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Between June 1983 and December 1987, 52 patients underwent resection of a thoracic descending aortic aneurysm. Thirty-day mortality was 11.5%; 4.8% for elective cases and 36.5% for patients operated upon in emergency. Spinal cord injury was present in two patients (4%). One patient was paraplegic, the other showed mild paraparesis, which was completely resolved. Both patients were operated for ruptured aneurysms. Severe postoperative renal dysfunction was present in 4 patients (7.5%) and was strongly related to intraoperative hypotension. The cumulative proportional survival rate was 81% at one year and 66% at two years of the total group, 85% at one year and 72% at two years for the patients presenting with nonruptured aneurysms. Aneurysms of the thoracic descending aorta can be resected with an acceptable mortality and morbidity. Just as in abdominal aneurysms, surgery definitely improves the outcome for these patients, who have a rather poor prognosis if left untreated.

Between January 1983 and June 1986, 61 patients underwent resection of a thoracoabdominal aneurysm (TAA) by means of simple cross-clamping without the use of adjuncts. All patients survived the operation. Mortality was 6.5% at 30 days and 16.4% at 1 year. Spinal cord injury occurred in 8 patients. Three patients sustained paraplegia and 5 patients recovered from paraparesis within 6 months. In univariate analysis, risk factors were the presence of symptoms (P less than or equal to 0.01) and emergency operation (P less than or equal to 0.03). Spinal cross-clamptime (ACX), aetiology and the number of open intercostal arteries (ICA) did not appear to be single denominators for spinal cord injury. Testing clusters of variable related to spinal cord injury revealed an increased risk for the group of patients (n = 20) with type I (most of the thoracic and the upper abdominal aorta) and type III (the distal half of the thoracic and varying segments of the abdominal aorta) aneurysms, when the number of ICA was greater than or equal to 4 or less than or equal to 1, with a spinal ACX of greater than or equal to 35 min, and in the presence of symptoms and previous dissection (P = 0.001). In patients (n = 19) with type II aneurysm (involving most of the thoracic and most of the abdominal aorta) an increased risk was present when the number of open ICA was greater than or equal to 4, with a spinal ACX of greater than or equal to 35 min and in the presence of symptoms (P = 0.01). Spinal cord injury was confined to these types of TAA (P less than or equal to 0.001) and paraplegia occurred only in type I and III aneurysms.

The cerebral perfusion pressure, as measured by ocular pneumoplethysmography (OPG-Gee), was used to evaluate the hemodynamic significance of carotid coiling in 25 patients, eight of whom had bilateral coiling. Positional studies were done with the head in the normal position and turned to the right and left. Seven of the 33 coilings (21%) were hemodynamically significant with the head in the normal position. A change in perfusion pressure when the head was turned was seen in 16 of 50 rotation studies (32%). There was a reduction in pressure in 11 instances and increase in five. In a control group of 24 subjects with normal angiograms, 18 of 48 studies (37%) showed a change in perfusion pressure with the head turned. Carotid coiling can be hemodynamically significant. Rotation of the head can compromise the carotid circulation whether coiling is present or not. OPG proved to be a simple means of evaluating the hemodynamic significance of carotid coiling and the effects of head rotation on the carotid circulation.

The value of intravenous arteriography, otherwise known as digital vascular imaging (DVI) in the late postoperative control of femoro-crural bypass operations is determined by comparing its results with those of conventional arteriography. Ten patients with 12 grafts were studied by both methods after a mean postoperative follow-up period of 83.5 months. DVI was 100% accurate in the determination of graft patency. In most patients it provided reliable information regarding the status of the distal anastomosis and the patency of the distal runoff. Since DVI has been proven accurate, has a good patient acceptance, and can be performed as an outpatient procedure, it is preferable to conventional arteriography for the objective documentation of long-term graft patency.

A female patient was transferred to our unit with the suspicion of fracture of her 70 degrees Bjørk-Shiley valve. A successful replacement of the broken device confirmed the diagnosis. In steep Trendelenburg position, using femoral arterial inflow, the disc could be returned into the operative field by temporarily declamping the aorta.

