studies published in PubMed/MEDLINE, EMBASE, and Cochrane Central Database from January 1, 2015 to June 5, 2023. The efficacy and/or effectiveness of minimally invasive procedural interventions to debulk vegetation due to RSIE were summarized following PRISMA guidelines.

RESULTS

A total of 11 studies with 208 RSIE patients were included. There were 9 studies that assessed the effectiveness of the AngioVac system and 2 assessed the Penumbra system. Overall procedure success rate was 87.9%. Among 8 studies that reported index hospitalization, 4 studies reported no death, while the other 4 studies reported 10 deaths.

CONCLUSIONS

This study demonstrates that multiple systems can provide minimally invasive procedure options for patients with RSIE with high procedural success. However, there are mixed results regarding complications and mortality rates. Further large cohort studies or randomized clinical trials are warranted to assess and/or compare the efficacy and safety of these systems.

What Are the Long-term Outcomes of Mortality, Quality of Life, and Hip Function after Prosthetic Joint Infection of the Hip? A 10-year Follow-up from Sweden

BACKGROUND

Prosthetic joint infection (PJI) is a complication after arthroplasty that negatively affects patient health. However, prior reports have not addressed the long-term consequences of hip PJI in terms of patient mortality, quality of life, and hip function.

QUESTIONS/PURPOSES

At a minimum of 10 years after PJI in patients undergoing primary THA, in the context of several large, national databases in Sweden, we asked: (1) Is mortality increased for patients with PJI after THA compared with patients with a noninfected THA? (2) Does PJI of the hip have a negative influence on quality of life as measured by the Euro-QoL-5D-5L (EQ-5D-5L), ambulatory aids, residential status, and hip function as measured by the Oxford Hip Score (OHS)? (3) Which factors are associated with poor patient-reported outcome measures (PROMs) for patients with PJI after primary THA?

METHODS

This study included 442 patients with a PJI after primary THA, from a previously published national study, including all patients with a THA performed from 2005 to 2008 in Sweden (n = 45,570) recruited from the Swedish Hip Arthroplasty Registry (SHAR). Possible deep PJIs were identified in the Swedish Dispensed Drug Registry and verified by review of medical records. Mortality in patients with PJI was compared with the remaining cohort of 45,128 patients undergoing primary THA who did not have PJI. Mortality data were retrieved from the SHAR, which in turn is updated daily from the population registry. A subgroup analysis of patients who underwent primary THA in 2008 was performed to adjust for the effect of comorbidities on mortality, as American Society of Anesthesiologists (ASA) scores became available in the SHAR at that time. For the PROM analysis, we identified three controls matched by age, gender, indication for surgery, and year of operation to each living PJI patient. A questionnaire including EQ-5D-5L, ambulatory aids, residential status, and OHS was collected from patients with PJI and controls at a mean of 11 years from the primary procedure. Apart from age and gender, we analyzed reoperation data (such as number of reoperations and surgical approach) and final prosthesis in situ to explore possible factors associated with poor PROM results.

RESULTS

After controlling for differences in sex, age, and indication for surgery, we found the all-cause 10-year mortality higher for patients with PJI (45%) compared with patients undergoing THA without PJI (29%) (odds ratio 1.4 [95% CI 1.2 to 1.6]; p < 0.001). The questionnaire, with a minimum of 10 years of follow-up, revealed a lower EQ-5D-5L index score (0.83 versus 0.94, -0.13 [95% CI -0.18 to -0.08; p < 0.001]), greater proportion of assisted living (21% versus 12%, OR 2.0 [95% CI 1.2 to 3.3]; p = 0.01), greater need of ambulatory aids (65% versus 42%, OR 3.1 [95% 2.1 to 4.8]; p < 0.001), and a lower OHS score (36 versus 44, -5.9 [-7.7 to -4.0]; p < 0.001) for patients with PJI than for matched controls. Factors associated with lower OHS score for patients with PJI were three or more reoperations (-8.0 [95% CI -13.0 to -3.2]; p = 0.01) and a direct lateral approach used at revision surgery compared with a posterior approach (-4.3 [95% CI -7.7 to -0.9]; p = 0.01).

CONCLUSION

In this study, we found that PJI after THA has a negative impact on mortality, long-term health-related quality of life, and hip function. Furthermore, the subgroup analysis showed that modifiable factors such as the number of reoperations and surgical approach are associated with poorer hip function. This emphasizes the importance of prompt, proper initial treatment to reduce repeated surgery to minimize the negative long-term effects of hip PJI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Contemporary Trends and Outcomes of Prosthetic Valve Infective Endocarditis in the United States: Insights from the Nationwide Inpatient Sample

BACKGROUND

Prosthetic valve endocarditis (PVE) carries high mortality and morbidity as compared to native valve endocarditis (NVE). Contemporary data on PVE are lacking, we aimed to study contemporary trends, outcomes, and burden of PVE using nationally representative data.

METHODS

We used the National Inpatient Sample from 2000 to 2017 to identify patients admitted with PVE using ICD-9-CM and ICD-10 codes. Risk-adjusted rates were calculated using an Analysis of Covariance (ANCOVA) with the Generalized Linear Model (GLM). Trends were assessed with linear regression and Pearson's Chi-square when appropriate. Binomial logistic regression was used to assess predictors of in-hospital mortality.

RESULTS

We identified 43,602 hospitalizations for PVE. PVE hospitalizations increased from 1803 in 2000 to 3450 in 2017. Risk-adjusted mortality decreased from 10.7% in 2002 to 7.3% in 2017 (P<0.01). Logistic regression analysis on mortality showed increase association with age (OR, 1.021, 95%CI [1.017-1.024], p<0.01), Hispanics (OR, 1.493, 95%CI [1.296-1.719], p<0.01) and patients with drug abuse(OR, 1.233, 95%CI [1.05-1.449], p=0.01). Co-morbid conditions like congestive heart failure (OR, 1.511, 95%CI [1.366-1.673], p<0.01), renal failure (OR, 1.572, 95%CI [1.427-1.732], p<0.01) and weight loss (OR, 1.425, 95%CI [1.093-1.419], p<0.01) were also associated with higher mortality.

CONCLUSIONS

Over the years the adjusted in-hospital mortality in PVE has trended down but the average cost of stay has increased despite decrease in length of stay.

In situ revascularization with rifampicin-soaked silver polyester graft for aortic infection: Results of a retrospective monocentric series of 18 cases

OBJECTIVE

To evaluate the short and long-term results of in situ prosthetic graft treatment using rifampicin-soaked silver polyester graft in patients with aortic infection.

MATERIAL AND METHOD

All the patients surgically managed in our center for an aortic infection were retrospectively analyzed. The primary endpoint was the intra-hospital mortality, secondary outcomes were limb salvage, persistent or recurrent infection, prosthetic graft patency, and long-term survival.

RESULTS

From January 2004 to December 2015, 18 consecutive patients (12 men and 6 women) were operated on for aortic infection. Six mycotic aneurysms and 12 prosthetic infections, including 8 para-entero-prosthetic fistulas, were treated. In 5 cases, surgery was performed in emergency. During the early postoperative period, we performed one major amputation and two aortic infections were persistent. Intra-hospital mortality was 27.7%. The median follow-up among the 13 surviving patients was 26 months. During follow-up, none of the 13 patients presented reinfection or bypass thrombosis.

CONCLUSION

This series shows that in situ revascularization with rifampicin-soaked silver polyester graft for aortic infection have results in agreement with the literature in terms of intra-hospital mortality with a low reinfection rate.

Outcome of rectus femoris muscle flaps for groin coverage after vascular surgery

OBJECTIVE

The aim of this retrospective cohort study was to investigate the outcome of rectus femoris muscle flaps (RFFs) for deep groin wound complications in vascular surgery patients and to compare the outcome with a cohort of sartorius muscle flaps (SMFs) because the RFF is a promising alternative technique for groin coverage.

METHODS

All RFFs and SMFs performed by vascular surgeons in a regional collaboration in The Southern Netherlands were retrospectively reviewed. Primary outcomes were muscle flap survival, overall and secondary graft salvage, and limb salvage. Secondary outcomes were 30-day groin wound complications and mortality, donor site and vascular complications, 1-year amputation-free survival, overall patient survival, impaired knee extensor function, and length of hospital stay.

RESULTS

A total of 96 RFFs were performed in 88 patients (mean age, 68 years; 67% male) and compared with a cohort of 30 SMFs in 28 patients (mean age, 64 years; 77% male). At a mean follow-up of 29 months and 23 months, respectively, comparable flap survival (94% vs 90%), secondary graft salvage (80% vs 92%), and limb salvage (89% vs 90%) rates were found. The 30-day mortality rates were 12% and 17%, respectively, and the 1-year amputation-free survival was comparable between treatment groups (71% vs 68%).

CONCLUSIONS

This study presents a large series of RFFs for deep groin wound complications after vascular surgery. We demonstrate that muscle flap coverage using the rectus femoris muscle by vascular surgeons is an effective way to manage complex groin wound infections in a challenging group of patients, achieving similarly good results as the SMF.

