Long-term results of in situ and extracorporeal surgery for renovascular hypertension caused by fibrodysplasia

In this study the early and late results of surgical reconstruction for renovascular hypertension caused by fibrodysplasia are evaluated in 53 patients treated between 1962 and 1983. There were 40 female and 13 male patients. The mean blood pressure was 208/126 mm Hg before medical therapy and 171/109 mm Hg thereafter. Bilateral renal artery stenoses were present in 12 patients. In situ revascularization was used in 26 patients and extracorporeal surgery to repair branch artery lesions was performed in 27 patients. Surgical therapy reduced the blood pressure to normal levels with minimal antihypertensive medications. This effect was already apparent 6 to 12 months after operation (mean blood pressure level of 140/90 mm Hg) and it was maintained during a mean follow-up period of 8.4 years (range 1 to 20 years) (mean blood pressure level of 134/85 mm Hg). At 6 to 12 months after operation, 79% of the patients were classified as either cured or improved. At this time the results did not appear to have been influenced by the preoperative duration of hypertension, nor by manifestations of extrarenal arteriosclerosis (ERA) as found in 10 patients, or by the surgical technique applied. But at the end of the long-term follow-up period (mean 8.3 years) the beneficial response rate of 87% appeared to have been adversely influenced by the presence of preoperative ERA, since beneficial response rates were 93% for those without and 67% for those with ERA (p = 0.17). We conclude that renal revascularization is effective both early and late for the treatment of renovascular hypertension caused by fibrodysplasia and that complex renovascular obstruction can be treated effectively with extracorporeal repair.     

Debatable problems of intravascular dilatation of the brachiocephalic artery

Roentgen--guided endovascular dilatation (RED) was conducted in 23 patients with atherosclerotic stenoses of branches of the arch of the aorta, in 20 with stenoses of the subclavian artery, and in 3 with stenoses of the brachiocephalic trunk. Before dilatation the patients had a systolic pressure gradient of 25 to 55 mm Hg in the region of the stenosis and constriction of the arterial lumen by 40 to 80%. Systolic pressure gradient disappeared completely in 17 cases and persisted at a level of 10 to 40 mm Hg in 7 cases. During RED of the left subclavian artery a complication, acute thrombosis of the distal part of the artery, occurred in one case. Indications for dilatation of stenosed subclavian arteries were elaborated on the basis of the accumulated experience.     

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)     

Spontaneous dissection of renal artery: long-term results of extracorporeal reconstruction and autotransplantation1

PURPOSE: We undertook this study to assess the outcome of spontaneous dissection of the renal artery and its branches surgically treated with extracorporeal reconstruction and autotransplantation. SUBJECTS: Between 1975 and 1996, 15 consecutive patients (19 kidneys) with spontaneous renal artery dissection underwent renal artery reconstruction. Fourteen patients had accelerated hypertension. Five patients had impaired renal function. In 14 patients the dissection was associated with fibrodysplasia, and in 1 patient it was related to arteriosclerosis. INTERVENTION: In 17 kidneys extracorporeal reconstruction and autotransplantation was used. The renal artery of 1 kidney was reconstructed in situ. One primary nephrectomy was performed. RESULTS: There were no operative deaths or major morbidity. All but 1 reconstruction was successful (94.4%). Results at follow-up (range, 1-8 years) were favorable in 14 patients; 79% had satisfactory blood pressure control, and all patients had normal renal function, including those with impaired renal function preoperatively. CONCLUSIONS: Extracorporeal reconstruction and autotransplantation can be effectively used in patients with spontaneous renal artery dissection located in or extending into the distal branches. Early recognition and appreciation of the clinical presentation of spontaneous renal artery dissection are important.     

Treatment of renal transplant artery stenosis by percutaneous transluminal dilatation

Transluminal arterial dilatation using a balloon catheter was performed in four patients with renal allografts and transplant artery stenosis. In three patients the procedure was uncomplicated and resulted in reduction in mean blood pressure from 180/100 mm Hg to 135/85 mm Hg immediately after and 135/90 mm Hg at a mean of eight months after angioplasty; renal function remained stable. In one patient with two stenoses the procedure was abandoned because of inaccessibility of the stenotic sites to the dilatation catheter; however, reversible acute renal failure ensued. Percutaneous transluminal angioplasty may thus offer a successful alternative to conventional surgical techniques in renal transplant artery stenosis in suitable patients.     