The prognosis in carotid disease is extremely variable and is influenced by the availability of collateral circulation. This study investigates the possibility of recognising patients with a poor collateral potential by using non-invasive tests. Preoperative OPG and EEG were compared with intraoperative EEG during test clamping in 208 carotid endarterectomies. Clamping ischaemia occurred in 29 patients (14%). Preoperative EEG had a sensitivity of 62% and a specificity of 82%. OPG showed a sensitivity of 96% and a specificity of 54%. Combined OPG and EEG resulted in a sensitivity of 93% and a specificity of 73%. Both tests are safe and easy to perform and interpret. These techniques can be used to identify those patients with carotid stenosis who have an increased risk of stroke due to a poor collateral circulation and may help to refine the indications for carotid endarterectomy.

Using positron emission computerized tomography (PCT), a high uptake of IV injected 13N-ammonia was observed in the muscles of the right forearm and leg of a patient with a rightsided static tremor. In some muscles the concentration of 13NH3 was 8.5 times higher than in the symmetrical normal limb. Confrontation of the clinical, neurological, and electromyographic findings with the results of the PCT proved that the muscles with the high uptake corresponded to the muscles responsible for the tremulous movements. There is strong evidence that the high uptake of 13NH3 was related to the increased blood flow produced by the continuous rhythmic exercise of the muscles involved in the tremor. To our knowledge a similar observation has not been described before. It is suggested that the combined use of suitable positron emitters and PCT might provide a valuable tool for the noninvasive study of perfusion of individual skeletal muscles.

EEG recordings from 230 carotid endarterectomies performed with an automatic EEG monitoring system were reviewed with the purpose of establishing the exact relation between EEG changes and intraoperative stroke. Patients were selectively shunted, based on the EEG changes occurring after carotid cross-clamping. Transient EEG asymmetry was not associated with intraoperative stroke. Only persisting EEG asymmetry reflected intraoperative major stroke, expressed by a positive predictive value of 0.50, but also in terms of specificity (0.99), sensitivity (0.80) and diagnostic gain (47.8%) of the EEG; minor strokes could not be detected with EEG monitoring. Analysis of the time course of the persisting asymmetry confirmed the thrombo-embolic origin of the majority of the major strokes.

In 83 patients with previous coronary artery bypass grafting, 92 percutaneous transluminal coronary angioplasty attempts were done, 33 in a venous bypass graft (success rate 97%) and 59 in a native coronary artery (success rate 86.4%). There were no procedural-related deaths and two myocardial infarctions. Forty-six percent of the patients with successful angioplasty after previous bypass grafting remain symptom free after 5 years versus 79% of the patients without previous bypass grafting (p less than 0.001). Long-term success rates for native vessel angioplasty as compared with bypass graft angioplasty are similar. Patients with a short interval between the recurrence of angina after bypass grafting and the angioplasty attempt have a better chance of long-term success. Repeat angiography indicates that a restenosis occurs after angioplasty of a venous graft in 31% and in the native system in 28.6% and that signs of progression of coronary artery disease elsewhere are present in 30%. Of the 83 patients, 11 had reoperation eventually. We conclude that percutaneous transluminal coronary angioplasty after coronary bypass grafting gives less satisfactory results than a primary procedure, that angioplasty provides symptomatic relief in a smaller number of patients than in those with primary angioplasty, but that symptomatic relief is often sufficient to further postpone or prevent bypass grafting and can be achieved with low mortality and low complication rates.

We analyzed perioperative strokes in 658 carotid endarterectomies with the purpose of explaining the pathogenesis from the morphologic aspect of the infarct on cerebral computed tomograms. All endarterectomies were performed with continuous electroencephalographic monitoring. Of the 42 ischemic strokes (6.4% of all endarterectomies), 34 could be studied. Seven infarcts were hemodynamically induced (five watershed infarcts, two patients with bilateral ischemia); all seven occurred during surgery. Twenty-three of the remaining 27 infarcts were within the territory of the middle cerebral artery (20) or anterior cerebral artery (three) and were probably of thromboembolic origin; 13 of these 23 occurred during surgery (57%). If intraoperative stroke was heralded by permanent electroencephalographic changes, these were not related to the moment of cross-clamping. In four patients the computed tomogram was normal. We believe these facts favor the hypothesis that thromboembolism is the most important factor in the pathogenesis of perioperative stroke associated with carotid endarterectomy under conditions of optimal cerebral monitoring.

