Saphenous vein aortorenal bypass grafts: Serial arteriographic study

Characteristics of Radial Artery Coronary Bypass Graft Failure and Outcomes Following Subsequent Percutaneous Coronary Intervention

BACKGROUND

When patients with prior coronary artery bypass grafting (CABG) undergo percutaneous coronary intervention (PCI), targeting the native vessel is preferred. Studies informing such recommendations are based predominantly on saphenous vein graft (SVG) PCI. There are few data regarding arterial graft intervention, particularly to a radial artery (RA) graft.

OBJECTIVES

The aim of this study was to report the characteristics of arterial graft stenoses and evaluate the feasibility of RA PCI.

METHODS

This study included 2,780 consecutive patients with prior CABG undergoing PCI between 2005 and 2018 who were prospectively enrolled in the MIG (Melbourne Interventional Group) registry. Data were stratified by PCI target vessel. RA graft PCI was compared with both native vessel (native PCI) and SVG PCI. Internal mammary graft PCI data were reported. The primary outcome was 3-year mortality.

RESULTS

Overall, 1,928 patients (69.4%) underwent native PCI, 716 (25.6%) SVG PCI, 86 (3.1%) RA PCI, and 50 (1.8%) internal mammary graft PCI. Compared with SVG PCI, the RA PCI cohort presented earlier after CABG, less frequently had acute coronary syndrome, and more commonly had ostial or distal anastomosis intervention (P < 0.005 for all). Compared with patients who underwent native PCI, those who underwent RA PCI were more likely to have diabetes and peripheral vascular disease (P < 0.001 for both) and to present with non-ST-segment elevation myocardial infarction (P = 0.010). The RA PCI group had no perforations or in-hospital myocardial infarctions, though no significant difference was found in periprocedural outcomes compared with either native or SVG PCI. No differences were found between RA PCI and either native or SVG PCI in 30-day outcomes or 3-year mortality.

CONCLUSIONS

Presenting and lesion characteristics differed between patients undergoing arterial compared with SVG PCI, implying a varied pathogenesis of graft stenosis. RA PCI appears feasible, safe, and where anatomically suitable, may be a viable alternative to native PCI.

Vein Graft Aneurysm after Aorto-Renal Bypass for Childhood Renovascular Hypertension Due to Fibromuscular Dysplasia

Renovascular hypertension (RVHT) is a major cause of surgically correctable secondary hypertension. Refractory hypertension despite multiple antihypertensive drugs requires angioplasty, surgical revascularization, or even nephrectomy. Herein, we report a pediatric patient who had been treated with angioplasty, nephrectomy, and aortorenal bypass surgery for RVHT due to fibromuscular dysplasia and re-do endoaneurysmal graft replacement for a vein graft aneurysm. This case highlights the various treatment modalities for RVHT and the recurrent nature of the disease with a rare presentation of a vein graft aneurysm after aortorenal bypass.

Outcomes of Visceral Arterial Reconstruction: A Systematic Review

Aims: The study aimed to review the use of synthetic grafts (SGs) and autologous vein grafts (AVGs) in visceral arterial reconstruction (VAR) in chronic visceral ischaemia. Methods: Systematic review methodology was employed. Results: Six studies were included (218 patients and 281 vessels). Two studies had data about AVG only, 3 had data about SG only and 1 had both AVG and SG data. Three studies reported outcomes for AVG (117 patients and 132 vessels revascularized). One-year primary patency was 87% (95% CI 71%, 97%). Graft thrombosis rate was 6% (95% CI 0%, 16%). Pooled stenosis rate at one-year was 11% (95% CI 1%, 28%). The 30-day (n = 96), one-year (n = 72) and 5-year mortality (n = 30) were 0%, 0% and 12%, respectively. Four studies reported outcomes for SGs (106 patients and 147 vessels). The pooled primary patency at one year was 100% (95% CI 99%, 100%). Pooled primary 5-year patency rate was 88% (95% CI 69%, 100%). There was no graft infection in 2 of the 3 studies. Overall pooled percentage of graft thrombosis and stenosis at one year was 0%. Jimenez et al. (2002) reported one graft thrombosis at 20 months and graft stenosis in 2 patients at 46 and 49 months. Illuminati et al (2017) reported graft thrombosis in 2/24 patients at 22 and 52 months. Thirty days, one-year and 5-year mortality was 1% (95% CI 0%, 6), 7% (95% CI 0%, 20%) and 39% (95% CI 11%), respectively. Conclusion: Patency was better with SG compared with AVG. Mortality was higher in the SG group. Graft dilatation does occur with vein grafts, but in this review no intervention was found necessary. Poorly designed studies, incomplete reporting and absence of morbidity and mortality indices preclude emphatic conclusions.

