Combined aortic and renal artery reconstruction

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.

Ultrasonography of the Abdominal Aorta: The Right Flank vs the EPI-Mesogastric Windows

Ultrasonography of the abdominal aorta should be performed as part of a complete echocardiographic study. As visualization may be difficult from the epi-mesogastric (E-M) window because of obesity or distension, we evaluated the feasibility of the right flank (RF) as an alternative acoustic window in 100 patients (62 male, 38 female, aged 7-83 years). Compared with the E-M window, our results showed that the right flank was significantly better in imaging of the infrarenal aorta: 89% (RF) vs 75% (E-M) (p < 0.05); right renal artery: 84% vs 71% (p < 0.05); and right renal artery Color Doppler: 84% vs 71% (p < 0.05). The Doppler sonification angle for the right proximal renal artery was 0 degrees-31 degrees (mean 12.7 degrees +/- 4.2 degrees) vs 64 degrees-76 degrees (mean 70.6 degrees +/- 4.1 degrees); for the left proximal renal artery 0 degrees-35 degrees (mean 23.1 degrees +/- 6.6 degrees) vs 62 degrees-73 degrees (mean 68.3 degrees +/- 4.2 degrees). Images obtained from the right flank were often of better quality than those obtained from the abdominal window because of a superior definition of acoustic interfaces and a better performance of Color Doppler sampling. Thus, the right flank could be considered a good alternative window for the echographic study of the abdominal aorta.

Prophylactic repair of renal artery stenosis is not justified in patients who require infrarenal aortic reconstruction

PURPOSE

Simultaneous prophylactic repair of asymptomatic renal artery stenosis (ARAS) in patients who require infrarenal aortoiliac reconstruction is controversial. This study documents the natural history of ARAS in patients who require aortic reconstruction.

METHODS

Two hundred patients who required aortic reconstruction from 1985 to 1990 for indications other than hypertension or renal salvage were identified. ARAS was not repaired. Preoperative angiograms were available for 171 of 200 patients and were reviewed for renal artery stenosis. Patients were assessed for atherosclerotic risk factors, survival, preoperative and follow-up blood pressure, serum creatinine level, antihypertensive medication usage, and need for dialysis.

RESULTS

The mean duration of follow-up was 6.3 years. Twenty-four of 171 patients (14%) had preoperative unilateral 70% to 99% diameter reduction ARAS, and eight (5%) had bilateral 70% to 99% ARAS. Clinical features associated with > or =70% ARAS included coronary artery disease, increased age, and a diagnosis of hypertension (p < 0.05). Patients with > or =70% ARAS did not have a decreased 7-year survival rate (66% vs 84%; p = 0.10) but had higher systolic blood pressures (153 +/- 25 vs 138 +/- 30 mm Hg; p < 0.05) as well as increased numbers of antihypertensive medications at follow-up (1.1 +/- 0.2 vs 0.7 +/- 1; p < 0.05). The mean serum creatinine level (1.1 +/- 0.3 preoperative vs 1.4 +/- 0.8 mg/dl; p = NS) was not increased. One patient (0.58%) with polycystic kidney disease and minimal renal artery stenosis required dialysis.

CONCLUSIONS

High-grade ARAS in patients who are undergoing infrarenal aortic reconstruction is associated at late follow-up with increased systolic blood pressure and a need for increased numbers of antihypertensive medications, but not decreased survival rate, dialysis dependence, or an increase in serum creatinine level. These data do not support renal artery repair in patients with ARAS who undergo infrarenal aortic reconstruction.

