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Biomedical subjects

R Verhelst

Publications and source records attributed to R Verhelst.

50 records · Page 3Linked to original sources
PubMed1992

Use of the inferior epigastric artery for coronary bypass.

Between December 1988 and April 1991, 74 free inferior epigastric arteries were used in 73 patients for coronary artery bypass grafts. In addition, 72 of the patients received a left internal mammary artery for single or sequential grafting to the left anterior descending system and 62 a right internal mammary artery to the circumflex or the right coronary artery. Twenty-seven patients had no saphenous vein available, and two had no suitable internal mammary artery; in an attempt to make a complete arterial revascularization, we chose the inferior epigastric artery as an alternative conduit in 24 young patients and in 10 reoperations; bilateral internal mammary artery dissection was avoided in four patients with impaired lung function and in six patients with selected two-vessel disease to spare one internal mammary artery. The technique for harvesting the inferior epigastric artery is described. Fifty-three inferior epigastric artery grafts were anastomosed to the distal right coronary artery or to its branches, 18 to the distal obtuse marginals of the circumflex artery (three as sequential grafts and one as a natural Y graft), and three to the left anterior descending system. The mean number of distal anastomoses is 3.60 per patient. Seventy proximal anastomoses of the inferior epigastric artery were made to the aorta and four to one internal mammary artery. There were four early deaths and one nonfatal myocardial infarction. Four abdominal wound hematomas needed surgical drainage. Sixty-one patients underwent angiographic study on postoperative day 10:59 of 61 inferior epigastric artery grafts (63 of 65 inferior epigastric artery distal anatomoses) and 111 of 111 internal mammary artery grafts (155 of 156 internal mammary artery distal anastomoses) were patent. Clinical follow-up of all the survivors (100% follow-up) could be obtained with a mean period of 9 months (1 to 28 months). There was no late cardiac death, no infarction, and all the patients were free of angina. Nineteen patients underwent a 6-month postoperative angiographic study. Seventeen of 19 inferior epigastric artery grafts were patent and 16 of 19 were intact; 34 of 34 internal mammary artery grafts (46 of 47 internal mammary artery distal anastomoses) were patent and intact. In conclusion, free inferior epigastric artery grafts can reach the diaphragmatic ischemic areas of the heart. The early patency rate and the clinical results are encouraging but only long-term evolution and evaluation can determine the true efficacy of the inferior epigastric artery graft as a reliable conduit for coronary artery bypass graft operations.

Abdominal Muscles↗
PubMed1991

[Myocardial revascularization with internal mammary artery graft: analysis of early and late post-operative respiratory morbidity].

To evaluate the respiratory morbidity resulting from myocardial revascularization with internal mammary artery (IMA) graft, we reviewed 153 patients operated on between April and November 1988. There were 124 men with a mean age of 61 years. A bilateral IMA graft was used in 30 patients (20%). During the harvesting of the mammary graft, the homolateral pleura was systematically opened. Acute respiratory failure was more frequent in patients with bilateral IMA (13%) than in patients with unilateral IMA graft (3%) (p less than 0.05). Consequently, the mean duration of mechanical ventilation was longer in patients with bilateral IMA graft: 56 versus 23 hours (p less than 0.05). Lung volume measurements were altered according to a restrictive pattern. On the 9th post-operative day, forced vital capacity was reduced to 59.6% of the pre-operative value in patients with unilateral IMA and to 47.1% in patients with bilateral IMA graft (p less than 0.001). Late results were obtained in 111 patients. After a mean follow-up of 7 months, forced vital capacity was still reduced to 86.8% of the pre-operative value in patients with single IMA and to 78.1% in patients with bilateral IMA graft (p less than 0.001). In conclusion, respiratory morbidity is not negligible. Bilateral IMA grafting should generally be reserved to young patients (less than 65 years) with normal pre-operative pulmonary function tests.

Adult↗
PubMed1991

Flow-induced vasomotor response to tachycardia of the human internal mammary artery and saphenous vein grafts late following bypass surgery.