The use of polytetrafluoroethylene graft for damaged renal artery in ABO-incompatible living donor kidney transplantation: a case report

Short donor renal vessels during donor nephrectomy represent a technical challenge. The allograft of vessels from deceased donors can be an option for reconstruction; however, cryopreserved vessels are not routinely prepared for living donor kidney transplantation (LDKT). We report a reconstruction of the damaged short renal artery (RA) in LDKT using a polytetrafluoroethylene (PTFE) graft. A 45-year-old male patient underwent ABO-incompatible LDKT from his wife. After donor nephrectomy, we detected a hematoma surrounding the proximal RA of the allograft. The injured segment of the RA was transected, and the short RA was connected to the right external artery of the recipient; however, the blood flow was interrupted by the graft location. Once the arterial anastomosis was removed, the graft was flushed with cold saline, and a PTFE graft was used for the reconstruction of the short RA. Immediate blood flow to the renal graft was excellent without sign of parenchymal infarction until fascial closure. Renal graft Doppler on postoperative day 7 and 3 months showed good blood flow. In this patient, the use of PTFE graft presented no additional morbidity to the kidney transplantation, and no postoperative complications related to its use were noted.

Gonadal vein as a bypass conduit for arterial reconstruction during an aortic debranching repair of a paravisceral aortic aneurysm

We report a case of a hybrid aortic debranching procedure for repair of a paravisceral inflammatory aortic aneurysm. Vein grafts were chosen over prosthetics because of concern for infection as a possible etiology. The gonadal vein was successfully used as a vein graft between the right common iliac artery and the right renal artery before aortic endograft placement.

Arterial reconstruction using the donor's gonadal vein in living renal transplantation with multiple renal arteries: a case report and a literature review

Background

Arterial reconstruction is one of the paramount procedures in kidney transplantation (KT) and greatly important if the procured kidney has multiple renal arteries (MRA). Despite various established techniques for arterial reconstruction, sometimes, the surgeon finds performing arterial anastomoses challenging in case of MRA. In our case, the donor’s gonadal vein and recipient’s internal iliac artery graft were used for arterial anastomoses, and 3 years after KT, the allograft did not present vascular complications.

Case presentation

A 34-year-old man underwent ABO-incompatible preemptive living KT. The allograft had three renal arteries and four renal veins. After donor nephrectomy, arterial reconstruction was performed on a back table. These arteries were reconstructed into one piece using the recipient’s internal iliac artery graft. The two arteries at the middle of the renal hilum were reconstructed using the conjoined method. As the superior renal artery was too short to anastomose, the donor’s gonadal vein was used for extension. The internal iliac artery graft was anastomosed to the original internal iliac artery. Intraoperative Doppler ultrasonography revealed that the blood flow in each renal artery was adequate, resulting in sufficient blood flow throughout the allograft. The allograft function was maintained with a serum creatinine level of approximately 0.9 mg/dL without vascular complications 3 years after KT.

Conclusions

The donor’s gonadal vein can be a candidate for extension of the renal artery in the allograft with MRA. Further follow-up is needed for the assessment of long-term outcomes.

Risk of rupture of an aortorenal vein graft aneurysm after the surgical repair of Takayasu arteritis-induced right renal artery stenosis: A case report and a literature review

INTRODUCTION

Takayasu arteritis (TA) is a chronic and nonspecific inflammatory disease mainly affecting the aorta and its major branches, resulting in the stenosis or occlusion of target arteries. Approximately 50% to 60% of patients with TA likely have renal artery stenosis (RAS), which results in refractory hypertension (HTN) and renal dysfunction. Aortorenal bypass with saphenous vein graft (SVG) is the classical procedure to relieve patients' symptoms. Graft restenosis is the most common complication during long-term follow-up. However, aortorenal vein graft aneurysm (AVGA) is uncommonly reported, and symptomatic or ruptured AVGA that needs reoperation is even rarer. Long-term follow-up results after AVGA reoperation also remain scare. Here, we introduced the long-term result of a symptomatic AVGA under the reoperation of polytetrafluoroethylene (PTFE) graft replacement and provided a literature review of AVGA reoperation after surgical bypass for RAS.

CLINICAL FINDING

An 18-year-old male complained about mild to severe right lumbar pain for 5 days. He underwent right aortorenal bypass with SVG for TA-induced right renal artery stenosis to relieve refractory HTN and renal dysfunction 2 years ago. However, this patient did not proceed with a follow-up after the procedure. Physical examination showed normal vital signs, and an obvious percussion tenderness over the right kidney region was detected. The updated computed tomography angiography (CTA) revealed a right AVGA with a maximum diameter of 26 mm. No restenosis of the proximal and distal anastomoses was detected.

DIAGNOSIS

The patient was diagnosed to have right aortorenal vein graft aneurysm at the risk of rupture and Takayasu arteritis.

INTERVENTIONS

The AVGA was resected with a 6 mm PTFE graft replacement. An end-to-side proximal anastomosis to the orifice of the original anastomosis on the abdominal aorta and an end-to-end distal anastomosis to the distal normal renal artery were made.

OUTCOMES

The patient had an uneventful postoperative clinical course and was discharged from the hospital 5 days after the operation. The 4-year updated CTA revealed no restenosis or aneurysmal degeneration of the prosthetic graft.

CONCLUSION

Symptomatic AVGA that needs reoperation is rare. Prosthetic graft replacement is an effective way to eliminate the risk of potential rupture. A 4-year satisfactory result indicative of a prosthetic graft can be the first choice for aortorenal bypass in RAS without active biological inflammation.

