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K J Hansen

Publications and source records attributed to K J Hansen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Infected renal artery pseudoaneurysm and mycotic aortic aneurysm after percutaneous transluminal renal artery angioplasty and stent placement in a patient with a solitary kidney.

Endovascular infections after percutaneous transluminal renal angioplasty with stenting (PTRAS) are rarely reported. Because strict longitudinal follow-up of patients undergoing PTRAS is lacking, the true incidence of such complications remains obscure. We report the first case of a patient with an infected renal artery pseudoaneurysm and de novo mycotic aortic aneurysm after PTRAS. This case serves to illustrate several important points, including (1) the retrieval of renal function in patients with renal artery occlusion, (2) the pathogenesis of infection after PTRAS, (3) the diagnosis and management of endovascular infection after percutaneous vascular intervention, and (4) recommendations for periprocedural antibiotic prophylaxis during PTRAS.

Aged↗
PubMed1998

Renovascular disease in blacks: prevalence and result of operative management. Consortium of Southeastern Hypertension Control.

Hypertension in blacks differs in a quantitative sense from hypertension in whites; it occurs in blacks with greater frequency and severity and at a younger age when compared with whites. In addition, elevated blood pressure at any level is associated with increased cardiovascular morbidity and mortality in black patients. Several mechanisms have been suggested to account for this form of hypertension, implying that hypertension in black patients is intrinsically different from that in whites. Although these mechanisms remain unproven, it has generally been accepted that correctable renovascular disease and renovascular hypertension (RVH) occur infrequently in blacks; the authors, however, will review preliminary population-based data which suggest that the presence of renal artery disease is not determined by race or ethnicity. In addition, the prevalence of renovascular disease in a large group of consecutive hypertensive subjects will be presented. Finally, the blood pressure and renal function response after surgical renal artery repair in blacks will be compared with whites treated at the authors' institution. Taken collectively, these data and clinical experience support the search for and treatment of renal artery disease in properly selected hypertensive blacks.

Adult↗
PubMed1998

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.

Adult↗
PubMed1997

Transaortic mesenteric endarterectomy.

Although a number of methods for mesenteric artery reconstruction have been suggested, we believe that patients with atherosclerotic stenosis and occlusion of mesenteric vessels presenting with either acute or chronic visceral ischemia are best managed by either antegrade aortomesenteric bypass or transaortic mesenteric endarterectomy. Antegrade bypass is the most versatile technique and is therefore best adapted to extensive mesenteric disease. Transaortic mesenteric endarterectomy lends itself well to simultaneous renal artery endarterectomy when clinically significant osteal atherosclerosis is present at both sites. With any method of reconstruction, the technical adequacy of repair should be defined intraoperatively. In this regard, intraoperative duplex sonography provides both anatomic and hemodynamic data necessary to ensure technical success and late patency.

Arterial Occlusive Diseases↗
PubMed1997

Renal artery repair in African-Americans.

PURPOSE: This retrospective review examines the results of atherosclerotic renal artery (RA) repair in consecutive hypertensive African-Americans treated at our center and compares these results with Caucasians treated during the same period. METHODS: From Jan. 1987 through Sep. 1996, a total of 485 patients underwent operative RA repair. Of these, 28 African-Americans and 370 Caucasians were managed for atherosclerotic renovascular disease. These cohorts were compared on the basis of preoperative blood pressure and renal function, extent of renal disease, extrarenal atherosclerosis, response to operation, and estimated survival. RESULTS: The African-American cohort included nine men and 19 women (mean age, 62 years) with hypertension (mean blood pressure, 204 +/- 31/109 +/- 20 mm Hg) for an average of 10.2 +/- 7.5 years. Ischemic nephropathy (serum creatinine level, > 1.3 mg/dl) was present in 82% (n = 23) of the African-American group. RA reconstructions were unilateral in nine patients and bilateral in 19 patients (including repair to two solitary kidneys), for a total of 45 RA reconstructions (30 RA bypass procedures; eight transrenal/transaortic RA endarterectomy procedures; two RA reimplantations; five nephrectomies). Nine patients underwent combined aortic procedures (four abdominal aortic aneurysm; five occlusive disease). There was one perioperative death in the African-American group as a result of sepsis and multiple organ failure. Among surgical survivors, 20 African-American patients (74%) had a beneficial hypertension response (7% cured, 67% improved). Mean estimated glomerular filtration rate improved significantly from 34 to 42 ml/min/1.73 m2 (p < 0.001). In the 23 patients with ischemic nephropathy, 13 (57%) demonstrated greater than 20% decrease in serum creatinine level. In comparison with the 370 Caucasians (191 men, 179 women), the African-American cohort had significantly more preoperative heart disease (congestive heart failure or left ventricular hypertrophy; 68% vs 46%; p = 0.03) and tended toward more severe renal dysfunction (mean serum creatinine level, 2.5 vs 2.1 mg/dl; p = 0.25). However, African-Americans demonstrated a beneficial blood pressure and renal function response after operation, similar to Caucasians. CONCLUSIONS: Our results indicate that the majority of selected African-Americans have a favorable blood pressure and renal function response to operative renal artery repair. This beneficial clinical response appears equivalent to the response observed in Caucasian patients and supports the search for RA disease in hypertensive African-Americans.