Surgical treatment of renovascular hypertension

The evaluation of patients with inadequate control of diastolic blood pressure for surgically correctable forms of hypertension led to the detection and surgical treatment of 56 patients. Detection was facilitated by the use of hypertensive intravenous pyelography and Hippuran renal Scanning. Aortography proved the presence of renal artery disease and renal vein renin assay established its significance in the etiology of the patients' hypertension. Renal artery reconstruction was performed in 50 patients, including 5 who also had reconstruction of major aortoiliac lesions. The extent of renal artery disease precluded arterial reconstruction in six patients, who required nephrectomy. Two postoperative deaths occurred, for a mortality rate of 3.6 per cent. Improvement in mean diastolic blood pressure for the total group of patients from 118 mm Hg preoperatively to 86 mm Hg postoperatively was achieved. Forty-six patients (85 per cent) have a diastolic blood pressure of 90 mm Hg or less; in 5 patients the diastolic blood pressure is 91 to 100 mm Hg but is at least 20 mm Hg lower than the preorative level.     

Improved renal function after renal artery revascularization

An experience with 20 patients with renovascular hypertension and renal insufficiency secondary to renal artery stenosis is presented. The mean follow-up was 29 months. Eighteen patients had atherosclerotic renal artery stenosis and two patients had transplant renal artery stenosis. The mean preoperative blood pressure of 162 +/- 5 mmHg decreased significantly to 105 +/- 2 mm Hg (p less than 0.001). The serum creatinine also decreased from a mean preoperative level of 4.7 +/- 0.7 mg/dl to a mean postoperative level of 2.3 +/- 0.3 mg/dl (p less than 0.001). Similarly, the creatinine clearance improved from a mean preoperative level of 28 +/- 2 ml /min to a mean postoperative level of 45 +/- 8 ml/min (p less than 0.03). Four patients (20%) with improved renal function died from 4 days to 15 months postoperatively. Two patients (10%) have progressed to end stage renal disease. These findings demonstrate that renal revascularization is clearly beneficial in the short-term and long-term improvement of renal function.     

Renal revascularization in Takayasu arteritis-induced renal artery stenosis

PURPOSE: This study was undertaken to define the long-term effects of renal revascularization on blood pressure, and renal and cardiac function in patients with Takayasu arteritis-induced renal artery stenosis (TARAS). METHODS: Twenty-seven patients (25 women; mean age, 27 years) with TARAS underwent intervention. Primary, primary assisted, and secondary patency rates were determined, and the late effects on blood pressure, renal and cardiac function, and survival were analyzed. RESULTS: All patients had hypertension (mean blood pressure, 167/99 mm Hg; 2.5 antihypertensive medications per patient). Mean estimated glomerular filtration rate in patients not receiving hemodialysis was 76 mL/min, and in five patients serum creatinine concentration was greater than 1.5 mg/dL. Three patients were hemodialysis-dependent, and two had intractable congestive heart failure. Forty interventions were performed, including 32 aortorenal bypass procedures, two repeat implantations, four nephrectomies, and two transluminal angioplasty procedures. Postoperative morbidity was 19%. There were no deaths. During follow-up (mean, 68 months), three graft stenoses, all due to intimal hyperplasia, and three graft occlusions occurred. Two of three graft stenoses were successfully revised. At 1, 3, and 5 years of follow-up, primary patency was 87%, 79%, and 79%, respectively; primary assisted patency was 93%, 89%, 89%, respectively; and secondary patency was 93%, 89%, and 89%, respectively. Intervention resulted in a decrease in blood pressure to a mean of 132/79 mm Hg (P<.0001), and the need for antihypertensive medications was reduced to one per patient (P<.01). Mean glomerular filtration rate increased to 88 mL/min (P<.005), and two patients no longer required hemodialysis. Congestive heart failure resolved in both patients, and did not recur. There were three deaths during follow-up, with 5-year and 10-year actuarial survival of 96% and 80%, respectively. CONCLUSIONS: Renal revascularization to treat TARAS is durable, has a salutary effect on blood pressure, and enhances long-term renal and cardiac function. This response establishes renal revascularization as a successful and durable intervention for TARAS, and a benchmark to which other therapies should be compared.     