Long-term complications in two patients after aortoaortic bypass for midaortic syndrome

The midaortic syndrome (MAS) refers to descending thoracic and abdominal aortic coarctation, which is rare and most common in the pediatric population. Open surgical repair, often with aortoaortic bypass, remains a highly effective treatment and is traditionally thought to be definitive despite concerns over patient growth postoperatively. This article presents 2 cases of MAS treated with aortoaortic bypass who developed long-term complications, one related to patient growth and the other to graft-enteric fistula. Consideration must be given to patient growth at operation for MAS, and long-term follow-up is necessary to identify other complications.

Adaptive changes in autogenous vein grafts for arterial reconstruction: clinical implications

For patients with the most severe manifestations of lower extremity arterial occlusive disease, bypass surgery using autogenous vein has been the most durable reconstruction. However, the incidence of bypass graft stenosis and graft failure remains substantial and wholesale improvements in patency are lacking. One potential explanation is that stenosis arises not only from over exuberant intimal hyperplasia, but also due to insufficient adaptation or remodeling of the vein to the arterial environment. Although in vivo human studies are difficult to conduct, recent advances in imaging technology have made possible a more comprehensive structural examination of vein bypass maturation. This review summarizes recent translational efforts to understand the structural and functional properties of human vein grafts and places it within the context of the rich existing literature of vein graft failure.

Treatment of venous aortorenal bypass graft aneurysm using a stent-graft

We present the case of a 77-year-old male patient who had undergone a bilateral venous aortorenal bypass graft 30 years previously. Thirteen years previously, the patient was shown to have a decrease in renal function, with mild shrinking of both kidneys; additionally, a stenosis was found in the left proximal anastomosis. At the most recent follow-up visit (1 year previously), ultrasound revealed an aneurysm (42 mm in diameter) of the left renal bypass graft; the finding was confirmed by CT angiography. A significant ostial stenosis of the left renal bypass graft was also confirmed. It was decided to place a self-expandable stent-graft into the aneurysm while also attempting to dilate the stenosis. Proximal endoleak after stent-graft placement necessitated the implantation of another, balloon-expandable stent-graft into the bypass graft ostium. Postprocedural angiography and follow-up by CT angiography at 3 months confirmed good patency of the stent-grafts and complete thrombosis of the aneurysmal sac, with preserved kidney perfusion. Renal function remained unaltered, while the hypertension is better controlled.

Saphenous vein graft aneurysm with graft-enteric fistula after renal artery bypass

A 65-year-old female presented with upper gastrointestinal hemorrhage thirty years following an aorta-to-right renal artery bypass constructed with saphenous vein. Upper endoscopy demonstrated a duodenal ulcer, and a CAT scan demonstrated aneurysmal degeneration of her renal artery bypass with duodenal impingement. Laparotomy demonstrated erosion of the aneurysm through the posterior wall of the duodenum; extra-anatomic renovascular reconstruction and primary duodenal repair was performed. Although aneurysmal degeneration of intraabdominal saphenous vein grafts is well described and rupture likewise reported, this report represents the first description of an intraabdominal autogenous vein graft aneurysm presenting with gastrointestinal erosion and fistula.

Guidelines for the Reporting of Renal Artery Revascularization in Clinical Trials

Although the treatment of atherosclerotic renal artery stenosis with use of percutaneous angioplasty, stent placement, and surgical revascularization has gained widespread use, there exist few prospective randomized controlled trials (RCTs) comparing these techniques to each other or against the standard of medical management alone. To facilitate this process as well as help answer many important questions regarding the appropriate application of renal revascularization, well-designed and rigorously conducted trials are needed. These trials must have clearly defined goals and must be sufficiently sized and performed so as to withstand intensive outcomes assessment. Toward this end, this document provides guidelines and definitions for the design, conduct, evaluation, and reporting of renal artery revascularization RCTs. In addition, areas of critically necessary renal artery revascularization investigation are identified. It is hoped that this information will be valuable to the investigator wishing to conduct research in this important area.

Use of external iliac artery in renal revascularization surgery: long-term angiographic assessment

PURPOSE

The external iliac artery has physical characteristics, in particular, caliber and length, similar to those of the renal artery and would thus seem to be an ideal substitute for it. However, there are no studies in the literature designed to confirm this possibility. The present study was designed to demonstrate the feasibility of use of the external iliac artery as a substitute for the renal artery in surgical revascularization of renal artery fibrodysplasia and to assess the long-term biologic behavior of the external iliac artery so used.

METHODS

Twelve patients (11 female, 1 male), ages 1 to 43 years (mean, 24.4 years), with severe hypertension underwent aortorenal bypass grafting with use of the external iliac artery to treat preocclusive stenotic lesions (n = 7), complete occlusion (n = 3), or aneurysm (n = 2) of the renal artery. It was considered unnecessary to reestablish circulation in the donor limb in 2 patients (young children), and transposition of the ipsilateral internal iliac artery was performed in 9 patients; in the remaining patient circulation was reestablished with insertion of an iliofemoral prosthesis.