Adult↗
PubMed1996

Is renal revascularization in diabetic patients worthwhile?

PURPOSE: This retrospective review describes surgical management of atherosclerotic renovascular disease (RVD) in hypertensive adults with diabetes mellitus. METHODS: From July 1987 through July 1995, 54 consecutive hypertensive diabetics (mean 213/103 mm Hg; mean medications three drugs) requiring either insulin (16 patients) or oral hypoglycemic therapy (38 patients) had operative repair of atherosclerotic RVD. Renal dysfunction (serum creatinine [SCr] > or = 1.3 mg/dl) was present in 82% of patients (mean SCr 2.4 mg/dl). Associations between blood pressure and renal function response to operation and preoperative parameters were examined. Clinical characteristics, response to operation, and dialysis-free survival were compared with those of 291 nondiabetic patients. RESULTS: Four (7.4%) operative deaths occurred. Among 50 survivors blood pressure response was considered cured or improved in 72% and unchanged in 28%. Of 42 patients with renal dysfunction 40% had improved function including three patients removed from dialysis. No preoperative parameter examined demonstrated a significant association with blood pressure or renal function response. During follow-up 10 additional patient deaths occurred, and eight patients progressed to dialysis dependence. Time to death or dialysis was associated with preoperative estimates of glomerular filtration (p = 0.03) and the change in estimates of glomerular filtration after operation (p = 0.01). Compared with 291 nondiabetics, the diabetic group had no statistical difference in improved function response (40% vs 51%, p = 0.21); however, diabetics had a significantly lower rate of beneficial blood pressure response (72% vs 89%, p = 0.01) and an increased risk of dialysis or death during follow-up (p = 0.02). By multivariate analysis independent predictors of time to death or dialysis included the presence of diabetes mellitus, patient age, history of congestive heart failure, and increased serum creatinine. CONCLUSIONS: Most of the selected diabetic patients had a beneficial blood pressure response after undergoing operative repair of atherosclerotic RVD, albeit at a lower rate compared with nondiabetics. In diabetics poor renal function before and after operation was associated with progression to dialysis and death. Improved renal function after operation was associated with improved survival; however, function response to renal revascularization was difficult to predict.

Aged↗
PubMed1996

Combined aortic and renal artery surgery. A contemporary experience.

