Surgical revision of complicated false and true vascular access–related aneurysms

Comparison of Open and Endovascular Aneurysm Repair in Native Arteriovenous Fistulas

BACKGROUND

Arteriovenous accesses develop aneurysms (FA) during their active use, resulting in pain, erosion, bleeding, and difficulty in cannulation. This study aims to evaluate the outcomes of open and endovascular management of single FA in arteriovenous fistulas (AVF).

METHODS

A retrospective review of all upper extremity primary AVFs over 12 years was undertaken at a single center. Patients undergoing elective open and endovascular repair of a single FA were identified. Thirty-day outcomes, cannulation failure, line placement, re-intervention, and functional dialysis (continuous hemodialysis) for 3 consecutive months were examined.

RESULTS

Three hundred and seventy nine patients presented with a single FA that met the requirements for intervention: 126 (33%) underwent endovascular repair, and the remainder 253 (67%) underwent open repair. Preoperative fistulogram identified anatomically significant issues in 91% of the cases, and these were treated by balloon angioplasty: 10% within the fistula tract, 44% within the outflow tract, and 47% in the central veins. In open repair, 57% underwent plication, 35% underwent resection and re-anastomosis, and the remainder (8%) underwent interposition grafting. In endovascular repair, successful placement of a stent was achieved in all cases with 1 ± 2 (mean ± standard deviation [SD]) covered stents (diameter: 6 -8 mm) placed, achieving successful exclusion of the FA. The combination of early thrombosis and cannulation failures led to the greater need for a tunneled central line in endovascular repair (6.5% vs. 2.4%; endovascular versus open repair; P = 0.04). As a result, the mean time for establishing renewed access in the index AVF was significantly higher in endovascular repair (2 ± 3 vs. 2 ± 2 weeks, mean ± SD; endovascular open repair versus open repair; P = 0.001). In follow-up, there were more secondary interventions per year in the endovascular compared to open repair groups (3.1 vs. 1.4 secondary interventions per year; endovascular versus open repair; P = 0.04). Median functional dialysis durations were superior in the open repair (48 ± 6%, mean + standard error) compared to the endovascular repair at 5 years. (26 ± 7%; P = 0.03).

CONCLUSIONS

Open repair results in a more rapid return to access use, lower need for a tunneled central line, lower secondary re-intervention rates, and superior functional dialysis durations compared to endovascular repair. Open FA repair should be considered for symptomatic single FA repairs before endovascular FA repair.

End-to-end anastomosis as a superior repair type to prevent recurrence of arteriovenous fistula aneurysms and improve patency outcomes

BACKGROUND

Arteriovenous fistulae (AVF) complicated by aneurysms are repaired through several mechanisms. Little is known about risk factors for aneurysm recurrence or the efficacy of subsequent repair of recurring aneurysms.

METHODS

About 291 patients underwent AVF aneurysm repair between 2009 and 2019 at a large urban medical center. Patients who underwent staged repair, had a primary graft with pseudoaneurysm, were status-post kidney transplant, or using other dialysis access at the time of repair were excluded. One hundred sixty-two patients were included in the study, of which 52 developed a secondary aneurysm. Chi-square and t-test analyses were used to compare demographics. Multivariate logistic regression was used to examine independent risk factors for aneurysm recurrence. Of the 52 patients with recurrent aneurysms, 41 were repaired again. Patency was examined for each group 1 year postoperatively.

RESULTS

Patients without secondary aneurysms were more likely to have a Charlson Comorbidity Index score ⩾5 (p = 0.045). Males were 2.8 times more likely to develop a secondary aneurysm compared to females (p = 0.023). Patients who underwent elective compared to emergent or urgent surgery for primary aneurysms were significantly less likely to recur (OR = 0.222; p = 0.016). Primary aneurysms repaired by end-to-end anastomosis, compared to aneurysmorrhaphy or graft, were significantly less likely to recur (OR = 0.239; p = 0.041). Among patients with secondary aneurysms, those repaired via end-to-end anastomosis had a significantly higher primary patency rate 1 year postoperatively (p = 0.024). Secondary aneurysm repairs exhibited 1-year primary and secondary patency rates of 51.2% and 82.9%, respectively.

CONCLUSIONS

End-to-end anastomosis reduces risk of recurrence and demonstrates superior patency rates when repairing recurrent aneurysms. It remains unclear why some patients are prone to aneurysm recurrence, however continued attempts to repair existing vascular access are proven to be successful.

Salvage of infected autogenous arteriovenous fistulas, is it possible?

BACKGROUND

Infection in autogenous arteriovenous fistulas (AVFs) is a critical situation in patients with end stage renal disease (ESRD) that can lead to life threatening rupture or septicemia. To date, no standard guidelines regarding the surgical repair of the infected AVFs is available.

AIM

To evaluate the safety and efficacy of the surgical repair in the infected autogenous AVFs.

METHODS

This prospective study involved 64 ESRD patients who presented with infected autogenous AVFs. Repair of the infected autogenous AVFs was done in 50 cases, while ligation was needed in the other 14 cases. Aneurysmorrhaphy was done in the 26 cases of puncture site infection over venous aneurysms. In 20 cases of AVFs with anastomotic disruption, higher recreation in a proximal clean field (AVF loop anastomosis) was performed, while abscess drainage was done in the remaining four cases presented with non-communicating abscess over the vein. The 14 cases of ligated AVFs included 9 cases of infected ruptured AVFs with active bleeding and 4 cases with non-reconstructable puncture site infection.

RESULTS

After 1 year of follow up, 41 cases (82%) of the repaired AVFs (n = 50) remained patent and functioning as re-infection occurred in 9 cases. Six tunneled permanent catheters were implanted in the 14 cases with ligated AVFs, while the remaining 8 cases had new AVFs established (7 cases of them retained patent AVFs during the follow up period).

CONCLUSION

Surgical repair of the infected AVFs is an effective procedure that achieves many goals, such as saving patients' lives, maintaining the patency of the native fistula, and avoidance of creation of new AVFs in another site with exhaustion the available veins.

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.

Salvage of a megafistula causing high-output cardiac failure in a young adult with aneurysmorrhaphy and banding

We present the case of a 21-year-old male with significant lengthening and aneurysmal degeneration of his brachiocephalic arteriovenous fistula resulting in a megafistula and high-output cardiac failure. A computed tomography angiogram showed narrowing at the cephalic arch. Further evaluation during the operation revealed kinking and elongation of the fistula in addition to compression of the cephalic arch in the deltopectoral groove leading to outflow obstruction. The aneurysmal fistula was treated successfully with aneurysmorrhaphy of the remaining conduit and banding of the inflow. This case demonstrates a unique etiology of venous outflow obstruction for a fistula and describes the surgical approach to its treatment in a young patient suffering from cardiac failure.