Prevention, treatment and outcomes of left ventricular assist device driveline infections. A single Center experience

INTRODUCTION

While the survival rates for patients with end-stage heart failure have dramatically improved with newer generations of left ventricular assist devices, LVAD-specific infections are important cause of morbidity, mortality, and hospital readmissions in these patients.

METHODS

We performed a retrospective analysis of all driveline infections in patients who had undergone LVAD implantation at a single cardiosurgical center. Between June 2013 and March 2017, 51 patients underwent implantation of LVAD. Among these, 12 received Heart Ware LVAD,34 Heart Mate II LVAD, and 5 Heart Mate III LVAD. The end goal for LVAD therapy was destination therapy in three patients and bridge-to-transplantation in 48 patients.

RESULTS

One month, six months, and one-year survival rates were 90%, 85%, and 81%, respectively. Five patients developed driveline infections. Median time from LVAD implantation to driveline infections was 126 days. One of these patients underwent heart transplantation. Two patients were treated with antibiotics and surgical driveline repositioning with extensive debridement of the wound. Two patients with a chronic infection were treated conservatively with regular wound cleaning.

CONCLUSION

Driveline infections remain a serious therapeutic challenge. With the development of surgical techniques and new devices, it is possible to reduce morbidity and increase survival rate in patients with implanted LVAD.

KEY WORDS

Driveline, Infections, LVAD.

Timing of implant-removal in late acute periprosthetic joint infection: A multicenter observational study

OBJECTIVES

We evaluated the treatment outcome in late acute (LA) periprosthetic joint infections (PJI) treated with debridement and implant retention (DAIR) versus implant removal.

METHODS

In a large multicenter study, LA PJIs of the hip and knee were retrospectively evaluated. Failure was defined as: PJI related death, prosthesis removal or the need for suppressive antibiotic therapy. LA PJI was defined as acute symptoms <3 weeks in patients more than 3 months after the index surgery and with a history of normal joint function.

RESULTS

445 patients were included, comprising 340 cases treated with DAIR and 105 cases treated with implant removal (19% one-stage revision (n = 20), 74.3% two-stage revision (n = 78) and 6.7% definitive implant removal (n = 7). Overall failure in patients treated with DAIR was 45.0% (153/340) compared to 24.8% (26/105) for implant removal (p < 0.001). Difference in failure rate remained after 1:1 propensity-score matching. A preoperative CRIME80-score ≥3 (OR 2.9), PJI caused by S. aureus (OR 1.8) and implant retention (OR 3.1) were independent predictors for failure in the multivariate analysis.

CONCLUSION

DAIR is a viable surgical treatment for most patients with LA PJI, but implant removal should be considered in a subset of patients, especially in those with a CRIME80-score ≥3.

Infective endocarditis: a retrospective cohort study

BACKGROUND

Infective endocarditis (IE) is a potentially life-threatening infection of the heart's endocardial surface. Despite advances in the diagnosis and management of IE, morbidity and mortality remain high.

AIM

To characterize the demographics, bacteriology and outcomes of IE cases presenting to an Irish tertiary referral centre.

DESIGN

Retrospective cohort study.

METHODS

Patients were identified using Hospital Inpatient Enquiry and Clinical Microbiology inpatient consult data, from January 2005 to January 2014. Patients were diagnosed with IE using Modified Duke Criteria. Standard Bayesian statistics were employed for analysis and cases were compared to contemporary international registries.

RESULTS

Two hundred and two patients were diagnosed with IE during this period. Mean age 54 years. Of these, 136 (67%) were native valve endocarditis (NVE), 50 (25%) were prosthetic valve endocarditis (PVE) and 22 (11%) were cardiovascular implantable electronic device-associated endocarditis. Culprit organism was identified in 176 (87.1%) cases and Staphylococcal species were the most common (57.5%). Fifty-nine per cent of NVE required surgery compared to 66% of PVE. Mean mortality rate was 17.3%, with NVE being the lowest (12.5%) and PVE the highest (32%). Increasing age was also associated with increased mortality. Fifty-three (26.2%) patients had embolic complications.

CONCLUSIONS

This Irish cohort exhibited first-world demographic patterns comparable to those published in contemporary international literature. PVE required surgery more often and was associated with higher rates of mortality than NVE. Embolic complications were relatively common and represent important sequelae, especially in the intravenous drug user population. It is also pertinent to aggressively treat older cohorts as they were associated with increased mortality.

Mechanical failure of articulating polymethylmethacrylate (PMMA) spacers in two-stage revision hip arthroplasty: the risk factors and the impact on interim function

BACKGROUND

This study aimed to investigate the risk factors for mechanical failure of cement spacers and the impact on hip function after two-stage exchange arthroplasty for periprosthetic joint infection (PJI).

METHODS

Thirty-one patients (19 males and 12 females) with hip PJIs underwent resection arthroplasty and implantation of cement spacers from January 2014 to December 2015. Patients who encountered spacer-associated mechanical complications in the interim period (14 of 31) were compared with those without complications (17 of 31). Complications were defined as spacer dislocation, spacer fracture, spacer fracture with dislocation, and femoral fracture during or following spacer implantation. Hip functional outcome was assessed using the Harris hip score (HHS). Treatment success was defined according to the following criteria: (1) no symptoms or signs indicative of infection; (2) no PJI-related mortality; and (3) no subsequent surgical intervention for infection after reimplantation surgery. Multivariate logistic regression and Kaplan-Meier survival curves were used for analysis.

RESULTS

Fourteen patients (14/31 = 45%) suffered at least one spacer-related complication within the interim period. The development of spacer complications was associated with a younger age (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.83-1.00, p = 0.045) and chronic PJI (OR 14.7, 95% CI 1.19-182, p = 0.036). Patients with spacer complications also had a lower median HHS (37 vs. 60, p < 0.001) before reimplantation in comparison to those without spacer complications. After reimplantation, the two groups had a similar median HHS (90 vs. 89, p = 0.945). Two patients did not undergo reimplantation due to extensive comorbidities, and subsequently retained the antibiotic spacer for definitive treatment. The 2-year treatment success rate was 84.6% in the spacer-complication group and 87.5% in the non-spacer-complication group (p = 0.81).

CONCLUSION

There was a high complication rate for articulating PMMA spacers during the interim period of two-stage revision total hip arthroplasty. A young age and chronic infection were the primary risk factors associated with mechanical complications. Patients at high risk of spacer-related mechanical complications should be advised accordingly by surgeons. Knowing the possible risk factors, surgeons should educate patients thoroughly to avoid spacer complications, thereby increasing patient satisfaction in the interim stage.

LEVEL OF EVIDENCE

Prognostic Level III.

Risk factors and prognostic impact of left ventricular assist device-associated infections

BACKGROUND

Left ventricular assist device (LVAD)-associated infections may be life-threatening and impact patients' outcome. We aimed to identify the characteristics, risk factors, and prognosis of LVAD-associated infections.

METHODS

Patients included in the ASSIST-ICD study (19 centers) were enrolled. The main outcome was the occurrence of LVAD-associated infection (driveline infection, pocket infection, or pump/cannula infection) during follow-up.

RESULTS

Of the 652 patients enrolled, 201 (30.1%) presented a total of 248 LVAD infections diagnosed 6.5 months after implantation, including 171 (26.2%), 51 (7.8%), and 26 (4.0%) percutaneous driveline infection, pocket infection, or pump/cannula infection, respectively. Patients with infections were aged 58.7 years, and most received HeartMate II (82.1%) or HeartWare (13.4%). Most patients (62%) had implantable cardioverter-defibrillators (ICDs) before LVAD, and 104 (16.0%) had ICD implantation, extraction, or replacement after the LVAD surgery. Main pathogens found among the 248 infections were Staphylococcus aureus (n = 113' 45.4%), Enterobacteriaceae (n = 61; 24.6%), Pseudomonas aeruginosa (n = 34; 13.7%), coagulase-negative staphylococci (n = 13; 5.2%), and Candida species (n = 13; 5.2%). In multivariable analysis, HeartMate II (subhazard ratio, 1.56; 95% CI, 1.03 to 2.36; P = .031) and ICD-related procedures post-LVAD (subhazard ratio, 1.43; 95% CI, 1.03-1.98; P = .031) were significantly associated with LVAD infections. Infections had no detrimental impact on survival.

CONCLUSIONS

Left ventricular assist device-associated infections affect one-third of LVAD recipients, mostly related to skin pathogens and gram-negative bacilli, with increased risk with HeartMate II as compared with HeartWare, and in patients who required ICD-related procedures post-LVAD. This is a plea to better select patients needing ICD implantation/replacement after LVAD implantation.

Antibacterial Envelope to Prevent Cardiac Implantable Device Infection

BACKGROUND

Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections.

METHODS

We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months.

RESULTS

A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P = 0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P<0.001 for noninferiority). The mean (±SD) duration of follow-up was 20.7±8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98).

CONCLUSIONS

Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications. (Funded by Medtronic; WRAP-IT ClinicalTrials.gov number, NCT02277990.).