Patent side branches do not affect coronary blood flow in internal thoracic artery-left anterior descending anastomosis: an experimental study.

BACKGROUND: It has been reported that large side branches of internal thoracic artery grafts may steal flow from the coronary circulation. Material an. METHODS: To assess the importance of the side branches, we measured the proximal and distal flow and pressures (mean subclavian artery pressure and mean arterial anastomotic pressure) at baseline and during infusion of adenosine (0.5 mg/kg/min) in 10 Landrace pigs in which an internal thoracic artery-left anterior descending anastomosis was constructed without interruption of the side branches. The difference between proximal and distal flow was considered to represent the blood flow of the internal thoracic artery side branches. Measurements were then repeated after surgical occlusion of all the side branches. RESULTS: At baseline, blood flow of the side branches represented 18% of the total flow in the proximal internal thoracic artery, and this percentage remained constant under the infusion of adenosine, which caused a 220% increase of the cardiac index and a 368% increase of the proximal flow. The infusion reduced the gradient along the left internal thoracic artery (mean subclavian artery pressure-mean arterial anastomotic pressure) from 15 to 10 mm Hg (P =.02) as the result of a lower mean subclavian artery pressure, although the mean arterial anastomotic pressure remained constant. Interruption of all the side branches resulted in a small and not significant increase in distal flow even after adenosine infusion. CONCLUSION: These observations suggest that blood flow in the side branches is minimal either at baseline and under combined systemic and coronary vasodilation. Clinically significant flow steal from the coronary circulation to the internal thoracic artery side branches seems then unlikely.     

Simultaneous aortic reconstruction and renal revascularization: risk factors and late results in eighty-nine patients

From 1973 through 1984, graft replacement of infrarenal aortic aneurysms (N = 56) or occlusive disease (N = 33) was performed in conjunction with simultaneous renal revascularization in 89 patients. Isolated renal artery stenosis was corrected by unilateral reconstruction in 56 patients (63%), but the remaining 33 (37%) had diffuse involvement that required either bilateral renal artery grafts or unilateral revascularization of solitary kidneys. The incidence of hypertension (greater than 180/90 mm Hg) refractory to preoperative medical therapy (88%), severe coronary disease documented by angiography (40%), and postoperative azotemia (33%) or oliguric renal failure (15%) was significantly higher among patients with bilateral renal artery disease (p less than 0.05). In addition, this group had twice the early mortality rate (15%) of patients having unilateral renal artery lesions (7.1%). During a mean follow-up interval of 37 months, medical control of hypertension was enhanced in 46 of the 80 operative survivors (58%), and renal function improved or remained stable in 63 survivors (79%). Five-year actuarial survival presently is 65% for the entire series, with a cumulative mortality rate of 38% among patients who underwent aneurysm resection (mean age 64 years) in comparison to 15% (p = 0.03) for those patients with aortoiliac occlusive disease (mean age 60 years).     

Combined operative angiodilation and arterial reconstruction for limb salvage

Fifteen high-risk patients with threatened limb loss underwent combined operative iliac angiodilation and infrainguinal vascular reconstruction for iliac and femoropopliteal occlusive disease. The patients were poor candidates for combined surgical inflow and outflow reconstruction because of associated cardiopulmonary disease. The mean systolic pressure gradient across the iliac stenosis was 34 +/- 5 mm Hg. Iliac artery angiodilation was accomplished intraoperatively and reduced all gradients to zero. Stenoses in the distal portion of the deep femoral artery were endarterectomized in nine patients, and six cross-femoral and six distal popliteal or tibial grafts were constructed. Life-table analysis at 36 months showed iliac patency in 86% of cases and successful distal reconstruction in 76%. Our limb salvage rate of 86% suggests that combined intraoperative angiodilation by the angiographer and arterial reconstruction by the vascular surgeon may provide effective therapy for high-risk patients.     

