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Biomedical subjects

R H Alexander

Publications and source records attributed to R H Alexander.

35 records · Page 2Linked to original sources
PubMed1982

Revascularization of kidneys with totally occluded renal arteries.

Nephrectomy has been the accepted treatment for renovascular hypertension due to an occluded renal artery but successful revascularization of occluded renal arteries has resulted in partial return of function and relief of hypertension. We performed aorticorenal bypass operations on four patients whose renal arteries were not patent. One graft failed immediately, two remained open for four to six months, and one is functioning at two years. In 70 other cases in which totally occluded arteries were revascularized, the overall patency rate was 96%. Hypertension was relieved for controlled in 77%.

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PubMed1982

Recurrent aortoduodenal fistula: a lesson in management.

Aortoenteric fistula (AEF) is a rare but often lethal complication of aortic reconstructive surgery. The diagnosis is often delayed due to the high percentage of false-negative using upper gastrointestinal series, angiography, and endoscopy. The diagnosis of AEF must be considered in any patient with a prosthetic graft and gastrointestinal bleeding. There are essentially two modalities of treatment: replacement of the graft or total removal of all prosthetic material and the construction of an extra anatomic bypass. A case report of a recurrent aortoduodenal fistula is presented that illustrated both delay in diagnosis and inappropriate treatment. We agree with the general trend in the literature that the appropriate management of this devastating complication is complete removal of the prosthetic graft, wide drainage, high-dose antibiotics, and extra anatomic bypass. Any deviation from these basic treatment steps - such as replacement of the graft - ignores the infectious component of this complication and can result in the devastating lethal complication seen in this patient. With appropriate suggested management this once uniformly fatal complication can be treated effectively, resulting in an acceptable morbidity and mortality.

Aorta↗
PubMed1981

Angiography in patients with abdominal aortic aneurysms.

We obtained angiograms on 61 consecutive patients being evaluated for elective aneurysmorrhaphy at the Gainesville VA Medical Center, Gainesville, Florida. Renal artery stenosis was documented in 33% of cases, aberrant or multiple renal arteries in 26%, and other aneurysmal disease, most commonly in the iliac system, was present in 51%. Occlusive disease was common (30%). In 72% of patients, the preoperative angiogram affected the operative plan. Only one complication was recorded, a retroperitoneal hematoma from catheter perforation. The results correlate well with previously published reports. We conclude that a significant majority of patients having abdominal aortic aneurysm have angiographic abnormalities. In a majority of these patients, the angiogram altered operative therapy.

Aorta, Abdominal↗
PubMed1980

Vein reconstruction of a mycotic internal carotid aneurysm.

Carotid aneurysms are an extremely rare entity; mycotic carotid aneurysms are even more uncommon. Most articles in the past have advocated ligation as treatment of mycotic carotid aneurysms due to the dangers of graft placement in an infected field. Unfortunately, stroke occurs in many patients so treated. As the cerebral complications were so high, bypass using autogenous vein and fine monofilament polypropylene sutures is attractive. This technique was used in a patient having a mycotic carotid aneurysm who was referred to the Vascular Service of the Shands Teaching Hospital. Pre- and postoperative antibiotics, resection of the aneurysm, anastomosis in a noninfected area, and long-term oral antibiotics were felt to be other important aspects of the patient's treatment. This individual is well one year after operation without neurological sequelae. This case suggests that if strict operative and therapeutic guidelines are observed, bypass with autogenous vein is a feasible operative alternative in patients having mycotic carotid aneurysms. The risk of this procedure must be carefully weighed against the devastating neurological sequellae that might result with ligation.

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PubMed1980

Axillofemoral bypass grafts using polytetrafluoroethylene.

More liberal indications for axillofemoral bypass grafts have recently been advocated if long-term patency were comparable to aortic bypass procedures. A clinical trial of polytetrafluoroethylene (PTFE) axillofemoral grafts was instituted in an attempt to maximize graft patency. The theoretic advantages of this material were: (1) a more rigid tube graft, (2) a surface impermeable to blood, (3) a thin pseudointima, and (4) better tissue incorporation. During the last two years, 29 axillofemoral bypass grafts of PTFE have been inserted. Four have failed, one of them now functioning after successful thrombectomization. The cumulative patency rate (life table) for 21 months is 79% "patent" grafts and 84% "functioning" grafts. Six patients have died (21%). There have been three complications, all involving avulsion of the graft at the proximal or distal anastomosis. There have been no infections. Our early results support broadened indications for axillofemoral grafts, since patency rates are comparable to those for aortoiliac/femoral grafts in many series. The characteristics of PTFE appear to be largely responsible for the early success of these grafts, with minimized blood loss and graft hematomas. Great care is required in sizing this rigid tube because tension may produce graft avulsion.

