PubMed Health⌕ Search

Biomedical subjects

E Ribbe

Publications and source records attributed to E Ribbe.

34 records · Page 2Linked to original sources
PubMed1992

Endothelialization of microporous polytetrafluoroethylene grafts in the infrarenal aorta and caval vein of the rat.

To study healing and endothelialization of vascular grafts, microporous polytetrafluoroethylene (PTFE) prostheses 2 mm in inner diameter and 5 mm long were implanted into the infrarenal aorta or caval vein of the rat. Patency was assessed in six rats from each group at days 3, 7, 14, 28, and 56 after implantation. Four grafts were occluded, two in the aorta (56 days) and two in the caval vein (3 and 14 days). The prostheses were examined via scanning electron and light microscopy for evaluation of endothelialization. At 3 days, the inner surface of the aortic grafts was covered by a plasma proteinaceous layer and that of the caval vein grafts by a thin mural thrombus. Endothelial cells then migrated from aorta/caval vein edges over the graft. At 14 days, the caval vein grafts were completely re-endothelialized, and, at 28 days, the mural thrombus in these grafts was replaced by neointima. In contrast, endothelialization of the aortic grafts had advanced only 1 mm at about 56 days, never forming a complete endothelial layer. We conclude that endothelialization of microporous PTFE prostheses is more rapid and complete in the caval vein than in the aorta of the rat.

Animals↗
PubMed1992

Surgical treatment versus thrombolysis in acute arterial occlusion: a randomised controlled study.

Thrombolytic treatment has been tried in various forms for acute limb ischaemia with varying degrees of success but is also often accompanied by bleeding problems. The present investigation compares the effect of surgical thrombectomy (TE) and thrombolysis (TL) using recombinant tissue plasminogen activator (rt-PA). Twenty patients with a need for intervention owing to ischaemia lasting more than 24 h but less than 14 days were included. Patients randomised to TE were operated under epidural anaesthesia and patients in the TL group received 30 mg rt-PA during a 3 h period through a catheter placed into the thrombus and advanced as lysis was achieved. Thrombectomy resulted in an immediate restitution of blood flow in six out of nine cases, in three cases a bypass procedure was performed, and one of these failed with a resultant amputation. Thrombolysis gave a good primary result in six cases which lasted in four of them. Three had a subsequent percutaneous transluminal angioplasty. Partial lysis was seen in two cases and a further two failed. Five went to surgery with three bypass and two fogarty procedures being necessary. There was no hospital mortality and there were no bleeding complications due to the rt-PA treatment in this series. In 19 out of 20 patients the circulation was re-established. Appropriate handling of acute ischaemic conditions implies the use of both thrombolysis and appropriate surgical procedures, including distal bypass grafts.

Acute Disease↗
PubMed1991

Visceral ischemia following aortic surgery.

Intestinal ischemia after aortic surgery is a rare (1-5%) complication, often with a fatal outcome (greater than 50%). During the period 1974-1987, 554 abdominal aortic operations were performed in our department. 17 patients (3%) were reoperated due to bowel ischemia, ten of these patients died. 12 patients were operated on due to aortic aneurysm (9 emergency operations) and 5 due to occlusive disease. A retrospective analysis of the files of the 17 patients was performed to try to identify the risk patient. Preoperative investigations demonstrated that the inferior mesenteric artery (IMA) was patent in 3 patients and occluded in 5 patients. As to the other 9 patients no information could be found (all with aneurysm). After the primary operation, 11 patients had persistent circulation via at least one of the hypogastric arteries and none of them had persistent circulation via the IMA. 11 patients had bloody diarrhea before reoperation and in 6 patients peritonitis was observed. Rectoscopy was performed in 8 patients and in 7 there was indication of ischemia. The most common finding among the laboratory tests was a rise in the creatinine level which was observed in 10 patients. Other laboratory tests such as blood gases, leucocytes, thrombocytes or temperature were of little predictive value per se. Patients operated on due to ruptured aortic aneurysm are risk patients. No other predictive symptom or sign was found to preoperatively identify the patient at risk for intestinal ischemia. An intraoperative method for evaluating the intestinal blood flow would be of great value when considering selective intestinal vascular reconstruction.

Aged↗
PubMed1990

Experimental evaluation of polymerized Dacron grafts in the iliac position of pigs.

Three differently polymerized Dacron grafts were compared to ordinary Dacron grafts and polytetrafluoroethylene grafts in the iliac artery of pigs. The grafts were inserted end-to-side and left for 40 days. Explantation was performed after glutaraldehyde pressure fixation. Gross morphology, light microscopy, and scanning electron microscopy were used to examine the specimens. We concluded that the polymerized grafts behaved similarly to polytetrafluoroethylene grafts and had a very limited foreign body reaction. Endothelial-like cells covered most of the graft surface.