Infrarenal Aortic Endograft Infection: A Single-Center Experience

PURPOSE:

Endograft infection is an infrequent but one of the most serious and challenging complications after endovascular aortic repair. The aim of this study was to assess the management of this complication in a tertiary center.

CASE SERIES:

A retrospective analysis of a prospective database was performed including all patients who underwent elective endovascular abdominal aortic repair (EVAR) from 2003 to 2016 in a tertiary center. Seven cases of endograft infection were identified during the follow-up period from a total of 473 (1.48%) EVAR. Most frequent symptoms at presentation were fever (71.4%) and lumbar pain (57.1%). One case developed an early infection, while 6 cases were diagnosed as late infections. Mean time from endograft placement to symptom presentation was 28.3 months (2-91.5 months). Gram-positive cocci were the microorganisms most commonly isolated in blood cultures (66%). Two cases were managed with endograft removal and aortic reconstruction with a cryopreserved allograft, 2 cases with surgical drainage, and 2 cases exclusively with antibiotic therapy. In 1 case, the diagnosis was performed postoperatively based on intraoperative findings associated with positive graft cultures; and graft explantation was performed with "in situ" reconstruction using a Dacron graft. Perioperative mortality was 42.9%. One-year mortality was 57.1%. Mean follow-up was 21.5 months.

CONCLUSION:

Endograft explantation is the gold standard of treatment; however, given the overall high morbi-mortality rates of this pathology, a tailored approach should always be offered depending on the patient's overall condition. Conservative management can be an acceptable option in those patients with short life expectancy and high surgical risk.

Gentamicin may have no effect on mortality of staphylococcal prosthetic valve endocarditis

PURPOSE

To analyze the influence of adding gentamicin to a regimen consisting of β-lactam or vancomycin plus rifampicin on survival in patients suffering from Staphylococcal prosthetic valve endocarditis (SPVE).

METHODS

From January 2008 to September 2016, 334 patients with definite SPVE were attended in the participating hospitals. Ninety-four patients (28.1%) received treatment based on β-lactam or vancomycin plus rifampicin and were included in the study. Variables were analyzed which related to patient survival during admission, including having received treatment with gentamicin.

RESULTS

Seventy-seven (81.9%) were treated with cloxacillin (or vancomycin) plus rifampicin plus gentamicin, and 17 patients (18.1%) received the same regimen without gentamicin. The causative microorganism was Staphylococcus aureus in 40 cases (42.6%) and coagulase-negative staphylococci in 54 cases (57.4%). Overall, 40 patients (42.6%) died during hospital admission, 33 patients (42.9%) in the group receiving gentamicin and 7 patients in the group that did not (41.2%, P = 0.899). Worsening renal function was observed in 42 patients (54.5%) who received gentamicin and in 9 patients (52.9%) who did not (p = 0.904). Heart failure as a complication of endocarditis (OR: 4.58; CI 95%: 1.84-11.42) and not performing surgery when indicated (OR: 2.68; CI 95%: 1.03-6.94) increased mortality. Gentamicin administration remained unrelated to mortality (OR: 1.001; CI 95%: 0.29-3.38) in the multivariable analysis.

CONCLUSIONS

The addition of gentamicin to a regimen containing vancomycin or cloxacillin plus rifampicin in SPVE was not associated to better outcome.

Early Onset Prosthetic Valve Endocarditis: Experience at a Cardiothoracic Surgical Hospital, 2006-2016

BACKGROUND

Early onset prosthetic valve endocarditis (EO-PVE) is an serious complication associated with heart valve replacement surgery.

OBJECTIVES

To describe the epidemiologic, clinical, and laboratory profile of patients with EO-PVE in a cardiac surgical hospital.

PATIENTS AND METHODS

A retrospective analysis of an endocarditis database, implemented prospectively, with a post hoc study driven by analysis of cases of adults with definite endocarditis occurring up to 12 months after heart valve surgery.

RESULTS

We identified 26 cases in 2,496 surgeries in the period 2006-2016. The average annual incidence was 1.04%. The median time between valve replacement and the diagnosis of EO-PVE was 33 days (interquartile range [IQR] 19.25-118.75). Biologic and mechanical prostheses were affected in 53.8% and 46.2%, respectively. Rheumatic disease was present in 57.7% of patients. The most common causative pathogens were Staphylococcus epidermidis (23.1%). No Staphylococcus aureus infection was reported. Complications were present in 73.1% of cases, including embolism (65.4%), acute renal failure (38.5%), and heart failure (23.1%). The mortality rate at 30 days and 12 months was 3.8% and 34.6%, respectively.

CONCLUSIONS

In our cohort EO-PVE was an serious complication of heart valve replacement with a high morbidity and mortality, despite its low frequency.

Vancomycin Povidone-Iodine Protocol Improves Survivorship of Periprosthetic Joint Infection Treated With Irrigation and Debridement

BACKGROUND

Irrigation and debridement with modular component and liner exchange (IDLE) is a low morbidity procedure for treatment of periprosthetic joint infection (PJI) with reported failure rates exceeding 50%. Dilute povidone-iodine lavage has been shown to be safe and effective in decreasing acute PJI in primary total joint arthroplasty. Vancomycin powder has also shown to be effective in preventing infection in spine surgery. We hypothesize that a vancomycin povidone-iodine protocol (VIP) used in conjunction with IDLE can increase infection-free survivorship after acute PJI.

METHODS

This is a single institution retrospective review of all PJIs treated with IDLE and VIP since March 2014. A consecutive matched control group of patients treated with IDLE for PJI for 2 years prior to March 2014 was also included for analysis. Primary outcome was failure, defined as return to operating room for an infection-related problem. Secondary outcome was chronic suppression with antibiotics at final follow-up. Minimum follow-up was 1 year.

RESULTS

A total of 36 patients in the VIP group and 38 patients in control group were identified. In the VIP group, 16.7% (6/36) failed at final follow-up compared to 37% failure rate (14/38) in the control group (P < .05). Three patients in the VIP group were on chronic antibiotic suppression at final follow-up. There were no medical complications secondary to the VIP.

CONCLUSIONS

The VIP group demonstrated a significant reduction in reinfection and failure rate following IDLE. The authors believe that a VIP is an effective adjunct for treating PJI with irrigation and debridement.

What Are the Frequency, Associated Factors, and Mortality of Amputation and Arthrodesis After a Failed Infected TKA?

BACKGROUND

For patients with failed surgical treatment of an infected TKA, salvage operations such as arthrodesis or above-knee amputation (AKA) may be considered. Clinical and institutional factors associated with AKA and arthrodesis after a failed TKA have not been investigated in a large-scale population, and the utilization rate and trend of these measures are not well known.

QUESTIONS/PURPOSES

(1) How has the frequency of arthrodesis and AKA after infected TKA changed over the last 10 years? (2) What clinical or institutional factors are associated with patients undergoing arthrodesis or AKA? (3) What is the risk of mortality after arthrodesis or AKA?

METHODS

The Medicare 100% National Inpatient Claims Database was used to identify 44,466 patients 65 years of age or older who were diagnosed with an infected TKA and who underwent revision between 2005 and 2014 based on International Classification of Diseases, 9^th Revision, Clinical Modification codes. Overall, 1182 knee arthrodeses and 1864 AKAs were identified among the study population. One year of data before the index infection-related knee revision were used to examine patient demographic, institutional, and clinical factors, including comorbidities, hospital volumes, and surgeon volumes. We developed Cox regression models to investigate the risk of arthrodesis, AKA, and death as outcomes. In addition, the year of the index revision was included as a covariate to determine if the risk of subsequent surgical interventions was changing over time. The risk of mortality was also assessed as the event of interest using a similar multivariate Cox model for each patient group (arthrodesis, AKA) in addition to those who underwent additional revisions but who did not undergo either of the salvage procedures.

RESULTS

The number of arthrodesis (hazard ratio [HR], 0.90, p < 0.001) and amputation (HR, 0.95, p < 0.001) procedures showed a declining trend. Clinical factors associated with arthrodesis included acute renal failure (HR, 1.22 [1.06-1.41], p = 0.006), obesity (HR, 1.58 [1.35-1.84], p < 0.001), and having additional infection-related revisions (HR for 2+ additional revisions, 1.36 [1.13-1.64], p = 0.001). Higher Charlson comorbidity score (HR for a score of 5+ versus 0, 2.56 [2.12-3.14], p < 0.001), obesity (HR, 1.14 [1.00-1.30], p = 0.044), deep vein thrombosis (HR, 1.34 [1.12-1.60], p = 0.001), and additional revisions (HR for 2+ additional revisions, 2.19 [1.91-2.49], p < 0.001) were factors associated with AKA, which in turn was an independent risk factor for mortality. The risk of death increased with amputation after adjusting for age, comorbidities, and other factors (HR, 1.28 [1.20-1.37], p < 0.001), but patients who received arthrodesis did not show a change in mortality compared with the patients who did not receive arthrodesis or amputation (HR, 1.00 [0.91-1.10], p = 0.971).