Renal revascularization for recurrent pulmonary edema in patients with poorly controlled hypertension and renal insufficiency: a distinct subgroup of patients with arteriosclerotic renal artery occlusive disease.

Recurrent pulmonary edema in patients with poorly controlled hypertension and renal insufficiency appears to be a marker of bilateral renal artery occlusive disease. The effectiveness of renal revascularization to prevent recurrent pulmonary edema in this distinct subgroup with renal artery occlusive disease was analyzed in 17 consecutive patients treated at the University of Michigan Hospital between 1984 and 1990. Their mean preoperative blood pressure was 207/110 mm Hg, and mean serum creatinine clearance was 3.8 mg/dl. Pulmonary edema occurred despite evidence of normal ventricular function in 65% of these patients. Bilateral renal artery occlusive disease affected 94% of the patients, and 54% had an occluded renal artery. Renal revascularization was accomplished by iliorenal bypass (41%), aortorenal bypass (29%), endarterectomy (24%), and transluminal angioplasty (6%). Contralateral nephrectomy (41%) and concomitant aortic reconstruction (24%) were also required frequently. No postoperative deaths occurred, and no patient had early postoperative pulmonary edema. Control of hypertension was improved in all patients, two of whom were discharged from the hospital on no antihypertensive medications. Two of the three patients requiring dialysis before operation were able to discontinue dialysis after operation. Late follow-up (mean, 2.4 years) revealed hypertension to be cured in one patient (6%), and improved in 16 patients (94%). Pulmonary edema occurred in one patient during late follow-up. Late follow-up showed renal function (mean creatinine, 1.7 mg/dl) to be improved in 77%, stable in 12%, and worse in two patients; one required dialysis. A single episode of pulmonary edema in a patient with poorly controlled hypertension and renal insufficiency should prompt consideration of this clinical syndrome and early diagnostic angiography.(ABSTRACT TRUNCATED AT 250 WORDS)     

Renal autotransplantation: an alternative to standard renal revascularization procedures

From January 1978 through December 1987, 22 patients underwent 23 renal autotransplantation procedures for the treatment of renovascular hypertension through the retroperitoneal approach. The causes of the renal artery stenosis were as follows: atherosclerosis (15), fibromuscular dysplasia (6), and Takayasu's arteritis (1). Indications for renal autotransplantation were as follow: disease extending into the renal artery branches (10), stenosis of multiple renal arteries (6), atherosclerotic aorta in high-risk patients (4), and stenosis of renal artery in children (2). The mean preoperative blood pressure of 205 +/- 6/109 +/- 3 mm Hg decreased significantly to 139 +/- 4/77 +/- 2 mm Hg (p less than 0.001). The serum creatinine decreased significantly from a mean preoperative level of 2.2 +/- 0.8 mg/dl to a mean postoperative level of 1.4 +/- 0.4 mg/dl (p less than 0.05). Eleven patients with preoperative renal dysfunction had a significant decrease in the serum creatinine from a mean preoperative level of 3.4 +/- 0.3 mg/dl to a mean postoperative level of 1.9 +/- 0.2 mg/dl (p less than 0.001). One operative death occurred as a result of myocardial infarction. There were three postoperative complications, none of which affected the ultimate result in blood pressure or renal function. This experience demonstrates that in selected patients, renal autotransplantation is an excellent alternative in the surgical treatment of renovascular hypertension.     

Neonatal aortic arch reconstruction avoiding circulatory arrest and direct arch vessel cannulation.

