International Multi-Institutional Experience with Presentation and Management of Aortic Arch Laterality in Aberrant Subclavian Artery and Kommerell's Diverticulum

BACKGROUND

Aberrant subclavian artery (ASA) with or without Kommerell's diverticulum (KD) is a rare anatomic aortic arch anomaly that can cause dysphagia and/or life-threatening rupture. The objective of this study is to compare outcomes of ASA/KD repair in patients with a left versus right aortic arch.

METHODS

Using the Vascular Low Frequency Disease Consortium methodology, a retrospective review was performed of patients ≥18 years old with surgical treatment of ASA/KD from 2000 to 2020 at 20 institutions.

RESULTS

288 patients with ASA with or without KD were identified; 222 left-sided aortic arch (LAA), and 66 right-sided aortic arch (RAA). Mean age at repair was younger in LAA 54 vs. 58 years (P = 0.06). Patients in RAA were more likely to undergo repair due to symptoms (72.7% vs. 55.9%, P = 0.01), and more likely to present with dysphagia (57.6% vs. 39.1%, P < 0.01). The hybrid open/endovascular approach was the most common repair type in both groups. Rates of intraoperative complications, death within 30 days, return to the operating room, symptom relief and endoleaks were not significantly different. For patients with symptom status follow-up data, in LAA, 61.7% had complete relief, 34.0% had partial relief and 4.3% had no change. In RAA, 60.7% had complete relief, 34.4% had partial relief and 4.9% had no change.

CONCLUSIONS

In patients with ASA/KD, RAA patients were less common than LAA, presented more frequently with dysphagia, had symptoms as an indication for intervention, and underwent treatment at a younger age. Open, endovascular and hybrid repair approaches appear equally effective, regardless of arch laterality.

Decubitus ulcers in patients undergoing vascular operations do not influence mortality but affect resource utilization

BACKGROUND

While it is anticipated that decubitus ulcers are detrimental to outcomes after vascular operations, the contemporary influence of perioperative decubitus ulcers in vascular surgery remains unknown.

METHODS

Using the National Impatient Survey, all adult patients who underwent vascular operation were selected. Patients were stratified by the presence or absence (non-decubitus ulcers) of decubitus ulcer. Case-mix adjusted hierarchical mixed-models examined in-hospital mortality, the occurrence of any complication, and discharge disposition.

RESULTS

A total of 538,808 cases were analyzed. Decubitus ulcers were most prevalent among Caucasian male Medicare beneficiaries (P < .001). Decubitus ulcer patients also underwent more nonelective vascular operations (P < .001). Wound, infectious, and procedural complications were more common in patients with decubitus ulcers (P < .001). Failure to rescue, defined as mortality after any complication, was more than doubled in decubitus ulcers (non-decubitus ulcers: 1.5%, decubitus ulcers: 3.2%, P < .001). Similarly, unadjusted mortality was also doubled in patients undergoing vascular operation with decubitus ulcers (non-decubitus ulcers: 3%, decubitus ulcers: 6%, P < .001). After risk adjustment among all patients, neither the presence of a decubitus ulcer nor specific ulcer staging increased the adjusted odds of death. Having a decubitus ulcer increased the adjusted odds of discharge to an intermediate care facility (odds ratio 2.9, P < .001). These patients also had 1.6 times the total charges compared to their non-decubitus ulcer cohort (non-decubitus ulcers: $49,460 ± $281 vs decubitus ulcers: $81,149 ± $5,855, P < .001).

CONCLUSION

Contrary to common perception, perioperative decubitus ulcer does not adversely affect mortality after vascular operation in patients proceeding to operative intervention. Patients with decubitus ulcers are, however, at higher risk for complications and incur sizeable additional charges.