CONCLUSIONS

The findings of this study suggest that clinicians may be more aggressively attempting to preserve the knee even in the face of chronic prosthetic joint infection but also show that a greater number of revisions is associated with a greater risk of subsequent AKA or arthrodesis. The results also suggest that recommending centers with a high volume of joint arthroplasties may be a way to reduce the risk of the salvage procedures.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Prosthetic Joint Infection following Total Hip Arthroplasty - Incidence, Mortality and Validation of the Diagnosis in the Danish Hip Arthroplasty Register

Prosthetic joint infection (PJI) is a rare, but devastating complication following primary total hip arthroplasty (THA). As PJI is a rare event, large cohorts of patients are required in order to study this complication. National arthroplasty registers offer such large and unselected cohorts, but studies have shown that these registers - used alone - underestimate the incidence of PJI. The aim of this thesis was to estimate the incidence of PJI and the mortality risk following a PJI by combining data from the Danish Hip Arthroplasty Register (DHR), the National Register of Patients (NRP), the Microbiology Databases, the Civil Registration System, the medical records, the Danish National Prescription Registry and the Clinical Biochemistry Databases. The thesis comprises the following four studies: Study I: The aim of this study was to estimate the "true" incidence of surgically treated PJI following primary THA. To estimate the true incidence, we developed an algorithm that classified the revisions as due to PJI or due to other causes. The algorithm incorporated data from the DHR, the NRP, medical records, the microbiological databases, the prescription database and the clinical biochemistry databases. The one- and five-year cumulative incidences were estimated to be 0.86% (95% confidence interval (CI): 0.77; 0.97) and 1.03% (95% CI: 0.87; 1.22), respectively. These figures are approximately 40% higher than the equivalent figures re-ported by the DHR and the NRP. Study II: The aim of the second study was to validate the PJI diagnosis in the DHR. We did this by comparing the PJI diagnosis in the DHR with the PJI diagnosis derived from the algorithm developed in Study I. We found a sensitivity of 67%, a specificity of 95%, a positive predictive value (PPV) of 77%, and a negative predictive value (NPV) of 92%. When the data from the DHR were linked with data from the microbiology databases, the sensitivity increased to 90% and the specificity also increased (to 100%) along with the PPV (98%) and the NPV (98%). Study III: The aim of the third study was to examine whether the incidence of PJI observed within the first year of primary THA in-creased in the course of the ten-year study period from 2005 to 2014. We used the validated PJI diagnosis described in Study II and found that the incidence of PJI did not appear to be increasing as the relative risk of PJI was 1.05 (95% CI: 0.82; 1.34) for the 2010-2014 period compared with the 2005-2010 period. Nor did we find any changes in the antimicrobial resistance pattern. Study IV: The aim of the fourth study was to estimate the mortality risk following a revision for PJI within one year following a primary THA. When combining data from the DHR with data from the microbiology databases, we found that the mortality risk of patients with a revision for PJI was 2.18 (95% CI: 1.54; 3.08) com-pared with the reference population, and 1.87 (95% CI: 1.11; 3.15) when compared with patients who had an aseptic revision. In conclusion, the incidence of PJI is approximately 40% higher than that reported by the NRP and the DHR. By linkage of the DHR and the microbiology databases, the validity of the PJI diagnosis can be improved notably. By such a combination of data from the DHR and the microbiology databases, we show that the incidence of PJI does not seem to be increasing and that revision for PJI is associated with a high mortality.

The Not-So-Good Prognosis of Streptococcal Periprosthetic Joint Infection Managed by Implant Retention: The Results of a Large Multicenter Study

BACKGROUND.

Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success.

METHODS.

A retrospective, observational, multicenter, international study was performed during 2003-2012. Eligible patients had a streptococcal PJI that was managed with DAIR. The primary endpoint was failure, defined as death related to infection, relapse/persistence of infection, or the need for salvage therapy.

RESULTS.

Overall, 462 cases were included (median age 72 years, 50% men). The most frequent species was Streptococcus agalactiae (34%), and 52% of all cases were hematogenous. Antibiotic treatment was primarily using β-lactams, and 37% of patients received rifampin. Outcomes were evaluable in 444 patients: failure occurred in 187 (42.1%; 95% confidence interval, 37.5%-46.7%) after a median of 62 days from debridement; patients without failure were followed up for a median of 802 days. Independent predictors (hazard ratios) of failure were rheumatoid arthritis (2.36), late post-surgical infection (2.20), and bacteremia (1.69). Independent predictors of success were exchange of removable components (0.60), early use of rifampin (0.98 per day of treatment within the first 30 days), and long treatments (≥21 days) with β-lactams, either as monotherapy (0.48) or in combination with rifampin (0.34).

CONCLUSIONS.

This is the largest series to our knowledge of streptococcal PJI managed by DAIR, showing a worse prognosis than previously reported. The beneficial effects of exchanging the removable components and of β-lactams are confirmed and maybe also a potential benefit from adding rifampin.

Examining the Association between Hemodialysis Access Type and Mortality: The Role of Access Complications

BACKGROUND AND OBJECTIVES

People receiving hemodialysis to treat kidney failure need a vascular access (a fistula, a graft, or a central venous catheter) to connect to the blood purification machine. Higher rates of access complications are considered the mechanism responsible for the excess mortality observed among catheter or graft users versus fistula users. We tested this hypothesis using mediation analysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied incident patients who started hemodialysis therapy from North America, Europe, and Australasia (the Dialysis Outcomes and Practice Patterns Study; 1996-2011). We evaluated the association between access type and time to noninfectious (e.g., thrombosis) and infectious complications of the access (mediator model) and the relationship between access type and time-dependent access complications with 6-month mortality from the creation of the first permanent access (outcome model). In mediation analysis, we formally tested whether access complications explain the association between access type and mortality.

RESULTS

Of the 6119 adults that we studied (mean age =64 [SD=15] years old; 58% men; 47% patients with diabetes), 50% had a permanent catheter for vascular access, 37% had a fistula, and 13% had a graft. During the 6-month study follow-up, 2084 participants (34%) developed a noninfectious complication of the access, 542 (8.9%) developed an infectious complication, and 526 (8.6%) died. Access type predicted the occurrence of access complications; both access type and complications predicted mortality. The associations between access type and mortality were nearly identical in models excluding and including access complications (hazard ratio, 2.00; 95% confidence interval, 1.55 to 2.58 versus hazard ratio, 2.01; 95% confidence interval, 1.56 to 2.59 for catheter versus fistula, respectively). In mediation analysis, higher mortality with catheters or grafts versus fistulas was not the result of increased rates of access complications.

CONCLUSIONS

Hemodialysis access complications do not seem to explain the association between access type and mortality. Clinical trials are needed to clarify whether these associations are causal or reflect confounding by underlying disease severity.

Retrospective comparative analysis of cardiovascular implantable electronic device infections with and without the use of antibacterial envelopes

BACKGROUND

Cardiovascular implantable electronic device (CIED) infections are associated with morbidity and mortality. Peri-operative systemic intravenous antibiotic prophylaxis reduces the rate of CIED infections. AIGIS_Rx, a polymer envelope implanted with the CIED, releases minocycline and rifampin, and has been introduced to reduce infections.

METHODS

Retrospective review of 184 patients who underwent CIED implantation was conducted. Ninety-two patients were implanted with an AIGIS_Rx envelope (AIGIS_Rx group) and 92 patients were not implanted with an AIGIS_Rx envelope (control group). Data were collected on demographics and risk factors for CIED infections (i.e. congestive heart failure, renal insufficiency, chronic kidney disease, oral anticoagulant use, chronic steroid use, need for lead replacement or revision, temporary pacing, early re-intervention, and having more than two leads in place). Rates of implantation success, major infections and mortality were compared between the AIGIS_Rx group and the control group.

RESULTS

The AIGIS_Rx group had longer hospitalizations (6.8±10.7 days vs 3.1±5.2 days; P=0.001), higher chronic corticosteroid use, higher rates of replacement or revision (51.1% vs 8.7%; P=0.001), and a greater proportion of devices with more than two intracardiac leads (42.4% vs 29.3%; P=0.03) than the control group. Successful implantation occurred in 97% of patients in both groups. Major infection was seen in 5.4% of cases in the AIGIS_Rx group and 1.1% of cases in the control group (P=0.048). Device removal was conducted in 3.3% of cases in the AIGIS_Rx group compared with 1.1% of cases in the control group (P=0.16). There were two deaths in the AIGIS_Rx group. Organisms cultured were meticillin-resistant Staphylococcus aureus, meticillin-susceptible S. aureus and Enterococcus faecalis.

CONCLUSION

The AIGIS_Rx group had higher rates of major infection but also higher risk factors compared with the control group. The rate of device extraction and CIED-related mortality was higher in the AIGIS_Rx group than in the control group.