Animals↗
PubMed1990

Immune response to collagen impregnated Dacron double velour grafts for aortic and aorto-femoral reconstructions.

This study presents 20 patients, randomised to receive either a collagen-treated or an ordinary Dacron graft for aortic reconstructions, and the results of a skin-prick test, blood parameters and ELISA for anti-collagen antibodies as well as NMR pictures during a 6 week follow-up period. Forty per cent (4/11) of those receiving a collagen impregnated graft had a significantly increased titre of antibodies and NMR revealed in two out of 11 patients either a slightly increased amount of fluid or fibrosis around the graft, both collagen impregnated. No differences were found between the graft groups concerning body temperature and leucocyte or platelet counts. The skin-prick test for collagen was negative in all cases.

Adult↗
PubMed1990

Intestinal hemodynamics during laparotomy: effects of thoracic epidural anesthesia and dopamine in humans.

The effects of thoracic epidural anesthesia (TEA) and dopamine infusion (4 micrograms.kg-1.min-1) on superior mesenteric artery blood flow (SMABF), the mesenteric arteriovenous oxygen difference (AVDO2), and the mesenteric venous lactate concentration were studied in nine patients before abdominal aortic reconstruction. Thoracic epidural anesthesia reduced SMABF, as measured by electromagnetic flowmetry, to 77% +/- 8% (mean +/- SEM) of control (P less than 0.05), and mean arterial pressure to 46% +/- 4% of control (P less than 0.01). The mesenteric AVDO2 increased from 27 +/- 3 to 39 +/- 6 mL/L (P less than 0.05) and superior mesenteric venous lactate from 1.03 +/- 0.11 to 1.60 +/- 0.38 mmol/kg (P less than 0.05); systemic AVDO2 and lactate did not change. Dopamine had no significant effect on SMABF and mean arterial pressure before TEA. However, dopamine increased SMABF during TEA (from 77% +/- 8% to 137% +/- 21% of control; P less than 0.01), returned mesenteric AVDO2 to 27 +/- 3 mL/L (P less than 0.05), and elevated mean arterial pressure to 62% +/- 4% of control (P less than 0.05). It is concluded that the decrease in perfusion pressure during TEA reduces SMABF with resultant evidence of intestinal reductive metabolism. The intestinal blood flow during TEA was improved by dopamine.

Aged↗
PubMed1989

Infections and antibiotic prophylaxis in reconstructive vascular surgery.

In 98 patients undergoing elective vascular surgery, specimens for bacterial cultures were obtained from urine, ischaemic ulcers, incisional wounds and the implanted grafts. Wound and graft infections were registered and compared with the results of these cultures and suspected risk factors in an attempt to find the source of infections. Antibiotic prophylaxis with cefuroxime was given for 24 h beginning at the start of surgery. Patients with ischaemic ulcers also received "spread prophylaxis", directed against isolated bacteria, for ten days. Three cases of graft infection and twelve cases of wound infection occurred. Positive postoperative cultures from wounds did not correlate with pre- or peroperative cultures. Peroperative cultures revealed small numbers of staphylococcus epidermidis in eleven patients, and none of them developed graft infection. Ischaemic ulcers, diabetes or re-do procedures were not accompanied by a significantly increased frequency of wound or graft infection, although each of three patients with graft infection had one of these risk factors. Bacteria, sensitive to cefuroxime, were found in one graft infection, six wound infections, and in two patients with urosepsis, whereas cefuroxime resistant organisms were isolated from one graft infection and three infected wounds. One of the three graft infections was probably caused by bacteria originating from the patient's ischaemic ulcer. In the other two patients the source of bacteria could not be determined. Cefuroxime seems to be an adequate alternative for prophylaxis of vascular graft infection, but in some patients with bacteriuria or indwelling catheters, a one day regimen may be too short.

Aortic Aneurysm↗
PubMed1989

Direct evidence of active sympathetic vasodilatation in the skin of the human foot.