PURPOSE: This retrospective study examines results with simultaneous aortic and renal artery repair in 133 consecutive hypertensive patients. These results are compared with consecutive patient groups undergoing aortic reconstruction alone (269 patients) or renal artery reconstruction alone (182 patients). METHODS: From January 1987 through July 1995, 61 women and 72 men (mean age, 62.5 years) underwent combined repair of renal artery and aortic disease (abdominal aortic aneurysm [AAA]: 47 patients; occlusive disease: 86 patients; both: 12 patients). All patients were hypertensive (mean blood pressure: 194/103 mmHg; mean medications: 2.4). Evidenced by serum creatinine levels > or = 2.0 mg/dL, 46 patients (35%) had significant renal dysfunction (mean serum creatinine level: 3.78 mg/dL; range 2.0-10.6 mg/dL, including 7 dialysis-dependent patients). Aortic replacements (29% tube grafts; 71% bifurcated grafts) were combined with unilateral renal artery repair in 47% of patients; 53% had bilateral repair. Preoperative clinical features and perioperative mortality were compared with those groups having isolated aortic and renal repairs. RESULTS: There were seven perioperative deaths (5.3%) after combined repair, which differed significantly from isolated aortic repair (mortality: 0.74%; p = 0.005), but did not reach statistical significance when compared with the isolated renal artery group (mortality: 1.65%; p = 0.145). Risk analysis did not reveal a significant association between preoperative clinical features and mortality in either the combined repair group or the groups undergoing renal repair alone or aortic repair alone. Among survivors in the combined group, a favorable hypertension response was observed in 63%. This differed significantly from the group receiving renal repair alone (90% cured/improved; p < 0.001). Based on a 20% decrease in serum creatinine levels, excretory renal function was improved in 33% of patients with combined repair, including four of the seven patients removed from hemodialysis. There were eight late deaths in the combined group. CONCLUSIONS: Our experience suggest that contemporary perioperative mortality for combined aortic and renal repair has improved compared with earlier reports; however, perioperative mortality for simultaneous reconstruction remains greater than repair of aortic disease alone. Moreover, a lower rate of favorable hypertension response was observed after combined correction compared with renal artery repair alone. These differences suggest that aortic and renal artery repair should only be combined for clinical indications rather than for prophylactic repair of clinically silent disease.

Adult↗
PubMed1995

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.

Adult↗
PubMed1995

Surgical management of dialysis-dependent ischemic nephropathy.

PURPOSE: This retrospective review describes surgical management of dialysis-dependent ischemic nephropathy. METHODS: From February 1987 through September 1993, 340 patients underwent operative renal artery (RA) reconstruction at our center. A subgroup of 20 patients (6 women; 14 men; mean age 66 years) dependent on hemodialysis immediately before RA repair form the basis of this report. Glomerular filtration rates (EGFR) were estimated from at least three serum creatinine measurements obtained 26 weeks before and after operation. A linear regression model was used to estimate the mean rate of change of EGFR before and after RA repair. Comparative analysis of kidney status and change in EGFR were performed. The influence of function response on follow-up survival was determined by the product-limit method. RESULTS: Hemodialysis was discontinued in 16 of 20 patients (80%). For these 16 patients, postoperative EGFR ranged from 9.0 to 56.1 ml/min/1.73 m2 (mean 32.4 ml/min/1.73 m2). Two of 16 patients resumed hemodialysis 4 and 6 months after surgery. Discontinuation of dialysis was more likely after bilateral or complete RA repair (15 of 16 patients) versus unilateral repair (one of four patients; p = 0.01). Permanent discontinuation of dialysis was associated with a rapid preoperative rate of decline in EGFR (mean slope log(e) EGFR: -0.1393 +/- 0.0340 without dialysis; -0.0188 +/- 0.0464 with dialysis; p = 0.04, but NS after controlling for multiple comparisons). Immediate increase in EGFR after operation was inversely correlated with the severity of nephrosclerosis (rank correlation: -0.57; 95% confidence interval [-0.83, -0.10]). Follow-up death was associated with dialysis dependence; two deaths occurred among 14 patients not receiving dialysis, whereas five of six patients dependent on dialysis died (p < 0.01). CONCLUSION: Surgical correction of ischemic nephropathy can retrieve renal function in selected patients dependent on dialysis characterized by a rapid decline in preoperative EGFR in combination with global renal ischemia treated by complete or bilateral renal revascularization. After RA repair, discontinuation of dialysis may be associated with improved survival rates when compared with continued dialysis dependence.

Aged↗
PubMed1995

Renovascular disease in older patients beginning renal replacement therapy.