Early Transposition of the Sartorius Muscle for Exposed Patent Infrainguinal Bypass Grafts

The traditional approach for patent and exposed and infected infrainguinal bypass grafts in the groin has included wide operative debridement and secondary or delayed primary closure. However, this has been associated with significant risk of further contamination and length of stay. The authors reviewed their experience using the wide debridement, sartorius muscle flap transposition, and primary wound closure as an alternative. During the past 5 years, they have had 50 patients with major wound necrosis or infection in the groin or thigh with the graft or native artery being exposed after debridement. This group included 28 men; 74% of the patients had hypertension, 58% had diabetes, and 20% had renal failure. The grafts were split evenly between native vein and prosthetic material. After wide debridement, closure was performed by the vascular surgeon using the sartorius muscle flap. Postoperatively, there was an 8% major amputation rate and a 12% mortality rate in the first 30 days. One patient developed a pseudoaneurysm 5 weeks after placement of the flap. This patient underwent removal of the infected polytetrafluoroethylene graft with ligation of the common femoral artery. None of the procedures have resulted in further systemic or graft sepsis. None have resulted in arterial or graft blowout. Follow-up was for an average of 18 months. Closure of groin and thigh wounds with exposed bypass graft or native artery can be safely performed with the sartorius muscle flap with excellent results. The length of stay of these patients compared to historical controls is acceptable. Furthermore, the chance of infection of the native artery or bypass may be reduced. Familiarity with this simple technique can be a valuable tool for the vascular surgeon.

Outcomes after retroflexed gracilis muscle flap for vascular infections in the groin

OBJECTIVE

Multiple catheterizations and procedures on the femoral arteries can increase the risk of infection and eventual destruction of the overlying skin and subcutaneous tissue. Without adequate tissue coverage, vascular structures are exposed and, thus, vulnerable to disruption. This can lead to loss of limb and/or life and carries a significant mortality. We hypothesized that gracilis muscle flap (GMF) was a reliable adjunct in providing healthy tissue coverage for a complex surgical problem.

METHODS

Retrospective review of charts was performed on all patients who had undergone GMF for groin infections at a tertiary care medical center.

RESULTS

From 1997 to 2012, GMF was performed in 68 limbs (64 patients) by vascular surgeons for infectious etiology to cover the common femoral artery. At the time the GMF was placed, the femoral artery had synthetic graft/patch in 14 limbs, whereas 54 limbs had procedures with autologous conduit. Complete healing was achieved in 58 (85%) limbs. Treatment was deemed not successful in 10 limbs where patients continued to have persistent infection. Six out of 10 limbs had anastomosis disruption requiring emergent ligation of the common femoral artery. Nine patients died during the perioperative period (30-day). There were a total of 13 amputations in 12 patients. Limb salvage was achieved in 55 limbs (81%). Univariate analysis suggested that patients that had revascularization procedures with synthetic graft had a higher complication rate compared with autologous/vein reconstruction (24% vs 5%; P = .021). This group also has a higher rate of persistent infection compared with the autologous group (24% vs 2%; P = .006). Patients older than 75 years at the time of GMF had a higher incidence of GMF-related complications (57% vs 5%; P = .04). Multivariate analysis confirmed that presence of prosthesis led to higher incidence treatment failures and muscle flap complications at the surgical site (odds ratio, 6.6; P = .04; and odds ratio, 13.3; P = .03, respectively).

CONCLUSIONS

GMF is technically simple to perform and provides durable soft tissue coverage with a high rate of healing for complex groin wounds even in the presence of synthetic conduit.

Diagnostic algorithms and treatment strategies in primary aortic and aortic graft infections

Aortic infections and aortic graft infections are one of the most dreadful clinical entities that a vascular surgeon can face. Clinical presentation of the patient can vary greatly and diagnosis can be difficult to make. In this manuscript, diagnostic modalities are reviewed and a diagnostic algorithm suggested. Further, results of present treatment options are evaluated and treatment strategies for different clinical scenarios suggested.

Clinical findings of bacteremic septic arthritis according to the site of acquisition: The overlap between health care-related and community- and nosocomial-acquired cases

BACKGROUND

The site of acquisition of infection may have a major impact on outcome. The health care-related (HCR) environment has recently come under scrutiny. In a group of patients with bacteremic septic arthritis (SA), we compared their characteristics, type of SA, microbiology and prognosis according to the site of acquisition: community-acquired (CA), nosocomial-acquired (NA), and HCR.

METHODS

We studied all patients with bacteremic SA seen at our institution between 1985 and 2013. Data were obtained from a protocol of prospectively recorded bacteremia cases.

RESULTS

There were 273 cases of bacteremic SA (CA: 51%; NA: 31%; and HCR: 18%). NA and HCR sites were more frequent in older and fragile patients. SA of peripheral joints was the most common presentation; infections of the axial skeleton predominated in CA and HCR (24%), and prosthetic joint infection in NA (44%). MRSA and Pseudomonas aeruginosa were mainly found in NA (21% and 6% respectively) and HCR (14% and 8% respectively), whereas Streptococcus spp. was more frequent in CA (30%) and HCR (28%). The 30-day mortality rates were: CA 7%, HCR 18%, and NA 26%.

CONCLUSION

The characteristics of HCR-SA overlapped with those of the CA or NA-SA cases. The HCR and NA cases presented more advanced age, greater fragility, and the predominance of difficult-to-treat microorganisms, while the HCR and CA cases presented an involvement of the axial skeleton, streptococcal etiology, and a lower number of prosthetic joint infections. Our data show that the site of acquisition should be considered when planning diagnostic and therapeutic management for SA.

Surgery for Aortic Root Abscess: A 15-Year Experience

Aortic root abscess is the most severe sequela of infective endocarditis, and its surgical management is a complicated procedure because of the high risk of morbidity and death. Twenty-seven patients were included in this 15-year retrospective study: 21 (77.8%) with native- and 6 (22.2%) with prosthetic-valve endocarditis. The surgical reconstruction of the aortic root consisted of aortic valve replacement in 19 patients (70.4%) with (11) or without (8) a pericardial patch, or total aortic root replacement in 7 patients (25.9%); 5 of the 27 (18.5%) underwent the modified Bentall procedure with the flanged conduit. Only one patient (3.7%) underwent subaortic pericardial patch reconstruction without valve replacement. A total of 7 patients (25.9%) underwent reoperation: 6 with prior valve surgery, and 1 with prior isolated sinus of Valsalva repair. The mean follow-up period was 6.8 ± 3.7 years. There were 6 (22.2%) in-hospital deaths, 3 (11.1%) of which were perioperative, among patients who underwent emergent surgery. Five patients (23.8%) died during follow-up, and the overall survival rates at 1, 5, and 10 years were 70.3% ± 5.8%, 62.9% ± 6.4%, and 59.2% ± 7.2%, respectively. Two of 21 patients (9.5%) underwent reoperation because of paravalvular leakage and early recurrence of infection during follow-up. After complete resection of the perianular abscess, replacement of the aortic root can be implemented for reconstruction of the aortic root, with or without left ventricular outflow tract injuries. Replacing the aortic root with a flanged composite graft might provide the best anatomic fit.

Multidrug-Resistant Organism Infections in Patients with Left Ventricular Assist Devices

Left ventricular assist devices improve survival prospects in patients with end-stage heart failure; however, infection complicates up to 59% of implantation cases. How many of these infections are caused by multidrug-resistant organisms is unknown. We sought to identify the incidence, risk factors, and outcomes of multidrug-resistant organism infection in patients who have left ventricular assist devices. We retrospectively evaluated the incidence of multidrug-resistant organisms and the independent risk factors associated with them in 57 patients who had permanent left ventricular assist devices implanted at our institution from May 2007 through October 2011. Outcomes included death, transplantation, device explantation, number of subsequent hospital admissions, and number of subsequent admissions related to infection. Infections were categorized in accordance with criteria from the Infectious Diseases Council of the International Society for Heart and Lung Transplantation. Multidrug-resistant organism infections developed in 18 of 57 patients (31.6%)-a high incidence. We found 3 independent risk factors: therapeutic goal (destination therapy vs bridging), P=0.01; body mass index, P=0.04; and exposed velour at driveline exit sites, P=0.004. We found no significant differences in mortality, transplantation, or device explantation rates; however, there was a statistically significant increase in postimplantation hospital admissions in patients with multidrug-resistant organism infection. To our knowledge, this is the first report in the medical literature concerning multidrug-resistant organism infection in patients who have permanent left ventricular assist devices.

Management of infected vascular grafts

Infections of vascular grafts are associated with significant mortality and morbidity risk and cost an estimated $640 million annually in the United States. Clinical presentation varies by time elapsed from implantation and by surgical site. A thorough history and physical examination in conjunction with a variety of imaging modalities is often essential to diagnosis. For infected aortic grafts, there are several options for treatment, including graft excision with extra-anatomic bypass, in situ reconstruction, or reconstruction with the neo-aortoiliac system. The management of infected endovascular aortic grafts is similar. For infected peripheral bypasses, graft preservation techniques can be utilized, but in cases where it is not possible, graft removal and revascularization through uninfected tissue planes is necessary. Infected dialysis access can be surgically treated by complete or subtotal graft excision. Diagnosis, general management, and surgical approaches to infected vascular grafts are discussed in this review.

