Search PubMed⌕ Search

Biomedical subjects

A Bass

Publications and source records attributed to A Bass.

180 records · Page 10Linked to original sources

Percutaneous transluminal aortic angioplasty: early and late results.

Percutaneous transluminal angioplasty of the infrarenal abdominal aorta (13 patients) and its bifurcation (15 patients) was performed in 28 patients with a total of 32 dilatation procedures. The group consisted of 16 female and 12 male patients and initial successful dilatation was achieved in all. Recurrence within 1 month requiring bypass surgery occurred in 1 patient. Three patients were lost to follow-up. Long-term follow-up in the remaining 24 patients ranged from 1 to 9 years with a mean of 4.5 years. During the follow-up period, repeat angioplasty of the original stenosis was performed in 3 patients and another patient underwent dilatation of a new lesion which developed in the aorta. According to clinical and noninvasive studies, these 4 patients, as well as the other 20, have maintained patency of the treated lesions and are symptom free. No immediate complications requiring surgery occurred. We conclude that angioplasty is the initial treatment of choice in focal lesions of the distal abdominal aorta and its bifurcation.

Adult↗

Renal collateral blood supply after acute unilateral renal artery occlusion.

Preformed arterial collaterals are critical to renal parenchymal survival after acute total renal artery occlusion. This study was designed to delineate and quantify preformed collaterals and assess their response to vasodilators. A Swan-Ganz catheter induced a sudden, total occlusion of a renal artery sufficient to reduce distal arterial pressure to near zero and prevent perfusion through the renal artery. Arteriography assessed the effectiveness of the occlusion and delineated the collateral arterial pathways. Strontium, cerium-, and chromium-labeled microspheres measured renal blood flow and cardiac output 1, 60, and 120 minutes after occlusion. In two additional series of experiments either contralateral nephrectomy was performed 5 to 8 days before the study, or dibenzylene, dopamine, or glucagon were administered in an attempt to increase blood flow through the collaterals. Collateral renal blood flow was demonstrated in all dogs. Mean blood flow to the occluded kidneys ranged from 0.13 +/- 0.05 cm3/minute/g to 0.22 +/- 0.08 cm3/minute/g, about 5% of control values. Neither prior contralateral nephrectomy nor vasodilator agents increased the flow to the obstructed kidneys. In the dogs with intact contralateral kidneys, however, there was a progressive decrease in cardiac output during the experiment, which was not found in uninephrectomized animals. We concluded that preformed arterial channels are available to maintain a small, but probably critical level of perfusion following sudden total occlusion of the renal artery. Neither hypertrophy due to prior contralateral nephrectomy nor active vasodilators modify flow through the preformed channels. It is likely that total renal ischemia provides a maximal stimulus for vasodilatation. The pattern of hind limb collaterals differed strikingly from those of the kidney, with maintenance of a greater portion of a normal flow and rapid increase in flow within 1 hour after femoral artery occlusion. Thus, data concerning collateral circulation cannot be generalized from one vascular bed to another even in the same species.

Animals↗

Randomized placebo-controlled, double-blind trial of ketanserin in treatment of intermittent claudication.

Ketanserin, a selective serotonin (5-HT) antagonist at 5-HT2 receptors, was investigated in a 12-month, double-blind placebo-controlled study in 35 patients with intermittent claudication. Benefit was assessed by repeated treadmill tests, recording claudication distance, and by measurement of Doppler ankle-brachial pressure indices (ABPI) and pulse volume recordings (PVR). Improvement in claudication distance of 42-44% was noted during the 12 months of the double-blind study and this trend continued to 53-67% during an additional 3 month run-out period on placebo. There were no significant differences between the group given Ketanserin and the placebo group. The hemodynamic measurements demonstrated no statistically significant change in either ABPI or PVR throughout the study period, and no significant differences between the two groups. The conclusion of the study indicates that Ketanserin is ineffective in the treatment of intermittent claudication.