Temporal Trends in Blood Stream Infection Isolates from Surgical Patients

BACKGROUND

Blood stream infections (BSIs) are a common source of morbidity and death in hospitalized patients. We hypothesized that the proportions of bacteremia from gram-positive and fungal pathogens have decreased over time, whereas rates of gram-negative bacteremia have increased as a result of better central venous catheter management.

METHODS

All U.S. Centers for Disease Control and Prevention-defined BSIs in patients treated on the general surgery and trauma services at our institution between January 1, 1998, and December 31, 2009 were identified prospectively. These cases were analyzed on a yearly basis to compare rates of various infections over time. The Cochran-Armitage test for trend was used to evaluate categorical data, whereas the Jonckheere-Terpstra test for ordered values was used to analyze continuous data.

RESULTS

A total of 1,040 patients had 1,441 episodes of BSI caused by 1,632 strains of bacteria or fungi. There was no difference over time in the proportion of BSI among overall infections. Rates of BSI for gram-negative and fungal pathogens increased over time (p=0.03 and<0.0001, respectively), whereas rates of gram-positive BSI decreased (p<0.0001). Positive changes in anaerobic BSI approached statistical significance.

CONCLUSION

Although our hypothesis was only partly true, over the last 12 y, our institution clearly has witnessed a shift in the types of organisms causing BSIs. There was a decrease in the rates of BSI caused by gram-positive pathogens with an associated increase in the rates of BSI of infections by fungal and gram-negative pathogens. Interventions to reduce institutional rates of BSI should include targeted therapies based on historical institutional trends.

Association of excessive duration of antibiotic therapy for intra-abdominal infection with subsequent extra-abdominal infection and death: a study of 2,552 consecutive infections

BACKGROUND

We hypothesized that a longer duration of antibiotic treatment for intra-abdominal infections (IAI) would be associated with an increased risk of extra-abdominal infections (EAI) and high mortality.

METHODS

We reviewed all IAI occurring in a single institution between 1997 and 2010. The IAI were divided into two groups consisting of those with a subsequent EAI and those without; the data for each group were analyzed. Patients with EAI following IAI were matched in a 1:2 ratio with patients who did not develop EAI on the basis of their Acute Physiology and Chronic Health Evaluation (APACHE II) score±1 point. Statistical analyses were done with the Student t-test, χ(2) analysis, Wilcoxon rank sum test, and multi-variable analysis.

RESULTS

We identified 2,552 IAI, of which 549 (21.5%) were followed by EAI. Those IAI that were followed by EAI were associated with a longer initial duration of antimicrobial therapy than were IAI without subsequent EAI (median 14 d [inter-quartile range (IQR) 10-22 d], vs. 10 d [IQR 6-15 d], respectively, p<0.01), a higher APACHE II score (16.6±0.3 vs. 11.2±0.2 points, p<0.01), and higher in-hospital mortality (17.1% vs. 5.4%, p<0.01). The rate of EAI following IAI in patients treated initially with antibiotics for 0-7 d was 13.3%, vs. 25.1% in patients treated initially for >7 d (p<0.01). A successful match was made of 469 patients with subsequent EAI to 938 patients without subsequent EAI, resulting in a mean APACHE II score of 15.2 for each group. After matching, IAI followed by EAI were associated with a longer duration of initial antimicrobial therapy than were IAI without subsequent EAI (median 14 d [9-22 d], vs. 11 d [7-16 d], respectively, p<0.01), and with a higher in-hospital mortality (14.9% vs. 9.0%, respectively, p<0.01). Logistic regression showed that days of antimicrobial therapy for IAI was an independent predictor of subsequent EAI (p<0.001).

CONCLUSIONS

A longer duration of antibiotic therapy for IAI is associated with an increased risk of subsequent EAI and increased mortality.

Predicting the need for urgent intubation in a surgical/trauma intensive care unit

BACKGROUND

Analysis and modeling of data monitoring vital signs and waveforms in patients in a surgical/trauma intensive care unit (STICU) may allow for early identification and treatment of patients with evolving respiratory failure.