Revision of Aneurysmal Arteriovenous Access with Immediate Use Graft Is Safe and Avoids Prolonged Use of Tunneled Hemodialysis Catheters

INTRODUCTION

Aneurysmal AVF can pose a difficult treatment dilemma for the vascular surgeon. Prolonged tunneled dialysis catheters (TDC) in patients requiring long-term dialysis are associated with significantly increased mortality compared to arteriovenous fistulas (AVF). We aimed to elucidate the outcomes of aneurysmal AV access revision with aneurysm resection and Artegraft® (LeMaitre, New Brunswick, NJ) Collage Vascular Graft placement to avoid prolonged use of TDCs.

METHODS

We reviewed all patients with aneurysmal AV access in which the access was revised with aneurysm resection and jump graft placement at a single institution from 2018 to 2021. Outcomes were time to cannulation, reintervention rates, time to reintervention and patency (primary, primary assisted and secondary). Patency rates were estimated with Kaplan-Meier Survival analysis.

RESULTS

A total of 51 revised aneurysmal AV access in 51 patients were studied, of which 23.5% (n=12) had perioperative TDC placement. Three patients were done for emergent bleeding. The cohort was 62.8% male (n=32) with a median age of 58 years (IQR: 49-67). Most patients had brachiocephalic AVF (n=37 [72.6%]). Median follow up time was 280 days. Median time to cannulation was 2 days. Time to cannulation was significantly longer in patients with perioperative TDC as compared with those without TDC (24 days vs 2 days, P<0.001). Reintervention was required in 41.2% of patients (n=21), at median time of 47 days. At 30, 90, 180, and 365 days, primary patency rates were 84.3%, 78.3%, 66.6%, and 54.9%; primary assisted patency rates were 94.1%, 88.1%, 79.4%, and 79.4% and secondary patency rates were 100%, 97.8%, 91.6% and 91.6% respectively.

CONCLUSIONS

Revision of aneurysmal AV access (urgent or elective) with Artegraft as jump graft is safe, with acceptable short and mid-term patency results. This allows dialysis patients to continue to have a functional access, decreasing the need for a tunneled catheter and reducing the associated risk of sepsis and increased mortality. This should be considered for all patients with aneurysmal, dysfunctional fistulas to maintain AV access and avoid TDC placement.

To Close, Observe, or Reconstruct: The Third Way of Managing Dialysis Fistula Aneurysms in Kidney Transplant Recipients

Background: The management of patent dialysis fistulas in patients after kidney transplantation (KTx) is controversial—the options that are usually considered are the fistula’s closure or observation. Many complications of dialysis fistulas occur in patients after KTx, and immunosuppression increases the risk of fistula aneurysms and hyperkinetic flow. This study aimed to evaluate the results of dialysis fistula aneurysm treatment in patients after KTx and to compare them to procedures performed in an end-stage renal disease (ESRD) dialyzed population. Methods: We enrolled 83 renal transplant recipients and 123 ESRD patients with dialysis fistula aneurysms qualified for surgical revision to this single-center, prospective study. The results of the surgical treatment of dialysis fistula aneurysms were analyzed, and the primary, assisted primary and secondary patency rate, percentage and type of complications were also assessed. Results: For the treatment of dialysis fistula aneurysms in transplant patients, we performed dialysis fistula excisions with fistula closure in 50 patients (60.2%), excision with primary fistula reconstruction (n = 10, 12.0%) or excision with PTFE bypasses (n = 23, 27.7%). Postoperative complications occurred in 11 patients (13.3%) during a follow-up (median follow-up, 36 months), mostly in distant periods (median time after correction procedure, 11.7 months). The most common complication was outflow stenosis, followed by hematoma, dialysis fistula thrombosis and the formation of a new aneurysm and postoperative bleeding, infection and lymphocele. The 12-month primary, primary assisted and secondary patency rates of fistulas corrected by aneurysm excision and primary reconstruction in the KTx group were all 100%; in the control ESRD group, the 12-month primary rate was 70%, and the primary assisted and secondary patency rates were 100%. The 12-month primary, primarily assisted and secondary patency rates after dialysis fistula aneurysm excision combined with PTFE bypass were better in the KTx group than in the control ESRD group (85% vs. 71.8%, 90% vs. 84.5% and 95% vs. 91.7%, respectively). Kaplan–Meier analysis showed a significant difference in primary patency (p = 0.018) and assisted primary (p = 0.018) rates and a strong tendency in secondary patency rates (p = 0.053) between the KTx and ESRD groups after dialysis fistula excisions combined with PTFE bypass. No statistically significant differences in patency rates between fistulas treated by primary reconstruction and reconstructed with PTFE bypass were observed in KTx patients. Conclusions: Reconstructions of dialysis fistula aneurysms give good long-term results, with a low risk of complications. The reconstruction of dialysis fistulas can be an effective treatment method. Thus, this is an attractive option in addition to fistula ligation or observation in patients after KTx. Reconstructions of dialysis fistula aneurysms enable the preservation of the dialysis fistula while reducing various complications.

Brief overview of surgical aspect of autologous arterio-venous fistula for dialysis access

Patients with the end-stage renal disease require renal replacement therapy in renal transplant, peritoneal dialysis, and intermittent hemodialysis. Hemodialysis remains the primary modality for renal replacement therapy. Excellent vascular access is a mainstay for performing hemodialysis. Here we present a brief review of the various surgical aspects of AV fistula creation. Preoperative physical examination and judicious use of the imaging modalities to define the artery and venous mapping provide a good outcome of the fistula formation. Surgical creation of RC-AVF is preferred for the end-stage renal disease patient. The end-to-side anastomosis between the radial artery and cephalic vein has shown very good results.

