Evolving strategies for the repair of complex renovascular lesions

Indications for and results of renal autotransplantation

PURPOSE OF REVIEW

To understand the indications and outcomes of renal autotransplantation, and when to consider this unique procedure for patients.

RECENT FINDINGS

Renal autotransplantation confers acceptably low rates of graft failure and prevents need for long-term dialysis. Renal autotransplantation remains an important management strategy in very select patients for complex renovascular disease, ureteral stricture disease, ureteral trauma, upper urinary tract urothelial carcinoma, renal cell carcinoma, and Loin-Pain Hematuria Syndrome. With advancements in minimally invasive procedures, the application of renal autotransplantation for refractory stone disease is rare but exists. Robot-assisted laparoscopic renal autotransplantation demonstrates reproducible graft success and complication rates with improved perioperative outcomes (ex. hospital length of stay) - though comparative studies are lacking. Patients would benefit from a multidisciplinary approach from renal transplant surgeons, vascular surgeons, urologists, nephrologists, dieticians, pain management providers, social workers, and psychiatrists.

SUMMARY

In experienced hands, renal autotransplantation is a reasonable treatment approach for complex and refractory renal vascular disease, Loin-Pain Hematuria Syndrome, ureteral strictures and trauma, upper urinary tract malignancy, and stone disease in highly select patients.

Revascularization of a giant right renal artery aneurysm near the hilum

This article describes a case of a giant right renal artery aneurysm near the hilum treated with surgical excision, ex vivo renal artery reconstruction, and orthotopic autotransplantation with successful outcome. The giant right renal artery aneurysm is rare, and the successful outcome in our case report proved the safety and effectiveness of the ex vivo reconstruction in treatment of complex renal artery lesions. A 57-year-old male smoker with a history of recurrent abdominal pain was diagnosed with a 5.1-cm right renal artery aneurysm near the hilum. We chose surgical excision, ex vivo reconstruction, and orthotopic renal autotransplantation to treat this patient according to the preoperative computed tomography angiography and glomerular filtration rate. The operation was successful and the patient recovered uneventfully.

Fibromuscular dysplasia affecting a two-branched renal artery in a patient with a solitary kidney: case presentation

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease, commonly involving the renal arteries. Here we report a case of a 16-year-old Chinese male who was found to have severe hypertension with proteinuria for 2 years. Computed tomography showed absence of the left kidney and enlargement of the right kidney. Subsequent angiography confirmed the above findings and revealed narrowing of both the upper and lower branches of the right renal artery caused by FMD. These combined lesions are very rare, and individuals affected are at increased risk of renal dysfunction if left untreated. Treatment with percutaneous balloon angioplasty is the first choice in such a patient and usually results in optimal outcomes.

Intraparenchymal renal artery aneurysms. Case report with review and update of the literature

Increased interest in aneurysms involving the renal artery and its branches has occurred during the past 3 decades. The prevalence of renal artery aneurysms is approximately 0.01%-1% in the general population as well as 2.5% in hypertensive patients undergoing angiography. Intraparenchymal renal artery aneurysms (IPRAAs) are rare since being detected in less than 10% of patients with renal artery aneurysms. The Authors report an unusual case of multiple small intrarenal artery aneurysms associated with a large IPRAA located in the mid portion of the right kidney. Usually, IPRAAs are secondary to diseases or injuries of the kidney vascular network. They are classified as true, false, saccular, fusiform, dissecting, and microaneurysms. Potential complications of IPRAAs include peripheral dissection, thrombosis, hypertension, renal infarction and rupture. IRAAs may be detected incidentally as well as present with urologic symptoms and signs related to complications. Actually, IRAAs are investigated by non invasive modalities including duplex ultrasound, magnetic resonance angiography, spiral three-dimensional computed tomography angiography, and three-dimensional reconstructed rotational digital substraction angiography of the segmental and distant branches of the renal artery. Angiography with intrarterial injection of contrast material is the gold standard in diagnosing IPRAAs. Treatment options for IPRAAs include observation, aneurysmectomy with surgical repair, endovascular procedures, nephrectomy or partial nephrectomy. Observation is indicated for asymptomatic intraparenchymal renal artery aneurysms measuring less than 2 cm in diameter. Surgical repair of IPRAAs includes aneurysmectomy and reconstruction of the renal artery by in vivo or ex vivo technique. The procedure is indicated for IPRAAs causing renovascular hypertension, dissection, urologic symptoms, embolization, local expansion and women of childbearing age with a potential for pregnancy. In recent years, transcatheter arterial embolization has emerged as a simple, useful and effective technique in managing IRAAs. The procedure is performed by transfemoral catheterization as well as by superselective catheterization and embolization of interlobar arteries with 3F microcatheters. Endovascular occlusion is obtained by using gelatin sponge, steel coils, detachable baloons, and conventional non-detachable microcoils delivered through a microcatheter. Nephrectomy or partial nephrectomy are reserved for conditions precluding renal revascularization which include overt RAA rupture, covert RAA rupture, artery-to-vein fistula, renal cell carcinoma, end stage nephropaty, renal infarction, severe ischemic renal atrophy or complex intrarenal aneurysms. Recently, partial nephrectomy by the laparoscopic approach has been proposed for managing IPRAAs and the procedure is considered feasible and safe.

