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Biomedical subjects

R H Dean

Publications and source records attributed to R H Dean.

At least 73 records · Page 4Linked to original sources
PubMed1984

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

From March 1960 through January 1968, 71 patients underwent operations for renovascular hypertension at our center. There were three operative deaths in 94 procedures. Primary nephrectomy was performed in 26 patients. Attempted revascularization of 62 kidneys was successful in 46 (74%). In 13 (87%) of the 15 cases considered operative failures, the patients underwent either secondary nephrectomy (11) or repeat revascularization (two). Based on the results of the final operation, initial blood pressure response (1 to 6 months postoperatively) in the surviving patients indicated 44% cured (30 patients), 40% improved (27), and 16% unchanged (11). The sequential clinical, functional, and anatomic follow-up evaluations to time of death or to date are available in 66 of the 68 patients (97%) who survived operation and form the basis of this report. Fifteen- to 20-year arteriographic follow-up in 16 patients revealed one late neointimal anastomotic stenosis and an additional three aortic suture line false aneurysms in Dacron aortorenal grafts. During this 15- to 23-year follow-up, 71% of atherosclerotic (AS) patients and 23% of fibromuscular dysplasia (FMD) patients died. Cardiovascular (CV) morbid events occurred in 77% of AS patients and in 19% of FMD patients. The cumulative incidence of death and CV morbid events during follow-up is examined by Kaplan-Meier life tables and Cox's proportional hazards regression analysis in these respective groups to identify preoperative markers predictive of longer event-free survival in relation to blood pressure benefit by operation (for example, focal vs. diffuse AS, presence of cerebrovascular disease, ischemic heart disease, left ventricular hypertrophy seen by electrocardiography, azotemia, smoking, diabetes, and hyperlipidemia).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Suprarenal vena caval occlusion. Principles of operative management.

Retrohepatic occlusion of the inferior vena cava caused by tumor complicates complete resection and not infrequently is associated with life-threatening symptoms that accelerate the lethality of the underlying malignant process. This report summarizes our experience with caval thrombectomy and reconstruction that allowed complete removal of all gross tumor in seven patients with malignant occlusion of the retrohepatic inferior vena cava. Included in this group are five patients with renal cell carcinoma and extension of tumor into the retrohepatic vena cava. Three of these patients had extension of tumor thrombus into the right atrium. A sixth patient had recurrent right adrenal cortical carcinoma with tumor invasion of the vena cava and occlusion to the right atrium. Associated hepatic vein occlusion and secondary Budd-Chiari syndrome also was successfully managed in this patient. The final patient with occlusion of the entire suprarenal vena cava required caval reconstruction after resection of a primary leiomyosarcoma of the retrohepatic portion of the vena cava. Careful planning of the operative procedure, adequate exposure, complete mobilization of the retrohepatic vena cava, and control of the hepatic venous effluent will allow patients with retrohepatic vena caval occlusions to be managed with safety and success.

Adenocarcinoma↗
PubMed1984

Renal artery dissection.

Renal artery dissections are stenotic or occlusive lesions most often observed in hypertensive patients with underlying atherosclerosis or fibromuscular disease. Acute dissections may present spontaneously, as a complication of diagnostic or therapeutic angiography or as an agonal event associated with overwhelming systemic illness. Chronic dissections may produce renovascular hypertension or be entirely asymptomatic. Fourteen renal artery dissections have been encountered in nine patients treated at Vanderbilt University Medical Center during the past decade. Eleven dissections have been found in seven patients with renovascular hypertension. Seven of these dissections were chronic (six functional, one silent) and four acute (two spontaneous, two secondary to angiography). Three agonal dissections were found in two additional patients postmortem: one at autopsy and bilateral dissections found at the time of cadaveric donor nephrectomy. Ten bypass procedures, including five complex branch reconstructions of which three were performed ex vivo, have been performed with 100% immediate patency and maintenance or improvement of renal function. Long-term follow-up of these patients has shown sustained patency of the reconstructed renal arteries, excellent blood pressure control, and normal renal function in all. Nephrectomy has not been required and there have been no associated deaths. Seventy-seven additional renal artery dissections in 72 patients collected from previous reports have been analyzed. Patient survival (55/72, 76.4%) and preservation of the involved kidney in surviving patients (26/55, 47.3%) were low in these earlier series. In addition, renal failure was associated with 59% of the deaths. The lethality of renal artery dissections and the ease and success of revascularization, which preserves renal function and ameliorates associated renovascular hypertension, emphasize the need for an aggressive approach to the recognition and treatment of this entity. Therapy should be directed toward arterial reconstructions and the preservation of functioning renal tissue.

Adult↗
PubMed1984

Aortic and renal vascular disease. Factors affecting the value of combined procedures.