Increasing blood flow results in endothelium-dependent vasodilation of angiographically normal epicardial coronary arteries in humans. To compare the ability of internal mammary artery (IMA) and saphenous vein (SV) used as coronary artery bypass grafts to adapt their vasomotor tone to an increase in myocardial blood flow demand induced by tachycardia, 10 IMA and seven SV grafts were studied by quantitative angiography more than 6 months (range, 6-82 months) after surgery in 17 patients. All grafts were angiographically smooth and implanted to large nonakinetic perfusion zones. Angiograms were obtained in basal sinus rhythm (71 +/- 10 beats/min), during atrial pacing (129 +/- 9 beats/min), and after intragraft infusion of 1 mg isosorbide dinitrate (ISDN). In basal sinus rhythm, the cross-sectional area of SV was superior to that of IMA (10.7 +/- 3.6 versus 5.4 +/- 1.7 mm2; p less than 0.01). All IMA dilated during pacing (+14.8 +/- 11.5%; p less than 0.005) and a further increase in IMA cross-sectional area occurred after ISDN (+27.4 +/- 20.1% versus basal; p less than 0.005). In contrast, SV failed to dilate during pacing (+0.3 +/- 5.4%; p = NS) and after ISDN (+0.7 +/- 6.0% versus basal; p = NS). Thus, an increase in myocardial blood flow demand induced by tachycardia results in dilation of IMA but not of SV grafted on coronary vessels. The ability of the endothelium to modulate the vasomotor tone of IMA grafts in response to changes in blood flow could contribute to their excellent long-term functional results after coronary artery bypass surgery.

Adaptation, Physiological↗
PubMed1990

A novel preservation medium protecting prostacyclin production and endothelial integrity of the human saphenous vein graft.

Patency rates of coronary artery saphenous vein bypass grafts can be as low as 50% in the first year after surgery. Of these occlusions, 70% can be attributed to mural thrombus formation. Improvements in surgical handling techniques and in preservation media have improved patency rates, as has the introduction of perioperative antiplatelet therapy. The authors describe a novel preservation medium consisting of heparinized blood from the patient, papaverine and dipyridamole. This medium enhances prostacyclin production and maintains endothelial integrity in preserved saphenous vein segments.

Blood Physiological Phenomena↗
PubMed1990

Surgical angioplasty of the left main coronary artery.

The conventional surgical treatment of isolated critical stenosis of the left main coronary artery restores a less physiologic perfusion of the myocardium, leads to occlusion of the left coronary ostium, and consumes an appreciable length of bypass material. Starting in June 1985, 23 surgical angioplasties have been performed in 22 patients. The left main stem was approached posteriorly in the first 11 patients, and an anterior approach was preferred in the last 12 because of better exposure. The onlay patch consisted of saphenous vein in the first 14 patients; pericardium was preferred in the last nine. The five failures occurred early. Four of these occurred in patients older than 60 years in whom calcifications of the left main stem had been seen on the preoperative angiogram. Eighteen procedures (78.3%) succeeded, but one patient (5.5%) died later of a massive air embolism. The 17 survivors are free of symptoms (maximal stress test combined with thallium scintigraphy) after a mean follow-up of 24.3 months. Angiographic restudy at an average of 8 months was obtained in 14 patients (82.3%) and revealed an excellent result in 13. In five patients, a late angiographic restudy (22 to 37 months) still revealed perfect patency of the left main stem. Provided that well-defined contraindications (calcifications, involvement of the distal bifurcation, older age) are respected, surgical angioplasty deserves a place in the array of surgical strategies.

Adult↗
PubMed1989

Sequential mammary grafting. Clinical, functional, and angiographic assessment 6 months postoperatively in 231 consecutive patients.

Between September 1985 and November 1987, 246 sequential mammary grafts were performed in 231 consecutive patients. Seventy-eight percent had triple vessel disease, and 33% required an urgent procedure. The length of the internal mammary artery pedicle was the only limitation to its use. No account was taken of the free cut-end flow of the internal mammary artery. There were 14 bilateral sequential mammary grafts and 15 free sequential mammary grafts. Of the 531 sequential mammary anastomoses, 482 were built with the left internal mammary artery; 113 (21%) were diamond-shaped anastomoses. The right internal mammary artery was brought through the transverse sinus in 44 cases, 10 times for sequential grafting of circumflex branches. Taking into account the adjunctive venous anastomoses and the single internal mammary artery anastomoses, there were 4.5 distal anastomoses per patient, 2.8 being mammary anastomoses and 2.3 being sequential mammary anastomoses. The hospital mortality rate was 2.6%. The prevalence of perioperative myocardial infarction was 5.2%. Follow-up was complete and averaged 15.4 months. Six patients (2.7%) still had angina pectoris. One hundred fifty-seven (71%) patients were recatheterized 6 months after the operation, and 95% of the sequential mammary anastomoses were still patent. The patency rate of the diamond-shaped mammary anastomoses was 94.5% and that of the anastomoses corresponding to the right internal mammary arteries brought through the transverse sinus was 94.3%. The gratifying functional results (maximal stress test combined with exercise thallium scintigraphy) obtained at an average of 6 months postoperatively illustrated the surprising physiologic adaptability of the internal mammary artery. As the attrition rate of the mammary artery grafts beyond 6 months postoperatively is thought to be minimal, gratifying long-term results with widespread use of sequential mammary grafts can be anticipated.

