Prosthetic patch remnants to treat infected arterial grafts

Surgical Referral for Hemodialysis Access Maintenance

Hemodialysis access is the lifeline for end-stage renal disease patients. However, dialysis access is associated with a host of complications, including thrombosis, recurrent stenosis, infection, aneurysmal changes and bleeding. Although endovascular therapy remains the first-line treatment owing to its less invasive nature, there are certain situations where surgical referral is recommended or even necessary. Regardless, management of dialysis access complications requires a multidisciplinary approach. Interventional radiologists should be familiar with the appropriate timing for surgical referral to better serve the complex patient population.

Clinical and Epidemiological Characteristics of Persistent Bacteremia: A Decadal Observational Study

Background: Bloodstream infections (BSIs), including persistent bacteremia (PB), are a leading source of morbidity and mortality globally. PB has a higher mortality rate than non- PB, but the clinical aspects of PB in terms of the causative pathogens and the presence of clearance of PB are not well elucidated. Therefore, this study aimed to describe the clinical and epidemiological characteristics of PB in a real-world clinical setting. Methods: We performed a retrospective observational survey of patients who underwent blood culture between January 2012 and December 2021 at Tohoku University Hospital. Cases of PB were divided into three groups depending on the causative pathogen: gram-positive cocci (GPC), gram-negative rods (GNRs), and Candida spp. For each group, we examined the clinical and epidemiological characteristics of PB, including differences in clinical features depending on the clearance of PB. The main outcome variable was mortality, assessed as early (30-day), late (30-90 day), and 90-day mortality. Results: Overall, we identified 31,591 cases of single bacteremia; in 6709 (21.2%) cases, the first blood culture was positive, and in 3124 (46.6%) cases, a follow-up blood culture (FUBC) was performed. Of the cases with FUBCs, 414 (13.2%) were confirmed to be PB. The proportion of PB cases caused by Candida spp. was significantly higher (29.6%, 67/226 episodes) than that for GPC (11.1%, 220/1974 episodes, p < 0.001) and GNRs (12.1%, 100/824 episodes, p < 0.001). The Candida spp. group also had the highest late (30-90 day) and 90-day mortality rates. In all three pathogen groups, the subgroup without the clearance of PB tended to have a higher mortality rate than the subgroup with clearance. Conclusions: Patients with PB due to Candida spp. have a higher late (30-90 day) and 90-day mortality rate than patients with PB due to GPC or GNRs. In patients with PB, FUBCs and confirming the clearance of PB are useful to improve the survival rate.

A systematic review of brachial artery ligation as a safe and feasible option in the management of arteriovenous dialysis access infection

OBJECTIVE

Creation of good long-term arteriovenous access is essential in patients requiring hemodialysis for end-stage renal failure. However, arteriovenous grafts or fistulae can be complicated by infection that may require emergency surgery. For infections that involve the brachial artery anastomosis, or if total graft explantation is indicated, brachial artery repair or reconstruction is often required. An alternative management strategy would be brachial artery ligation (BAL). We performed a systematic review to evaluate the outcomes of BAL that has been performed for infected arteriovenous grafts or fistulae.

METHODS

A thorough literature search was conducted using various electronic databases. We included articles that reported outcomes of BAL performed for infected arteriovenous grafts or fistulae. The primary outcome was the incidence of upper limb ischemia after BAL. Secondary outcomes were the need for urgent revascularization, need for upper limb amputation, and incidence of postoperative neurological deficit after BAL.

RESULTS

A total of five studies with a total of 125 patients were included in our systematic review. BAL was performed for infected arteriovenous grafts or fistulae for all studies. Follow-up period ranged from 1 to 27 months. The incidence of upper limb ischemia after BAL was low. Only a single study reported three patients who developed upper limb ischemia. Two patients required urgent revascularization, and one patient required forearm amputation after proximal ligation. All studies reported clearance of infection with no recurrence.

CONCLUSIONS

Distal BAL may be performed safely for patients with infected arteriovenous fistulae or grafts with low risk of upper limb ischemia, postoperative neurological deficit, and recurrent infection.