RESULTS

There were no operative deaths. In 1 patient nephrectomy was necessary because of occlusion of the graft as a consequence of technical complications. In 8 patients there was immediate normalization of blood pressure without aid of medication, and in the remaining 3 patients an antihypertensive drug was prescribed. Two patients were lost to follow-up; the other 9 were assessed with angiography at a mean of 8.8 years after the operation. All grafts were found to be in excellent condition, with no evidence of dilatation, kinking, twisting, anastomotic fibroplasia, or wall irregularities.

CONCLUSION

On the basis of this experience, the external iliac artery is confirmed as a substitute for the renal artery, and the excellent long-term results would seem to make it particularly useful in young patients with long life expectancy, such as those with renal artery fibrodysplasia.

Guidelines for the reporting of renal artery revascularization in clinical trials

Although the treatment of atherosclerotic renal artery stenosis with use of percutaneous angioplasty, stent placement, and surgical revascularization has gained widespread use, there exist few prospective randomized controlled trials (RCTs) comparing these techniques to each other or against the standard of medical management alone. To facilitate this process as well as help answer many important questions regarding the appropriate application of renal revascularization, well-designed and rigorously conducted trials are needed. These trials must have clearly defined goals and must be sufficiently sized and performed so as to withstand intensive outcomes assessment. Toward this end, this document provides guidelines and definitions for the design, conduct, evaluation, and reporting of renal artery revascularization RCTs. In addition, areas of critically necessary renal artery revascularization investigation are identified. It is hoped that this information will be valuable to the investigator wishing to conduct research in this important area.

Laparoscopic aortorenal bypass using a PTFE graft: survival study in the porcine model

PURPOSE

To verify the technical feasibility of laparoscopic aortorenal bypass in a porcine model and to evaluate renal pathologic findings after a short survival time.

MATERIALS AND METHODS

Laparoscopic aorta-to-left-renal artery bypass using an interposition Gore-Tex graft was performed in five animals. Renal function was assessed 1 week postoperatively and euthanasia performed after 14 days for histologic examination.

RESULTS

The median surgical time was 210 minutes (range 160-260 minutes). The median time needed to perform the aorta-to-graft anastomosis was 65 minutes (range 50-75 minutes), and the median time required to create the graft-to-renal artery anastomosis was 50 minutes (range 45-60 minutes). No conversion to open surgery was needed. Two intraoperative complications were observed: one large-bowel perforation, which was managed laparoscopically, and one obstruction of the aorta-to-graft anastomosis caused by clots, which was managed by removal of clots with a balloon catheter. No major postoperative complications were observed. The mean preoperative and postoperative serum creatinine concentrations were 0.8 +/- 1.2 and 0.7 +/- 1.6 mg/dL, respectively. At autopsy, all but one of the pigs were found to have a patent aortorenal bypass. In one pig, we found a partially clotted graft. Histologic examination demonstrated an unremarkable kidney in four cases and a kidney showing aspects of coagulative necrosis with viable cells in the animal with the partially clotted graft.

CONCLUSIONS

Laparoscopic aortorenal bypass is feasible. The short-term effect of the bypass on kidney vascularization seems promising, as demonstrated by pathologic findings. Laparoscopic aortorenal bypass could extend the indications for renal revascularization surgery.

The surgical management of renovascular hypertension in children and young adults

OBJECTIVES

To assess the outcome and durability of operative revascularisation in young patients with renovascular hypertension.

DESIGN

Retrospective study.

METHOD

The records of all young patients (under 25 years) operated on for renovascular hypertension at St Mary's Hospital 1988-1998 were reviewed. We assessed the aetiology of hypertension, operations performed, effect of treatment on blood pressure, renal function and requirement for antihypertensive medication during follow-up.

RESULTS

Ten patients were identified who had been considered for surgery, of median age 16 years (22 months to 22 years). Fibromuscular dysplasia was present in five patients, mid-aortic syndrome (MAS) in four and neurofibromatosis in one. Operations performed were aortorenal bypass (three), aorto-aortic bypass+/-renal bypass (three), splenorenal bypass (one) and autotransplantation (one). Of the three patients treated by balloon angioplasty, only one had a successful result. One patient with MAS is currently awaiting surgery. Over a median follow-up of 24 months (8-144), seven patients are normotensive off all antihypertensive medication. Of two patients on reduced doses of medication, one (splenorenal bypass) required surgical repair of a late (9 years) coeliac stenosis.

CONCLUSIONS

The surgical treatment of renovascular hypertension in carefully selected young patients gives durable results. Blood pressure is well controlled long-term, and the need for antihypertensive medication is removed altogether in the majority of patients.

Vascular reconstruction in urology

Vascular reconstructive surgery in urology includes techniques of revascularization of the renal artery for renovascular hypertension or ischemic nephropathy in situ or extracorporeal renal artery reconstruction. The indications for aortorenal bypass, extra-anatomic bypass, or simultaneous aortic substitution and renal revascularization are based on the cause, location, and extent of the vascular lesion. Techniques of bench surgery mainly depend on location of the renal artery disease and availability of autologous graft material.

Chronic renal artery occlusion: nephrectomy versus revascularization

PURPOSE

The surgical management of chronic atherosclerotic renal artery occlusion (RA-OCC) was studied.