[Surgical treatment of true aneurysms of permanent vascular access]

Analyzed herein are the results of surgical treatment of true diffuse aneurysms of the permanent vascular access in 44 patients. Of these, there were 29 men and 15 women, mean age 48.1±2.3 years (19-78 years). The average time having elapsed since the formation of the native access was 109.4±9.5 months (12-276, median - 108 months). The indications for surgical treatment were as follows: haemorrhage including recurrent bleedings (3), thrombosis of the permanent vascular access (26), its dysfunction (5), high flow syndrome (3), large-size aneurysm with disordered function of the limb, pain syndrome or a pronounced cosmetic defect (7). In 14 cases, reconstruction was not performed. We carried out ligating operations, in some instances with partial removal of the aneurysm and establishing a new vascular access. 3 patients underwent resection of the aneurysm with replacement by a graft. In the remote period 1 patient at 46 months developed infection of the prosthesis, resulting in loss of the access. Follow up of the remaining 2 patients demonstrated satisfactory function of the vascular access at 6 and 60 months. 16 patients were subjected to total plasty of the aneurysm using autotissues. On a cylindrical template measuring 6 mm in diameter after dissection of excessive tissues along the posterior wall of the vein, an uninterrupted suture was formed followed by placing the formed transplant into a new bed. 11 patients underwent the operation according to the analogous technique, but the formed autotransplant was reinforced with a thin-wall exoprosthesis made of polytetrafluoroethylene up to 0.2-mm thick and 10 mm in diameter ('Ecoflon'). Two (12.5%) of 16 patients subjected to reconstruction of the aneurysm without reinforcement developed haemorrhage in the early postoperative period, and one developed thrombosis thus resulting in loss of the access. In-hospital patency amounted to 81.3%. In plasty with reinforcement, there were no complications in the early postoperative period. Long-term primary patency after total plasty without reinforcement at 1, 3, and 5 years amounted to 68.2±11.8%, 56.8±14.3%, and 22.7±13.7%, respectively, with secondary patency of 68.2±11.8% at the above-mentioned terms. In the majority of patients aneurysmatic transformation of the transplant occurred again in the remote period. Primary patency at 1, 3 and 4 years after plasty with reinforcement amounted to 80.8±12.2%, 80.8±12-2% and 60.6±19.8%, respectively, with the secondary patency rates of 90.9±8.7% at the above mentioned terms.

A dual-plane approach for surgical treatment of pseudoaneurysm with arteriovenous fistula in hemodialysis patients

Background

We report the efficacy of a dual-plane approach using a Dufourmentel skin flap with a purse-string suture of the de-epithelized dermis to manage pseudoaneurysm at the vascular access site for hemodialysis.

Methods

A retrospective analysis was conducted of 61 patients from 2013 to 2018 with pseudoaneurysms at the arteriovenous fistula or graft who were treated with rhomboid excision, vessel repair with a purse-string suture, and a full-thickness Dufourmentel skin flap. The success rate was defined as the probability of complete wound closure and intact vascular access patency without infection or other complications.

Results

The success rate was 93.4% at 6 months postoperatively. Complications included newly occurring pseudoaneurysms (n=2), wound dehiscence (n=1) and bleeding (n=1). There were no complications such as stenosis or thrombosis from the procedure.

Conclusions

A dual-plane approach using a Dufourmentel skin flap with a purse-string suture for vessel repair was shown to be a favorable option for managing stable, small (diameter <2 cm) pseudoaneurysms without infection, rapid expansion, or patency issues of the vascular access.

Midterm results of salvage surgery for autogenous dialysis access in aneurysmal arteriovenous fistulas

Autologous arteriovenous fistulas are commonly constructed in patients undergoing hemodialysis for end-stage renal disease. However, they are associated with a high rate of aneurysm formation, and aneurysmal arteriovenous fistulas that have become symptomatic require surgical intervention. This study was performed to evaluate the midterm results of salvage surgery for autogenous dialysis access in patients with aneurysmal arteriovenous fistulas. Of 1326 arteriovenous fistula operations, 81 involving surgery for aneurysmal arteriovenous fistulas between January 2008 and January 2012 were included in this study. The database was searched to identify all complicated arteriovenous fistula patients undergoing surgery for vascular access. The number of complicated arteriovenous fistula surgeries, for example for aneurysms, was greater than the number of patients undergoing surgery to create a new arteriovenous fistula. We performed three different surgical procedures to treat arteriovenous-related aneurysms in our clinic: primary repair, resection and saphenous vein interposition, and resection and polytetrafluoroethylene (PTFE) interposition. We compared the patency rates at the 12- and 24-month follow-ups among these three techniques. The study population consisted of 24 cases of primary repair, 29 cases of resection and saphenous vein interposition, and 30 cases of resection and PTFE graft interposition. True aneurysms occurring in patients undergoing hemodialysis did not require treatment unless they were symptomatic. Arteriovenous access salvage therapy is recommended after the aneurysm has become symptomatic. Symptomatic arteriovenous fistula aneurysms can be treated by maintaining arteriovenous fistula continuity. Moreover, patient safety is ensured by long-term patency.

Aneurysm Excision With Arteriovenous Anastomosis Proximalization for Dialysis Fistula Aneurysm Treatment

INTRODUCTION

Dialysis fistula aneurysms are common complications, which require surgical revision in selective cases. The results of aneurysm excision with arteriovenous anastomosis proximalization for the treatment of dialysis fistula aneurysms have been described below.

METHODS

Patients qualified for the reconstruction of a dialysis fistula aneurysm underwent a duplex ultrasound examination. The diameter, length of the aneurysm, relations with the artery, thrombus presence and blood flow were determined. In the case of favorable anatomical conditions, we performed aneurysm excision with arteriovenous anastomosis proximalization as the procedure of choice. Patients, dialysis access, operative data and the results obtained during a median follow-up of 41 months were then analyzed.

FINDINGS

Since 2012, we have performed 20 aneurysm excision combined with primary anastomosis as dialysis fistula aneurysm treatment. In 18 patients, aneurysm excision was combined with simple re-anastomosis in the more proximal arterial segment. In 2 autogenous radio-cephalic forearm direct fistulas the aneurysm excision was combined with switching anastomosis type from side-to-end to end-to-end. The 12- and 24-month primary patency rates of corrected fistulas in the observed group were 94.7% and 82.4%, respectively. No early complications were noted. In 7 patients (35%) we observed late complications, which required reintervention or led to access failure. Dialysis fistula thrombosis as an indication for treatment was a significant risk factor for late re-occlusion.

DISCUSSION

A simple primary reconstruction by arteriovenous anastomosis proximalization and aneurysm excision for the surgical correction of dialysis fistula aneurysms has potential benefits compared to established methods-aneurysmorraphy and aneurysm excision with a vascular prosthesis bypass. The obtained data showed the efficiency, safety and excellent long-term results of this procedure.