Assessment of the predictive value of preoperative factors in the determination of operative risk in 50 patients who underwent simultaneous aortic and renovascular procedures over a 10-year period is reported. There were six operative mortalities (12%). Factors associated with increased mortal risk were azotemia (43% vs. 7%), associated complex renal or visceral procedures (31% vs. 5%), treatment of aortic aneurysm vs. occlusive disease (17% vs. 5%), positive EKG (19% vs. 4%), age over 60 years (20% vs. 4%), and a history of diffuse peripheral vascular disease (18% vs. 7%). None of these differences, by themselves, had statistical significance. Through discriminate analysis with assignment of weighted scores to the five most powerful predictors of operative death (complex procedure--4, azotemia--4, aortic aneurysm repair--3, positive electrocardiogram--2, history of diffuse vascular disease--2), a weighted score of greater than or equal to 10 predicted operative death with an 83% sensitivity and 93% specificity (p = 0.003). Although advanced age, diabetes, severity of hypertension, and history of heart disease were associated with increased operative risk, they contributed minimal discriminate value to that provided by the preceding five variables. This was because these weaker risk factors were usually found in association with the predictors in the discriminant score. This study suggests that in patients with high weighted discriminant scores (greater than or equal to 10), consideration of operative risk is particularly important in evaluation of the proposed value of combined procedures.

Adult↗
PubMed1984

Late results of aortorenal bypass.

Much of the controversy about operative intervention for renovascular hypertension stems from reports that show a low rate of blood pressure benefit, a high technical failure rate of revascularization, or a high operative risk. Current results in centers having a large operative experience with the management of renovascular hypertension, however, demonstrate the practical value of aortorenal bypass. At Vanderbilt University, sequential angiographic study demonstrates that most bypass grafts (88 per cent) remain stable, with no adverse changes during long-term follow-up. Similarly, comparison of initial blood pressure response to blood pressure status after 15 to 20 years shows that the benefit of aortorenal bypass is maintained.

Adolescent↗
PubMed1983

Pseudotumor of the pancreas.

A 29-year-old black woman had a peculiar variety of chronic pancreatitis that initially presented as a solid, discrete mass in the head of the pancreas. It mimicked carcinoma and exemplifies the diagnostic and therapeutic dilemma produced by such "pseudotumors" of the pancreas.

Adult↗
PubMed1983

Histoplasma infection of abdominal aortic aneurysms.

Fungal endarteritis resulting from progressive disseminated histoplasmosis may cause arterial aneurysms, or lead to infection of pre-existing aneurysms. Three patients with Histoplasma capsulatum infections of abdominal aortic aneurysms are reported. All had previous disseminated histoplasmosis and atherosclerotic peripheral vascular disease. All were considered cured of systemic infection when their aneurysms were discovered. Atherosclerotic vascular lesions may become infected during the course of systemic fungal disease and may serve as a haven for viable organisms in patients whose dissemination recurs despite seemingly adequate antifungal therapy. In treating these patients, resection of all infected arterial tissue, revascularization through uninfected tissues, and long-term antimicrobial therapy are recommended.

Adult↗
PubMed1982

Obturator foramen grafts: the preferable alternate route?

Although the femoral canal is the standard entrance route for vascular grafts to the lower extremity, several situations may arise that preclude the use of this route. In these circumstances an alternate pathway for revascularization is required. Experience in our center with the use of obturator foramen grafts for revascularization of nine limbs in eight patients is reported and underscores the value of this pathway as an alternative route for limb revascularization. The obturator foramen was employed to circumvent an infected arterial prosthesis at the groin level in seven patients (eight limbs) from 12 days to 4.5 years after the initial vascular procedure. The organisms responsible for graft infection included Staphylococcus aureus, Enterobacter cloacae, and Bacteroides fragilis. The final patient required iliac to superficial femoral artery bypass via the obturator foramen to manage occlusion and autolysis of the femoral artery by a mycotic embolus containing beta-hemolytic Streptococcus. Graft material used for these remedial procedures, included saphenous vein (three), Gore-Tex (three), and Dacron (three). Revascularization was satisfactory in each case. Each groin infection healed. Two patients died of unrelated causes at 1.5 and 5 months after operation. The seven remaining grafts at risk (six patients) remained patent 12 months in each case. Four grafts were doing well at 18, 36, 50, and 52 months. Three grafts failed at 13, 19, and 28 months; one was revised successfully, one was re-done and failed again. Obturator foramen bypass grafting provides satisfactory and durable revascularization when an alternate route to the lower extremity is required.

Adult↗
PubMed1982

Surgical experience with retrogastric and retropancreatic pheochromocytomas.

From 1972 to 1981 at Vanderbilt University Hospital there were seven patients with midline retrogastric or retropancreatic pheochromocytomas. Each of these tumors arose between the aorta and the inferior vena cava. This report details the difficulties in localization before and at operation in the smaller tumors in these sites. Our experience suggests that small midline pheochromocytomas in these sites may be readily missed by computerized tomographic scan, aortography, or surgical search at laparotomy unless subtraction arteriograms are used and the Kocher maneuver is employed at operation routinely.

Adolescent↗
PubMed1981

Renovascular hypertension: anatomic and renal function changes during drug therapy.