METHODS

Between February 2011 and March 2012, data of vital signs and waveforms for STICU patients were collected. Every-15-minute calculations (n = 172,326) of means and standard deviations of heart rate (HR), respiratory rate (RR), pulse-oxygen saturation (SpO2), cross-correlation coefficients, and cross-sample entropy for HR-RR, RR-SpO2, and HR-SpO2, and cardiorespiratory coupling were calculated. Urgent intubations were recorded. Univariate analyses were performed for the periods <24 and ≥24 hours before intubation. Multivariate predictive models for the risk of unplanned intubation were developed and validated internally by subsequent sample and bootstrapping techniques.

RESULTS

Fifty unplanned intubations (41 patients) were identified from 798 STICU patients. The optimal multivariate predictive model (HR, RR, and SpO2 means, and RR-SpO2 correlation coefficient) had a receiving operating characteristic (ROC) area of 0.770 (95% confidence interval [CI], 0.712-0.841). For this model, relative risks of intubation in the next 24 hours for the lowest and highest quintiles were 0.20 and 2.95, respectively (15-fold increase, baseline risk 1.46%). Adding age and days since previous extubation to this model increased ROC area to 0.865 (95 % CI, 0.821-0.910).

CONCLUSION

Among STICU patients, a multivariate model predicted increases in risk of intubation in the following 24 hours based on vital sign data available currently on bedside monitors. Further refinement could allow for earlier detection of respiratory decompensation and intervention to decrease preventable morbidity and mortality in surgical/trauma patients.

Use of silver in the prevention and treatment of infections: silver review

BACKGROUND

The use of silver for the treatment of various maladies or to prevent the transmission of infection dates back to at least 4000 b.c.e. Medical applications are documented in the literature throughout the 17th and 18th centuries. The bactericidal activity of silver is well established. Silver nitrate was used topically throughout the 1800 s for the treatment of burns, ulcerations, and infected wounds, and although its use declined after World War II and the advent of antibiotics, Fox revitalized its use in the form of silver sulfadiazine in 1968.

METHOD

Review of the pertinent English-language literature.

RESULTS

Since Fox's work, the use of topical silver to reduce bacterial burden and promote healing has been investigated in the setting of chronic wounds and ulcers, post-operative incision dressings, blood and urinary catheter designs, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. The beneficial effects of silver in reducing or preventing infection have been seen in the topical treatment of burns and chronic wounds and in its use as a coating for many medical devices. However, silver has been unsuccessful in certain applications, such as the Silzone heart valve. In other settings, such as orthopedic hardware coatings, its benefit remains unproved.

CONCLUSION

Silver remains a reasonable addition to the armamentarium against infection and has relatively few side effects. However, one should weigh the benefits of silver-containing products against the known side effects and the other options available for the intended purpose when selecting the most appropriate therapy.

Options for closure of the infected abdomen

BACKGROUND

The infected abdomen poses substantial challenges to surgeons, and often, both temporary and definitive closure techniques are required. We reviewed the options available to close the abdominal wall defect encountered frequently during and after the management of complicated intra-abdominal infections.

METHODS

A comprehensive review was performed of the techniques and literature on abdominal closure in the setting of intra-abdominal infection.

RESULTS

Temporary abdominal closure options include the Wittmann Patch, Bogota bag, vacuum-assisted closure (VAC), the AbThera™ device, and synthetic or biologic mesh. Definitive reconstruction has been described with mesh, components separation, and autologous tissue transfer.

CONCLUSION

Reconstructing the infected abdomen, both temporarily and definitively, can be accomplished with various techniques, each of which is associated with unique advantages and disadvantages. Appropriate judgment is required to optimize surgical outcomes in these complex cases.