METHODS

From January 1987 through December 1996, 397 consecutive patients were treated for atherosclerotic renal artery disease. Ninety-five hypertensive patients (mean blood pressure, 204 +/- 31/106 +/- 20 mm Hg; mean medications, 3.0 +/- 1.1 drugs) were treated for 100 RA-OCCs. Eighty-four (88%) patients had renal dysfunction, defined by serum creatinine levels >/=1.3 mg/dL (mean serum creatinine level, 2.8 +/- 2.0 mg/dL). Demographic characteristics, operative morbidity and mortality, blood pressure/renal function response, and postoperative decline in renal function were examined and compared with that of 302 patients treated for renal artery stenosis (RAS).

RESULTS

After operation, there were 5 perioperative deaths (5.2%), 2 (2.8%) after revascularization and 3 (12%) after nephrectomy (P =.11), compared with 12 (4.0%) perioperative deaths in the RAS group (P =.59). After controlling for important covariates, estimated survival and blood pressure benefits did not differ between RA-OCC patients treated by nephrectomy or revascularization (P =.13; 87% vs 92%, P =.54). Excretory renal function was considered improved in 49% of 79 RA-OCC patients with renal dysfunction, including 9 patients removed from dialysis-dependence. Among patients treated for unilateral disease, revascularization for RA-OCC was associated with significant improvement in renal function (P <.01); however, nephrectomy alone did not increase renal function significantly. Improved renal function after operation was associated with a significant and independent increase in survival (P <.01) and dialysis-free survival (P <.01) among patients treated for RA-OCC. In addition, blood pressure benefit, renal function response, and estimated survival did not differ significantly after reconstruction for RA-OCC or RAS.

CONCLUSION

Among hypertensive patients treated for RA-OCC, equivalent beneficial blood pressure response was observed after both revascularization and nephrectomy. In patients who underwent bilateral renal artery revascularization, the change in excretory renal function attributable to repair of RA-OCC cannot be defined. In patients treated for unilateral disease, however, improvement in function was observed only after revascularization. Moreover, improved renal function demonstrated a significant and independent association with improved survival. This experience supports renal revascularization in preference to nephrectomy for RA-OCC in select hypertensive patients when a normal distal artery is demonstrated at operation.

Renal artery repair: consequence of operative failures

OBJECTIVE

This report examines the blood pressure and renal function response in 20 consecutive patients after secondary renal revascularization following failed operative repair.

SUMMARY BACKGROUND DATA

Most reports describing operative failure of renal artery (RA) repair emphasize the technical aspects of redo RA reconstruction and the immediate blood-pressure response to secondary operation. This report examines the eventual renal function and estimated survival after secondary intervention.

METHODS

Primary methods of RA reconstruction, primary blood pressure and renal function responses, and causes of failed RA repair were defined for 20 patients requiring reoperation for recurrent hypertension or renal insufficiency. These parameters were compared with secondary procedures and eventual blood pressure and renal function response. The eventual outcome for these 20 patients was compared with 514 patients managed by primary renal revascularization during the same period.

RESULTS

Failure of primary RA repair correlated with complex fibromuscular dysplasia requiring branch ex vivo reconstruction (p = 0.020). RA thrombosis frequently required nephrectomy (83%), whereas RA stenosis was successfully reconstructed (91 %; p = 0.001). Primary and secondary blood-pressure responses were equivalent (94% vs. 95% cured or improved); however, primary and eventual renal function responses differed significantly (p = 0.015), with seven patients dialysis-dependent on follow-up. Eventual dialysis dependence was associated with preoperative azotemia (p = 0.022), bilateral failure of primary RA repair (p = 0.007), and an increased risk of follow-up death (p = 0.002). Considering all 534 patients, failed RA repair demonstrated a significant and independent association with eventual dialysis dependence and decreased dialysis-free survival.

CONCLUSIONS

Contemporary rates of reoperation after surgical RA repair are low. In properly selected patients, beneficial blood-pressure response is reliably observed after both primary and secondary operative procedures. However, secondary procedures are associated with a significant and independent risk of eventual dialysis dependence.

Renal artery repair: consequence of operative failures

OBJECTIVE

This report examines the blood pressure and renal function response in 20 consecutive patients after secondary renal revascularization following failed operative repair.

SUMMARY BACKGROUND DATA

Most reports describing operative failure of renal artery (RA) repair emphasize the technical aspects of redo RA reconstruction and the immediate blood-pressure response to secondary operation. This report examines the eventual renal function and estimated survival after secondary intervention.

METHODS

Primary methods of RA reconstruction, primary blood pressure and renal function responses, and causes of failed RA repair were defined for 20 patients requiring reoperation for recurrent hypertension or renal insufficiency. These parameters were compared with secondary procedures and eventual blood pressure and renal function response. The eventual outcome for these 20 patients was compared with 514 patients managed by primary renal revascularization during the same period.