Rescue of kidney and pancreas grafts with complex vascular lesions

BACKGROUND

The organ shortage mandates that grafts with complex vascular lesions be considered for graft rescue.

METHODS

Surgical graft rescue was attempted in 8 patients bearing 8 kidneys and 2 pancreata that showed complex vascular lesions deemed not suitable for interventional radiology procedures.

RESULTS

All procedures but 1 were performed under elective conditions. Seven grafts were repaired in situ, while cooling the organ through retrograde venous perfusion, and 3 kidneys were explanted, repaired extracorporeally, and retransplanted. All vascular reconstructions remain patent after a mean follow-up period of 3.3 years (+/-2.1 years).

CONCLUSIONS

Careful patient selection, multidisciplinary evaluation, and personalized surgical technique may allow the rescue of kidney and pancreas grafts with complex vascular lesions that, otherwise, would be lost.

[Extracorporeal surgery of the renal artery]

PURPOSE

The aim of the study was to assess the short- and long-term results of ex situ renal artery repair in a homogeneous series of patients operated on for complex lesions of this artery.

MATERIAL AND METHODS

Seventy-seven patients (38 males and 39 females) underwent 80 extracorporeal repairs of the renal artery. The operated lesions were: aneurysms of the artery and/or of its branches with or without associated dysplasia (30 cases), extensive fibrodysplasia extending to distal branches (31 cases), spontaneous dissection of the artery with extension to the branches (nine cases), reoperation on the renal artery (six cases), miscellaneous (four cases). In all cases, the kidney was exteriorized after transsection of its vessels and cooled by perfusion of cold Collin's solution. After repair, it was reimplanted in the lumbar (36 cases) or iliac fossa (44 cases). An arterial substitute was used in 59 cases.

RESULT

No mortality was observed in this series. Five postoperative thromboses occurred leading to kidney loss (6.25%). Segmental thrombosis leading to partial atrophy of the kidney occurred in three cases (3.75%). During the long-term follow-up, one repeat stenosis and four fusiform dilations of venous autografts were observed. All other repairs were successful (89.3%). Results on blood pressure control were favourable in 88.7% of the cases.

CONCLUSIONS

Ex situ repair must be reserved to lesions involving several branches of the artery whose repair requires prolonged circulatory arrest and lesions profoundly situated in the renal sinus whose repair is difficult by conventional in situ surgery.

Pulmonary artery augmentation with autologous aortic tissue

OBJECTIVE

To assess durability and viability of autologous aortic tissue used to augment severe branch pulmonary artery stenosis with a novice surgical technique.

PATIENTS AND METHODS

Seven patients underwent corrective surgery for complex cyanotic congenital heart disease. Their age ranged from 3-6 years, and their weight 11-17.4 kg. All had concomitant branch pulmonary artery stenosis repaired utilizing an autologous patch, harvested from the patient's own aorta by excising a ring and opening it to form the patch. The aorta is reconstructed directly by end to end anastomosis.

RESULTS

One patient died in hospital. Another patient died at 18 months at home. The surviving five patients have remained well in the follow up period of mean 31 months (range 10-52). All patients were restudied by follow up echocardiography and remain with no evidence of the aortic autograft tissue calcification or stenosis. The reconstructed aorta showed no stenosis at the site of anastomosis.

CONCLUSION

The intermediate term results of this novice surgical technique appear encouraging and justify the technique. However, longer follow up will be required to confirm the continued growth of this patch material.

The case for renal revascularization

This report reviews renovascular disease, hypertension and renal parenchymal dysfunction. The primary lesions responsible are discussed as well as the strategies for restoring normal renal perfusion. The natural history studies document progressive impairment of renal perfusion and the consequence of renal dysfunction. Renal revascularization interrupts this pathway by relieving or lessening hypertension and preserving renal function which are the therapeutic options.

Pediatric renovascular hypertension: a thirty-year experience of operative treatment

PURPOSE

This study was undertaken to characterize the changing operative treatment of pediatric renovascular hypertension and subsequent outcomes in a 30-year experience at a single institution.

