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Biomedical subjects

R G DePalma

Publications and source records attributed to R G DePalma.

At least 19 recordsLinked to original sources

Preoperative and postoperative dynamic cavernosography and cavernosometry: objective assessment of venous ligation for impotence.

A total of 11 men (mean age 51.4 years, 1-year followup) with venous leakage impotence underwent surgical venous ligation. Of the men 8 had erections twice per week immediately after the procedure but at 3 months only 2 remained potent. Dynamic pharmacological cavernosography and cavernosometry were repeated 3 months postoperatively and 6 of the 11 men had venous leakage. These men with venous leakage underwent percutaneous embolization with platinum coils and 4 had successful results. Three additional men became potent after embolization. Of the 11 men 9 are documented to have normal dynamic cavernosography and cavernosometry findings after the combination of an operation and embolization, and 5 are potent. The postoperative and post-embolization dynamic cavernosometry data show that all 11 men have a marked decrease in the flow to maintain erection. Eight men have erections with papaverine or prostaglandin E1 intracorporeal injections. Postoperative dynamic cavernosography and cavernosometry can be diagnostic as well as therapeutic with embolization.

Adult

Noninvasive assessment of impotence.

The examinations described provide quantitative data on hemodynamics of the erectile process. Comprehensive study cannot be totally noninvasive because it does require measurements of intracavernous pressure. Patients selected for invasive study should exhibit normal neurologic function. These tests generally do not display anatomy underlying the physiologic disorder, although ultrasound has great promise in this regard. Angiography is needed for rational planning of operative procedures. Angiographic examination that includes arteriography of large and small arteries and delineation of cavernosal venous drainage or cavernosography defines both the location and the nature of defects causing erectile failure. It is our belief that both noninvasive and invasive tests (physiologic measurements to assess penile blood flow and cavernosal competence and comprehensive angiography using artificial erection) must be obtained prior to operation.

Blood Pressure Determination

Distribution of vasoactive intestinal peptide and its receptors in the arteries of the rabbit.

Vasoactive intestinal peptide (VIP) is a widely distributed neurotransmitter whose dilatory effects on vascular smooth muscle are believed to be mediated via specific receptors. To determine the possible role of VIP in regulating specific vascular beds, we examined the relationship between arterial wall VIP content as determined by radioimmunoassay and VIP receptors mapped by autoradiography. Analysis of arteries from 12 adult New Zealand rabbits showed that VIP receptors were consistently located in the wall of all muscular arteries, and that the 125I-VIP grain density correlated with VIP content. 125I-VIP binding in the mesenteric, renal, and iliac arteries was abundant and their VIP content was 192 +/- 56, 51 +/- 5, and 74 +/- 23 fmole/mg protein, respectively. 125I-VIP binding to the thoracic aorta was indistinguishable from nonspecific binding, its VIP content being 15 +/- 2 fmole/mg protein. The abundance of VIP receptors and the high VIP levels associated with the mesenteric, renal, and iliac arteries suggest that VIP is a potential regulator of flow to the vascular beds supplied by these arteries. In contrast, the much lower density of receptors in the extracranial carotid, which is also a muscular artery, suggests that, in rabbits, control of carotid vasomotion may be less dependent on VIP innervation. Furthermore, these results suggest that VIP receptors and VIP-containing neurons are not uniformly distributed in the arterial vasculature and that VIP may have selective vasodilatory effects.

Animals

Experience in diagnosis and treatment of impotence caused by cavernosal leak syndrome.

To delineate neural, arterial, and venous components contributing to impotence, we used a previously described noninvasive screening sequence combined with stimulation of artificial erection with papaverine injection, selective pudendal arteriography (SPA), and dynamic cavernosography (DC). Among 572 men with impotence, age range 17 to 78 years (average age 54.8 years), 26 men with potential cavernosal leaks in absence of other factors were identified; 16 underwent DC; among these five had normal cavernous venous drainage. Eight men with abnormal cavernosal venous drainage required cavernous infusion flow rates higher than 120 ml/min to obtain erection and higher than 40 ml/min to maintain erection. Radiographic studies showed cavernosal leakage in all eight patients. Eight men, ages 39 to 61 years, underwent surgical ablation of abnormal cavernosal venous drainage. Among these, five men have had excellent results for up to 3 years. One failure was related to unrecognized penile arterial disease later shown by SPA. In two men small doses of papaverine now induce erection. We now recommend SPA before DC to rule out an arterial abnormality. Accurate identification of factors contributing to erectile failure is critical for successful treatment; in this experience candidates for correction of cavernosal leak syndrome were uncommon.