Combined renal artery stenosis and aortic aneurysm: treatment options

The purpose of this study was to analyze outcomes of two different treatment strategies in patients treated for renal artery (RA) stenosis and a coincidental abdominal aortic aneurysm (AAA). A total of 50 patients were encountered who required treatment for concomitant RA stenosis and an AAA from 1980 to 1994. Simultaneous operative aortic and RA reconstruction was done in 32 patients, whereas 18 patients where treated with preoperative percutaneous transluminal renal artery angioplasty (PTRA). The two groups were well matched with respect to age, AAA size, incidence of hypertension, preoperative creatinine level, and creatinine clearance (all p values > 0.07). Aortorenal bypass (18 RAs), reimplantation (18 RAs), or endarterectomy (2 RAs) was performed to correct a mean RA stenosis of 88%, whereas 23 RAs (91% mean stenosis) were treated with preoperative PTRA. PTRA failed in four patients with RA stenosis, and they were successfully treated with surgery (3 bypasses and 1 reimplantation). Statistical analysis did not demonstrate a significant difference between these four failed PTRA patients, the 14 successful PTRA patients, and the 32 RA reconstruction patients in terms of operating time (p = 0.15), operative blood loss (p = 0.20), intensive care unit days (p = 0.71), or total hospital days (p = 0.94). Among the 40 patients available for follow-up, hypertension was cured in seven, improved in 10, unchanged in 15, and worse in eight with no difference demonstrated between the groups (p = 0.73). These data suggest that preoperative PTRA has no specific advantage over surgical RA reconstruction in patients with concomitant RA stenosis and AAA. Failed PTRA did not preclude or complicate subsequent operative RA revascularization.

Renal endarterectomy vs. bypass for combined aortic and renal reconstruction: is there a difference in clinical outcome?

Are there differences in the patient characteristics and clinical outcome for transaortic renal endarterectomy vs. bypass grafting when either technique is combined with infrarenal aortic replacement for occlusive or aneurysmal disease? Two common perceptions persist: (1) combined aortic and renal procedures have a high risk and (2) bypass is easier and safer than endarterectomy. To address these controversies we compared 52 consecutive patients undergoing concomitant aortic and renal reconstruction between 1987 and 1991: 26 with bypass and 26 with endarterectomy. Bypass patients were older (70 vs. 64 years, p = 0.001), had more extensive plaque extending into the distal renal artery and more severe baseline azotemia (creatinine = 2.6 vs 1.7 mg/dl, p = 0.01), more clinically evident coronary heart disease (89% vs. 56%, p = 0.001), and a greater need for nephrectomy of a small nonfunctional pressor kidney (23% vs. 0%) than endarterectomy patients. In contrast, endarterectomy patients more commonly required aortic replacement for occlusive disease than for an aortic aneurysm (endarterectomy: 65% vs. 35%; bypass: 19% vs 81%, p = 0.002) and tended to require more intraoperative technical revisions (12% vs. 4%) than bypass patients. Both groups, however, experienced no operative mortality, had similar cardiorespiratory morbidity, and achieved equal improvement in hypertension (69% vs. 65%). Bypass patients, who already had more severe preoperative azotemia than endarterectomy patients, showed less improvement in the creatinine level (Cr = 2.1 vs. 1.4 mg/dl, p = 0.01) and had greater need for late dialysis (30% vs. 4%, p = 0.01). Only one patient on dialysis had graft occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

MR angiography in the preoperative evaluation of abdominal aortic aneurysms: a preliminary study

PURPOSE

The ability of magnetic resonance (MR) angiography to depict visceral and renal vessels was evaluated in patients with abdominal aortic aneurysms (AAAs).

PATIENTS AND METHODS

MR sequences (sagittal T1-weighted, two-dimensional coronal, and three-dimensional axial time-of-flight) were compared in a prospective blinded fashion with conventional angiograms obtained preoperatively in 23 patients with AAAs. Results were correlated with surgical findings when available.

RESULTS

Operative aortic clamp site was correctly predicted with conventional angiography in 95% of patients and with MR angiography in 86% (P > .1). Aneurysm neck measurements obtained with the two modalities were within 1 cm in 91% of cases. With conventional angiography as the standard of reference, 96% of all renal arteries were identified on MR angiograms but 36% of accessory arteries were missed. MR angiography enabled identification of patients who had at least one renal artery stenosis greater than 50% with a sensitivity of 100% and specificity of 89%. For identifying individual renal artery, celiac artery, and superior mesenteric artery stenoses of similar severity, the sensitivity and specificity were 67% and in excess of 96%, respectively. The celiac artery could not be evaluated in one case.