Aortobisiliac Bypass Using a Venous Homograft Concomitant With Kidney Transplantation in a Patient With Severe Bilateral Iliac Occlusive Disease: A Case Report

Aortoiliac occlusive disease (AOD) is a great threat for kidney transplantation (KT). Here we report the case of an aortoiliac bypass, performed simultaneously with renal transplantation using venous grafts obtained from the deceased donor. The recipient was a 68-year-old woman with significant stenosis of the aortoiliac axis. We performed an aortobisiliac bypass using donor's femoral veins because presence of methicillin-resistant Staphylococcus aureus was detected on donor hemoculture and contraindicated a prosthetic implant on the recipient. KT was then carried out using standard technique. Operative time amounted to 330 minutes and cold ischemia time of the renal graft was 900 minutes. Delayed graft function was observed until postoperative day 12, but the patient showed a good urine output and a serum creatinine of 2.1 mg/dL at discharge. AOD is not an absolute contraindication to renal transplantation, and simultaneous surgical repair of aortoiliac lesions with KT seems feasible. The patient's return to function after initial delayed graft function suggests that such interventions may allow transplantation to be offered to those patients who otherwise may be excluded for severe vascular comorbidities. Homologous vascular grafts are an excellent choice because prosthetic vascular replacement during immunosuppression must be avoided as long as possible, especially in patients with coexisting infective risk.

Lateral femoral bypass for prosthetic arterial graft infections in the groin

OBJECTIVE

Prosthetic arterial graft infections (PAGIs) in the groin pose significant challenges in terms of revascularization options and risk of limb loss as well as associated morbidities. Although obturator canal bypass (OCB) has been suggested for revascularization of the extremity in these cases, moderate success rates and technical challenges have limited widespread use. Our study analyzed lateral femoral bypass (LFB) as an alternative approach for the treatment of groin PAGIs.

METHODS

This is a retrospective review of a prospectively maintained database of patients who underwent LFB for groin PAGIs at a single center from 2000 to 2017. Patients' data including demographics, comorbidities, perioperative complications, graft patency, and need for reintervention were used. Patients were observed after LFB with duplex ultrasound surveillance in an accredited noninvasive vascular laboratory every 3 months during the first year, followed by every 6 months for the second year and yearly thereafter. After isolation of the infected wound with sterile dressings, remote proximal and distal arterial exposure incisions were made. LFBs were tunneled under the inguinal ligament and lateral to the infected wound from an uninvolved inflow artery or bypass graft to an uninvolved outflow vessel.

RESULTS

A total of 19 LFBs were performed in 16 patients (mean age, 69 ± 12.6 years). Three LFBs were performed urgently for acute bleeding. Choice of conduit included 6 (31.6%) autogenous vein grafts, 10 (52.6%) cadaveric grafts, 2 (10.5%) rifampin-soaked Dacron grafts, and 1 (5.3%) polytetrafluoroethylene graft. Average follow-up was 33 months (range, 0-103 months). Major adverse events occurring within 30 days of the operation included one (5.3%) death and one (5.3%) graft excision for pseudoaneurysm. Primary patency and primary assisted patency at 12 and 24 months were 73% and 83%, respectively. One patient required an amputation 17 months after surgery after failure of repeated revascularization attempts. Overall limb salvage was 93.8% during this follow-up period.

CONCLUSIONS

In this series, LFB for management of groin PAGIs demonstrated higher patency and limb salvage rates compared with previous reports of OCB. Diligent postoperative duplex ultrasound surveillance is critical to the achievement of limb salvage and maintenance of graft patency. These results suggest that LFB, which is technically less complex than OCB, should be considered the first choice for revascularization in select cases of PAGIs involving the groin.

Surgical Excision of Infected Arteriovenous Grafts: Technique and Review

Infected prosthetic arteriovenous grafts for hemodialysis present a profound risk to patient well being. Here we present five recent cases and describe our technique for total graft excision. We also review the literature and discuss the much debated role of partial, subtotal, and total graft excision.

Management of Infected Aortic Prosthetic Grafts

The management of infected prosthetic grafts is one of the most challenging problems facing vascular surgeons. High mortality and morbidity rates with traditional treatment have led many surgeons to consider different and novel strategies. Diagnosis is usually straightforward, but occasionally is unclear even after extensive clinical and radiologic investigations. Although routine total graft excision for all infected aortic grafts is still favored by some vascular surgeons, most favor only partial graft excision if only the distal limb of the graft is involved. Placement of in situ autologous vein or cryopreserved grafts have gained popularity, and investigations are continuing regarding the use of in situ antibiotic and silver-coated prosthetic grafts. In this article the authors review the incidence and etiology of aortic graft infections, methods to prevent these complications, the diagnosis of infected aortic grafts, and lastly the management of these complicated cases, including total graft excision and partial and complete graft preservation.