Upper extremity reconstruction following open surgical repair of giant arteriovenous fistula aneurysm: clinical case and systematic review of the literature

Background:

Nearly 30% of arteriovenous fistulas (AVFs) located in the upper extremity for hemodialysis access result in short- and long-term adverse effects, such as rupture, necessitating emergent surgical management and extensive soft-tissue reconstruction. With this systematic review, we aimed to compile all reported open surgical techniques used for complicated AVF repair in the upper extremity, the respective soft-tissue reconstructive outcomes, and vascular patency rates at final follow-up.

Methods:

Using Ovid Medline/PubMed databases, we conducted a review of the English-language literature on AVF aneurysm surgical management in the upper extremity, filtered for relevance to open surgical technique and outcomes in vascular patency after aneurysmal repair at long-term follow-up (≥6 months postoperatively). We include a detailed case of surgical removal of a giant AVF aneurysm and subsequent flap elevation and reconstruction of the upper extremity.

Results:

Of 150 articles found in the initial search, 19 (from 2010-2017) met inclusion criteria. From the reviewed studies, 675 patients underwent open surgical repair of AVF aneurysm in the upper extremity. Surgical approaches included partial-to-full aneurysm excision, interposition graft, tubularized extracellular matrix, sutured and stapled aneurysmorrhaphy, and stent graft. Rates of vascular patency at repair site ranged from 47% to 100%, with a pooled average of 78% at 6 months or longer postoperatively.

Conclusions:

For plastic and hand surgeons, aneurysmal ligation and excision is feasible even in severe cases and is associated with overall good vascular and soft-tissue reconstructive outcomes in the upper extremity. (www.actabiomedica.it)

Arteriovenous fistula takedown in hemodialysis patients: our experience of 26 cases

Introduction

Creation of arteriovenous fistulas (AVF) for providing vascular access in patients dependent on hemodialysis is a very frequent type of surgery. One of the common complications of such a fistula is the formation of an aneurysm or a pseudoaneurysm and the risk of impending rupture. These are a few of the reasons why such surgically created AVF have to be taken down surgically. Some of these may be taken down for cosmetic reasons electively while some present in an emergency due to rupture of the aneurysm itself.

Aim

This is a retrospective study of 26 patients who underwent AVF takedown at our center over a period of 4 years.

Material and methods

We intended to study the patient profile, the surgery that they underwent and the post-operative course of these patients.

Results

We found that aneurysm formation was the most common reason for a takedown, although we did see a good percentage of patients who presented to us with a ruptured AVF aneurysm. Our procedure was a ligation of the aneurysm with resection of the aneurysmal segment and maintaining arterial continuity. No attempt to preserve the fistula was made in any of these cases.

Conclusions

This article gives a brief overview of our experience in AVF takedown.

Hybrid procedures in the dialysis fistula aneurysm treatment

OBJECTIVES

Dialysis fistula aneurysms are common complications which in selective cases require surgical revision. It is recommended to detect and treat outflow stenosis concurrent with a dialysis fistula aneurysm, but usually, the treatment is divided into two stages - the open and endovascular stages are performed separately. We describe the results of hybrid procedures composed of aneurysm resection and endovascular correction for outflow veins performed for a dialysis fistula aneurysm treatment.

METHODS

From March 2012, we performed hybrid procedures in 28 patients to correct dialysis fistula aneurysms. Patients, dialysis access, operative data, and the results obtained during a median follow-up of 28.5 months were analyzed.

RESULTS

For dialysis fistula aneurysm correction, we performed 27 bypasses and 1 aneurysmorraphy. For outflow vein stenosis correction, we performed standard balloon angioplasty, no stents or stentgraft were used. The average increase in minimal diameter after angioplasty was 135.5% (range 57-275%). The 12- and 24-month primary patency rates of corrected fistulas in the observed group were 92.3% and 80%, respectively. A significant difference in the one-year patency rates between the urgent and planned procedures was observed (81.2% vs. 100%, respectively). No early complications related to endovascular or open procedures were observed. Late complications were observed in seven patients (25%) - mainly thrombosis caused by the recurrence of outflow vein stenosis (six patients, 21.5%), infection, lymphocele, and hematoma (one case of each complication).

CONCLUSIONS

A hybrid procedure for the surgical correction of dialysis fistula aneurysms with the simultaneous correction of outflow pathologies enables effective long-term treatment. The obtained data showed the efficiency and good results of this procedure. Procedures performed for urgent indications significantly increase the risk for later complications, especially fistula thrombosis and loss of dialysis access.

[Conservative aneurysmorrhaphy for hemodialysis arteriovenous fistula]

The aim of this study was to evaluate the results of conservative surgical treatment of the aneurysmal complications of arteriovenous hemodialysis fistulae and to determine the factors predictive of long- and mid-term patency of treated fistulae. The surgical treatment was mainly based on caliber reduction and reconstruction.

METHODS

This was a descriptive retrospective study with a five-year duration, going from January 2013 to December 2018. This study included 40 patients presenting aneurysmal complications of their hemodialysis vascular access who were treated with aneurysmorrhaphy.

RESULTS

The mean age of the aneurysmal-complicated hemodialysis vascular access was 42 months. The indications for treatment were puncture-related difficulties in 42.5% of cases, rapid increase of the aneurysmal diameter in 27.5%, skin thinning in 25% and aneurysmal rupture in 5%. The mean aneurysmal course was 6.6 months with an average diameter of 3.25cm at the moment of management. The initial technical success rate was 100%. Twenty patients had complications in the postoperative period. Patency rates at 3, 6, 12 and 24 months were 89.5%, 81.6%, 71% and 63.1%, respectively. Factors predictive of thrombosis were diabetes (P=0.001), peripheral arterial disease (P=0.003), number of punctures per week (P=0.003) and context of emergency presentation (P=0.001).

CONCLUSION

Aneurysmorrhaphy seems to be the best conservative surgical treatment for aneurysmal complications of hemodialysis vascular access fistulae. This surgical approach allows us to conserve the native autologous vascular access and spare the patient's venous network.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Early cannulation of bovine carotid artery grafts (Artegraft) after primary vascular access and fistula revision procedures

OBJECTIVE

Tunneled dialysis catheter (TDC) use has been associated with increased infectious complications and mortality in hemodialysis-dependent patients. Unfortunately, patients who undergo fistula revisions or creation of a new arteriovenous fistula frequently require a TDC during the postoperative period. Bovine carotid artery grafts (BCAGs) can be used as an early-access dialysis conduit to reduce TDC dependence. This study describes the performance of BCAGs that were cannulated early (<3 days) after implantation and associated clinical outcomes.