Vascular complications and surgical interventions after world's largest Q fever outbreak

OBJECTIVE

Since chronic Q fever often develops insidiously, and symptoms are not always recognized at an early stage, complications are often present at the time of diagnosis. We describe complications associated with vascular chronic Q fever as found in the largest cohort of chronic Q fever patients so far.

METHODS

Patients with proven or probable chronic Q fever with a focus of infection in an aortic aneurysm or vascular graft were included in this study, using the Dutch national chronic Q fever database.

RESULTS

A total of 122 patients were diagnosed with vascular chronic Q fever between April 2008 and June 2012. The infection affected a vascular graft in 62 patients (50.8%) and an aneurysm in 53 patients (43.7%). Seven patients (5.7%) had a different vascular focus. Thirty-six patients (29.5%) presented with acute complications, and 35 of these patients (97.2%) underwent surgery. Following diagnosis and start of antibiotic treatment, 26 patients (21.3%) presented with a variety of complications requiring surgical treatment during a mean follow-up of 14.1 ± 9.1 months. The overall mortality rate was 23.7%. Among these patients, mortality was associated with chronic Q fever in 18 patients (62.1%).

CONCLUSIONS

The management of vascular infections with C. burnetii tends to be complicated. Diagnosis is often difficult due to asymptomatic presentation. Patients undergo challenging surgical corrections and long-term antibiotic treatment. Complication rates and mortality are high in this patient cohort.

Outcomes of infected cardiovascular implantable devices in dialysis patients

BACKGROUND/AIMS

Dialysis patients are at a higher risk for cardiovascular implantable electronic device (CIED) infection-related hospitalizations. We compared the outcomes and cost for dialysis and non-dialysis patients hospitalized with CIED infections.

METHODS

We conducted a retrospective analysis of the Nationwide Inpatient Sample (NIS) discharge records from 2005 to 2010. Patients with CIED infections were identified using ICD-9 codes for device-related infections or device procedure along with bacteremia, endocarditis or systemic infection. Dialysis patients were identified using ICD-9 codes. Multivariable logistic and linear regressions were performed to examine in-hospital mortality, length of stay and cost.

RESULTS

Of the 87,798 estimated hospitalizations with CIED infections, 6,665 (7.6%) were dialysis patients. CIED-infection-related hospitalization has increased over time among dialysis patients. In-hospital mortality was higher among dialysis patients (13.6% vs. 5.9%, p < 0.001). In the multivariable model, dialysis patients had higher odds of in-hospital mortality (odds ratio 1.98; 95% CI: 1.6, 2.4) compared to the non-dialysis group. Dialysis patients had a longer median length of stay (12 days vs. 7 days, p < 0.001) and majority required extended care facility upon discharge (51.2% vs. 35.0%, p < 0.001) compared to the non-dialysis group. Dialysis status was associated with 50.3% increased cost of hospitalization (p < 0.001).

CONCLUSION

CIED-infection related hospitalization is increasing among patients undergoing dialysis and is associated with higher in-hospital mortality, longer hospital stay and higher costs of hospitalization. Future studies should examine the reasons for such a high risk and find means to improve outcomes in dialysis population.

Mid- and long-term results after replacement of infected peripheral vascular prosthetic grafts with biosynthetic collagen prosthesis

AIM

We assess mid- and long-term outcome after prosthetic graft replacement with biosynthetic collagen prosthesis (Omniflow II®) in the presence of graft infection.

METHODS

Between December 2010 and January 2012, an analysis of 9 consecutive patients was performed, who underwent replacement of an infected peripheral graft with a biosynthetic prosthesis. Morbidity, in-hospital mortality, primary and secondary patency were analyzed. FDG-PET was performed to diagnose graft infection, and exclude reinfection at long-term follow-up.

RESULTS

Graft infection occurred after a median of 12 (range 3-97) months after the initial procedure. Replacement surgery was performed successfully in all 9 patients without intraoperative complications. Microbiological cultures revealed pathogenic infection in 7 cases. In 2 patients, no pathogen was isolated. The morbidity rate was 55.5% with no in-hospital deaths. Early and late bypass occlusion occurred in 2 patients. One high above-knee amputation was performed due to patient deterioration. The median length of stay was 23 (range 12-122) days and after graft replacement 13 (range 10-62) days. The median time of follow up was 23 (range 8-25) months. Primary and secondary patency rates were 66.6% and 78% at 19 months, respectively. FDG-PET was performed in 6 (85.5%) patients after a median follow up period of 19 (range 3-23) months, and excluded graft reinfection in all patients.

CONCLUSION

Replacement of infected peripheral prosthetic grafts with the prosthesis (Omniflow II®) has encouraging results. The collagen prosthesis appears to be a promising alternative with a low reocclusion rate and no reinfection.

Can total knee arthroplasty be safely performed among nonagenarians? An evaluation of morbidity and mortality within a total joint replacement registry

As the nonagenarian patient population continues to grow, more patients aged 90 and over will become candidates for total knee arthroplasty (TKA). This study evaluated the patient characteristics and incidence of postoperative morbidity and mortality of 216 nonagenarian TKA patients among 81,835 primary TKA patients followed by a total joint replacement registry. Nonagenarians had a greater number of comorbidities preoperatively, experienced a higher rate of deep vein thrombosis and 30 day mortality, and had a longer hospital length of stay. However, nonagenarians did not have an increased risk of infection nor pulmonary embolism and postoperative mortality was within expected rates for individuals 90 years and older. Higher readmission rates, however, highlight the benefits of close follow up during a prolonged postoperative period.

Native and prosthetic valve infective endocarditis: clinicopathologic correlation and review of the literature

BACKGROUND

The incidence of infective endocarditis is 1.5-4.95 cases per 100,000 individuals per year, with a mortality of 14-46% 1-year post infection. The management and decision to operate on selected patients remains controversial. Our study reviews cases of native and prosthetic valve endocarditis in a surgical population, in an attempt to identify and compare clinical and microbiologic features between the two groups. In addition, we compared our findings with other published series to identify if there are changes with these parameters over time.

METHODS

A retrospective analysis of patient records at one institution over an 11-year period identified cases of explanted native (NVE) and prosthetic (PVE) valves with confirmed infective endocarditis (IE) on pathological analysis. Patient records were reviewed to identify patient demographics, risk factors, microbiology and outcomes. Gross features and histological sections were reviewed in all cases.

RESULTS

Two hundred and nine valves were explanted over the study period, 164 of which were native actively infected valves (average age 50.7 + 16.4 years, 77% of males) and 45 prosthetic actively infected valves (average age 55.2 + 16.2 years, 71% of males). Prominent risk factors in the NVE group were bicuspid aortic valve, dental procedures and intravenous drug use, while rheumatic heart disease and diabetes mellitus were most common in the PVE group. Streptococcus and staphylococcus were the most common organisms in both groups. In-hospital mortality was not significantly different between the two groups.

CONCLUSIONS

Surgical intervention remains a part of the management of IE. Despite early recognition and advanced surgical techniques, risk factors have not dramatically changed between the other reviewed studies (patients enrolled from 1978-2004), with the exception of diabetes mellitus becoming more prevalent over time. In addition, despite the change of preprocedural antibiotics prior to dental and other procedures, there does not appear to be an increase in IE cases with previous procedural intervention in our cohort compared to others series, which were published before 2008. Mortality in our cohort was not statistically significant between the NVE and PVE groups, and may be due to careful patient selection for redo surgery in the PVE group. Compared to previous studies, mortality rates remain the same over the last decade.

Epidemiology of infective endocarditis in a tertiary-center in Jerusalem: a 3-year prospective survey

BACKGROUND

Epidemiological features of infective endocarditis have changed during the last decades because of increases in the prevalence of health care exposure and of Staphylococcus aureus bloodstream infection. Consequently, the role of surgery is evolving. We aim to provide a contemporary profile of epidemiological, microbiological, and clinical features of infective endocarditis in a tertiary medical center, and identify predictors of mortality.

METHODS

A prospective observational cohort study of consecutive adult patients with definite endocarditis according to the modified Duke criteria. Data were collected from January 1, 2009 through October 31, 2011 following a predefined case report form designed by the ICE-PCS.

RESULTS

Among 70 endocarditis episodes, 25.7% involved prosthetic valves and 11.5% were device related. Forty-four percent of episodes were health-care associated. The predominant causative microorganism on native valve, prosthetic valve and device related endocarditis was Staphylococcus aureus (33.3%). Viridans group streptococci accounted for the majority of community-acquired endocarditis (36.1%). At least one complication occurred in 50% of the episodes. One third of the patients who had an indication for surgery were operated upon. Six month case fatality ratio was 40%. Sixty-five percent of patients with a contraindication to surgery died, compared with 9% and 28.5% who were treated surgically and medically, respectively. In multivariable analysis, age was a predictor of mortality.

CONCLUSION

Compared with other series, we observed more health-care associated endocarditis, and a higher mortality. Nearly half of all deaths were in patients who had a contraindication to surgery. Careful evaluation of contraindications to surgery is warranted.