Late Infection of a Dacron Carotid Endarterectomy Patch

This unique case reports the nonsurgical management of a late (2 years) methicillin-resistant Staphylococcus aureus neck infection around a Dacron-patched carotid endarterectomy. Because the patient was elderly with multiple serious risk factors and no drainable material, IV and oral antibiotics were selected as initial management. Follow-up computed tomography of the neck, however, documented complete resolution of the phlegmon. While the authors remain uncertain of the long-term outcome the patient is free of local infection 2 years after diagnosis and nonoperative treatment.

Vascular graft infections and role of PET/CT in patients with persistent bacteraemia

Prosthetic vascular graft infection although a rare complication of vascular reconstruction surgery; has been associated with significant morbidity and mortality. The author presents two patients with prosthetic aortic graft presenting as fever and methicillin sensitive Staphylococcus aureus bacteraemia without any other localising sign of infection. Both patients had a history of postoperative wound infection after their graft placement. Patients remained persistently bacteraemic on appropriate antimicrobial therapy making the clinician suspicious of a vascular graft infection. A [18 F] fluoro-2-deoxy-d glucose positron emission tomography associated to CT scan was used to identify the prosthetic vascular graft infection and since both patients were high-risk surgical candidates, a conservative medical approach was used. They were treated with 6 weeks of nafcillin and rifampin, followed by long-term doxycycline for suppression. This highlights the importance of considering vascular graft infection in patients with recurrent and persistent bacteraemia despite adequate therapy.

Establishing a swine model to compare vascular prostheses in a contaminated field

OBJECTIVE

Patch arteriotomies are performed during many vascular procedures. Whereas synthetic materials are generally felt to be inappropriate for infected environments, the suitability of glutaraldehyde-treated bovine pericardium (GBP), a biologic material, in such instances is unknown. Our main objectives were to develop an animal model to study vascular prostheses while comparing the infectability of polyester (Dacron) and GBP in a topically infected environment.

METHODS

Twenty-three pigs underwent transabdominal patch arteriotomy of the infrarenal aorta with either Dacron or GBP. The patches were inoculated with sterile saline (1 per group), Staphylococcus aureus 10(4) colony-forming units (CFUs) (4 per group), or S. aureus 10(5) CFUs (6 per group). At 3 wk, the animals were euthanized, and the patches were removed via a left retroperitoneal approach. Specimens were collected for microbiologic and histologic analysis.

RESULTS

One animal from each group inoculated with 10(5) CFUs died during the study period, and another died immediately postoperatively of an airway complication. All aortas were patent and without evidence of pseudoaneurysm formation. Gross abscesses were found in 4/6 Dacron and 5/6 GBP animals receiving 10(5) CFUs. Similarly, 4/6 animals implanted with Dacron and 5/6 animals implanted with GBP had positive tissue cultures. A histologic grading system of inflammation substantiated the culture results.

CONCLUSIONS

No significant difference exists between Dacron and GBP to resist bacterial infection at 3 wk. We have established a reproducible in vivo model to study arterial patch materials in a topically infected environment.

Is balloon angioplasty of peri-anastomotic stenoses of failing peripheral arterial bypasses worthwhile?

INTRODUCTION

Surgical revision of failing peripheral arterial bypass grafts has generally been shown to provide superior patency rates compared to balloon angioplasty. We analyzed whether balloon angioplasty, specifically of peri-anastomotic stenoses (PAS), provided acceptable patency rates, because surgery for these lesions is more difficult and is likely associated with higher complication rates compared to surgical revision of stenoses in the body of a graft.

METHODS

This is a retrospective review of PAS balloon angioplasties performed at a single institution between January 1, 1999, and September 1, 2005. We report ''primary site patency'' as a stenosis treated by balloon angioplasty, ''revised primary site patency'' as a stenosis treated by repeat balloon angioplasty, and ''secondary site patency'' as an angioplastied stenosis treated surgically or when the graft thrombosed and was revised surgically. All procedures were performed in an endovascular operating room based on duplex scan findings suggesting a significant stenosis.