Renovascular disease (RVD) in older patients can cause progressive renal insufficiency and even end-stage renal disease (ESRD). The frequency of this clinical problem is not well defined. Renal duplex sonography (RDS) correctly identifies the presence of RVD with an overall accuracy of approximately 95%. Therefore, the purpose of this study was to utilize RDS as a noninvasive tool to identify the presence of critical RVD (> or = 60% diameter-reducing stenosis or occlusion) in patients 50 years of age or older beginning renal replacement therapy. A total of 53 consecutive participating patients were prospectively interrogated. Complete interrogations occurred in 45 of the 53 patients (85%), and 92 of the 103 kidneys (89%). Critical RVD was noted in 10 of 45 patients (22%). RVD was bilateral in 5 patients, unilateral in 5 patients, and there were 4 renal artery occlusions noted. All patients with critical RVD were white (10 of 25 white patients or 40%). Total pack years of smoking as well as associated cardiovascular and cerebrovascular conditions were greater in those patients with critical RVD compared to those without. These results indicate that RDS remains technically feasible as renal blood flow and function decline. Unsuspected RVD possibly contributory to renal insufficiency exists in a significant number of primarily white patients 50 years of age or older beginning renal replacement therapy. These patients are generally smokers with a high frequency of associated extrarenal atherosclerosis The addition of RVD as a separate category of disease causing ESRD would improve U.S. Renal Data System ESRD classification. RVD should be recognized as a cause of ESRD.

Aged↗
PubMed1994

Prevalence of ischemic nephropathy in the atherosclerotic population.

Available data fail to define the prevalence of ischemic nephropathy or the association of critical renovascular disease (RVD) with renal function in the atherosclerotic population. The data do suggest, however, that critical RVD is prevalent and that the prevalence increases with age, increasing serum creatinine and clinical atherosclerosis at extrarenal sites. Furthermore, our preliminary data suggest that critical RVD may be either the cause or an important superimposed accelerant of renal insufficiency in a larger portion of the atherosclerotic population with renal insufficiency than previously recognized. In this latter group, critical RVD as a cause of renal insufficiency appears to be rapidly progressive and may contribute to end-stage renal disease with increasing frequency. Conclusive definition of the importance of ischemic nephropathy as a contributor to progressive renal insufficiency and end-stage renal disease will require population-based studies that estimate the prevalence of ischemic nephropathy and the natural history of the disease. Presently, renal duplex sonography appears to be the screening test of choice to define critical RVD for such population-based studies.

Arteriosclerosis↗
PubMed1993

Renal duplex sonography after treatment of renovascular disease.

PURPOSE: To define the value of renal duplex sonography (RDS) to detect the presence of critical renal artery (RA) stenosis or occlusion after surgical repair or percutaneous transluminal balloon angioplasty (PTRA), we retrospectively reviewed our recent 71-month experience. METHODS: From January 1987 through November 1992, 272 patients underwent 279 operative RA repairs and 35 patients underwent PTRA. Three hundred twenty-five RDS examinations were performed in 176 patients after operative intervention or PTRA during the study period. Forty-one of these patients had conventional angiography providing 61 RA for RDS comparison, and these data form the basis of this analysis. Twenty-four women and 17 men (mean age 57 years) underwent 44 operative RA repairs or 17 PTRA for correction of atherosclerotic disease (51 arteries) or fibromuscular dysplasia (10 arteries). Before their renovascular procedure each patient had significant hypertension (mean 193/106 mm Hg). RDS after surgery or PTRA was technically complete for all 61 RA. RESULTS: Compared with angiography RDS correctly identified 47 of 48 repairs with less than 60% RA stenosis , 7 of 11 repairs with 60% to 99% stenosis, and 2 renal artery occlusions, providing a 69% sensitivity rate, 98% specificity rate, 90% positive predictive value, and a 92% negative predictive value. These results were adversely affected by branch RA disease, which accounted for three of four false-negative RDS study results. For 50 kidneys undergoing correction of main RA disease, RDS demonstrated an 89% sensitivity rate, 98% specificity rate, and 96% overall accuracy. RDS results were equivalent for both surgical and PTRA treatment. CONCLUSIONS: From this experience we conclude that RDS is useful for anatomic evaluation after surgical RA repair or PTRA. A negative RDS result excludes stenosis or occlusion of a main RA reconstruction but does not exclude significant branch level disease.

Adult↗
PubMed1993

Operative treatment of abdominal aortic aneurysms in octogenarians. When is it too much too late?