METHODS

BCAGs were implanted in 63 consecutive dialysis-dependent patients. Patients and dialysis centers were directly provided early cannulation instructions; 31 (49%) patients were cannulated early, and of the 31 patients cannulated early, 21 (68%) were cannulated during the first postoperative day. Early complications, primary patency, secondary patency, and TDC incidence were monitored through clinic visits, hospital records, and phone calls to dialysis centers.

RESULTS

The primary patency of BCAGs at 1 year in the early and late cannulation cohorts was 28% and 39%, respectively. The secondary patency of BCAGs at 1 year in the early and late cannulation cohorts was 74% and 77%, respectively. Early complications occurred in 11 (19%) patients who received a BCAG. There were no significant differences in complication rates between early and late cannulation patients. Of the 24 patients who underwent the operation without a pre-existing TDC, only three (13%) required TDC placement during the 30-day postoperative period.

CONCLUSIONS

BCAGs can be cannulated early without increased complication rates or a negative impact on midterm patency. Early cannulation of BCAGs obviates the need for a TDC postoperatively in dialysis-dependent patients undergoing primary vascular access or fistula revision procedures.

A technique for the salvage of megafistulas allowing immediate dialysis access

OBJECTIVE

Almost two million individuals are undergoing renal replacement therapy worldwide, with hemodialysis being the common form. Many factors influence the primary patency of an arteriovenous fistula (AVF), including vessel size, fistula flow rates, cannulation practice, and thrombotic tendencies. Excess dilation of the AVF, resulting in the development of a megafistula, is a complication that can result in a need for AVF revision and subsequent failure.

METHODS

The charts of patients who underwent autogenous AVF revision because of the development of a megafistula with aneurysmectomy and vein transposition by a single surgeon during a 7-year period from 2009 through 2016 were reviewed. A technique is described in which after aneurysmorrhaphy, the repaired venous component of the AVF is transposed through a new tunnel while the vein is rotated 90 degrees. This allows the AVF to be accessed immediately, making placement of a tunneled dialysis catheter unnecessary.

RESULTS

There were 102 patients included in the study, with follow-up ranging from 7 to 95 months. In our cohort, 92 of the 102 revised AVFs (90.2%) maintained primary functional patency. Of the 102 patients who underwent this revision technique, there were 10 fistulas that subsequently failed after a mean of 29 months. There were only seven patients who experienced recurrent fistula dilation requiring repeated aneurysmectomy.

CONCLUSIONS

We describe a technique for management of the development of a megafistula that uses only autogenous tissue and, perhaps most important, eliminates the need for temporary dialysis catheter placement.

A Hybrid Approach to Salvage a Failing Long-Standing Autogenous Aneurysmal Fistula in a Hemodialysis Patient

Very few studies have addressed the repair of autogenous and prosthetic-related false arteriovenous access (AVA) aneurysms in hemodialysis patients. Surgical management of complicated AVA-related aneurysms remains the gold standard method although covered stents have recently been introduced for the exclusion of such aneurysms, offering a minimally invasive therapy. In this paper, we describe a combination of open and endovascular repair for treating an anastomotic and a puncture-site aneurysm to salvage a failing long-standing autogenous radial-cephalic fistula in the wrist. Resection of the anastomotic aneurysm and reconstruction of the anastomosis proximally was initially performed. Via the first cm of the anastomosis, a Fluency® stent graft (SG) was inserted and it successfully excluded the mid-outflow vein false aneurysm. Such hybrid therapies may be the future of AVA revisions and this trend should not be overlooked by nephrologists and vascular surgeons.

Endovascular Proximal Forearm Arteriovenous Fistula for Hemodialysis Access: Results of the Prospective, Multicenter Novel Endovascular Access Trial (NEAT)

BACKGROUND

Hemodialysis arteriovenous fistulas (AVFs) are suboptimally used primarily due to problems with maturation, early thrombosis, and patient nonacceptance. An endovascular approach to fistula creation without open surgery offers another hemodialysis vascular access option.

STUDY DESIGN

Prospective, single-arm, multicenter study (Novel Endovascular Access Trial [NEAT]).

SETTINGS & PARTICIPANTS

Consecutive adult non-dialysis-dependent and dialysis-dependent patients referred for vascular access creation at 9 centers in Canada, Australia, and New Zealand.

INTERVENTION

Using catheter-based endovascular technology and radiofrequency energy, an anastomosis was created between target vessels, resulting in an endovascular AVF (endoAVF).

OUTCOMES

Safety, efficacy, functional usability, and patency end points.

MEASUREMENTS

Safety as percentage of device-related serious adverse events; efficacy as percentage of endoAVFs physiologically suitable (brachial artery flow ≥ 500mL/min, vein diameter ≥ 4mm) for dialysis within 3 months; functional usability of endoAVFs to provide prescribed dialysis via 2-needle cannulation; primary and cumulative endoAVF patencies per standardized definitions.

RESULTS

80 patients were enrolled (20 roll-in and 60 participants in the full analysis set; the latter are reported). EndoAVFs were created in 98% of participants; 8% had a serious procedure-related adverse event (2% device related). 87% were physiologically suitable for dialysis (eg, mean brachial artery flow, 918mL/min; endoAVF vein diameter, 5.2mm [cephalic vein]). EndoAVF functional usability was 64% in participants who received dialysis. 12-month primary and cumulative patencies were 69% and 84%, respectively.

LIMITATIONS

Due to the unique anatomy and vessels used to create endoAVFs, this was a single-arm study without a surgical comparator.

CONCLUSIONS

An endoAVF can be reliably created using a radiofrequency magnetic catheter-based system, without open surgery and with minimal complications. The endoAVF can be successfully used for hemodialysis and demonstrated high 12-month cumulative patencies. It may be a viable alternative option for achieving AVFs for hemodialysis patients in need of vascular access.

Dialysis Access Hemorrhage: Access Rescue from a Surgical Emergency

BACKGROUND

Hemorrhage from a dialysis access can be a life-threatening condition. This study details our experience using access rescue strategies, including in situ graft replacement, primary repair, or conversion to an autogenous fistula, coupled with treatment of central vein occlusion to maintain access usage in patients presenting with conduit hemorrhage.