RESULTS

Failure of primary RA repair correlated with complex fibromuscular dysplasia requiring branch ex vivo reconstruction (p = 0.020). RA thrombosis frequently required nephrectomy (83%), whereas RA stenosis was successfully reconstructed (91 %; p = 0.001). Primary and secondary blood-pressure responses were equivalent (94% vs. 95% cured or improved); however, primary and eventual renal function responses differed significantly (p = 0.015), with seven patients dialysis-dependent on follow-up. Eventual dialysis dependence was associated with preoperative azotemia (p = 0.022), bilateral failure of primary RA repair (p = 0.007), and an increased risk of follow-up death (p = 0.002). Considering all 534 patients, failed RA repair demonstrated a significant and independent association with eventual dialysis dependence and decreased dialysis-free survival.

CONCLUSIONS

Contemporary rates of reoperation after surgical RA repair are low. In properly selected patients, beneficial blood-pressure response is reliably observed after both primary and secondary operative procedures. However, secondary procedures are associated with a significant and independent risk of eventual dialysis dependence.

Ex vivo surgery for renal artery aneurysms

BACKGROUND

Renal artery aneurysms (RAAs), once considered rare, are being recognized with increasing frequency. The treatment of aneurysms of the first ramification of the main renal artery is still controversial.

METHODS

From November 1984 to May 1992, we treated 8 patients with RAA at the first ramification. All the patients were treated with an ex vivo technique and autotransplantation.

RESULTS

The results, evaluated with intravenous pyelogram and arteriography were satisfactory. No operative deaths and no complications were noted.

CONCLUSION

We concluded that surgery with an ex vivo technique and autotransplantation is an excellent method of treating this type of lesion.

Renal artery fibromuscular dysplasia: results of current surgical therapy

PURPOSE

This retrospective review describes current surgical management of renal artery (RA) fibromuscular dysplasia (FMD) to define contemporary clinical characteristics and surgical results in patients over the age of 21 years.

METHODS

From January 1987 through March 1994, 40 consecutive adults with hypertension had operative RA repair of FMD at our center and form the basis of this report. From histologic and angiographic appearance, FMD was classified with regard to specific type, noting the presence of RA dissections, RA macroaneurysms and branch RA involvement. Associations between blood pressure response to operation and patient age, duration of hypertension, presence of extrarenal atherosclerosis, presence of branch renal artery disease, and primary or secondary procedure were examined. Clinical characteristics and blood pressure response in these contemporary patients were compared with the results reported from an earlier surgical series.

RESULTS

Unilateral RA repair was performed in 34 patients, and bilateral procedures were required in six patients. Branch renal artery repair was performed in 28 instances, including ex vivo RA repair in 11 patients. There were no perioperative or follow-up deaths; however, three RA grafts (7%) failed within 30 days of operation. Initial blood pressure response was considered cured in 33%, improved in 57%, and failed in 10%. Analysis demonstrated that patients older than 45 years of age had a significantly decreased rate of hypertension cure compared with younger patients; among patients younger than 45 years of age, duration of hypertension was inversely related to cure. Compared with earlier surgical series, our current group of patients was significantly older, with more frequent branch renal artery involvement and extrarenal atherosclerosis, and demonstrated decreased rate of hypertension cure.

CONCLUSION

A beneficial blood pressure response is currently observed in most selected patients after surgical correction of RA-FMD. Compared with earlier series, however, the present day patient differs in many respects, including a significantly decreased chance for hypertension cure after surgical repair.

Pathophysiology of vein graft failure: a review

Vein bypass grafting is an integral component of cardiovascular surgical practice for both arterial and venous diseases. However, many of these grafts will eventually fail due to either intrinsic or extrinsic causes. This review examines the current understanding and knowledge of venous histology, vein graft pathology and the associated endothelial and smooth muscle cell physiology and pharmacology. In addition, the status of research on the therapeutic control of vein graft intimal hyperplasia and accelerated atherosclerosis is assessed.

Follow-up evaluation after renal artery bypass surgery with use of carbon dioxide arteriography and color-flow duplex scanning

PURPOSE

Postoperative evaluation of renal artery bypass grafts historically has been obtained by contrast renal arteriography before discharge from the hospital. Recent reports have advocated replacing arteriography with abdominal duplex scanning for evaluating and monitoring the integrity of renal artery bypasses. We propose a combination of these two techniques, which provides minimal risk to the patient and renal parenchymal function.

PURPOSE

Between July 1, 1990, and Dec. 31, 1991, 17 patients (8 men, 9 women) underwent 24 renal artery bypasses for poorly controlled hypertension or deteriorating renal function. In the immediate postoperative period each patient underwent carbon dioxide (CO2) renal arteriography to detect any technical defects and to define bypass graft anatomy. Subsequently, color-flow duplex scanning of the renal artery bypass grafts were done at 3-month intervals with the postoperative CO2 arteriogram for baseline comparison. CO2 arteriography clearly defined proximal/distal anastomotic anatomy, bypass conduit integrity, and bypass conduit runoff.

RESULTS

Procedural morbidity was zero because no hematomas developed and serum creatinine remained stable. Duplex scanning for a mean follow-up of 8.3 months revealed antegrade flow in 23 bypasses with peak systolic velocity of 60 to 100 cm/sec. One bypass graft had a peak systolic velocity greater than 150 cm/sec suggestive of a proximal anastomotic stenosis; however, the patient died before a repeat, verifying CO2 arteriogram could be obtained. Recurrent hypertension developed in one patient with velocities less than 100/cm/sec, and repeat CO2 arteriography revealed no evidence of graft or anastomotic stenosis.