Adolescent

Vein cuff interposition prevents juxta-anastomotic neointimal hyperplasia.

This study sought to minimize juxta-anastomotic neointimal hyperplasia (JNIH) following the use of polytetrafluorethylene (PTFE) conduits. PTFE anastomoses to canine carotid arteries (noncuff grafts) were compared with grafts with vein cuffs interposed proximally and distally between the graft and native artery. This technique has been suggested clinically for below-knee PTFE femoropopliteal reconstruction. Twelve dogs received aspirin for 1 week before operation, which was continued after each animal received bilateral cuff and noncuff 4-mm PTFE grafts. At sacrifice, after 3-12 weeks, graft patency was assessed and luminal diameters measured with ophthalmic calipers at three sites along the anastomoses and 1 mm proximal or distal to graft toe (A' diameter). Specimens were perfusion fixed at arterial pressure for gross and histologic study; selected arteries were additionally fixed with 4% buffered glutaraldehyde, stored at 4 C, and examined immunochemically using antimyosin antibody immunopurified for smooth muscle. Overall patency of noncuff grafts in 11 long-term surviving dogs was 4 of 11; patency of the cuff grafts was 7 of 11. Regardless of graft thrombosis, antibody positive cellular proliferation occurred mainly at noncuffed PTFE anastomoses. Luminal encroachment was predominantly due to subintimal proliferation of cells highly reactive to smooth muscle derived antibody. JNIH was most prominent 1 mm distal to the graft toe (A' distal diameter). Average A' for noncuff grafts was 1.82 mm +/- 0.97 SEM; average A' diameter for cuff grafts was 3.41 mm +/- 0.74 SEM (p less than 0.001). Vein cuff inhibition of proliferation of smooth muscle or cells derived from smooth muscle possibly relates to wider distribution of kinetic energy (less compliance mismatch) or to interposition of venous endothelium.

Animals

A screening sequence for vasculogenic impotence.

Delineation of neural, arterial, and venous components contributing to penile erectile failure is critical to proper patient selection for surgical interventions, particularly for a subset of men with impotence as the sole manifestation of pelvic arterial disease. In addition to obtaining a history and physical examination specific for disordered erectile function and vascular risk factors, we developed a sequence of testing to include noninvasive estimates of penile perfusion, pulse volume recording (PVR), and penile/brachial blood pressure indices (PBPI); somatosensory evoked potentials from dorsal penile (PEP) and posterior tibial nerve stimulation (SEP) and bulbocavernosus reflex time (BCR); stimulation of artificial erection with injection of papaverine (AE); and selective hypogastric-pudendal arteriography with patients under epidural anesthesia, and corpus cavernosography with AE. Three hundred fifty-three men complaining of impotence were screened by PVR and PBPI; among these 42 impotent men and 20 additional concurrent potent control subjects had evoked potentials and BCR measurements, and 55 men received one or more AE injections. On the basis of these results, angiographic investigation was recommended. Age and risk factors were similar in the two groups. Abnormal penile blood perfusion was associated significantly only with cigarette smoking (p less than 0.0001) or overt large vessel disease. Impotent men with (138) or without perfusion abnormalities (215) averaged 54 and 56 years of age, respectively; impotent men with normal flow patterns most commonly had treated hypertension or diabetes (79 of 215 men). Covert neurologic abnormalities were detected in 28 of 42 impotent men. Abnormal penile perfusion plus failure of AE predicted isolated ischiopudendal trunk or pudendal artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Optimal fluid management after aortic reconstruction: a prospective study of two crystalloid solutions.

To determine optimal fluid management after elective aortic surgery we compared postoperative administration of 5% dextrose Ringer's lactate solution (102 patients) with 5% dextrose half-normal saline solution (80 patients). For 72 hours after operation, intravenous fluids were titrated to maintain urine output between 50 and 100 ml/hr. The group receiving 5% dextrose Ringer's lactate required less intravenous volume per day (2005 +/- 138 ml [mean +/- standard error of the mean] vs. 2701 +/- 145 ml, p less than 0.05), gained less weight (0.8 +/- 0.2 kg vs. 3.2 +/- 0.2 kg, p less than 0.05), and sustained less hyponatremia (serum sodium reduction, 0.1 mEq/L vs. 4.5 mEq/L, p less than 0.05). The group receiving 5% dextrose Ringer's lactate exhibited consistently lower pulmonary capillary wedge pressure (7.3 +/- 1.0 mm Hg vs. 11.4 +/- 1.9 mm Hg) and required treatment for fluid overload in 9 of 102 instances compared with 30 of 80 instances with hypotonic saline solution (p less than 0.05). The patients receiving 5% dextrose Ringer's lactate maintained higher arterial PO2 at 40% forced inspiratory oxygen (PaO2, 83 +/- 3 torr vs. PaO2, 67 +/- 5 torr, p less than 0.05). Optimal fluid management was approached by the use of 5% dextrose Ringer's lactate solution postoperatively. The use of hypotonic saline solution after aortic surgery offered no advantage and predisposed the patient to volume overload.