CONCLUSION

The results of this small study suggest that the role of MR angiography in the preoperative evaluation of AAA warrants further investigation.

Ischemic nephropathy and concomitant aortic disease: a ten-year experience

PURPOSE

The durability of renal preservation after surgical intervention has not been well defined, particularly in patients with associated aortic disease. A review of all patients at the Emory University Hospital with renal insufficiency (creatinine level > or = 1.8) and concomitant atherosclerotic aortic and renovascular disease was undertaken.

METHODS

Fifty patients underwent both renal revascularization (71 kidneys) and the repair of aneurysmal or symptomatic aortic occlusive disease between 1982 and 1992. Hypertension was present in 96% of patients and diabetes was present in 10%. The preoperative estimated glomerular filtration rate (EGFR) was 25.18 +/- 8.29 ml/min (creatinine level 3.1 +/- 1.5 mg/dl). Operative management included bilateral renal artery repair (n = 21), unilateral repair alone (n = 17), and unilateral repair with contralateral nephrectomy (n = 12). The relative percent change in the postoperative EGFR (> or = 7 days after operation) increased by at least 20% in 42% of the patients, had decreased by 20% or more in only 4%, and was otherwise categorized as unchanged in the remaining 54% of the study group.

RESULTS

The 30-day operative mortality rate was 2.0% (1 of 50). Forty-five of the surviving 49 patients (91.8%) were available for follow-up (median 49 months). During this period nine patients (18.4%) eventually required dialysis, four within 6 months of operation, and 19 patients died. Neither subgroup experienced a retrieval of renal function after operation. Five-year survival rate was 61%, and a trend was noted between the risk of death and the relative change in EGFR after operation (p = 0.13). The likelihood of eventually requiring long-term dialysis was highest among those patients with low preoperative functional renal reserve as measured by preoperative creatinine level of 3 mg/dl or greater (p < 0.0001), or preoperative EGFR less than 20 ml/min (p = 0.0001). Blood pressure was cured or improved in 50% at late follow-up.

CONCLUSIONS

Early improvement of renal function may be observed in nearly one half of patients subjected to combined aortic and renal revascularization. Nonetheless, renal preservation may not be sustainable in patients with compromised preoperative function. Intervention before marked functional decline remains the best option for minimizing the risk of eventual dialysis.

Extra-anatomic renal revascularization in patients with renal artery stenosis and abdominal aortic occlusion

Thirteen patients with atherosclerotic renal artery stenosis and total abdominal aortic occlusion underwent extra-anatomic surgical renal revascularization without aortic replacement. Renal artery stenosis was present unilaterally (n = 2), bilaterally (n = 7), or in a solitary kidney (n = 4). Surgical renal revascularization was indicated for treatment of severe hypertension in all patients and for preservation of renal function in 10 patients. The level of abdominal aortic occlusion was suprarenal (n = 3), perirenal (n = 2), or infrarenal (n = 8). All patients had extensive collateral vascular supply to the lower extremities with absent (n = 7) or mild (n = 6) claudication. Surgical renal revascularization was achieved with hepatorenal bypass (n = 6), mesenterorenal bypass (n = 4), or splenorenal bypass (n = 3). None of the patients underwent concomitant aortic replacement. There were no operative deaths. Postoperatively, hypertension was improved in 10 patients, unchanged in 2 patients, and worse in 1 patient. Renal function was improved in 8 patients, stable in 2 patients, and worse in 3 patients. After surgical renal revascularization, no patient required aortic replacement, while 1 patient underwent extra-anatomic revascularization of the lower extremities. We conclude that some patients with renal artery stenosis and abdominal aortic occlusion can be managed by surgical renal revascularization alone without a more extensive and potentially hazardous aortic replacement. In these patients, extra-anatomic techniques can allow safe and successful surgical renal revascularization while avoiding surgery on the diseased aorta.

