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Biomedical subjects

R H Dean

Publications and source records attributed to R H Dean.

At least 91 records · Page 5Linked to original sources
PubMed1979

Revascularization of the poorly functioning kidney.

The effect of renal vascularization on renal function in kidneys with poor preoperative excretory function is summarized in this report. Twenty-five patients with kidneys having preoperative creatinine clearance of less than 30 ml/min, as determined during split renal function studies (SRFS), which were revascularized for treatment of secondary renovascular hypertension and then were reevaluated by repeat SRFS form the basis of this report. There were 13 male and 12 female patients. The type of renal artery lesion was atherosclerotic in 21 patients and fibromuscular dysplastic in four patients. Eight individuals had total renal artery occlusion. Significant contralateral renal artery disease was present in 15 patients (60%). Preoperative creatinine clearances in the affected kidneys ranged from 0.27 ml/min (mean, 16 +/- 9 ml/min). after operation, creatinine clearances ranged from 0 to 72 ml/min (mean, 32 +/- 16 ml/mn). Fifteen of the 16 kidneys with preoperative creatinine clearances less than 20 ml/min had improvement in renal function following revascularization (P less than 0.01). Improvement (60%) or cure (36%) in hypertension followed revascularization in 24 of the 25 patients. The most dependable predictor of successful management of both hypertension and retrieval of renal function in these patients was the arteriographic demonstration of a patent distal vessel without evidence of severe intrarenal stenoses. These results support an aggressive attitude toward the use of revascularization in the operative treatment of such patients with renovascular hypertension, even when the residual excretory function is minimal or absent.

Adult↗
PubMed1978

Hypertension secondary to complete occlusion of the renal artery.

In summary, we feel the results of this study support an aggressive approach toward the diagnostic evaluation and operative management of patients with renovascular hypertension secondary to complete occlusion of the renal artery. Further, the frequent presence of contralateral disease and the progressive nature of renal artery occlusions represent a significant threat to renal function. Since renal function is frequently compromised but potentially retrievable by revascularization, nephrectomy should be employed only when hypertension is difficult to control, revascularization is impossible, and excretory function in the affected kidney is minimal.

Aged↗
PubMed1977

Surgical management of renovascular hypertension in older patients.

In hypertensive patients over 50 years of age, the high prevalence of renovascular hypertension (31 per cent), the low operative risk for its correction (1 to 2 per cent), and the frequency of benefit from operation (80 to 87 per cent) support an aggressive attitude toward screening and management. Diastolic hypertension greater than 105 mm Hg in the older patient warrants investigation. If such a patient has advanced atherosclerosis with evidence of significant cardiac disease or cerebrovascular disease, the indications for operative management of renovascular hypertension correlated with the severity of hypertension, difficulty of control, and imminence of renal function deterioration. If complicating risk factors are not severe, any patient with diastolic hypertension greater than 105 mm Hg is considered an appropriate operative candidate. In contrast, when risk factors are severe, operative management is undertaken only when hypertension is difficult to control or deterioration of renal function is thought to be secondary to the renal artery stenosis. In these patients the risk of operation is obviously greater and the long term benefits are more limited. Nevertheless, based on our experience, we feel the risk of poorly controlled hypertension or impending renal failure is even higher and justifies operative intervention. Hypertension accelerates the progress of atherosclerosis, and halting or slowing the unrelenting course of atherosclerosis is worthwhile objective if this can be done without unnecessary risk.

Female↗
PubMed1977

Morbid obesity: problems associated with operative management.

A review of the problems associated with extensive jejunoileal bypass for morbid obesity in a series of 175 carefully selected patients is presented. Five postoperative deaths occurred (3%). Nonfatal complications occurred in 21%, with wound infections (14 patients) being the most common. Good results marked by weight reduction to the range of ideal weight without significant electrolyte or metabolic aberrations was observed in 82% of the patients receiving the current dimensional modificatiom of end-to-end jejunoileal bypass (30 cm to 20cm). An additional 13% had fair results and only 5% had poor results. There were six deaths during follow-up: liver failure in four patients (secondary to alcohol abuse in two), myocardial infarction in one, and one from unknown causes. Bypass reversal was necessary for refractory liver failure in three patients (two from alcohol abuse), and for persistent diarrhea with secondary electrolyte depletion in two patients. One of these patients was complicated by severe emotional instability. This experience suggests that the majority of carefully selected patients will have a good response to jejunoileal bypass.

Adolescent↗
PubMed1977

Pancreaticoduodenal arterial aneurysms.

Experience with four aneurysms of the pancreaticoduodenal artery is reviewed and compared to the reported experience of 19 other cases. In view of the common presentation of such lesions as intra-abdominal hemorrhage preceded by non-specific abdominal pain and other digestive symptoms, it is suggested that angiography perfomed preoperatively or intraoperatively allows definitive diagnosis and leads to specific therapy.

Aged↗
PubMed1977

Expanded polytetrafluoroethylene as dialysis access grafts: serial study of histology and fibrinolytic activity.

Expanded polytetrafluoroethylene (Gore-Tex) grafts were evaluated as hemodialysis access shunts. A serial study of cellular ingrowth and endothelialization was performed. The development of fibrinolytic activator was sequentially monitored and shown to be consistently higher in the Gore-Tex grafts than in either knitted or woven Dacron prostheses. Functional assessment by repeated needle puncture demonstrated that PTFE grafts were durable, had uniform patency (6 mm ID size) and showed no evidence of degeneration during the time limit of this study. Although these are favorable characteristics, further long-term evaluation of PTFE grafts is necessary before its role as a vascular prosthesis applicable to clinical practice, can be established.

Animals↗
PubMed1977

Bilateral renal artery stenosis and renovascular hypertension.

Experience with the diagnostic evaluation and operative management of 38 hypertensive patients having bilateral renal revascularization is presented. Twenty-four patients had atherosclerotic occlusions and 14 had fibromuscular dysplasia. Renal vein renin assays (RVRA) and/or split renal function studies (SRFS) were performed in 37 of the 38 patients before operation. Although RVRA was negative in 29 percent and SRFS negative in 31 percent, 24 of 26 patients (92 percent) having both tests done had at least one positive study. Twenty-one patients had simultaneous bilateral repairs and 12 had staged bilateral reconstructions. The incidence of technical failures in these two groups was 21 and 9 percent, respectively. Excluding three uncorrected technical failures and two patients with recurrent branch renal artery lesions, 90 percent of patients with atherosclerosis and all patients with fibromuscular dysplasia had a favorable blood pressure response to operation. This study supports the use of both RVRA and SRFS in the diagnostic evaluation of hypertensive patients with renal artery stenosis. If these functional tests lateralize to one side, repair of that side only is recommended. If the functional studies do not lateralize, operation is suggested only when hypertension is severe and is not controlled readily with medications. In this circumstance reconstruction of the side that appears to be diseased most severely is recommended. Contralateral repair is undertaken only when hypertension persists and when repeat functional studies lateralize to the unoperated side.

Adult↗