Operative management of renovascular hypertension. Results after a follow-up of fifteen to twenty-three years

Outcome following renal autotransplantation in renal artery stenosis

Introduction

With significant advances in the area of interventional radiology, angioplasty and stenting have become preferred first-line treatment in patients with significant renal artery stenosis. However, not all patients have favorable anatomy to undergo minimally invasive treatments, and reconstruction of the renal artery is an option. In select cases, either improved renal function or maintenance of existing function and sometimes resolution of hypertension can follow surgical treatment.

Material and Methods

This was a prospective observational study conducted from August 2010 to June 2016. Patients <45 years of age with uncontrolled hypertension secondary to renovascular hypertension (RVH) and refractory to medical management and renal arterial disease unfavorable for percutaneous intervention were included in the study. All patients were evaluated thoroughly using computed tomography angiography and diethylenetriaminepentaacetic acid renal scan. Patients underwent autotransplantation either into the right or left iliac fossa. Some kidneys required bench reconstruction of the renal artery and/or its branches before being implanted into either iliac fossa.

Results

Nine patients were included in the study. The mean age was 27 years. Seven were males and two were females. Five patients had bilateral renal artery stenosis. After autotransplantation, initially five patients became free of antihypertensive medicines, but on the follow-up, two patients showed rising trend of blood pressure. The evaluation revealed narrowing at anastomosis site in both patients with salvageable kidney function in one patient. Angioplasty with stenting was done in this patient while the second patient underwent secondary nephrectomy. At 2 years of follow-up, four patients required no antihypertensive medicines.

Conclusion

Autotransplantation can be a successful treatment of severe RVH and should be considered in patients with renal arterial disease unfavorable for percutaneous intervention.

The MHC, disease and selection

Given large sample sizes, whole genome screens are now able to identify even quite modest contributions of common human genetic variation to disease. These approaches, made possible by the development of high-throughput, dense SNP genotyping, find few associations stronger than those for the human MHC, in multigenic autoimmune conditions. They confirm earlier findings that the major variants affecting susceptibility and resistance to autoimmunity relate to MHC class I and class II genes. It is generally assumed, although there are few good examples, that selection for resistance to infection drives evolution of MHC variation. Many MHC-associated diseases may be the price paid for an effective immune response. Interestingly, the MHC appears to influence susceptibility to conditions unrelated to immunity, including some neuropathologies. The infectious history of the individual, conditioned by their MHC, may exert an indirect effect on these diseases, although there are hints of more direct involvement of MHC molecules in neuronal systems. Here I survey the variety of conditions associated with the MHC in relation to ideas that selection through disease resistance is dependent upon MHC variation, not only at the level of the individual, but also at the level of the population.

Outcome of renal artery reconstruction: analysis of 687 procedures

OBJECTIVE

To evaluate the short- and long-term results of surgical reconstruction of the renal arteries, the authors review their experience with more than 600 reconstructions performed over a 12-year period.

SUMMARY BACKGROUND DATA

Reconstruction of the renal arteries, whether for primary renal indications or concomitantly with aortic reconstruction, has evolved over the past 40 years. There is concern that renal artery reconstructions carry significant rates of mortality and morbidity and may fare poorly compared with less-invasive procedures.

METHODS

From 1986 to 1998, 687 renal artery reconstructions were performed in 568 patients. Of these, 105 patients had simultaneous bilateral renal artery reconstructions. Fifty-six percent of the patients were male; 11% had diabetes; 35% admitted to smoking at the time of surgery. Mean age was 67 (range, 1 to 92). One hundred fifty-six (23%) were primary procedures and the remainder were adjunctive procedures with aortic reconstructions; 406 were abdominal aortic aneurysms and 125 were aortoiliac occlusive disease. Five hundred procedures were bypasses, 108 were endarterectomies, 72 were reimplantation, and 7 were patch angioplasties. There were 31 surgical deaths (elective and emergent) in the entire group for a mortality rate of 5.5%. Predictors of increased risk of death were patients with aortoiliac occlusive disease and patients undergoing bilateral simultaneous renal artery revascularization. Cause of death was primarily cardiac. Other nonfatal complications included bleeding (nine patients) and wound infection (three patients). There were 9 immediate occlusions (1.3%) and 10 late occlusions (1.5%). Thirty-three patients (4.8%) had temporary worsening of their renal function after surgery.

CONCLUSION

Renal artery revascularization is a safe and durable procedure. It can be performed in selected patients for primary renovascular pathology. It can also be an adjunct to aortic reconstruction with acceptable mortality and morbidity rates.