BACKGROUND: Aortic arch reconstruction in neonates routinely requires deep hypothermic circulatory arrest. We reviewed our experience with techniques of continuous low-flow cerebral perfusion (LFCP) avoiding direct arch vessel cannulation. METHODS: Eighteen patients, with a median age of 11 days (range 1 to 85 days) and a mean weight of 3.2 +/- 0.8 kg, underwent aortic arch reconstruction with LFCP. Seven had biventricular repairs with arch reconstruction, 9 underwent the Norwood operation and 2 had isolated arch repairs. In 1 Norwood and 7 biventricular repair patients, LFCP was maintained by advancing the cannula from the distal ascending aorta into the innominate artery. In 8 of 9 Norwood patients, LFCP was maintained by directing the arterial cannula into the pulmonary artery confluence and perfusing the innominate artery through the right modified Blalock-Taussig shunt fully constructed before cannulation for cardiopulmonary bypass. In 2 patients requiring isolated arch reconstruction, the ascending aorta was cannulated and the cross-clamp was applied just distal to the innominate artery. RESULTS: LFCP was maintained at 0.6 +/- 0.2 L x min(-1) x m(-2) for 41.0 +/- 13.9 minutes at 18.5 degrees C +/- 1.1 degrees C. In 10 of the 18 patients, blood pressure during LFCP was 15 +/- 8 mm Hg remote from the innominate artery (left radial, umbilical or femoral arteries). In 8 of the 18 patients, right radial pressure during LFCP was 24 +/- 10 mm Hg. The mean mixed-venous saturation was 79.8% +/- 10% during LFCP. Two patients had preoperative seizures, whereas none had seizures postoperatively. One patient died. CONCLUSIONS: Neonatal aortic arch reconstruction is possible without circulatory arrest or direct arch vessel cannulation. These techniques maintained adequate mixed-venous oxygen saturations with no associated adverse neurologic outcomes.     

Branch renal artery repair with cold perfusion protection

PURPOSE: This retrospective review describes the use and clinical outcome of cold perfusion protection during branch renal artery (RA) repair in 77 consecutive patients. METHODS: From July 1987 through November 2006, 874 patients had open operative RA repair to 1312 kidneys. Seventy-seven patients (62 women, 15 men; mean age, 44 +/- 17 years) had branch RA reconstruction using ex vivo or in situ cold perfusion protection for 78 kidneys. Demographic data and surgical technique were examined. Blood pressure response and renal function were estimated. Patency of repair was determined by angiography and renal duplex ultrasound (RDUS) imaging. Primary RA patency was estimated by life-table methods. RESULTS: Seventy-eight RAs were repaired using ex vivo (49 kidneys) or in situ (29 kidneys) cold perfusion protection. Bilateral RA repair was performed in eight patients, with 13 repairs to solitary kidneys. RA disease included aneurysm (RAA) in 50, fibromuscular dysplasia (FMD) in 37, atherosclerosis in 5, and arteritis in 2; 16 patients had both FMD and RAA. Hypertension was present in 93.5% (mean blood pressure, 184 +/- 35/107 +/- 19 mm Hg; mean of 1.9 +/- 1.1 drugs). RA repair included bypass using saphenous vein in 69, hypogastric artery in 3, polytetrafluoroethylene (PTFE) in 2, composite vein/PTFE in 2, cephalic vein in 1, or aneurysmorrhaphy in 1. The eight bilateral RA repairs were staged. One patient required bilateral cold perfusion protection. One planned nephrectomy was performed at the time of contralateral ex vivo reconstruction. No primary nephrectomies were required for intended reconstruction. Each RA reconstruction required branch dissection and reconstruction (mean of 2.8 +/- 1.6 branches were repaired). Mean cold ischemia time was 125 +/- 40 minutes. Each kidney was reconstructed in an orthotopic fashion. Five early failures of repair required three nephrectomies and one operative revision. Based on postoperative angiography or RDUS, or both, primary patency of RA repair at 12 months was 85% +/- 5%; assisted primary patency was 93% +/- 4%. Among patients with preoperative hypertension, 15% were cured, 65% were improved, and 20% were considered failed. Early renal function was improved in 35%, unchanged in 48%, and worse in 17%. Four patients had perioperative acute tubular necrosis. No patient progressed to dialysis-dependence. CONCLUSION: Both ex vivo and in situ cold perfusion protection extend the safe renal ischemia time for complex branch RA repair and avoid the need for nephrectomy.     