METHODS

Clinical data were analyzed on 57 pediatric patients, 24 girls and 33 boys, ranging in age from 10 months to 17 years, who underwent operations for renovascular hypertension from 1963 to 1993 at the University of Michigan. Renal artery disease included atypical medial-perimedial dysplasia, often with secondary intimal fibroplasia (88%), and inflammatory mural fibrosis (12%). Abdominal aortic narrowings affected 15 patients. Data were categorized into three chronologic eras (I:1963-1972, II:1973-1980, and III:1981-1993) to allow identification of therapeutic trends.

RESULTS

Primary surgical procedures were undertaken 74 times. Ex vivo reconstruction was necessary once. Primary operations included aortorenal bypass with autogenous vein grafts (n = 26) or internal iliac artery grafts (n = 7); iliorenal bypass with vein grafts (n = 2); renal artery resection beyond the stenosis and reimplantation into the aorta (n = 10), the main renal artery (n = 2), an adjacent segmental renal artery (n = 3), or the superior mesenteric artery (n = 3); renal artery resection and reanastomosis (n = 3); focal renal arterioplasty (n = 2); operative dilation (n = 7); splenorenal bypass (n = 2); and primary nephrectomy (n = 7). Among 23 primary operations performed in era I, 56.5% were aortorenal bypasses with vein grafts, but in era III this form of revascularization represented only 3% of 33 primary operations. No reimplantations were performed in era I, whereas reimplantations accounted for 51.5% of era III procedures. Thirteen patients underwent staged or concomitant aortic reconstructions with thoracoabdominal aortoaortic bypass grafts (n = 5) or patch aortoplasty (n = 8). Fourteen patients underwent a total of 20 secondary operations, including seven secondary nephrectomies. Operative therapy benefited 98% of these children: hypertension was cured in 45 (79%), improved in 11 (19%), and unchanged in one (2%). There were no operative deaths.

CONCLUSIONS

Contemporary surgical management emphasizes direct reimplantation of main renal arteries into the aorta, reimplantation of segmental arteries into adjacent renal arteries, patch aortoplasty for associated abdominal aortic coarctations, and single-stage revascularizations. Pediatric patients with renovascular hypertension clearly benefit from carefully executed operative therapy.

Complex branch renovascular disease: management options and late results

PURPOSE

The purpose of this report is to review management options and late results of complex renovascular disease managed over the last 22 years.

METHODS

Complex branch renal artery disease in 84 kidneys was repaired during 75 operations performed in 68 consecutive patients. There were 61 females (90%) and 7 males (10%) whose predominant pathologic diagnosis was fibromuscular dysplasia manifesting as either renovascular hypertension or aneurysmal degeneration. These patients underwent 15 in situ, 52 ex vivo, and 8 combined reconstructions. In situ repair primarily with use of the bifurcated internal iliac artery autograft was used for primary lesions of the proximal renal artery bifurcation (two branches). Ex vivo repairs, primarily with use of the multibranch internal iliac autograft and hypothermic perfusion preservation, were used for all other patterns of distal renal artery branch disease and reoperative problems.

RESULTS

Renovascular reconstruction was successful in salvaging 83 of 84 kidneys (98.8%) in 67 of 68 patients. There were no operative deaths. Two reconstructions thrombosed in the early postoperative period. One was due to severe aortic disease, the other to branch artery dissection after a failed balloon angioplasty. Both patients continued to have hypertension. Before hospital discharge 65 patients had 81 renal revascularizations proven patent by arteriography. Their renal function was assessed and blood pressure was determined in a follow-up extending to 20 years (mean 7.5 years, median 7.9 years). Late arteriograms were obtained in 30 patients (46%) an average of 52 months after operation (range 6 months to 18 years). They demonstrate stable renal artery repair with no evidence of late graft failure in each. Hypertension was cured or improved in 51 of 53 patients (96%) with a proven patent reconstruction. Aneurysms were successfully repaired in 11 patients. Renal function was improved in four patients with ex vivo repairs, unchanged in 59 patients (15 in situ, 44 ex vivo), and persistently worse in only three patients, all of whom had in situ repairs.

CONCLUSION

The branched arterial autograft allows the restoration of normal renal arterial anatomy and function when inserted to replace complex distal renovascular disease. This provides a durable repair, essential for younger patients affected by this pattern of disease who anticipate a normal life span after renovascular repair. Successful long-term correction of diastolic hypertension and aneurysmal disease was accomplished without significant morbidity.