Aortic Diseases

Regional nerve block for femoropopliteal and tibial arterial reconstructions.

Thirteen high-risk patients underwent lower extremity revascularization anesthetized with a regional nerve block technique. The sciatic, femoral, and obturator nerves were infiltrated with 1% lidocaine and 0.25% bupivacaine. Eight femoropopliteal and five femorotibial bypasses were performed for limb salvage (11 patients), disabling claudication (one patient), and popliteal artery aneurysm (one patient). Analgesia was adequate with only one patient who needed supplemental nitrous oxide. One patient died on the sixth postoperative day of a myocardial infarction. Regional nerve block is an effective anesthetic technique that should be considered if general or spinal anesthesia is inappropriate.

Adult

Timing of carotid artery endarterectomy after stroke.

Carotid endarterectomy has been advocated to prevent further neurologic deterioration in patients who have had a stroke. Previous reports have shown that endarterectomy within 2 weeks of a stroke is associated with high morbidity and mortality rates presumably from hemorrhagic complications in the brain. Some recommend a 2- to 6-week waiting period after a stroke, but the safety of operation in the interval of time beyond 2 weeks has not been documented in the literature. The present study investigated the morbidity and mortality rates of 352 consecutive carotid endarterectomies. Three hundred three endarterectomies were performed on patients with symptoms other than stroke. Forty-nine endarterectomies were performed on patients with a deficit lasting more than 24 hours. Of these, 27 carotid endarterectomies were performed in an interval less than 5 weeks after initial stroke (early interval) and 22 operations were performed in a 5- to 20-week interval after stroke (late interval). Five strokes occurred in the 27 patients operated on within 5 weeks, an incidence of 18.5%; none of the patients operated on after 5 weeks exhibited worsening of their preoperative neurologic status. With the use of Fisher's exact test to compare these two intervals, the results were found to be significant (p less than 0.05). The cause of stroke in those operated on in the early interval was investigated by postoperative CT scans; in only one instance was there a hemorrhagic infarct of the ipsilateral hemisphere. The literature suggests that a variety of intracerebral vascular changes render the brain more susceptible to reinfarction soon after stroke. This study suggests an unstable situation in the 5-week interval following stroke that contraindicates carotid endarterectomy.

Adult

Diabetes mellitus and atherosclerotic involvement of the profunda femoris artery.

Arteriosclerotic involvement of the PFA is correlated with diabetes mellitus. While patients without diabetes have disease limited to the PFA orifice and the circumflex vessels of the PFA, patients with diabetes are prone to extensive PFA involvement. Severity of atherosclerosis involving the CFA and SFA was not found to be specifically related to diabetes.

Angiography

Management of aortocaval fistula due to abdominal aortic aneurysm.

Anasarca and intractable congestive heart failure were the presenting signs of an abdominal aortic aneurysm with aortocaval fistula. Management with careful monitoring of cardiovascular function using a Swan-Ganz catheter before, during, and after surgery resulted in an uneventful recovery.

Aged

Surgical therapy for venous stasis: results of a modified Linton operation.

Bipedicled flaps in the natural skin lines permit ligation of offending perforating and communicating veins of the postphlebitic leg with stasis change. This technic affords safer immediate postoperative healing and durable long-term results. The indications for operation have been extended to include more elderly patients as well as selected patients with ulcerations due to combined venous stasis and arterial insufficiency.

Adult

Effect of regenerated endothelium on collagen content in the injured artery.

Collagen content and intimal thickness were measured in endothelialized and nonendothelialized zones of the aorta in rabbits for 30 days after a standard embolectomy balloon injury. A large increase in collagen content and intimal thickness were seen in the arterial wall covered by regenerating endothelium. In areas devoid of endothelial coverage, minimal intimal thickness occurred; no measurable increase in collagen content was measured. Interaction between arterial smooth muscle cells and regenerated endothelium appear to be necessary for collagen accumulation and intimal thickening after arterial injury and repair.

Animals