Long-term results of arterial allograft below-knee bypass grafts for limb salvage: a retrospective multicenter study

PURPOSE: Arterial allografts (AAs) have been recently reconsidered in the treatment of critical limb ischemia when vein material is absent, because of the disappointing results with artificial grafts. The aim of this study was to report the results observed in three centers where AAs were used for infrainguinal reconstruction in limb-threatening ischemia. METHODS: Between 1991 and 1997, 165 AA bypass procedures were performed in 148 patients (male, 90) with a mean age of 70 years (range, 20-93 years). Indications for operation were rest pain in 54 cases and tissue loss in 111 cases. Mean resting ankle pressure was 53 mm Hg in 96 patients who did not have diabetes and mean transcutaneous pressure of oxygen was 10 mm Hg in 52 patients who did have diabetes. In 123 cases (75%), there was at least one previous revascularization on the same limb. AAs were obtained from cadaveric donors. The distal anastomosis was to the below-knee popliteal artery in 34 cases, to a tibial artery in 114 cases, and to a pedal artery in 17 cases. RESULTS: At 30 days, the mortality rate was 3.4%; the primary patency rate was 83.3%; the secondary patency rate was 90%; and the limb salvage rate was 98%. During follow-up (mean, 31 months), 65 grafts failed primarily. Causes of primary failure were thought to be progression of the distal disease in 15 cases, myointimal hyperplasia in 16 cases, graft degradation in 10 cases (four dilations, three stenoses, two ruptures, and one dissection), miscellaneous in eight cases, and not known in 16 cases. Primary patency rates at 1, 3, and 5 years were, respectively, 48.7% +/- 4%, 34.9% +/- 6%, and 16.1% +/- 7%. Secondary patency rates at 1, 3, and 5 years were, respectively, 59. 8% +/- 4%, 42.1% +/- 5%, and 25.9% +/- 8%. Limb salvage rates at 1, 3, and 5 years were, respectively, 83.8% +/- 3%, 76.4% +/- 5%, and 74.2 % +/- 8%. CONCLUSION: AA leads to an acceptable limb salvage rate but poor patency rates. A randomized trial that will compare AAs and polytetrafluoroethylene should be undertaken.     

Endovascular revascularization of renal artery stenosis: technical and clinical results

PURPOSE: The natural history of renal artery stenosis is progression with subsequent deterioration of kidney function and development of renovascular hypertension. Percutaneous transluminal renal angioplasty is effective in the treatment of nonostial lesions but less effective for ostial stenoses. Because of the poor technical success experienced with percutaneous transluminal renal angioplasty, stenting of ostial stenoses is becoming the standard of endovascular care. In this retrospective study we analyzed the technical and clinical outcomes after renal artery stenting in 73 consecutive patients. PATIENTS AND METHODS: From July 1992 to January 1999, 88 Palmaz stents were deployed in 85 renal artery stenoses in 73 patients, with a mean age of 67.9 +/- 9.4 years. Twelve patients (16%) underwent bilateral stent placement. Atheromatous lesions were the most prevalent (99%: 82% ostial, 16% nonostial). Most stents were implanted for suboptimal balloon dilation (52%) or dissection (24%). Mean percent stenosis was 86% +/- 12%. Renal insufficiency (creatinine level > or = 1.5 mg/dL) was present in 50 (68%) patients, and uncontrolled hypertension (systolic > or = 160 mm Hg or diastolic > or = 90 mm Hg with more than two medications) was present in 57 (78%). RESULTS: Primary technical success was achieved in 89%. At the initial procedure, three additional stents were placed for residual stenoses, and urokinase was used to treat one intraprocedural stent thrombosis, resulting in an assisted primary technical success rate of 94%. Major complications occurred in 9.1% of stents placed: access artery thrombosis (n = 4), renal artery extravasation (n = 1), renal artery thrombosis (n = 1), and hematoma requiring operation (n = 2). Long-term clinical data were available on 69 (95%) patients at 20 +/- 17 months. Overall, a significant decrease in systolic and diastolic pressures (P <.001) and reduction of medication (P <.01) were noted without a change in renal function (P = NS). Angiography was performed on 22 patients at 11.3 +/- 10.3 months for persistent or worsening renal function or hypertension or for other reasons; 10 patients had significant restenoses in 14 renal arteries. CONCLUSION: Our retrospective analysis demonstrates that endovascular stenting of renal artery stenosis in patients with poorly controlled hypertension or deteriorating renal function is a safe and effective alternative treatment to surgical management.     