An initial experience with a technique of restorative proctocolectomy utilizing a rectal mucosectomy, total colectomy, and ileal reservoir (Parks S-pouch) with ileoanal anastomosis for patients with ulcerative colitis and familial polyposis is presented. Although there were no deaths, significant morbidity did occur and was attributed to the use of a temporary loop ileostomy which may not be necessary. Early functional results are promising and to date, patient satisfaction is very high.

To determine whether the large volumes of cardiotomy suction which occur during long perfusions can obscure the hematological advantage of the membrane oxygenator (MO) over the bubble oxygenator (BO), we studied 23 patients undergoing a coronary artery bypass grafting operation with an expected perfusion time of 3 hours (MO group, N = 10, SciMed spiral coil; BO group, N = 13, Shiley 100-A). During MO perfusion we found significantly higher platelet numbers, better platelet function (adenosine diphosphate-induced platelet aggregation), and less hemolysis (plasma hemoglobin), than during the BO perfusion. After the MO perfusion we measured significantly shorter bleeding times (Simplate II) and fewer transfusions of blood products. However, blood loss and whole-blood transfusions 18 hours after perfusion did not differ significantly between both groups. So in coronary artery bypass grafting operations with long perfusion times (mean, 3 hours), the MO still causes significantly less platelet and erythrocyte damage than the BO, despite the large volumes of cardiotomy suction known to occur during these operations.

Cerebral blood flow and oxygen metabolism have been measured with the steady-state oxygen-15 technique and positron emission tomography in anesthetized dogs. Regional microembolization was induced by infusing Sephadex particles (diameter, 40 micron) into one of the common carotid arteries. In the first series of experiments, 2.5 mg Sephadex was infused, and the dogs were examined within 3-4 hours after embolization. In a second series 0.55 mg Sephadex was infused, and the dogs were examined either in the first 3-4 hours or 24-48 hours after embolization. Cerebral blood flow, oxygen extraction ratio, and cerebral oxygen utilization were measured at 3 PCO2 levels. In the acute experiments, cerebral oxygen utilization in the embolized hemisphere was 6 (0.55 mg Sephadex) and 25% (2.5 mg Sephadex) lower than on the contralateral side. While cerebral blood flow was symmetrically distributed in normocapnia and hypocapnia, it was 9 (0.55 mg Sephadex) and 35% (2.5 mg Sephadex) lower in the embolized hemisphere during hypercapnia. In normocapnia and hypocapnia the lower oxygen utilization in the embolized hemisphere was characterized by a lower oxygen extraction ratio, and in hypercapnia by an unchanged (0.55 mg Sephadex) or by a higher (2.5 mg Sephadex) extraction ratio. The different effect on oxygen extraction ratio in the control and embolized hemispheres resulted in images of uncoupling between perfusion and oxygen demand that varied according to the PCO2. The experiments also showed a fall in cerebral blood flow in the embolized hemisphere after 3-4 hours, indicating delayed hypoperfusion. After 24-48 hours, blood flow was about 10% higher in the embolized hemisphere, and this was observed at the 3 PCO2 levels, while the oxygen extraction ratio was systematically lower. Oxygen utilization in the embolized hemisphere was depressed to practically the same extent as in acute experiments. It can be concluded that between 4 and 24 hours after microembolization the cerebral microcirculation shows important changes, with installation of luxury perfusion in the face of an unchanging decreased oxygen metabolism.