RESULTS

48 PAS in 33 autologous vein and 15 prosthetic grafts were treated by balloon angioplasty in 42 patients. Mean follow-up was 12 months (range, 1-49 months). Interventions were performed on 22 femoropopliteal grafts (11 proximal, 11 distal), 20 femorotibial grafts (5 proximal, 15 distal), 2 axillofemoral grafts (2 proximal anastomoses), 2 popliteal-pedal grafts (1 proximal, 1 distal), and 1 common iliac-femoral graft (proximal). Life-table analysis revealed 2-year primary, assisted primary, and secondary patency rates of 38%, 58%, and 84%, respectively. No major complications occurred with any endovascular intervention.

CONCLUSION

Balloon angioplasty of PAS resulted in acceptable 2-year assisted primary patency rate of almost 60%. Endovascular intervention avoided repeat incisions in scarred groins, higher rates of nerve injury and infection, significant blood loss, and longer length of hospital stays. We recommend that balloon angioplasty of PAS be attempted before resorting to surgical intervention, especially in cases of hostile anastomotic wounds.

Brachial artery ligation with total graft excision is a safe and effective approach to prosthetic arteriovenous graft infections

OBJECTIVE

While autogenous arteriovenous access is preferred, prosthetic arteriovenous grafts (AVG) are still required in a large number of patients. Infection of AVGs occurs frequently and may cause life-threatening bleeding or sepsis. Multiple treatment strategies have been advocated (ranging from graft preservation to excision with complex concomitant reconstructions), indicating a lack of consensus on appropriate management of infected AVGs. We undertook this study to evaluate if, in the setting of anastomotic involvement, brachial artery ligation distal to the origin of the deep brachial artery accompanied by total graft excision (BAL) is safe and effective.

METHODS

All prosthetic arteriovenous graft infections managed by a single surgeon between 1995 and 2006 were reviewed retrospectively. Patients were identified from a computerized vascular registry, and data were obtained via patient charts and the electronic medical record.

RESULTS

We identified 45 AVG infections in 43 patients. Twenty-one patients (49%) demonstrated arterial anastomotic involvement and were treated with BAL; these form the cohort for this analysis. Mean patient age was 53.2 (SD 9.5) years. The primary etiologies for end stage renal disease (ESRD) were hypertension (29%), HIV (24%), and diabetes (19%). An upper arm AVG was present in 95% of patients; one (5%) had a forearm AVG. The majority of grafts were polytetrafluoroethylene (PTFE) (90%). Follow-up was 100% at 1 month, 86% at 3 months, and 67% at 6 months. No ischemic or septic complications occurred in the 21 patients who underwent BAL.

CONCLUSION

BAL is an effective and expeditious method to deal with an infected arm AVG in frequently critically ill patients with densely scarred wounds. In the short term, BAL appears to be well tolerated without resulting ischemic complications. Further study with longer duration of follow-up is necessary to ascertain whether BAL results in definitive cure, or whether patients may ultimately manifest ischemic changes and require additional intervention.

Cryopreserved arterial allograft reconstruction for peripheral graft infection

OBJECTIVE

This prospective, observational study evaluated the safety and efficacy of cryopreserved arterial allograft reconstruction in the management of major peripheral arterial graft infections.

METHODS

From April 1996 to May 2003, data from patients with major peripheral arterial graft infection who underwent graft excision and cryopreserved arterial allograft reconstruction were prospectively collected. Arterial allografts were harvested from multiple organ donors and cryopreserved at -80 degrees C. The patients were observed for survival, limb salvage, persistence or recurrence of infection, and allograft patency. The results were calculated with the Kaplan-Meier method.