OBJECTIVE: This study evaluated the value of operation for treatment of all octogenarians with ruptured abdominal aortic aneurysms (AAA). SUMMARY BACKGROUND DATA: Elective AAA resection in octogenarians is safe, with published operative mortality rates of approximately 5%. Published operative mortality rates of ruptured AAA in this age group, however, vary from 27 to 92%. METHODS: To evaluate this question, we extracted the clinical course of the 34 octogenarians submitted to AAA resection by the authors from our total experience of 548 resections performed during the past 7 1/2 years. In this subgroup of octogenarians, 18 underwent elective AAA replacement, 5 were submitted to urgent resection of active but intact AAAs, and 11 had operations for ruptured AAAs. There were 23 males and 11 females in the group. The ages ranged from 80 to 91 years. RESULTS: Operative mortality in the patients managed electively was 5.6%. Two of the five patients (40%) submitted to operation for active yet unruptured aneurysms died in the preoperative period. Finally, 10 of the 11 patients (91%) with ruptured AAAs were operative mortalities. All of these operative mortalities in the ruptured AAA subgroup had severe hypotension preoperatively (mean systolic blood pressure: 23 mm Hg). The charges associated with the management of the ruptured AAA group averaged $84,486 (range $12,537-$199,233). CONCLUSIONS: Although elective replacement of AAA in properly selected octogenarians appears valuable to prolong worthwhile life expectancy, this experience leads us to consider observation only in the treatment of octogenarians with ruptured AAA who present with severe hemodynamic instability.

Age Factors↗
PubMed1993

Femoral catheters and deep venous thrombosis: a prospective evaluation with venous duplex sonography.

Femoral vein cannulation (FVC) with 8.5F Swan-Ganz catheter introducers allows expeditious intravenous access and rapid volume infusion; however, the incidence of associated iliofemoral deep venous thrombosis (DVT) is unknown. Trauma patients (n = 76) requiring unilateral FVC were prospectively entered into a study where they were resuscitated via FVC and serially evaluated with bilateral venous duplex sonography (VDS). The incidence of DVT in catheterized femoral veins was compared with that in uncatheterized femoral veins. Catheters were removed promptly and VDS was performed within 24 hours and weekly for 1 month. Iliofemoral DVTs were identified in 11 of the 76 patients (14%). Iliofemoral DVTs occurred on the cannulated side in 9 (81.8%) compared with 2 (18.2%) on the uncannulated side (p < 0.05). We conclude that the use of the 8.5F FVC is associated with an increased incidence of DVT and that despite its convenience, this technique should not be routine.

Adult↗
PubMed1992

Contemporary surgical management of renovascular disease.

To examine the treatment methods and early results of renovascular repair in our contemporary patient population, we reviewed our surgical experience during a recent 54-month period. From January 1987 to July 1991, 200 patients ranging in age from 5 to 80 years (mean, 56 years) were operated on for correction of nonatherosclerotic (43 patients) and atherosclerotic (157 patients) renovascular disease. The group included 92 men and 108 women, with blood pressures ranging from 300/198 mm Hg to 120/70 mm Hg (mean, 205/113 mm Hg). Defined by preoperative serum creatinine, 129 patients (65%) had evidence of renal insufficiency (Cr greater than or equal to 1.3 mg/dl), whereas 71 patients (36%) had severe renal insufficiency (Cr greater than 2.0 mg/dl; 11 patients were dependent on dialysis). One hundred forty-seven patients with atherosclerotic renovascular disease (94%) demonstrated organ-specific atherosclerotic damage. Operative management of 291 kidneys included unilateral renal artery repair in 117 patients (58%), bilateral repair in 78 patients (39%), and primary nephrectomy in five patients (2.5%). Simultaneous aortic reconstruction was required in 64 patients (32%). There were five operative deaths (2.5% mortality rate) and four occluded renovascular repairs (1.4% primary failure) within 30 days of surgery. Hypertension was considered cured in 21% and improved in 70% of 195 operative survivors. In 70 patients with severe renal insufficiency before operation, estimated glomerular filtration rate was improved in 49% (8 of 11 patients removed from dialysis), unchanged in 36%, and worsened in 15%. Renal function response was significantly influenced by the site of disease and the operation. Twenty-six additional postoperative deaths occurred during follow-up (range, 6 to 58 months; mean, 24.4 months). Extreme atherosclerotic-renovascular disease, preoperative renal insufficiency, failure to improve renal function, and progression to dependence on dialysis after operation were associated with follow-up deaths. Although most patients had a beneficial outcome, failure to improve extreme renal insufficiency was associated with a rapid rate of death during a relatively short follow-up period.

Adult↗