Serial renal function studies were performed on 41 patients wtih renovascular hypertension (RVH) secondary to atherosclerotic renal artery disease who had been randomly selected for nonoperative management. In 19 patients, serum creatinine levels increased between 25% and 120%. The glomerular filtration rates dropped between 25% and 50% in 12 patients. Fourteen patients (37%) lost more than 10% of renal length. In four patients (12%), a significant stenosis progressed to total occlusion. Seventeen patients (41%) had deterioration of renal function or loss of renal size that led to operation. One patient required removal of a previously reconstructible kidney. Of the 17 patients with deterioration, 15 had acceptable blood pressure (BP) control during the period of nonoperative observation. Progressive deterioration of renal function in nonoperatively treated patients with atherosclerotic renal artery stenosis and RVH is common, and occurs even in the presence of BP control with drugs.

Adult↗
PubMed1980

The role of vagotomy in pancreaticoduodenectomy.

In a series of 41 pancreatoduodenectomies the Whipple procedure was done in 27 patients and total pancreatoduodenectomy in 14 others with two postoperative deaths. Among 39 survivors, seven developed evidence of stomal ulcer 20 days to six years after operation; details of their courses are summarized. Proven stomal ulcer occurred in five of 14 patients who did not have concomitant vagotomy with pancreatoduodenectomy (36%). Each of these required vagotomy secondarily in management. When two patients with hematemesis in whom stomal ulcer was suspected but not proven are included, the incidence of stomal ulcer in nonvagotomized patients with pancreatoduodenectomy (7/14) is 50%. There were no stomal ulcers in patients with pancreatoduodenectomy who had concomitant vagotomy (0/25). It is logical to add the protective effects of vagotomy to pancreatoduodenectomy, especially when the disease process favors prolonged survival.

Adenocarcinoma↗
PubMed1980

Resection of abdominal aortic aneurysms in the over-80 age group.

We reviewed the risk of resecting an abdominal aortic aneurysm in 38 patients aged 80 years or older. The operative mortality for an elective aneurysm was 5.2%, for symptomatic but nonruptured aneurysm 26.6%, and for ruptured aneurysm 66.7%. The preoperative risk factors were essentially the same for the elective and ruptured group. Several of the patients with ruptured aneurysm had been followed up with their aneurysm for several years by nonsurgeons. To better understand why these patients were not being referred for elective repair, 100 nonsurgeons were sent a questionnaire concerning abdominal aortic aneurysms in octogenarians. The results showed that 81% overestimated the elective operative mortality and as a result did not recommend elective resection.

Aged↗
PubMed1980

[Surgical treatment of renovascular hypertension: results of operation in 400 patients with renal artery stenosis (author's transl)].

A report is given on patients treated surgically for renal artery stenosis (RAS) and renovascular hypertension. High-quality arteriograms, as well as renal vein (RVR) determination and split-function studies (SFS) are the most important preoperative diagnostic procedures. Since only 40% of the patients with renal artery stenosis have renovascular hypertension, the value of RVR and SFS for diagnosis, indication and prognosis in surgical cases is stressed. Unilateral RAS patients show a 50% cure rate with regard to arteriosclerosis (AS) and 74% in fibromuscular displasia (FD). Improvement following surgery was recorded in 92% and 96% of cases, respectively. Bilateral reconstructions are preferably done as staged procedures. Simultaneous repair results in a higher postoperative thrombosis rate, as well as being a significant risk to both kidneys; only 50% of patients really do need surgical treatment of the contralateral kidney. Patients older than 50 years became normotensive in 36% of cases, 86% showed improvement and 13% no benefit from operation; the mortality rate was 1.3% in patients over 50. Cases with a severe reduction in kidney function (less than 30 ml/min/kidney creatinine clearance) showed a significant increase in creatinine clearance with a 90% improvement in and 36% cure of hypertension, after reconstruction. 50% of totally occluded renal arteries could be revascularized via an appropriate distal vessel; the cure rate in this group was 55%. A higher incidence of renovascular hypertension is seen in patients under the age of 20. 68% of this group became normotensive, whilst only 8% did not show any benefit from surgery. Combined diagnostic procedures to evaluate morphology and functional status of the kidney, as well as the indications for and prognosis of surgery are emphasized; a more refined technical approach to RAS revascularisation is described.

Adolescent↗
PubMed1979

Coarctation of the abdominal aorta: pathophysiologic and therapeutic considerations.

Coarctation of the aorta is the most frequent cause of hypertension in infants and children. Ninety-eight per cent of coarctations occur in the descending aorta near the ligamentum arteriosus. Five patients are presented with the relatively rare problem of coarctation of the abdominal aorta. The anatomic,pathophysiologic and clinical aspects in these patients cover a range of variants. Clinical and laboratory studies of the genesis of hypertension in coarctation are reviewed in chronologic outline. An experimental model of abdominal coarctation with hypertensive and renin-angiotensin II correlations suggests but does not prove a renal mechanism for the hypertension. The same conclusion must be drawn from study of the clinical cases.

Adolescent↗