RESULTS

During the 7-year study period, 17 patients (14 men, 3 women; mean age, 68 years) with major peripheral graft infection underwent graft excision and cryopreserved arterial allograft reconstruction. Eight patients (47%) had systemic sepsis, 5 (29%) had acute ischemia at the time of the allograft reconstruction, and 9 (53%) had experienced anastomotic rupture. Allograft reconstruction was performed as an emergency procedure in 7 patients (41%). There were no perioperative deaths or early amputations. Two patients had allograft ruptures in the groin during the early postoperative period. The mean follow-up period was 34 months (range, 8 to 80 months). There was no persistent or recurrent infection, and none of the patients received long-term (>3 months) antibiotic therapy. Reoperation for allograft revision, excision, or replacement was performed in 2 patients. The 18-month primary and secondary allograft patency rates were 68% and 86%; the overall limb salvage rate was 82% at 2 years.

CONCLUSION

Our experience with cryopreserved arterial allograft in the management of major peripheral bypass graft infection suggests that this technique seems to be a useful option for treating one of the most dreaded vascular complications.

Management of hemodialysis access infections

Management of hemodialysis (HD) access infection is one of the most challenging and most common problems faced by surgeons, interventional radiologists, and nephrologists. The goal to eradicate infection is often at odds with the need to maintain access. Patients on HD are immunocompromised and typically have significant comorbid conditions placing them at high risk for the occurrence of access infection. Infection is most common with central-vein catheter access, followed by prosthetic arteriovenous grafts (AVG) and is rare with autogenous fistulas. The diagnosis is usually evident on physical exam, but it is not uncommon for these patients to present with atypical symptoms and lack of clinical findings. Although Staphylococcal species are the most common organism to cause infection, early empiric antimicrobial therapy should also include coverage for Gram-negative organisms. Management of central-vein catheter infection includes removal and delayed replacement or, in patients with mild clinical symptoms, catheter exchange over a guide wire. Our management of AVG infection includes total graft excision when patients present with sepsis or the entire graft is bathed in pus, subtotal graft excision when all of the graft is removed except a small oversewn cuff of prosthetic material on an underlying patent artery, and partial graft excision when only a limited infected portion of the graft is removed and a new graft is rerouted in adjacent sterile tissue to maintain patency of the original graft. This strategy has proven to be highly successful in the management of these complicated cases.

Management of infected prosthetic dialysis arteriovenous grafts

BACKGROUND

Hemodialysis access is one of the most common vascular procedures that is performed by vascular and general surgeons. Prosthetic arteriovenous graft (AVG) infections pose potentially life-threatening septic and bleeding complications, as well as loss of dialysis access. Strategies employed to preserve some grafts, prevent morbidity in those with major infections, and maintain access are presented.

METHODS

Between July 1, 1995 and August 1, 2002, 1441 AVG procedures were performed at a single institution. Fifty-one (3.5%) prosthetic AVG infections in 45 patients were identified. Twenty-seven graft infections occurred at a prior incision for placement or revision of a graft. The other 24 infections were located within the body of the graft, and 14 of these were documented to be at a recent puncture site for hemodialysis access. The most common presentation (47% [24/51]) was an exposed graft or a draining sinus tract. Management included total graft excision (TGE) when patients presented with sepsis or the entire graft was bathed in pus; subtotal graft excision (SGE), when all of the graft was removed except an oversewn small cuff of prosthetic material on an underlying patent artery; and partial graft excision (PGE), when only a limited infected portion of the graft was removed and a new graft was rerouted through adjacent sterile tissue to maintain patency of the original graft.

RESULTS

None of the 45 patients died or developed hand ischemia. A uniformly successful outcome was achieved in all patients who were treated with TGE (13/13: 8 vein patches, 4 primary closure, 1 arterial ligation) or SGE (15/15). However, these treatments necessitated placement of a central venous catheter for temporary dialysis access and a new AVG later. All of these 28 wounds healed by secondary intention, including all 15 cases in which an oversewn cuff of prosthetic material remained. Graft patency and wound healing were achieved in 74% (17/23) of infections treated with PGE, and placement of a temporary dialysis access catheter and new AVG were avoided. The 6 failures of PGE ultimately required TGE because of nonhealing wounds, but there were no acute hemorrhagic or septic events.

CONCLUSIONS

Systemic sepsis caused by prosthetic AVG infections mandates TGE. SGE and PGE can be safely employed in selected patients with infected prosthetic AVGs. SGE maintains patency of the underlying artery and avoids a difficult and time-consuming dissection. PGE offers the advantage of minimizing extensive dissection of well-incorporated uninfected graft segments and allows continued dialysis access at the incorporated portion of the graft.