Anatomic popliteal entrapment syndrome is often a difficult diagnosis

Anatomic popliteal artery entrapment can be challenging to diagnose. Four cases are described in which initial diagnosis and treatment failed to identify and correct the anatomic defect responsible for patients' symptoms. In 3 of these cases, initial assessment and diagnosis was exertional compartment syndrome, yet compartment release did not resolve the complaint. Following accurate diagnosis, surgical release of aberrant popliteal fossa anatomy provided all 4 patients with lasting symptom resolution, though 1 patient with bilateral operations has had relief of only 1 side. In the diagnostic algorithm for these patients, angiography with forced plantarflexion against resistance aids in eliciting the pathognomonic images of arterial occlusion in this disorder.

Aggressive versus conservative initiation of antimicrobial treatment in critically ill surgical patients with suspected intensive-care-unit-acquired infection: a quasi-experimental, before and after observational cohort study

BACKGROUND

Antimicrobial treatment in critically ill patients can either be started as soon as infection is suspected or after objective data confirm an infection. We postulated that delaying antimicrobial treatment of patients with suspected infections in the surgical intensive care unit (SICU) until objective evidence of infection had been obtained would not worsen patient mortality.

METHODS

We did a 2-year, quasi-experimental, before and after observational cohort study of patients aged 18 years or older who were admitted to the SICU of the University of Virginia (Charlottesville, VA, USA). From Sept 1, 2008, to Aug 31, 2009, aggressive treatment was used: patients suspected of having an infection on the basis of clinical grounds had blood cultures sent and antimicrobial treatment started. From Sept 1, 2009, to Aug 31, 2010, a conservative strategy was used, with antimicrobial treatment started only after objective findings confirmed an infection. Our primary outcome was in-hospital mortality. Analyses were by intention to treat.

FINDINGS

Admissions to the SICU for the first and second years were 762 and 721, respectively, with 101 patients with SICU-acquired infections during the aggressive year and 100 patients during the conservative year. Compared with the aggressive approach, the conservative approach was associated with lower all-cause mortality (13/100 [13%] vs 27/101 [27%]; p=0·015), more initially appropriate therapy (158/214 [74%] vs 144/231 [62%]; p=0·0095), and a shorter mean duration of therapy (12·5 days [SD 10·7] vs 17·7 [28·1]; p=0·0080). After adjusting for age, sex, trauma involvement, acute physiology and chronic health evaluation (APACHE) II score, and site of infection, the odds ratio for the risk of mortality in the aggressive therapy group compared with the conservative therapy group was 2·5 (95% CI 1·5-4·0).

INTERPRETATION

Waiting for objective data to diagnose infection before treatment with antimicrobial drugs for suspected SICU-acquired infections does not worsen mortality and might be associated with better outcomes and use of antimicrobial drugs.

FUNDING

National Institutes of Health.

Quarantine, isolation, and cohorting: from cholera to Klebsiella

BACKGROUND

Isolation is defined as the separation of persons with communicable diseases from those who are healthy. This public health practice, along with quarantine, is used to limit the transmission of infectious diseases and provides the foundation of current-day cohorting.

METHODS

Review of the pertinent English-language literature.

RESULTS

Mass isolation developed during the medieval Black Death outbreaks in order to protect ports from the transmission of epidemics. In the mid-1800s, infectious disease hospitals were opened. It now is clear that isolation and cohorting of patients and staff interrupts the transmission of disease. Over the next century, with the discovery of penicillin and vaccines against many infectious agents, the contagious disease hospitals began to close. Today, we find smaller outbreaks of microorganisms that have acquired substantial resistance to antimicrobial agents. In the resource-limited hospital, a dedicated area or region of a unit may suffice to separate affected from unaffected patients.

CONCLUSION

Quarantine, or cohorting when patients are infected with the same pathogen, interrupts the spread of infections, just as the contagious disease hospitals did during the epidemics of the 18th and 19th centuries.