Advocates of carotid artery patching claim a reduced incidence of recurrent stenosis after endarterectomy. A prospective study was undertaken to determine its value with random selection between primary closure and saphenous vein patching. A consecutive series of 129 carotid endarterectomies was evaluated by duplex scanning at 3, 6, and 12 months after operation. Intravenous digital subtraction angiography (DSA) was performed in the first postoperative days for control of the surgical technique and after 1 year to serve as a reference for the duplex scanning. Sixty-two patients were selected to have primary closure and 67 were chosen for the patching technique. Both groups were identical with regard to risk factors (mean age 63 years, 74% were men, 57% had hypertension, 41% had coronary disease, 37% had peripheral arterial disease, and 9% had diabetes mellitus), side of operation (55% left), symptoms (18% were asymptomatic), and postoperative DSA (81% were normal, 17% had residual lesions, and 2% had occlusions). A complete 1-year follow-up was obtained in 105 cases (81%); duplex scanning showed recurrent stenosis of more than 50% in 12 cases (11%). This was significantly higher after primary closure (10 of 48 patients = 21%) compared with patch closure (2 of 57 = 3.5%; p = 0.006) and also in women (6 of 25 = 24%) compared with men (6 of 80 = 7.5%; p = 0.03). Recurrent stenosis was present in 6 of 11 women with primary closure (55%), 4 of 37 men with primary closure (11%), 2 of 43 men with patching (5%), and none of 14 women with patch closure (0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral one stage carotid endarteriectomy was performed in 11 patients presenting with bilateral symptomatics stenoses without neurological nor cardiac major complications. We only found one such experience in the literature (1). The choice of a simultaneous procedure is based solely on electroencephalogram analysis and on the residual pressure after the test of carotid occlusion; the side where occlusion is tolerated and/or where the residual pressure is highest, is operated first. This simultaneous bilateral procedure carries the theoretical risk of ischemia. It has the advantage of decreasing the cardiac complications and the risk of neurological deficit and at the same token avoids intercurrent controlateral thrombosis and recurrent symptoms between two non-simultaneous procedures. In cases of symptomatic lesions, the indication of surgery is evident; for asymptomatic lesions we only consider a simultaneous procedure in special cases where there exists a threat of neurological complications.

The recent advances in technology have made it possible to decompress acute pseudo-obstruction of the colon with colonoscope instead of celiotomy and cecostomy. Twenty-two patients who developed acute pseudo-obstruction of the colon and underwent colonoscopy were analyzed. The authors were successful in completely or partially decompressing the dilated colon in 19 of 22 patients. There were no complications. Acute pseudo-obstruction of the colon is usually secondary to intra- or extra-abdominal insult resulting in direct or reflex derangement of the sacral parasympathetic outflow. This causes a functional obstruction of the left colon. The goal of management is to prevent colonic perforation while treating the primary problems. Once the diagnosis has been made, colonoscopy should be attempted. Celiotomy should be reserved to cases in which colonoscopy is unsuccessful or in cases with perforation or impending perforation.

A perineal rectosigmoidectomy can be performed safely in the elderly poor risk patient with procidentia. An excellent anastomosis can be obtained using an intraluminal stapler or end to end anastomosis autosuture device. This technique can also be used for performing the perineal anastomosis in a colonic pull-through surgical procedure.

The combined approach of extracranial arterial lesions in patients undergoing open heart surgery decreases the high cardiac and neurological morbidity and mortality presented by patients operated sequentially. Besides the anatomically sound simultaneous approach of arch lesions and heart surgery, both to be operated by median sternotomy, the authors present their criteria used in the selection of neurologically symptomatic and asymptomatic patients with carotid and vertebral disease to be operated simultaneously. Results in 17 personal cases are presented.

Simultaneous surgery for extensive extracranial and coronary revascularization was performed in 168 patients (mean age 61 years), from 1974 up to June 1987; 116 patients (69%) were in NYHA class III or IV, 133 (79%) had triple vessel disease and 51 (30%) had left main stem lesions. One or more previous myocardial infarctions were present in 96 patients (57%); normal preoperative left ventricular function was present in only 35%. In 22 cases, additional cardiac procedures were performed. Symptomatic extracranial disease was present in 76 patients (45%), arch vessel surgery was performed in 29 (17%) and bilateral haemodynamically significant carotid disease was present in 58 (35%). Operative mortality (3%) was mainly cardiac and operative morbidity mainly neurological (7%). Actuarial survival at 5 years (75%) and 10 years (57%) was mainly determined by the cardiac survival (87% at 5 years and 70% at 10 years), while neurological follow-up deaths were rare (neurological survival 97% at 5 years and 91% at 10 years). Late morbidity was more cardiac than neurologically determined; actuarial curves showed 72% to be free of all serious events or death at 5 years, and 47% at 10 years.

A modified solenoid having a semi-circular cross section is evaluated as an applicator for radio-frequency heating of biological materials. The operating efficiency of this applicator and the distribution of the electric field established within a simulated biological sample are determined for a number of modes of excitation. It is shown that uniform heating to a substantial depth is possible at efficiencies in excess of 80 percent.