Dysplastic lesions of renal artery branches: late results of ex vivo repair

Between November 1980 and July 1989, 29 ex vivo reconstructions were performed in 12 women and five men (mean age: 42 years) for dysplastic lesions of renal artery branches. Fifteen patients had hypertension, associated with advanced renal failure in one case. The internal iliac artery was used routinely for reconstruction. The saphenous vein was used on one side where bilateral repairs were necessary. A total of 52 distal anastomoses were performed, an average of 2.6 per revascularized kidney. Mean follow-up was four years and 10 months. No patients were lost to follow-up. There were no early or late deaths. At least one follow-up arteriogram and technetium99 diethylene triamine pentacetic acid scintiscan was obtained for all patients. Forty-five (86%) of 52 anastomoses remained patent. Eleven of 15 hypertensive patients completely recovered while four were improved. Systolic arterial blood pressure decreased by an average of 42 mmHg (p less than 0.001), and results remained stable with time. For fibromuscular dysplasia occurring in young patients whose life expectancy is usually long, this type of surgery provides excellent long-term clinical and anatomical results.

Bench repair of complex renal arterial lesions

Between 1968 and 1989, 160 patients underwent aortorenal bypass for renovascular hypertension. During the same interval, 13 patients had ex-vivo bench repair of complex renal arterial pathology. There were eight men and five women, with a mean age of 36 years. Twelve of the 13 patients had fibromuscular disease; one had atherosclerosis. Twelve patients had renovascular hypertension with complex stenotic disease beyond the main renal artery. Seven of these also had an associated renal aneurysm as did the sole normotensive patient. Saphenous vein patch or bypass were used to correct stenotic segments in four patients, while the remaining nine patients had excision of stenotic or aneurysmal segments with primary arterial anastomosis. There were no deaths in the series. One kidney was lost because of arterial thrombosis. One patient required reoperation to control postoperative bleeding. Nine of the 12 patients with renovascular hypertension were normotensive off medication, and three were improved, with reduced medication controlling their blood pressure. Ureteric obstruction occurred in two patients; this settled spontaneously in one patient and was corrected by reoperation in the other. From this experience, we conclude that bench repair is a safe and effective way to maximize salvage of kidneys affected by complex arterial pathology.

The role of renal autotransplantation in complex urological reconstruction

From 1972 to 1988, 108 patients underwent renal autotransplantation for renal artery disease (67), ureteral replacement (27), or renal cell carcinoma present bilaterally or in a solitary kidney (14). The most common indication for renal autotransplantation was to allow extracorporeal repair of complex branch renal artery lesions. Of the 54 patients in this group technically satisfactory branch renal arterial reconstruction and a successful clinical outcome were achieved in 52 (96%). Renal autotransplantation is the treatment of choice in these patients and also in selected children with main renal artery disease. Renal autotransplantation provided excellent results in 25 of 27 patients (92%) who required replacement of all or a major portion of the ureter. Over-all renal function was well preserved in these patients and only 1 has experienced chronic bacteriuria. Renal autotransplantation is a useful alternative to ileal interposition in this setting. Extracorporeal partial nephrectomy and renal autotransplantation were successful in 12 of 14 patients (85%) undergoing a nephron-sparing operation for renal cell carcinoma. In situ techniques are associated with less morbidity and currently are preferred in this group.

Renovascular hypertension in children: current concepts in evaluation and treatment

Since 1981, we have evaluated and treated 22 children with renovascular hypertension (RVH). Seventeen patients had stenosis of their native renal arteries, and five had stenosis of the artery in a transplanted kidney. RVH was caused by fibromuscular dysplasia in 13 patients, by trauma in 2 patients, and by arteritis in 2 patients. Among the patients who had transplanted kidneys, three had technical causes for stenosis and two had stenosis due to rejection. The disease was unilateral in 10 patients, bilateral in 5, and present in a solitary kidney in 7, including the five renal transplants. Diagnostic studies that strongly suggested the presence of renovascular disease were an initial diastolic blood pressure greater than 100 mm Hg, an elevated peripheral vein renin activity level, and an abnormal renal scan if the patient's hypertension was being controlled with an angiotensin-converting enzyme inhibitor (ACEI). Only the renal arteriogram was 100% accurate in confirming the presence of RVH. Percutaneous angiographic correction was attempted in 13 patients and resulted in lasting improvement of the hypertension in five (38%). Surgical revascularization was attempted in 17 children, including the 8 with failed angioplasty, with improvement or cure of the hypertension in 15 patients (88%). Combining percutaneous transluminal angioplasty (PTA) and surgical results gave 20 of 22 patients (91%) with cure or improvement of their hypertension. Four of 27 affected kidneys (15%) could not be revascularized and were removed. We conclude from this series of patients that despite improvements in noninvasive studies, renal arteriogram remains the only study that is 100% accurate in evaluating children for RVH.(ABSTRACT TRUNCATED AT 250 WORDS)

Future aspects of renal transplantation

New and exciting advances in renal transplantation are continuously being made, and the horizons for organ transplantation are bright and open. This article reviews only a few of the newer advances that will allow renal transplantation to become even more widespread and successful. The important and exciting implications for extrarenal organ transplantation are immediately evident.