Effective cohorting and "superisolation" in a single intensive care unit in response to an outbreak of diverse multi-drug-resistant organisms

BACKGROUND

Cohorting patients in dedicated hospital wards or wings during infection outbreaks reduces transmission of organisms, yet frequently, this may not be feasible because of inadequate capacity, especially in the intensive care unit (ICU). We hypothesized that cohorting isolation patients in one geographic location in a single ICU and using enhanced isolation procedures ("superisolation") can prevent the further spread of highly multi-drug-resistant organisms (MDRO).

METHODS

Six patients dispersed throughout our Surgical Trauma Burn ICU had infections with carbapenem-resistant, non-clonal gram-negative MDRO, namely Klebsiella pneumoniae, Citrobacter freundii, Stenotrophomonas maltophilia, Aeromonas hydrophilia, Proteus mirabilis, Pseudomonas aeruginosa, and Providencia rettgeri. Five of the six patients also had simultaneous isolation of vancomycin-resistant enterococci (VRE). Under threat of unit closure and after all standard isolation procedures had been enacted, these six patients were moved to the front six beds of the unit, the front entrance was closed, and all traffic was redirected through the back entrance. Nursing staff were assigned to either two isolation or two non-isolation patients. In accordance with the practice of Semmelweis, rounds were conducted so as to end at the rooms of the patients with the most highly-resistant bacterial infections.

RESULTS

A few months after these interventions, all six patients had been discharged from the ICU (three alive and three dead), and no new cases of infection with any of their pathogens (based on species and antibiogram) or VRE occurred. The mean ICU stay and overall hospital length of stay for these six patients were 78.3 days and 117.2 days respectively, with a mortality rate of 50%.

CONCLUSION

Cohorting patients to one area and altering work routines to minimize contact with patients with MDRO (essentially designating a "high-risk" zone) may be beneficial in stopping patient-to-patient spread of highly resistant bacteria without the need for a dedicated isolation unit.

The surgical care improvement project and prevention of post-operative infection, including surgical site infection

BACKGROUND

In response to inconsistent compliance with infection prevention measures, the Centers for Medicare & Medicaid Services collaborated with the U.S. Centers for Disease Control and Prevention on the Surgical Infection Prevention (SIP) project, introduced in 2002.

METHODS

Quality improvement measures were developed to standardize processes to increase compliance. In 2006, the Surgical Care Improvement Project (SCIP) developed out of the SIP project and its process measures. These initiatives, published in the Specifications Manual for National Inpatient Quality Measures, outline process and outcome measures. This continually evolving manual is intended to provide standard quality measures to unify documentation and track standards of care.

RESULTS

Seven of the SCIP initiatives apply to the peri-operative period: Prophylactic antibiotics should be received within 1 h prior to surgical incision (1), be selected for activity against the most probable antimicrobial contaminants (2), and be discontinued within 24 h after the surgery end-time (3); (4) euglycemia should be maintained, with well-controlled morning blood glucose concentrations on the first two post-operative days, especially in cardiac surgery patients; (6) hair at the surgical site should be removed with clippers or by depilatory methods, not with a blade; (9) urinary catheters are to be removed within the first two post-operative days; and (10) normothermia should be maintained peri-operatively.

CONCLUSIONS

There is strong evidence that implementation of protocols that standardize practices reduce the risk of surgical infection. The SCIP initiative targets complications that account for a significant portion of preventable morbidity as well as cost. One of the goals of the SCIP guidelines was a 25% reduction in the incidence of surgical site infections from implementation through 2010. Process measures are becoming routine, and as we practice more evidence-based medicine, it falls to us, the surgeons and scientists, to be active, not only in the implementation and execution of these measures, but in the investigation of clinical questions and the writing of protocols. We are responsible for ensuring that out-of-date practices are removed from use and that new practices are appropriate, achievable, and effective.