Does concomitant aortic bypass and renal artery revascularization using the retroperitoneal approach increase perioperative risk?

While elective repair of abdominal aortic aneurysms and aortoiliac occlusive disease is associated with an acceptable (3%) mortality rate, combined aortic and renal revascularization has usually been reported to have a higher perioperative mortality. Over the past 5 years, 785 elective aortic procedures have been performed at the authors' medical center. During the same period, 77 renal artery reconstructions have been performed in 73 patients in conjunction with aortic procedures. All were done using the retroperitoneal approach to the aorta and renal arteries. Indication for concomitant renal artery revascularization included 79% (61 of 77 patients) for either significant stenosis or anatomic involvement, 18% for renovascular hypertension (14 of 73) and 3% (two of 73) for renal impairment. The demographics and risk factors were similar in both groups. Operative mortality rate was 2.9% (23 of 785) in the aortic group and 3% (two of 73) in the combined group. Complications in the combined group were one stroke (1.4%), one re-exploration for bleeding (1.4%), two pulmonary pneumonia (2.7%) and five patients had elevated serum creatinine (> 350 mumol/l) after operation. Of these patients two died, one had an occluded graft and two eventually improved. There was one early graft thrombosis and one late thrombosis. In the authors' experience, concomitant aortic bypass and renal artery revascularization can be performed with an acceptable mortality and morbidity using the retroperitoneal approach.

[Transluminal dilatation and other nonsurgical catheter technics in the treatment of renovascular hypertension]

The development of percutaneous transluminal techniques has brought up new possibilities for causative treatment of renovascular hypertension. In renal artery stenosis transluminal angioplasty is meanwhile routinely applied; experience with angioplasty to date exceeds by far the number of 1000 published cases. Technical success is obtained in more than 90%. The clinical success in the therapy of reno-vascular hypertension is approximately 76% over all with nearly equal cure and improvement rates. In fibromuscular stenosis clinical success has been obtained in 95% with a cure rate of 56% and improval in 39%. The cure rate is particularly low in patients with atherosclerotic stenosis with 19%, however in 60% improvement has been obtained, resulting in clinical benefit in 79%. Results obtained by surgery seem to be superior to those of dilatation, especially with regard to cure rates. However, the differences are minor and are compensated by the evident advantages of transluminal dilatation, especially its easy application and lower risk. Thus, 8 years after its introduction in nephrology, transluminal dilatation is the therapy of choice in renal artery stenosis. Other nonoperative interventional techniques, including transcatheter aspiration and embolectomy, intraarterial thrombolysis, embolisation and modified angioplasty provided valuable alternatives to usual surgical therapy. However, experience with some of these procedures is still limited. The complication rate of transluminal angioplasty of 10-20%, necessitating surgery in nearly 5%, prohibits its uncritical use.

Retrieval of renal function by revascularization. Study of preoperative outcome predictors

Results of renal revascularization for retrieval of function in poorly functioning kidneys are variable, but criteria for prediction of benefit and patient selection for operation are ill-defined. This report examines preoperative parameters in 64 hypertensive patients who underwent successful revascularization of poorly functioning kidneys as defined by creatinine clearance less than or equal to 15 ml/min (measured by preoperative split renal function studies [SRFS]) or preoperative serum creatinine greater than or equal to 3.5 mg/dl (range: up to 8.9 mg/dl) to identify markers of value in prediction of a beneficial response in renal function. Ages ranged from 35 to 75 years. There were 35 men and 29 women. The renovascular lesion was atherosclerotic in 58 patients and fibrodysplastic in six. Total renal artery occlusion was present in 32 cases. No urine flow was detectable before surgery on SRFS from 13 kidneys. Kidney lengths ranged from 7.7 cm to 15.1 cm. Fifty-four unilateral and 10 bilateral revascularizations were performed. A beneficial blood pressure response to operation was observed in 94%. Benefit in excretory function was determined by comparison of preoperative and postoperative data which included SRFS parameters, renal length, serum creatinine, isotopically derived split functioning renal mass, and glomerular filtration rates. Overall, 56 patients could be classified in regard to functional response. Twenty-two patients received no or minimal benefit; nine patients received modest improvement, and 25 patients exhibited more marked improvement. Statistical evaluation of preoperative anatomic and functional parameters as predictors of functional response suggested that multiple variables influence the probability of function retrieval by revascularization. Useful among these predictive variables are the status of the distal vessel beyond the occlusion, the bilaterality of reconstructable disease in azotemic patients, the amount of residual renal mass available for revascularization, and the degree of hyperconcentration of nonreabsorbable solutes from the involved kidney after surgery.

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.