Simultaneous reconstruction of infrarenal abdominal aorta and renal arteries

From 1980 to 1990, 48 (4.7%) of 1,002 patients underwent elective aortic reconstruction and simultaneous renal artery reconstruction. Forty-five men and three women (mean age: 66.5 years) had 59 renal artery lesions (51 stenoses, six occlusions, one dysplasia, and one aneurysm) associated with 20 infrarenal aortic aneurysms and 28 aortoiliac occlusive lesions. One nephrectomy and 58 renal artery reconstructions were performed (35 prosthetic bypasses, 11 vein bypasses, six direct reimplantations, five transaortic endarterectomies, and one resection of an intrahilar aneurysm followed by autotransplantation). Operation was always indicated for the aortic lesions. Indication for renal artery repair was hypertension in 33 cases (17 associated with renal insufficiency) and one with isolated renal insufficiency. In the remaining 14 cases, surgery was deemed preventive. One patient died (2%). There were 12 nonfatal complications two of which were kidney failures requiring chronic extrarenal epuration. Routine follow-up arteriograms showed four postoperative renal artery occlusions. Mean follow-up was 35.8 months. Four patients were lost to follow-up; 10 died secondarily. Five year survival was 72.1 +/- 19.1%. Secondary patency of renal artery reconstruction was 89.5 +/- 9.4% at five years. Late results were favorable in 45% of patients with hypertension and in 39% of patients with renal insufficiency. Mortality in simultaneous aortic and renal artery reconstruction is not superior to that of isolated infrarenal aortic surgery.

Combined aortic and visceral arterial reconstruction: risks and results

The indications, morbidity, and efficacy of combined reconstruction of the abdominal aorta and visceral arteries (renal and superior mesenteric; excluding suprarenal aortic aneurysms) were analyzed retrospectively in 29 consecutive patients who underwent surgery from June 1984 through February 1990. Seventeen men and 12 women ages 32 to 76 years (mean, 66 years) were studied. Follow-up was complete in all patients to either death or calendar year 1989 to 1990 (mean, 31.9 months; range, 2 to 66 months). All patients underwent bypass of angiographically proven severe lesions of one renal artery (19 patients), both renal arteries (8 patients), or the superior mesenteric artery and renal arteries (2 patients), in concert with synthetic distal aortic replacement for occlusive disease (10 patients) or aneurysm (19 patients). Indications for renal artery repair included severe hypertension in 13 patients, ischemic renal insufficiency in 8 patients, and lesion morphology alone in 8 patients. Operative mortality rate was 3 of 29 (10.3%), and each death was the result of multisystem organ failure. Nonfatal complications occurred in 11 of the 26 survivors (42%), and this group differed significantly from the uncomplicated 15 patients only in having a higher mean preoperative serum creatinine (2.5 +/- 1.1 mg/dl vs 1.6 +/- 0.9 mg/dl, p = 0.04, t test). The mortality rate of patients with preoperative serum creatinine greater than or equal to 2.0 mg/dl, was 15.4% (2/13 patients), compared to 6.2% (1/16) in patients with creatinine less than 2.0 mg/dl. Three late deaths occurred (2 stroke, 1 cancer). Hypertension control improved in 64% of patients overall, and in 7 of 9 patients whose major operative indication was renovascular hypertension. Renal function remained stable or improved in 12 of 15 patients (80%) with renal insufficiency, but 3 patients progressed to require dialysis. Long-term graft patency was demonstrated by angiography or on duplex scan in all studied survivors (21 patients). Although operative risks are clearly increased compared to less complex vascular procedures, careful patient selection and management will yield a favorable outcome in most patients with such combined lesions.

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.