Axillary Artery↗
PubMed1974

Thrombophlebitis and thromboembolism: results of a prospective study.

Thrombophlebitis leading to pulmonary embolism has been stated to cause as many as 9% of hospital deaths. Its diagnosis, sites of common occurrence, treatment and immediate sequelae have long been controversial subjects. A prospective study of thrombophlebitis was set up to evaluate these problems. One hundred and sixty-six patients diagnosed clinically as having thrombophlebitis or pulnmonary embolus were studied with the ultrasonic flow detector (doppler). To assess the stated accuracy of this instrument, venograms were done when possible. The doppler proved in this series to be 93% accurate as compared to venography which is comparable to other series. Pulmonary scans and angiograms were obtained from patients suspected of having pulmonary emboli. Results were as follows: 1) Of 113 patients suspected of having thrombophlebitis clinically, only 26 (23%) of the cases were confirmed by doppler; 2) Of 53 patients suspected of having pulmonary embolus clinically, only 18 (34%) had confirmation by scan, angiogram or doppler; 3) Of 39 patients in this series who had thrombophlebitis, 11 (23%) were not suspected of having lower extremity venous disease until pulmonary embolus occurred, 4) Calf vein thrombosis without additional proximal occlusion was present in only 10% of cases; and 5) Thirty per cent of doppler or venographically proven cases of thrombophlebitis occurred after orthopedic injuries or operations. It was concluded that physical examination alone was grossly inaccurate in determining the recurrence of lower extremity thrombosis. In fact physical examination alone appeared to select out for treatment large numbers of patients without venous disease while a significant number of patients with thrombophlebitis remained clinically asymptomatic until pulmonary embolism occurred. Most deep venous disease was found in the larger veins above the knee, explaining the paucity of diagnostic symptoms in these individuals. The ultrasonic flow detector was found to be an extremely accurate, simple and rapid bedside test that could be applied daily to the high risk groups. The appearance of thrombosis could then be treated with heparin with excellent prospects of preventing occurrence of pulmonary embolus.

Angiography↗
PubMed1966

Stability of the Lactobacillus population in feces and stomach contents of rats prevented from coprophagy.

Lev, Meir (Albert Einstein College of Medicine, New York, N.Y.), Raymond H. Alexander, and Stanley M. Levenson. Stability of the Lactobacillus population in feces and stomach contents of rats prevented from coprophagy. J. Bacteriol. 92: 13-16. 1966.-Lactobacilli were enumerated in the feces of rats prevented from coprophagy by tail-cupping. No differences were found when numbers of these organisms were compared with lactobacilli in feces of control rats, without tail-cups. High and similar numbers of lactobacilli were found in the stomachs of rats with and without tail-cups. The effect of coprophagy on fecal lactobacilli was therefore negligible.

Animals↗
PubMedDate not supplied

Effect of enteral and parenteral nutrition on amino acid levels in cancer patients.

BACKGROUND: The syndrome of cancer cachexia can have a significant impact on response to therapy as well as on survival in cancer patients. Therapies directed at metabolic perturbations in cachectic patients are dependent on nutritional repletion and maintenance of adequate amino acid substrate levels. This study compares the ability of oral feeding, enteral nutrition, and total parenteral nutrition to alter plasma amino acid levels in cancer patients. METHODS: Patients with esophageal cancer were stratified by weight loss. Patients with < 20% weight loss were randomized to continue an ad libitum oral diet (group I) or to receive total parenteral nutrition (group II) for 2 weeks; patients with > 20% weight loss were randomized to receive either enteral nutrition (group III) or total parenteral nutrition (group IV) for 2 weeks. Plasma amino acid levels were measured before the study and again after 2 weeks of nutrition support. RESULTS: Before therapy, there was no difference between the groups in total or essential amino acid levels; however, patients in all groups had significantly lower total amino acid levels compared with those of normal controls. After 2 weeks of treatment, patients in group I and III showed no difference in individual, essential, or total amino acid levels. However, patients in groups II and IV showed significant increases in a number of individual amino acids as well as in essential and total amino acid levels after 2 weeks of TPN. CONCLUSIONS: Patients with esophageal cancer demonstrated significant alterations in amino acid profiles compared with those of normal controls. Total parenteral nutrition was superior to ad libitum oral feeding and jejunostomy feeding in repleting plasma amino acid levels.

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