CONCLUSION

CO2 arteriography and duplex scanning provide an accurate means of initially evaluating and subsequently monitoring renal artery bypass grafts, with minimal risk of renal or patient morbidity.

Renal artery revascularization with polytetrafluoroethylene bypass graft

Between January 1979 and December 1986, a total of 74 renal revascularizations were performed in 68 patients using the reinforced expanded polytetrafluoroethylene prosthetic graft. These 74 revascularizations represent 29% of 251 surgical renal revascularizations performed during the same period of time. Eight patients had a total of nine revascularizations in the emergency setting (group I) for ruptured suprarenal aneurysm or acute thrombosis of the renal arteries. Only one patient survived and six years later, his anatomic and functional results are satisfactory. Sixty-five revascularizations were performed electively in 60 patients (group II). This group consisted of 19 renal revascularizations alone, and 46 combined aortic and renal revascularizations. One patient died of respiratory complications two months after operation after his thoracoabdominal aneurysm was cured. Early repeat postoperative arteriography showed that six reconstructions had occluded (three major renal arteries, three polar arteries). One patient was lost to follow-up. The remaining patients were followed for a mean of 41 months. Follow-up arteriograms obtained during 1987 showed that there were two late occlusions and two distal anastomotic stenoses. Actuarial patency was 85 +/- 10% at 72 months. Polytetrafluoroethylene prosthetic grafts constitute a reliable material for renal revascularization and combined aortic and renal reconstruction in certain anatomic conditions.

Long-term results of renal artery reconstruction with autogenous artery in patients with renovascular hypertension

Renal artery reconstruction for the treatment of renovascular hypertension is preferably performed with an autologous graft when a graft is required. Although satisfactory results with vein grafts have been reported, stenosis and dilatation are not infrequent complications which have been observed only occasionally in arterial grafts. We have analysed our long-term results obtained with autogenous arterial grafts for renal artery reconstruction to determine the functional and anatomical results with regard to these complications. The data from 57 survivors operated on from 1959 through 1983 were analysed. All patients were hypertensive and the average systolic and diastolic blood pressure was 173/109 mmHg (mean number of 2.2 drugs). The renal artery stenosis was caused by arteriosclerosis and fibrodysplasia in 24 and 33 patients, respectively. In situ repair was performed in 30 patients (arterial bypass: 17 patients; splenorenal bypass: 13 patients). Extracorporeal repair of fibrodysplastic branch lesions was performed in 27 patients using branched hypogastric artery grafts (mean number of 2.4 branch anastomoses per kidney). Results were evaluated in the short (mean 8.3 months) and long term (mean 7.5 years) and the blood pressure response classified as either beneficial (cured/improved) or failed. Anatomical results were evaluated by angiography in the short-term in 87% of the patients and the long-term in 70%. A beneficial blood pressure response was obtained in 77% and 86% of patients in the short and long-term, respectively. The average blood pressure level after an interval of several years (long term) was 144/87 mmHg (mean number of 0.9 antihypertensive drugs). After in situ reconstruction, 2 and 1 anatomical failures were observed in the short and long-term, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal repair of renal artery branch lesions

Complex renal artery lesions which formerly would have been treated by nephrectomy may now be reconstructed by extracorporeal surgery and autotransplantation. Our experience in 15 patients (17 operations) with renal artery lesions extending into its branches or confined to them is described. Two patients underwent separate operations on both sides. The indications for surgery were severe renovascular hypertension (10 cases), renal artery aneurysm, (5 cases) and deteriorating renal function (2 cases). Overall clinical results after a mean follow up of 3 years were considered excellent in 13 procedures (11 patients). Improvement in 2 patients and failure in the other 2, who ultimately underwent nephrectomy. Discussion is focussed on results, vascular indications, (namely aneurysm, stenosis, dissecting aneurysm and trauma) and surgical techniques. Preservation of functioning renal tissue should be the ultimate goal of renovascular surgery where the ex vivo technique, when indicated, will achieve favorable results in most patients.

Renovascular hypertension in children. Surgical repair with special reference to the use of reinforced vein grafts