Atherosclerotic lesions of the aorta and renal arteries: results of simultaneous surgical treatment

Between 1975 and 1985, 43 patients underwent simultaneous aortic and renal artery reconstruction. Twenty-two patients had infrarenal abdominal aortic aneurysms and 21 had aortoiliac occlusive disease. In addition, 40 patients had severe lesions of one or both renal arteries and three patients had a lesion in an accessory renal artery. Hypertension was present in 29 patients, 15 of whom had impaired renal function. Four patients had chronic renal insufficiency without hypertension. Ten patients underwent prophylactic renal artery reconstruction. Infrarenal aortic repair was carried out simultaneously with thromboendarterectomy of one or both renal arteries, or reimplantation of a renal artery into the aorta, in two cases with contralateral nephrectomy. In one patient, the celiac and superior mesenteric arteries were also bypassed. Three patients (7%) died in the immediate postoperative period, two of these from myocardial infarction. Long-term survival was studied in 37 patients. Sixty-seven percent of patients with preoperative hypertension and less than 50% of those with preoperative renal insufficiency had good results.

Superior mesenterorenal bypass for renal revascularization with infrarenal aortic occlusion

The technique of renal revascularization using a saphenous vein bypass graft from the superior mesenteric artery is described. This operation has been performed for the correction of renal artery stenosis in 4 patients with atherosclerotic aortic occlusion. When the requisite conditions are present, mesenterorenal bypass offers a safe and effective method of renal revascularization, and is preferable to aortic replacement in selected patients.

Trends in reconstruction for atherosclerotic renal vascular disease

Twenty-eight patients underwent renal vascular reconstruction for atherosclerotic renal vascular stenosis. Ten patients had therapeutic renal artery reconstruction for isolated renal artery stenosis causing severe hypertension, nine patients had therapeutic renal artery reconstruction for severe hypertension combined with simultaneous aortic reconstruction, and nine patients had prophylactic renal artery reconstruction for renal artery stenosis combined with simultaneous aortic reconstruction. Ninety percent of patients undergoing therapeutic renal revascularization procedures for hypertension were cured or improved. The 10 patients undergoing prophylactic renal artery reconstruction combined with aortic reconstruction had an average 72 percent reduction in the diameter of the vessel. Dacron side grafts sutured to the aortic graft were used for revascularization in each of the patients with prophylactic revascularization and was found to be an expedient means of reconstruction with good patency rates. No increased morbidity or mortality rate was noted in the prophylactic group. We believe that prophylactic revascularization should be carried out in patients with atherosclerotic high-grade stenosis of the renal arteries to prevent hypertension and preserve renal function.

Juxtarenal aortic atherosclerosis. Surgical experience and functional result

Ninety patients underwent combined aortic (90) and renal artery (138 arteries) reconstruction for severe, symptomatic aortic occlusive disease (47 patients), aortic aneurysmal disease (30 patients), and visceral atherosclerosis (13 patients). Transaortic endarterectomy was used for 67% of renal artery reconstructions and 69% of visceral arteries. Aortic reconstruction required prosthetic grafting in 74%. A standard transabdominal approach was used in 72 of 90 patients (80%), and thoraco-retroperitoneal exposure was necessary in 18 patients. Perioperative mortality was 9% (8/90) and morbidity 16% (14/90). Ninety per cent of the patients were evaluated at long-term (mean 32 months). Hypertension was cured or improved at discharge in 82% (59/72), and in 96% hypertension improvement was sustained during the follow-up interval. Renal function was improved or preserved in 93% (40/43) at discharge, and this response was sustained in 84% during the follow-up period. Late mortality (8/74, 11%) was lower than expected and is attributed to the technique of combined repair, the cure and control of hypertension, the prevention of ongoing renal ischemia, and the preservation of renal function.

Coarctation of the abdominal aorta: current options in surgical management

Coarctation or hypoplasia of the abdominal aorta is a rare cause of life-threatening hypertension. In most cases the mechanism of hypertension is elevated blood renin levels secondary to associated renal artery stenosis. Medical control of the hypertension is often difficult, and thus patients usually require renal artery revascularization combined with aortic bypass or replacement early in life. Current surgical management should optimize the use of autogenous methods of renal artery reconstruction including saphenous vein aortorenal bypass, splenorenal arterial anastomosis, hepatorenal saphenous vein bypass, and renal autotransplantation. In selected patients the reconstruction can be staged by correction of the renal artery stenosis and postponement of definitive repair of the aortic coarctation until it becomes hemodynamically significant.