METHODS

During a 3-year period (2012-2014), 26 patients (14 women, 12 men) on chronic hemodialysis were treated for access conduit bleeding (n = 18) or life-threatening hemorrhage (n = 8), located in the upper extremity (n = 23) or thigh (n = 3). All patients had developed bleeding from a skin eschar/ulcer over a bovine (n = 9) or polytetrafluoroethylene (n = 9) bridge graft, or aneurysmal autogenous fistula (n = 8). A retrospective review of outcome relative to clinical signs, etiology of conduit bleeding (infection, wall erosion), and the type of rescue procedure(s) was performed. Duplex ultrasound testing was used to guide therapy based on the presence of aneurysmal degeneration, perigraft fluid, or access flow pattern indicative of venous outflow obstruction.

RESULTS

One-half of the patients were taken emergently to the operating room for hemorrhage control or impending rupture of an infected false aneurysm, the remaining repaired on an urgent basis. In 18 patients, emergency room personnel attempted control of access site bleeding by suturing (n = 14) or tourniquet (n = 4). Dialysis access salvage was achieved in 22 (85%) of 26 patients by in situ conduit replacement using a rifampin-soaked polytetrafluoroethylene conduit (n = 19) or primary repair (n = 3). Two patients with sepsis and ruptured, infected false aneurysm were treated by ligation, and 2 patients with nonsalvable access had conversion to an autogenous fistula. One-third of rescued accesses (n = 7) had staged endovascular treatment of central vein stenosis. One patient died within 30 days. All dialysis access revisions remained patent and used for immediate dialysis (n = 5), within 4-5 weeks (n = 19), or after vein maturation (n = 2). One replaced graft was revised for infection. Positive blood or bleeding site cultures were obtained from 9 (45%) of 20 patients tested.

CONCLUSIONS

Salvage of a functional dialysis access is possible in the majority of patients presenting with conduit hemorrhage. Loss of wall integrity, infection, and venous hypertension were etiologic factors. Application of in situ graft replacement strategies known to be effective in the treatment of graft infection should be considered in the management of this surgical emergency.

Concomitant Staple Aneurysmorrhaphy and Flow-Calibrated Arteriovenous Fistula Banding Over a Coronary Dilator to Treat Hand Steal Syndrome

BACKGROUND

True venous aneurysm formation can occur in patients with arteriovenous fistulas (AVFs) for hemodialysis but association with steal syndrome is uncommon.

METHODS

To describe a case of a patient on chronic hemodialysis through a right brachiocephalic fistula, who presents with associated steal syndrome and true arteriovenous access aneurysm.

RESULTS

A 34-year-old female with true AVF aneurysm presented with hand steal syndrome confirmed by noninvasive studies. The patient underwent a successful vein aneurysmorrhaphy with a commercially available stapler device and duplex ultrasound flow-calibrated banding. At 1-year follow-up, she remains pain free and the fistula remains functional with no recurrence of venous aneurysmal degeneration.

CONCLUSION

The use of a commercially available surgical stapler devices along with flow-calibrated banding guided by duplex ultrasound over a coronary dilator during the same operation is an elegant, efficacious, and a durable alternative for patients with hand steal syndrome and concomitant AVF aneurysms.

Characteristics, Management, and Outcomes of Surgically Treated Arteriovenous Fistula Aneurysm in Patients on Regular Hemodialysis

BACKGROUND

To investigate the clinical characteristics, surgical interventions, and outcomes of arteriovenous fistula (AVF) aneurysms, we retrospectively analyzed patients on regular hemodialysis (HD).

METHODS

We conducted a cohort study of all patients with HD access who presented with AVF aneurysms and underwent operative procedures over a 11-year period. Patients' demographics, comorbidities, vascular access characteristics, management of aneurysms, complications, and outcomes were analyzed.

RESULTS

Of the 700 end-stage renal failure patients, 530 patients were maintained on HD (130 through PermCath and 400 through AV access in terms of AVF and arteriovenous graft). We identified 129 patients who developed AV aneurysms, and 40 of them required surgical interventions (24 men and 16 women) with a mean age of 58 ± 14.6 years. The 40 patients who developed AVF aneurysms underwent 43 surgical interventions. The majority of aneurysms were presented with thinning and ulceration (82.5%) of the overlying skin. Thirty-four patients had true aneurysms and 6 had pseudoaneurysms. The aneurysmal AVF comprised 26 brachiocephalic fistulas, 9 radiocephalic fistulas, 3 brachial artery grafts, 1 ulnar-basilic fistula, and 1 Fem-Fem graft at presentation. Patients were treated mainly with ligation (13; 32.5%), excision and repair with graft interposition (15; 37.5%) or vein interposition (11; 27.5%), and end-to-end AVF (1; 2.5%). The median follow-up postsurgery duration was 53 months (range 1-192) and the median duration from fistula creation to the surgical intervention was 52 months (range 4-182). On follow-up, 34 patients continued on HD, while 5 underwent renal transplantation and 1 shifted to peritoneal dialysis. The overall all-cause mortality rate was 37.5% and the leading causes of mortality were sepsis/pneumonia (60%), myocardial infarction, and heart failure (40%).

CONCLUSIONS

In HD patients, the rate of AVF aneurysmal formation is high with a significant rate of morbidity and mortality. Therefore, timely and appropriate evaluation and surgical intervention are crucial.

Aneurysms in Vascular Access: State of the Art and Future Developments

A master class was held at the Vascular Access at Charing Cross (VA@CX2017) conference in April 2017 with invited experts and active audience participation to discuss arteriovenous (AV) vascular access aneurysms, a serious and common complication of vascular access (VA). The natural history of aneurysms in VA is poorly defined, and although classifications exist they are not uniformly applied in studies or clinical practice. True and pseudo aneurysms of AV access occur. Whilst an AV fistula by definition is an abnormal dilatation of a blood vessel, an agreed definition of 18 mm, or 3 times accepted maturation diameter, is proposed. The mechanism of aneurysmal dilatation is unknown but appears to be a combination of excessive external remodeling, wall changes due to injury, and obstruction of outflow. Diagnosis of AV aneurysms is based on physical examination and ultrasound. Venography and cross-sectional imaging may assist and be required for the investigation of outflow stenosis. Treatment of pseudo aneurysms and true aneurysms of VA (AVA) is not evidence-based, but relies on clinical experience and available facilities. In many AVA, a conservative approach with surveillance is suitable, although intervals and modalities are unclear. Avoidance of rupture is imperative and preemptive treatment should aim for access preservation, ideally with avoidance of prosthetic materials. Different techniques of aneurysmorrhaphy are described with good results in published series. Although endovascular approaches and stenting are described with good short-term results, issues with cannulation of stented areas occur and, while possible, this is not recommended, and long-term access revision is recommended.