Adult↗
PubMed1989

[Surgical plasty of the left main coronary artery].

Critical stenosis of left main coronary artery (LMCA) is usually treated by conventional bypass surgery. However, this approach consumes an appreciable length of conduit, leads to occlusion of LMCA, and restores only a retrograde perfusion of a rather extensive myocardial area. As from June 1985, we performed 13 LMCA patch plasties in 12 patients. LMCA was approached either posteriorly via a curved aortotomy (9 cases), or anteriorly (4 cases) after retraction, partial or complete division of the main pulmonary artery. In 1 patient, a posterior LMCA plasty failed and a conventional double by-pass graft was needed. This patient underwent, 8 months later, a successful repeat patch plasty using a transpulmonary anterior approach. There was no perioperative myocardial infarction. There was no mortality. All of the patients underwent a 6 months postoperative angiographic control, with an excellent result in 12 cases: a significant restenosis of LMCA was successfully treated by percutaneous coronary angioplasty in 1 asymptomatic patient having concomitantly received a sequential mammary graft. All of the 4 patients are asymptomatic. A direct surgical approach to critical stenosis of LMCA is a valuable alternative treatment for this condition.

Adult↗
PubMedDate not supplied

Intra-operative acute leg ischaemia after free fibula flap harvest for mandible reconstruction.

Osteosarcomas of the cranial bones need a large surgical radical resection. The best option to reconstruct mandible defect after resection is the free fibula flap. In our patient an acute ischaemic leg occurred just after the free fibula flap harvest for mandible reconstruction. The abnormal distribution of the calf arteries leads to catastrophic consequences. The peroneal artery could be the main dominant artery of the leg in a small number of patients. We reported an extremely rare case of "peronea magna", described in less than 0.2% of the global population. A careful pre-operative workup of the calf vessels is required in all the patients who need free fibula flap harvest.

Adult↗
PubMedDate not supplied

Ischemic complications of abdominal aortic surgery.

From 1982 through 1988, 634 consecutive patients underwent abdominal aortic reconstruction for occlusive (37%) or aneurysmal (63%) disease. We studied the ischemic problems affecting the branches of the aorta, excluding the coeliac and superior mesenteric arteries. Ischemic colitis (0.6%), spinal cord ischemia (0.16%), renal insufficiency (17%), and lower limbs ischemia (6.5%) were the major problems encountered. We identified the most significant factors associated with these complications such as hypotension, emergency, hypovolemia, preoperative renal function, suprarenal clamping, the quality of the preoperative investigation, and have suggested some specific preventive measures.

Adult↗
PubMedDate not supplied

Sequential mammary artery grafts in one hundred and twenty consecutive patients: indications, operative technique, 6 months postoperative functional and angiographic controls.

In the hope of establishing the internal mammary artery (IMA) as a true but superior substitute for the saphenous vein (SV) we reviewed our initial experience in complex IMA grafting. The first 120 consecutive patients, having received at least one sequential IMA graft were analyzed. The length of the IMA pedicle was the only limitation imposed on its use. Technical artifices enhancing the versatility of the IMA are described. The significant peri-operative myocardial infarction rate was 3.3%. There was no cardiac operative mortality, and 1 late mortality (0.8%). Excellent functional results were illustrated by a 2.5% rate of residual angina and dyspnoea. Six months postoperative angiographic controls could be performed in 70% of the patients: all of the sequential mammary conduits were patent, as were 95% of the anastomoses. By contrast 87.2% of the concomitant venous anastomoses were still functioning. With the expanding utilization of the free graft, IMA is expected to become a true, better and all round substitute for the saphenous vein.

Adult↗
PubMedDate not supplied

[Pressure and flow measurements in the choledochus in acute pancreatitis of biliary origin (author's transl)].

During 4,528 operations on the biliary tract 216 cases showed proof of acute pancreatitis. In 153 instances hemorrhagic and necrotic pancreatitis was diagnosed. Pressure and flow measurements in the choledochus allow us to distinguish 3 categories: Immediate surgery (14) demonstrated marked oedemes of the duodenum at the papille of Vater (twice "cocarde" sign) with sustained high pressures and cascade-like flow. Operations 72 to 96 hours past the onset of pancreatitis (68) demonstrated intolerance duodenal anti-peristaltic waves and reflux into the enlarged Wirsung under physiological pressures (20 cm). Cases operated 8 days past the onset (71) showed under pressures (+/- 10 cm) massive and permanent reflux into the canal of Wirsung with low residual pressures and images representative of low duodenal tone. A single case of massive pancreatitis necrosis showed visualisation of the entire pancreatic ductal system under low pressure. The mechanism of reflux is discussed.

Acute Disease↗