Surgical correction of renovascular hypertension in children is especially challenging because there is high incidence of bilateral renal artery lesions and stenosis of the abdominal aorta. Seventeen patients with severe hypertension, whose ages ranged from 2 to 16 years (mean 10.2 years), had surgical repair of these lesions from 1974 to 1987. Twenty-nine renal artery lesions were repaired. Twelve (71%) were bilateral, five (29%) were unilateral, and eight patients (47%) had abdominal aortic lesions (midaortic stenosis). Twenty-eight saphenous vein grafts and one splenorenal graft were used to bypass the renal artery lesions. The midaortic lesions were bypassed with Dacron grafts from the superceliac aorta to the aortic bifurcation. No operative deaths occurred. Nineteen of the 28 vein grafts were reinforced with a 6 mm diameter tubular Dacron mesh to prevent aneurysmal degeneration seen in three of nine unsupported vein grafts. Follow-up arteriograms were available in 15 patients up to 11 years after operation (mean 5.0 years). There has been no aneurysmal dilatation in the 19 mesh-supported grafts. The ratio of vein graft diameter to the diameter of the native aorta was 1.25 +/- 0.38 (+/- standard deviation) in unsupported grafts and 0.65 +/- 0.09 in mesh-supported grafts, representing a 92% increased diameter in the unsupported grafts. Three vein grafts (10.3%) required percutaneous transluminal angioplasty for late postoperative vein graft stenoses, but no stenotic lesions have developed at the aortic suture lines. One graft occluded 7 years postoperatively after replacement of an aneurysmal vein graft, and one early postoperative graft occlusion occurred, for a graft failure rate of 7%. Seventy-six percent of patients (13 of 17) are normotensive without medication, and 24% (4 of 17) are considered improved with hypertension controlled with a lower dose of medication. Our results attest to the safety and efficacy of this complicated surgery. Saphenous veins, supported by external Dacron mesh, appear to be a suitable graft material for renal reconstruction in this population.

Surgical correction of renovascular hypertension

The role of surgical revascularization in the management of patients with renal artery disease has changed in recent years. This has occurred owing to the advent of transluminal angioplasty as an effective method of treatment for certain patients, improved results of surgical revascularization in older patients with atherosclerosis, an enhanced appreciation of advanced atherosclerotic renal artery disease as a correctable cause of renal failure, and the development of more effective surgical techniques for patients with severe aortic atherosclerosis and branch renal artery disease. Surgical revascularization is at present the treatment of choice for patients with branch renal artery disease, ostial atherosclerotic renal artery disease, a renal artery aneurysm, and patients in whom renal angioplasty has been unsuccessful. Excellent clinical results continue to be achieved with surgical revascularization in properly selected patients.

Evolving strategies for the repair of complex renovascular lesions

Fifty-five patients with 59 complex renovascular lesions required two or more branch artery anastomoses during aortorenal grafting. Forty-five reconstructions involving 112 branches were facilitated using hypothermic ex vivo perfusion preservation, whereas 14 involving 28 branches were repaired in situ. Ex vivo repair was used whenever the kidney was considered unreconstructable by in situ techniques. Fibromuscular dysplasia predominated and the branched internal iliac artery was used for renal artery substitution. There were no deaths and only one kidney (ex vivo) was lost. Branch vessel occlusion occurred in two of 140 anastomoses (1.4%). Ninety-eight per cent (51/52) of the heparinized patients had cure or improvement at mean follow-up of 5 years. No late graft dysfunction occurred in postoperative angiographic follow-up. The branched internal iliac artery is uniquely suited and remains the preference of the authors for the replacement of the diseased renal artery and its branches. The in situ repair is ideally suited for lesions limited to the renal artery bifurcation. Ex vivo repair is reserved for complex or reoperative distal arterial lesions. Unique characteristics in the group include: bilateral lesions (25%), solitary kidney (22%), reoperative lesions (16%), children (9%), and coexisting significant aortic disease (7%). In situ and ex vivo repair meet all the challenges of complex renovascular disease. The strategies outlined will achieve outstanding long-term total and segmental renal salvage in the treatment of hypertension or aneurysmal disease. When ex vivo repair is required, it can be accomplished with only one additional simple maneuver, the reanastomosis of the renal vein.

Extracorporeal replacement of the renal artery: techniques, indications and long-term results

Extracorporeal repair of the renal artery was done in 24 patients for complex lesions extending to branches of the renal artery (9 dysplasias, 5 atheromas and 10 aneurysms). The renal artery and its branches were replaced by a hypogastric branched autograft in 20 patients and a saphenous vein graft in 4. Indications for an extracorporeal operation were hypertension, preservation of renal function against progressive deterioration and extension of the lesion to more than 2 branches of the renal artery. Of 76 peripheral anastomoses 68 were patent postoperatively. Two secondary nephrectomies were performed. Mean followup was 54 months. Hypertension was cured in 19 patients and improved in 2, while 2 failed treatment and 1 died. An extracorporeal operation may represent the best alternative for treatment of renal arterial lesions involving more than 2 branches.

Diffuse dilatation of autogenous saphenous vein grafts used to replace the renal and superior mesenteric arteries. A case report

Of the many different materials used to replace diseased arteries, autogenous saphenous vein grafts are among the most favored. This view is also explicitly expressed regarding patients who suffer from occlusive arterial disease of the abdominal viscera, particularly the renal vessels. There is, however, recent information which suggests that for reasons unknown saphenous vein grafts in the renal position are likely to be subject to both diffuse and aneurysmatic dilatation, a complication seen only seldom in the femoral and practically never in the coronary position. The purpose of this paper is to present the case of a young woman with fibromuscular stenosis of both her abdominal renal and the mesenteric arteries whose condition was surgically corrected using autogenous vein grafts. Despite the fact that at the time of her surgery her saphenous vein appeared to be both macroscopically and microscopically intact and postoperatively her blood pressure returned to normal, she developed diffuse, aneurysmatic dilatation of all of her vein grafts.