Diagnosis, Treatment, and Prevention of Hemodialysis Emergencies

Given the high comorbidity in patients on hemodialysis and the complexity of the dialysis treatment, it is remarkable how rarely a life-threatening complication occurs during dialysis. The low rate of dialysis emergencies can be attributed to numerous safety features in modern dialysis machines; meticulous treatment and testing of the dialysate solution to prevent exposure to trace elements, toxins, and pathogens; adherence to detailed treatment protocols; and extensive training of dialysis staff to handle medical emergencies. Most hemodialysis emergencies can be attributed to human error. A smaller number are due to rare idiosyncratic reactions. In this review, we highlight major emergencies that may occur during hemodialysis treatments, describe their pathogenesis, offer measures to minimize them, and provide specific interventions to prevent catastrophic consequences on the rare occasions when such emergencies arise. These emergencies include dialysis disequilibrium syndrome, venous air embolism, hemolysis, venous needle dislodgement, vascular access hemorrhage, major allergic reactions to the dialyzer or treatment medications, and disruption or contamination of the dialysis water system. Finally, we describe root cause analysis after a dialysis emergency has occurred to prevent a future recurrence.

Comparison of standard forearm prosthetic loop grafts to composite semiloop forearm grafts ("semi-grafts") in hemodialysis patients: A prospective study

INTRODUCTION

To prospectively assess the performance of composite semiloop antebrachial grafts ("semi-grafts," SGs) in hemodialysis patients.

METHODS

Eighty-five patients who received 67 loop antebrachial grafts (LG-group) and 25 antebrachial semigrafts (SG-group) were enrolled. SGs were defined as those originating from the brachial artery and anastomosed with the proximal mature mid-antebrachial cephalic vein. Cephalic vein length should be at least 10 cm in length and of ≥5 mm in diameter for inclusion in the SG-group. LG-group included all possible outflow vein options of minimum diameter 3 mm. Kaplan-Meier statistics was used for comparison of groups.

FINDINGS

Main indication for a SG was a failing radiocephalic fistula with extensive distal cephalic vein stenosis not amenable to correction or failed after endovascular repair or requiring long interposition grafting. The mean follow-up period was 20.16 ± 22.6 and 29.6 ± 36.7 months for the LG- and SG-group, respectively (P = 0.14). Forty-two patients died during the follow-up. Primary patency (up to first intervention or failure) at 6 and 12 months for LG- vs. SG-group was 93.9% vs. 83.7% and 47% vs. 55.8% (P = 0.08). Secondary patency (up to abandonment) was 58.2% vs. 61.1% and 36% vs. 45.8% at 12 and 24 months (P = 0.18). Mortality at 48 months was 22.4% (LG-group) and 24% (SG-group) (P = 0.9).

DISCUSSION

There was a trend toward better primary and secondary patency rates for the SGs especially in the long-term. This is a valuable option in selected patients that access surgeons and nephrologists should be aware of.

GIA-Aneurysmorrhaphy and Dermal Detachment: A Novel Technique to Repair Arteriovenous Fistula Aneurysms

This report describes a simplified technique for management of aneurysmal arteriovenous fistulas along with results of initial clinical experience in 12 patients. Various techniques have been described which seek to repair the arteriovenous fistula and lengthen its duration of use. Here, we introduce the GIA-aneurysmorrhaphy and dermal detachment (GADD) procedure, a novel technique which requires minimal dissection to decompress tension on the overlying skin. Transverse incisions were made proximally and distally to the aneurysmal segment, which was then bluntly dissected along its length on either side. A GIA stapler is then fired along the longitudinal axis, narrowing the lumen of the fistula and separating the aneurysm from the skin. After the operation, the arteriovenous fistulae were used continuously until death (1 patient for 12 months), until thrombosis (1 patient for 13 months), or continue to be in use (9 patients, mean patency 18 months). One patient underwent conversion to open aneurysmorrhaphy due to intraoperative fistula occlusion. Five patients resumed hemodialysis immediately, while the remaining resumed hemodialysis within 3 months. The most common complication was cellulitis (3 patients). The GADD procedure as described in this report offers an effective and low-risk option for the management of venous aneurysms with threatened skin in hemodialysis patients.

Surgical interventions for late complications of arteriovenous fistulas

Our aim was to determine the most effective surgical treatment for arteriovenous fistula (AVF) complications after all other methods of salvage have failed. We evaluated 110 patients for 139 complications that occurred after the initial AVF placement and for whom surgical intervention was the last hope for retaining fistula access. Vascular steal syndrome and venous hypertension were the most common complications seen in our patients. The anastomoses of 17 of the vascular steal syndrome cases were narrowed either by stitches or by a polytetrafluoroethylene graft. The second most performed revision surgery was excision of the aneurysm and repair with primary suturing, followed by excision of the aneurysm and interposition grafting. Successful surgical outcomes were achieved in 111 of 139 procedures after revision surgery without constructing a new AVF. AVF salvage surgery is of paramount importance in order to increase the patency rate, which prolongs survival and increases the patient's quality of life.

Partial Aneurysmectomy of Venous Aneurysms in Arteriovenous Dialysis Fistulas

Upper extremity native arteriovenous fistulas (AVFs) continue to be the standard of care for hemodialysis patient’s access. Although autogenous fistulas are superior to catheters and synthetic grafts, they are not without their own complications. One complication is venous aneurysms that can lead to skin erosion, bleeding, and site loss. Although traditionally repaired with ligation, interposition grafts, or stent placement, in this article, we discuss our experience with aneurysmorrhaphy utilizing a thoracoabdominal (TA) stapler. Thirteen aneurysms were treated with the TA stapler at a single, nonuniversity hospital for all patients from 2012 to 2014. The average aneurysm diameter was 3.6 cm, and the average fistula age was 57.9 months. There were no bleeding complications or recurrences. The primary patency was 80% at 6 months, with a primary assisted patency of 90% during the same time frame. Aneurysmorrhaphy with the TA stapler appears to be a safe and viable option for the treatment of venous aneurysms associated with AVFs.