Effects of renal arterial endothelin-1 and endogenous endothelins on regional kidney blood flow and renal antihypertensive mechanisms in anesthetized rabbits

To determine how endothelins affect regional kidney blood flow and responses to increased renal artery pressure (RAP), an extracorporeal circuit was established to control RAP independent of the mean systemic arterial pressure (MAP). RAP was first set at approximately 65 mm Hg, and endothelin-1 (1 ng/kg/min for 30 min then 0.4 ng/kg/min) or vehicle was infused into the renal artery, or the ET(A)/ET(B) antagonist TAK-044 (3 mg/kg plus 3 mg/kg/h) or vehicle was administered intravenously. RAP was then progressively increased in steps from approximately 65 to approximately 160 mm Hg. When RAP was approximately 65 mm Hg, endothelin-1 increased renal vascular resistance (RVR, 72%), and reduced cortical (CBF, 26%) but not medullary blood flow (MBF). TAK-044 reduced MAP (12%) and RVR (15%) and increased CBF (21%) but not MBF. When RAP was increased, renal blood flow (RBF), glomerular filtration rate, and urine and sodium excretion increased, while MAP fell. These responses were unaffected by endothelin-1. TAK-044 potentiated the increases in RBF and reductions in MAP in response to increased RAP, but did not affect urine and sodium excretion. Plasma renin activity was reduced by endothelin-1 and increased by TAK-044. Thus, both exogenous and endogenous endothelins reduce CBF but not MBF, and reduce plasma renin activity, but neither affect pressure natriuresis.     

Preoperative estimation of run off in patients with multiple level arterial obstructions as a guide to partial reconstructive surgery.

Preoperative measurements of direct femoral artery systolic pressure, indirect ankle systolic pressure and direct brachial artery systolic pressure were carried out in nine patients with severe ischemia and arterial occlusions both proximal and distal to the ingvinal ligament. The pressure-rise at the ankle was estimated preoperatively by assuming that the ankle pressure would rise in proportion to the rise in femoral artery pressure. Thus it was predicted that reconstruction of the iliac obstruction with aorta-femoral pressure gradients from 44 to 96 mm Hg would result in a rise in ankle pressure of 16--54 mm Hg. The actual rise in ankle pressure one month after reconstruction of the iliac arteries ranged from 10 to 46 mm Hg and was well correlated to the preoperative estimations. In conclusion, by proper pressure measurements the run-off problem of multiple level arterial occlusions can be evaluated. Thus the result of successful partial reconstruction can be assessed preoperatively.     

Extracorporeal membrane oxygenation during bronchopulmonary lavage.

Extracorporeal membrane oxygenation (ECMO) in a venoarterial perfusion circuit was used to provide support of gas exchange during bronchopulmonary lavage in a 32-year-old man with pulmonary alveolar proteinosis and severe arterial hypoxemia. Prior to the lavage, Pao2 during mechanical ventilation with 100% oxygen and positive end-expiratory pressure was only 125 mm Hg. Extracorporeal perfusion at a flow rate of 3 liters/min, with oxygen delivery of 244 ml/min, increased the Pao2 to 227 mmHg and lowered the mean pulmonary artery pressure from 28 to 24 mm Hg. During bronchopulmonary lavage and ECMO, the Pao2 ranged between 46 and 96 mm Hg. After the procedure, pulmonary performance decidely improved. By reducing the chances of fatal hypoxemia, ECMO allowed treatment to be instituted for this potentially reversible disorder and proved helpful as a form of support during the management of pulmonary alveolar proteinosis when severe hypoxemia may have other wise precluded bronchopulmonary lavage.