Mortality following revision total knee arthroplasty: a matched cohort study of septic versus aseptic revisions

We report the medium-term mortality after septic versus aseptic revision total knee arthroplasty (TKA) and factors that can contribute to mortality in revision TKA. Mortality rates of 88 patients undergoing septic revision (septic group) were compared with age- and year of surgery-matched 88 patients of aseptic revision (aseptic group). The overall mortality after revision TKA was 10.7% at a median of 4 years of follow-up (range, 2-7 years). However, the mortality after septic revision (18%, 16/88) was six times higher than that of aseptic revision (3%, 3/88) (P = 0.003). Infections with Staphylococcus aureus and/or methicillin resistance was not associated with higher mortality rates. Multivariate analysis indicated that increased age (P < 0.001), higher ASA class (P = 0.002), and septic revision (P < 0.001) were identified as independent predictors of increased mortality after revision TKA.

Early and late outcomes after reoperation for prosthetic valve endocarditis

OBJECTIVE

Prosthetic valve endocarditis remains a challenging complication after heart valve replacement. To identify predictive risk factors, we have reviewed 30 patients who underwent surgery for prosthetic valve endocarditis between March 1986 and May 1999.

METHODS

There were 15 men and 15 women (mean age 51 years). Prosthetic valve endocarditis was classified as early (< or = 1 year after operation) in 10 cases, and as late in the other 20 cases. The most common indication for surgery was moderate to severe congestive heart failure due to prosthetic valve dysfunction in 21 (70%) patients. The average follow-up period was 6.5 years, with a range of 0.3 to 14.1 years.

RESULTS

The most common microorganism was Staphylococcus epidermidis in both patients with early (50%) and late prosthetic valve endocarditis (25%). The in-hospital mortality was 13.3% (4/30). There were six late deaths. The actuarial survival at 5 years was 78% and 66% at 10 years. An early onset of prosthetic valve endocarditis was the only significant determinant of both in-hospital mortality (p = 0.005) and overall mortality (p = 0.021). Emergency surgery had a statistically significant relationship with in-hospital mortality (p = 0.045). No significant influence on mortality after reoperation for prosthetic valve endocarditis was found in age, sex, valve position, antecedent native valve endocarditis, or in the type of pathological findings (ring abscess, valve dehiscence, and vegetation).

CONCLUSION

Early onset of prosthetic valve endocarditis and emergency surgery were important risk factors for mortality due to prosthetic valve endocarditis.

Homografts and extra-anatomical reconstructions for infected vascular grafts

Managing graft infections is a challenge in vascular surgery. The incidence of vascular graft infections varies between 2% and 6%. The number of patients treated by means of implantation of artificial prostheses is constantly growing. The treatment of vascular graft infections remains controversial. This article discusses in-situ repair and the role of extra-anatomic routes. Homografts present the lowest rate of reinfection with acceptable rates of degradation and aneurysm formation. Silvergrafts and synthetic grafts coated with antimicrobials show similar early and late mortality rates, but higher reinfection rates. The outcome extra-anatomic bypass surgery seems to be improved in actual series compared with historical results but their disadvantages (limited patency, higher rate of amputations as well as high rates of reintervention combined with higher early mortality) are obvious.

Survival of patients with biventricular devices after device infection, extraction, and reimplantation

OBJECTIVES

This study sought to compare outcomes in patients with biventricular device infections who undergo successful treatment including extraction and reimplantation to patients with biventricular devices never known to become infected.

BACKGROUND

Infection of a cardiac implantable electronic device (CIED) is associated with substantial morbidity and mortality. Survival in patients with cardiac resynchronization therapy (CRT) device infections undergoing full system extraction is unknown.

METHODS

We extracted data on all patients undergoing extraction of a biventricular pacing device for an infectious indication at the Cleveland Clinic between February 16, 2000, and June 30, 2011. Survival of patients who presented with a CRT device infection, extraction, and successful reimplantation was compared to that of a large cohort of consecutive patients undergoing initial CRT implantation without a known history of subsequent device-related infection. In addition, long-term outcomes were compared between patients who were extracted and deemed to be cured with and without successful biventricular device reimplantation.

RESULTS

In all, 151 patients underwent biventricular device extraction for infection, of whom 81 were successfully reimplanted. The noninfected cohort consisted of 879 patients. In a multivariate Cox regression model controlling for sex, a history of ischemic cardiomyopathy, creatinine, hemoglobin, beta-blocker use, angiotensin-converting enzyme inhibitor use, and diuretic use, no significant association between subsequent infection with reimplantation and all-cause mortality was noted (p = 0.21). There was a trend toward worse outcomes for patients extracted, deemed cured, and not reimplanted compared to patients with successful CRT reimplantation.

CONCLUSIONS

Patients with a biventricular device infection who are successfully extracted, treated with antibiotics, and reimplanted with a biventricular device have outcomes similar to those of patients with biventricular devices not known to have become infected.

[Morbimortality of infective endocarditis associated with permanent cardiovascular implantable electronic devices]

Infective endocarditis (IE) associated with permanent cardiovascular implantable electronic devices (CIEDs) is a complication of low frequency, but high mortality without adequate treatment. Progress on the knowledge of this disease and the development of therapeutic strategies such as early diagnosis, antibiotic management and better extraction techniques, among others, have improved the prognosis of these patients. The objectives of this study were to evaluate the in-hospital and out-of-hospital morbidity, and analyze some factors that explain the differences among the published mortality data. Patients diagnosed with IE associated with CIEDs were studied, retrospectively, between March/2002 and March/2011. We analyzed baseline, diagnostic and therapeutic characteristics, and in-hospital and out-of-hospital courses of the disease. We included 26 cases treated in our hospital, 23 of whom were referred from other centers for diagnosis and treatment. The average age of the patients was 67.5 years. All patients received antibiotics for six weeks and underwent complete removal of the device system, in 95% of patients by percutaneous extraction and 2 patients required a median sternotomy, atriotomy and epicardial pacemaker placement. Mortality was 4% and the follow up mortality was zero. The in-hospital morbidity was 31%. In the follow-ups there were no reinfections or other complications. In conclusion, IE is a serious condition that has a high morbidity with prolonged hospital stays, but with a low mortality. The explanation may lie in the use percutaneous extraction techniques, experience, complete extraction of the device system, the time of reimplantation of the new device and early treatment, among other factors.

Comparison of mortality in women versus men with infections involving cardiovascular implantable electronic device

Device infection is a complication of implantable cardioverter-defibrillator (ICD) therapy that significantly increases mortality. Risk factors associated with death and ICD infection are poorly understood. The purpose of this study was to identify patient characteristics associated with death after cardiovascular implantable electronic device (CIED) infection. This is a retrospective cohort study of 64,903 Medicare fee-for-service patients who received an ICD in 2007, including 1,855 with device infection. Long-term survival was significantly reduced with CIED infection (71.6% vs 85.0%, p <0.001). Regression analysis accounting for age, race, gender, and 28 co-morbidities identified only 2 patient characteristics associated with decreased long-term survival with CIED infection: female gender and human immunodeficiency virus/acquired immunodeficiency syndrome. In patients with CIED infection, women had substantially reduced long-term survival compared with men (67.3% vs 72.9%, p <0.02). The risk-adjusted hazard ratio for long-term mortality with device infection in women compared with that in men increased significantly from 0.86 (95% confidence interval [CI] 0.82 to 0.91) to 1.25 (95% CI 1.02 to 1.53), corresponding to a risk increase of >45%. Importantly, a substantial portion of this excess mortality occurred after the index admission for infection, when the hazard ratio for death in women compared with that in men increased from 0.86 (95% CI 0.82 to 0.91) to 1.20 (95% CI 0.96 to 1.51) with CIED infection, despite little gender difference in admission length of stay, disposition, and cost. In conclusion, women are significantly more likely than men to die with CIED infection. A substantial part of this excess mortality occurs after discharge. It will be important to identify and address the cause(s) of this gender difference in mortality.

Comparison between early and late prosthetic valve endocarditis: clinical characteristics and outcomes

BACKGROUND AND AIM OF THE STUDY

Prosthetic valve endocarditis (PVE) is considered a time-related event. The study aim was to compare the clinical characteristics and outcomes of early- and late-onset PVE, and to investigate potential preventive measures for each condition.

METHODS

A total of 47 consecutive patients undergoing surgery for PVE between January 1986 and December 2011 were analyzed retrospectively, and classified as an early-onset group (n = 26; PVE occurring within 12 months after previous surgery) and late-onset group (n = 21; PVE occurring after 12 months).

RESULTS

The prosthetic valve position significantly affected the incidence of endocarditis: 21 cases (80.7%) in the early-onset group had infected aortic prostheses, while 18 (85.7%) in the late-onset group had infected mitral prostheses (p = 0.028). PVE significantly affected bioprosthetic valves in the early-onset group (18 cases, 69.2%) and mechanical valves in the late-onset group (17 cases, 80.9%) (p < 0.01). Staphylococcus spp. infections were predominant in the early-onset group (21 cases, 80.7%), and Streptococcus spp. in the late-onset group (five cases, 23.8%) (p = 0.03). Operative deaths occurred in both the early-onset (n = 6; 23.0%) and late-onset (n = 2; 9.5%) groups (p = 0.11). The long-term mortality in the early-onset and late-onset groups, respectively, was 40.3 +/- 17.7% and 85.1 +/- 7.9% at 10 years, and 40.3 +/- 17.7% and 72.9 +/- 13.1% at 15 years (p 0.047). Freedom from recurrent endocarditis after two years in the early- and late-onset groups, respectively, was 67.8 +/- 10.1% and 88.8 +/- 7.4% (p = 0.048).