[Management of complications of arteriovenous fistulas for chronic hemodialysis]

La fistule artério-veineuse native est l'accès vasculaire de choix pour l'hémodialyse chronique en raison de sa longévité, son taux faible de complication et de mortalité par rapport aux pontages artério-veineux et aux cathéters. Cependant, il arrive assez souvent que l'on assiste à des complications qui sont dominées par la sténose et la thrombose. C'est une étude rétrospective des complications ayants survenues pour 31 fistules artério-veineuses pour hémodialyse chronique des 200 fistules réalisées chez 200 patients au sein du service de chirurgie vasculaire du CHU Hassan II de Fès sur une période de trois ans, étendue de Janvier 2007 à Décembre 2009. Ces complications ont été présentés par les thromboses dans 14 cas soit 45,15% de l'ensemble des complications, les sténoses dans 4 cas (12,90%,) les anévrismes dans 4 cas (12,90%), les complications ischémiques dans 3 cas (9,67%), l'infection dans 3 cas (9,67%), l'hémorragie dans 2 cas (6,45%) et l’ hyperdébit dans un seul cas soit 3,22%. On a pu conserver 22 fistules soit 70,96% par traitement chirurgical ou endovasculaire, on a confectionné une nouvelle fistule dans 8 cas soit 25,80%, et on a adressé une patiente (3,22%) pour pose d'un cathéter veineux tunnelisé permanent. Les complications des fistules artério-veineuses pour l'hémodialyse chronique sont la principale cause de morbidité chez les patients hémodialysés, il est donc important de s'impliquer lors de leur création, et de donner un maximum d'attention quand ils sont manipulés. Ceci suggère la mise en place d'un programme de surveillance de ces fistules en raison de l'impact des complications sur la morbi-mortalité du patient hémodialysé et sur le plan financier.

Aneurysms and pseudoaneurysms in dialysis access

Aneurysms are a common and often difficult complication seen with arteriovenous vascular access for haemodialysis. The purpose of this narrative review is to define and describe the scale of the problem and suggested therapeutic strategies. A narrative review of the published literature illustrated by individual cases is presented with the aim of summarising the relevant literature. The definitions of aneurysm are inconsistent throughout the literature and therefore systematic review is impossible. They vary from qualitative descriptions to quantitative definitions using absolute size, relative size and also size plus characteristics. The incidence and aetiology are also ill defined but separation into true aneurysms and false, or pseudoaneurysms may be helpful in planning treatment, which may be conservative, surgical or radiological. The lack of useful definitions and classification along with the multitude of management strategies proposed make firm evidence based conclusions difficult to draw. Further robust well designed studies are required to define best practice for this common problem.

True aneurysm in autologous hemodialysis fistulae: definitions, classification and indications for treatment

Introduction

Definition, etiology, classification and indication for treatment of the arteriovenous access (AVA) aneurysm are poorly described in medical literature. The objectives of the paper are to complete this information gap according to the extensive review of the literature.

Methods

A literature search was performed of the articles published between April 1, 1967, and March 1, 2014. The databases searched included Medline and the Cochrane Database of Systematic Reviews. The eligibility criteria in this review studies the need to assess the association of aneurysms and pseudoaneurysms with autologous AVA. Aneurysms and pseudoaneurysms involving prosthetic AVA were not included in this literature review. From a total of 327 papers, 54 non-English papers, 40 case reports and 167 papers which did not meet the eligibility criteria were removed. The remaining 66 papers were reviewed.

Results

Based on the literature the indication for the treatment of an AVA aneurysm is its clinical presentation related to the patient's discomfort, bleeding prevention and inadequate access flow. A new classification system of AVA aneurysm, which divides it into the four types, was also suggested.

Conclusions

AVA aneurysm is characterized by an enlargement of all three vessel layers with a diameter of more than 18 mm and can be presented in four types according to the presence of stenosis and/or thrombosis. The management of an AVA aneurysm depends on several factors including skin condition, clinical symptoms, ease of cannulation and access flow. The diameter of the AVA aneurysm as a solo parameter is not an indication for the treatment.

A Novel Classification System for Autogenous Arteriovenous Fistula Aneurysms in Renal Access Patients

Introduction:

Arteriovenous fistulae (AVFs) constructed for hemodialysis access are prone to aneurysmal degeneration. This can lead to life-threatening sequelae such as aneurysmal rupture. The literature includes various guidelines on the management of certain aspects of access-related aneurysm formation; however, no classification system exists to guide reporting or prognostication. We aimed to create a universally acceptable classification for these aneurysms and establish guidance about their management.

Methods:

We clinically examined, duplex scanned, and photographed all of the autologous arteriovenous fistulae in our local renal failure population in January 2010 in order to categorize morphology. We then followed up the cohort for 2 years prospectively to assess outcomes, primarily of rupture or surgical intervention for bleeding.

Results:

A total of 344 patients were included (292 currently needling their fistula and 52 with low creatinine clearance awaiting dialysis). In all, 43.5% of dialyzed patients had aneurysmal fistulae. We propose a classification system as follows: type 1a: dilated along the length of the vein; type 1b: postanastomotic aneurysm; type 2a: classic “camel hump”; type 2b: combination of type 2a and 1b; type 3: complex; and type 4: pseudoaneurysm. Six fistulae needed emergency surgery for bleeding in the 2-year follow-up period and 5 of these were type 2 aneurysms. The remaining one was in the nonaneurysmal group, although it had become aneurysmal by the time it bled.

Conclusion:

Type 1 aneurysms are much commoner in patients who have not yet needled their fistula and have a relatively innocuous course although type 1a aneurysms should be monitored for high flow and physiological consequences thereof. Type 2 aneurysms are associated with needling of AVFs. They are at significant risk of rupture and need to be monitored carefully or treated prophylactically.

Aneurysm Formation and Infection in AV Prosthesis

In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent type, aneurysms in prosthetic AV grafts are mostly false aneurysms and less frequently anastomotic ones. Indications for repair comprise false aneurysms exceeding twofold the graft diameter, those with rapid enlargement or with skin thinning or erosion, the ruptured, those causing pain or severely limiting the cannulable area and the infected ones. They can be managed either with conventional surgery or with endovascular techniques; However, conventional surgery represents the current standard treatment consisting of either aneurysm resection and interposition graft in situ or resection/exclusion and bypass via a new route to avoid a potentially contaminated area.