Blood Pressure↗

Pharmacokinetic activity of nitrites evaluated by digital pulse volume recording.

Evaluation of the pharmacological properties of vasoactive drugs using routine pharmaco-chemical methods is often complex, time consuming and expensive. We used finger plethysmography for the evaluation of the bioactivity of two long-acting nitrite preparations. Eight healthy male volunteers were exposed to four different drugs: (1) Nitroglycerin; (2) Placebo; (3) Isosorbide dinitrate as Isotard Forte; (4) Isosorbide dinitrate as Cordil-40 SR. Digital pulse volume recording (PVR) was monitored for twelve hour periods. The shape of the PVR curve was used to calculate the diastolic amplitude response intensity, an indication of the vasoactive effect of the drug. There was no measurable response to the administration of placebo. The effect of nitroglycerin was maximal one hour after administration and disappeared after three hours. The long term effect of the two long-acting nitrite preparations was clearly demonstrated as compared to nitroglycerin. Noninvasive measurements of peripheral blood flow can serve as a convenient and accurate tool for pharmacokinetic studies of vasoactive drugs.

Adult↗

Scoring of vascular disease in the lower extremities.

Lack of standardisation in reporting the vascular status of patients leads to difficulties in comparing different series. A method of vascular scoring is presented, integrating symptoms, physical examination, vascular laboratory studies and arteriography. The score is expressed in a concise form by several letters and numbers supplying the relevant information as to the main segment involved, the severity of the ischaemia and the completeness of the examination. The files of 100 candidates for vascular surgery were recorded with the scoring method. Vascular indices were calculated by dividing the sum of points assigned to each item by the maximal available score. The internal consistency of the method was evaluated by computing separate indices for the three components of the scoring--clinical examination (CE), vascular laboratory (VL) and arteriography (AR)--and comparing them with the overall index and with each other. Correlation coefficients with the overall index were for CE 0.90, for VL 0.92 and for AR 0.75. The data on the 200 limbs were reviewed independently by three experienced vascular surgeons and ranked in order of increasing severity of ischaemia; the correlation coefficient between this ranking and one based solely on the scoring method was 0.91. A vascular scoring method may help create a mutual language among practitioners, enabling them to compare results and benefit from accumulating worldwide experience.

Adult↗

Tube graft replacement of abdominal aortic aneurysm: is concomitant iliac disease a contraindication?

One hundred and fifty nine patients underwent surgery for abdominal aortic aneurysm (AAA) from 1975 to 1985. Of these, a tube graft was inserted in 86 patients (55.1%). Immediate and late results of these 86 patients were evaluated retrospectively as to the effect of concomitant common iliac artery (CIA) disease on early and late results. There were 77 males and nine females aged 35-91 (average 70.7) years. Surgery was elective in 44 patients (51.2%), and as an emergency due to expanding, ruptured or thrombosed AAA in 42 patients (48.8%). The CIAs showed unilateral or bilateral aneurysmal dilatation or atherosclerotic changes in 47 patients (54.7%). At the time of surgery additional bypass grafting from the tube graft to one femoral artery was performed in four patients, and patch angioplasty to the CIA in one. Operative mortality was 4.6% (two patients) in the elective group, and 45.2% (19 patients) in the emergency operations. Follow-up was 94% complete for a mean of 4.1 (range 0.5-10) years). Late mortality for the whole series was 20.0% (12 patients). Only one patient died of a cause related to the AAA operation. All but one of the 48 late survivors are free of any peripheral vascular problems. We conclude that tube graft replacement of AAA is a good choice even in the presence of some degree of CIA atherosclerosis or aneurysmal dilatation.

Aged↗

Pulmonary embolism in post-mortem material with clinical correlations in 425 cases.