CONCLUSION

Clinical characteristics and outcomes differed significantly between early- and late-onset PVE. The clinical outcomes of patients with early PVE tend to be serious, and therefore stringent care should be taken to avoid contamination during the initial surgery and hence to reduce the incidence of the condition.

Long-term survival after operations for native and prosthetic valve endocarditis

BACKGROUND

The objective was to compare long-term survival after operations for active infective endocarditis (IE) in native or prosthetic valves. We also investigated differences in early death and postoperative complications.

METHODS

We conducted a population-based cohort study including all patients who underwent operations for IE between January 2002 and July 2012. The SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) registry and patients records were used to acquire information about patient characteristics, preoperative comorbidities, and postoperative complications. Date of death was ascertained by using the Swedish personal identity number and the Total Population Register at Statistics Sweden. We used multivariable Cox regression to analyze the association between prosthetic valve IE and survival.

RESULTS

Of the 252 included patients, 22% underwent operations for prosthetic valve IE. There was no significant difference in unadjusted 5-year survival between patients who underwent operations for prosthetic valve IE compared with native valve IE (75% vs 65%; p = 0.34). We found no significant association between operations for prosthetic valve IE and death (multivariable adjusted hazard ratio, 0.83; 95% confidence interval, 0.46 to 1.49) compared with native valve IE. There was no significant difference in 30-day mortality between prosthetic and native valve IE (14% vs 12%; p = 0.61), with a multivariable adjusted odds ratio of 0.62 (95% confidence interval, 0.24 to 1.64).

CONCLUSIONS

We found no significant difference in long-term survival between patients who underwent operations for prosthetic valve IE compared with native valve IE. Early death and morbidity were also similar between the groups. These results are promising because an increasing amount of patients with IE have prosthetic valve infections.

Predictors of mortality in patients with cardiovascular implantable electronic device infections

Infection reduces survival in cardiovascular implantable electronic device (CIED) recipients. However, the clinical predictors of short- and long-term mortality in patients with CIED infection are not well understood. We retrospectively reviewed all patients with CIED infection who were admitted to Mayo Clinic from January 1991 to December 2008. Survival data were obtained from the medical records and the United Sates Social Security Index. The purported risk factors for short-term (30-day) and long-term (>30-day) mortality were analyzed using univariate and multivariate models. Overall, 415 cases of CIED infection were identified during the study period. The mean follow-up duration for the 243 patients who were alive at the last follow-up visit was 6.9 years. In a multivariate model, heart failure (odds ratio 9.31, 95% confidence interval 2.08 to 41.67), corticosteroid therapy (odds ratio 4.04, 95% confidence interval 1.40 to 11.60), and presentation with CIED-related infective endocarditis (odds ratio 5.60, 95% confidence interval 2.25 to 13.92) were associated with increased short-term mortality. The factors associated with long-term mortality in the multivariate model included patient age (hazard ratio 1.20, 95% confidence interval 1.06 to 1.36), heart failure (hazard ratio 2.01, 95% confidence interval 1.42 to 2.86), metastatic malignancy (hazard ratio 5.99, 95% confidence interval 1.67 to 21.53), corticosteroid therapy (hazard ratio 1.97, 95% confidence interval 1.22 to 3.18), renal failure (hazard ratio 1.94, 95% confidence interval 1.37 to 2.74), and CIED-related infective endocarditis (hazard ratio 1.68, 95% confidence interval 1.17 to 2.41). In conclusion, these data suggest that the development of CIED-related infective endocarditis and the presence of co-morbid conditions are associated with increased short- and long-term mortality in patients with CIED infection.

A large multicenter study of methicillin-susceptible and methicillin-resistant Staphylococcus aureus prosthetic joint infections managed with implant retention

BACKGROUND

Several series predicting the prognosis of staphylococcal prosthetic joint infection (PJI) managed with debridement, antibiotics, and implant retention (DAIR) have been published, but some of their conclusions are controversial. At present, little is known regarding the efficacy of the different antibiotics that are used or their ability to eliminate methicillin-resistant S. aureus (MRSA) infection.

METHODS

This was a retrospective, multicenter, observational study of cases of PJI by S. aureus that were managed with DAIR (2003-2010). Cases were classified as failures when infection persistence/relapse, death, need for salvage therapy, or prosthesis removal occurred. The parameters that predicted failure were analyzed with logistic and Cox regression.

RESULTS

Out of 345 episodes (41% men, 73 years), 81 episodes were caused by MRSA. Fifty-two were hematogenous, with poorer prognoses, and 88% were caused by methicillin-susceptible S. aureus (MSSA). Antibiotics were used for a median of 93 days, with similar use of rifampin-based combinations in MSSA- and MRSA-PJI. Failure occurred in 45% of episodes, often early after debridement. The median survival time was 1257 days. There were no overall prognostic differences between MSSA- and MRSA-PJI, but there was a higher incidence of MRSA-PJI treatment failure during the period of treatment (HR 2.34), while there was a higher incidence of MSSA-PJI treatment failure after therapy. Rifampin-based combinations exhibited an independent protective effect. Other independent predictors of outcome were polymicrobial, inflammatory, and bacteremic infections requiring more than 1 debridement, immunosuppressive therapy, and the exchange of removable components of the prosthesis.

CONCLUSIONS

This is the largest series of PJI by S. aureus managed with DAIR reported to date. The success rate was 55%. The use of rifampin may have contributed to homogenizing MSSA and MRSA prognoses, although the specific rifampin combinations may have had different efficacies.

Do all patients with prosthetic valve endocarditis need surgery?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was 'do all patients with prosthetic valve endocarditis need surgery?' Seventeen papers were found using the reported search that represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. These studies compared the outcome and survival between surgically and non-surgically treated patients with prosthetic valve endocarditis. Of these studies, two were prospective observational studies and the rest were retrospective studies. The results of most of these papers were in accordance with the guidelines of the American College of Cardiology and American Heart association. These studies showed that unless a patient is not a surgical candidate, an operation is the treatment of choice in prosthetic valve endocarditis. Surgery should be performed as soon as possible, particularly in haemodynamically unstable patients and those who develop complications such as heart failure, valvular dysfunction, regurgitation/obstruction, dehiscence and annular abscess. In addition to the above indications and cardiac/valvularrelated complications of prosthetic valve endocarditis, infection with Staphylococcus aureus plays an important role in the outcome, and the presence of this micro-organism should be considered an urgent surgical indication in the treatment of prosthetic valve endocarditis. Surgery should be performed before the development of any cerebral or other complications. In contrast, in stable patients with other micro-organisms, particularly those with organisms sensitive to antibiotic treatment who have no structural valvular damage or cardiac complications, surgery can be postponed. The option of surgical intervention can also be revisited if there is a change in response to the treatment. This option is reserved for selected patients only and we conclude that as soon as the diagnosis of prosthetic valve endocarditis is made, cardiac surgeons should be involved.

Effect of early diagnosis and treatment with percutaneous lead extraction on survival in patients with cardiac device infections

Cardiac device infections (CDIs) represent a serious complication after the implantation of pacemakers and defibrillators. In addition to antimicrobials, complete hardware removal, mostly with percutaneous lead extraction (PLE), is necessary to limit recurrences. However, CDI diagnosis is often difficult and is sometimes delayed, and scarce data exist on how the timing of PLE may affect clinical outcomes. In this study, the in-hospital outcomes of 52 consecutive patients with CDIs who underwent PLE were retrospectively analyze. Co-morbidities such as diabetes mellitus, congestive heart failure, renal insufficiency, and end-stage renal disease were highly prevalent in the study cohort. Patients were divided into group A (bacteremia or device endocarditis) and group B (localized pocket infection). In-hospital mortality was 29% in group A and 5% in group B (p = 0.02) and was due mostly to sepsis. Hospital stays were shorter in group B patients (5.7 vs 21.7 days, p <0.001). Presentation with hypotension was more commonly observed in group A patients and was associated with higher in-hospital mortality, whereas pocket findings correlated with better survival. Postoperative courses after PLE were uneventful in most patients, and no fatal complications were observed. PLE was performed significantly earlier in group B patients (hospitalization day 1.3 vs 7.6, p <0.001). PLE performed within 3 hospitalization days was associated with lower in-hospital mortality (p = 0.01). In conclusion, PLE performed within 3 days from admission is associated with shorter hospitalization and better survival. A timely diagnosis is crucial, particularly in the absence of local findings, because early treatment with PLE is likely to prevent the catastrophic outcomes of unrelenting CDIs.