Differences in morbidity and mortality with percutaneous versus open surgical drainage of postoperative intra-abdominal infections: a review of 686 cases

Intra-abdominal infections following surgical procedures result from organ-space surgical site infections, visceral perforations, or anastomotic leaks. We hypothesized that open surgical drainage is associated with increased patient morbidity and mortality compared with percutaneous drainage. A single-institution, prospectively collected database over a 13-year period revealed 2776 intra-abdominal infections, 686 of which required an intervention after the index operation. Percutaneous procedures (simple aspiration or catheter placement) were compared with all other open procedures by univariate and multivariate analyses. Analysis revealed 327 infections in 240 patients undergoing open surgical drainage and 359 infections in 260 patients receiving percutaneous drainage. Those undergoing open drainage had significantly higher Acute Physiology Score (APS) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores and were more likely to be immunosuppressed, require intensive care unit treatment, and have longer hospital stays. Mortality was higher in the open group: 14.6 versus 4.2 per cent (P = 0.0001). Variables independently associated with death by multivariate analysis were APACHE II, dialysis, intensive care unit (ICU) care, age, immunosuppression, and drainage method. Open intervention for postsurgical intra-abdominal infections is associated with increased mortality compared with percutaneous drainage even after controlling for severity of illness by multivariate analysis. Although some patients are not candidates for percutaneous drainage, it should be considered the preferential treatment in eligible patients.

Differences in Morbidity and Mortality with Percutaneous versus Open Surgical Drainage of Postoperative Intra-abdominal Infections: A Review of 686 Cases

Intra-abdominal infections following surgical procedures result from organ-space surgical site infections, visceral perforations, or anastomotic leaks. We hypothesized that open surgical drainage is associated with increased patient morbidity and mortality compared with percutaneous drainage. A single-institution, prospectively collected database over a 13-year period revealed 2776 intra-abdominal infections, 686 of which required an intervention after the index operation. Percutaneous procedures (simple aspiration or catheter placement) were compared with all other open procedures by univariate and multivariate analyses. Analysis revealed 327 infections in 240 patients undergoing open surgical drainage and 359 infections in 260 patients receiving percutaneous drainage. Those undergoing open drainage had significantly higher Acute Physiology Score (APS) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores and were more likely to be immunosuppressed, require intensive care unit treatment, and have longer hospital stays. Mortality was higher in the open group: 14.6 versus 4.2 per cent ( P = 0.0001). Variables independently associated with death by multivariate analysis were APACHE II, dialysis, intensive care unit (ICU) care, age, immunosuppression, and drainage method. Open intervention for postsurgical intra-abdominal infections is associated with increased mortality compared with percutaneous drainage even after controlling for severity of illness by multivariate analysis. Although some patients are not candidates for percutaneous drainage, it should be considered the preferential treatment in eligible patients.

NXL-103, a combination of flopristin and linopristin, for the potential treatment of bacterial infections including community-acquired pneumonia and MRSA

Novexel is developing the novel, orally active, semisynthetic streptogramin NXL-103, which has potential therapeutic application in the treatment of community-acquired pneumonia, community- or hospital-acquired MRSA, vancomycin-resistant enterococcus, and acute bacterial skin and soft tissue infections. NXL-103 is a combination of streptogramin A:streptogramin B components, initially developed in a 70:30 dose ratio. In multiple in vitro studies, NXL-103 demonstrated potent activity against different types of bacteria, such as Staphylococcus aureus (including MRSA), Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecium, Enterococcus faecalis, Haemophilus influenzae and Haemophilus parainfluenzae. NXL-103 was not affected by the resistance profiles of bacteria against other commonly used antibiotics. In phase I clinical trials, NXL-103 achieved bactericidal levels in plasma and was generally well tolerated, with side effects primarily on the gastrointestinal system. The first phase II trial conducted to evaluate the efficacy of NXL-103 against community-acquired pneumonia revealed that the compound was comparable with amoxicillin. NXL-103 has promise to become an important agent in the treatment of community-acquired pneumonia and complex skin and soft tissue infections, pending further development.