425 patients with pulmonary emboli at post mortem were studied retrospectively with the main focus on the clinical diagnosis. The diagnosis of pulmonary embolus was made or suspected while the patient was still alive in 59 patients (14%) and was first written in the post mortem request form in 130 patients (30%). In 236 patients (56%) the diagnosis was made only at post mortem. Even in fatal emboli the diagnosis was missed in 43% of cases. A multiplicity of non specific symptoms and signs was observed with a minority of patients showing signs and symptoms considered as typical. Of 231 thrombophlebitis processes found in locations which could give rise to clinical symptoms in the lower extremities the diagnosis was noted only in 25 cases. Chest x-ray and ECG were negative in two thirds of the cases. The high rate of misdiagnosis derived from two reasons: (a) subjective factors: lack of awareness; (b) objective difficulties: lack of specificity of clinical symptoms and signs as well as of results of the routine tests (chest x-ray and ECG). Since sophisticated confirmative tests for pulmonary emboli will be performed only on the basis of clinical suspicion, clinical awareness based on the observations detailed in this survey is still the cornerstone of diagnosis.

Aged↗

Antithrombosis routines and hemorrhagic complications: a seven year survey comparing vascular and general surgical operations.

Prospective monitoring of the occurrence of venous thromboembolism (VTE) and bleeding complications was carried out during a seven year period in a department of general and vascular surgery. Low dose heparin was given by pre-determined criteria to over 1200 patients undergoing general surgical operations, and to almost 700 patients having vascular surgical operations. Over 450 vascular patients received full dose anticoagulation and 3400 patients from both groups received no antithrombotic treatment. Clinically significant major VTE occurred in one percent of all patients. Nine patients died of pulmonary emboli (0.15%). There were 130 patients with bleeding complications (2.2%) half of them severe. Both VTE and bleeding were more common in the vascular patients (1.4 and 3.1% respectively) as compared with general surgery (0.7 and 1.6%). Patients receiving low dose heparin had a 3.4 percent incidence of bleeding but in one half of these cases a technical factor or a breach of the treatment protocol could have contributed to the bleeding. Possible modifications of antithrombosis routines are suggested.

Adult↗

Peripheral nerve section as palliation for severe ischemic foot pain.

Multisensory peripheral nerve divisions were performed in 17 elderly patients with severe ischemia, forefoot pain and non-healing lesions or localised gangrene. They were unsuitable for a vascular reconstructive operation, or for localised foot amputation. The mean age of the patients was 73 years; 13 were males and 10 had diabetes mellitus. All were faced with a major amputation. Considerable pain relief was achieved in all patients but only five patients retained a functional lower extremity for more than 6 months. Of these five one was a diabetic and four were non diabetic. Peripheral nerve section is a useful procedure, but should be applied very selectively and only rarely in diabetic patients.

Aged↗

Initial experience with mesocaval H grafts: comparison with other portosystemic shunts.

Two policies concerning portosystemic shunt for bleeding esophageal varices were compared. In 18 patients, splenorenal or portocaval shunts were performed according to anatomic and hematologic considerations. In 13 patients, only mesocaval H grafts were performed. In the latter group, more patients had poor liver reserve and required urgent surgery. Accordingly, early and late mortality and morbidity were higher in these patients. the technical ease of performance of the mesocaval H graft did not cancel out increased risk in poorer candidates for surgery.

Adult↗

Closure of the abdomen by mesh for planned re-laparotomy. A technical modification.

Temporary closure of the abdomen with a synthetic mesh and multiple planned relaparotomies are the essentials of the modern strategy for treating severe intra-abdominal sepsis or pancreatic necrosis. One of the complications associated with mesh closure of the abdomen is facial necrosis at the wound edges leading to evisceration. Tension of the strictures between mesh and facia called local ischemia, which combined with infection leads to the facial disintegration and separation of the mesh from the abdominal wall. A modified technique of suturing the mesh was developed in our department and its technical details are presented. Twenty-four patients treated with the "open abdominal technique and planned relaparotomies" are presented. The new technique was used in 9 patients for closure of evisceration after mesh separation.

Adult↗