1. During operative aorto-femoral vascular reconstructions on sixteen patients, the sympathetic chain was stimulated electrically between the L2 and L4 ganglia while blood flow was monitored by laser doppler flowmeters from the skin on the sole of the foot and the ankle and by an electromagnetic flowmeter from the deep femoral artery. Epidural anaesthesia to at least the T6 level was used which excluded reflex effects. 2. Stimulation (10 Hz) at 1-12 mA current strengths for 30 s evoked both reductions and increases of blood flow in glabrous and hairy skin. Initial short-lasting flow increases (durations 9-19 s) followed by sustained decreases were common: sometimes there were sustained flow increases at low and decreases at high current strengths. 3. In the deep femoral artery (supplying predominantly muscle) only flow reductions were evoked. 4. The results provide evidence for sympathetically mediated vasodilatation in the skin of the human foot whereas leg muscles may be supplied by vasoconstrictor nerves only.

Aged↗
PubMed1989

Eleven years of aortic aneurysm surgery: changes in techniques and results.

This study presents data from aortic aneurysm surgery during the two periods 1974-1981 and 1982-1984. During the last period most elective patients were operated on under epidural analgesia. The proportion of electively operated patients increased from 44% to 65%. The blood loss decreased significantly from the early to the late period. The mortality rate decreased from 58% to 43% for acute, and from 12% to 6% for elective patients.

Acute Disease↗
PubMed1987

Secondary aortoenteric fistulas--an analysis of 42 cases.

Secondary aortoenteric fistulas are seen with an increasing frequency which parallels the expansion of reconstructive vascular surgery. During a 12-year period 42 cases have been collected from the hospitals, which perform most of the vascular surgery in Sweden (0.7% of vascular operations). Twenty-five were seen after operation for aortic aneurysm, 15 for aortoiliac occlusive disease, one after renal artery ligation (as a part of reconstruction for renovascular hypertension) and one after operation for an iliac pseudoaneurysm. The frequency of complications during and after the primary operation was high. The interval between operation and onset of fistula symptoms was significantly shorter if there had been infectious complications, the median interval was 32 months, the longest being 10 years. The most important symptom was gastrointestinal haemorrhage, consisting of several small bleeds often combined with septic complications. A large number of negative investigations usually preceded the final diagnosis which was made at exploratory laparotomy. After surgery for the fistula the frequency of complications and mortality, were very high. Mortality was 58%, the most common cause of death being a blow out of the aortic stump. Of those leaving hospital, several further operations were performed with a high mortality. Recurrence of the fistula occurred in 16 out of 34 patients who survived surgery. At follow-up (12-74 months after fistula closure) seven patients were still alive.

Adolescent↗
PubMed1985

A neurophysiologic investigation of thoracic outlet syndrome.

Earlier reports have been conflicting as regards the value of neurophysiologic measurements in the diagnosis of thoracic outlet syndrome (TOS), presumably due to differences in selection of patients and in selection and standardization of neurophysiologic tests. The object of the present study was to assess the value of extensive conventional neurophysiologic measurements for the diagnosis of brachial plexus compression in patients with clinical TOS as determined from standardized criteria. The results are discussed in the light of expected neurophysiologic findings at different degrees of brachial plexus compression.

Adolescent↗
PubMedDate not supplied

Intra-operative digital angiography as a control of the in situ saphenous vein by-pass grafts.

Forty-two patients undergoing in situ saphenous vein by-pass grafting procedures, in two patients bilaterally, were examined intra-operatively with digital subtraction angiography. In 19 (43%) of the examinations the graft and the anastomoses appeared adequate. In 8 cases (18%) significant abnormalities were found, including stenoses (11%), deficient anastomoses (5%) and graft kinking (2%). Remaining arteriovenous fistulas were found in 17 patients (39%). In most cases immediate correction was possible avoiding later re-operation. At follow up 11 of the 44 grafts were occluded, 10 of these during the first five months and of these five during the first week.

Adult↗
PubMedDate not supplied

Distal bypass with the saphenous vein in situ. Technical aspects and early results.

The in situ saphenous vein graft has theoretical advantages, e.g. preservation of vasa vasorum and normally functioning endothelium, over the reversed vein graft and has gained popularity in recent years. Forty-three patients underwent 45 distal in situ saphenous vein bypasses for limb salvage during a 15-month period. The Hall valve stripper was found to be superior to the Mill valvulotome for valve incision. Intraarterial digital subtraction angiography (DSA) was a useful tool for perioperative anastomosis and graft evaluation. The incidence of early graft failure, 8/45 (18%), was mostly due to identifiable causes, mainly small caliber veins (less than 2.5 mm diameter). The cumulative patency rate of 77% remained stable during the follow-up period of 15 months. Perioperative mortality was zero. The main technical advantage with the in situ method is the reduced size disparity at the anastomotic sites. The in situ technique allowed the successful use of veins as small as 2.5 mm in diameter which resulted in a vein utilization rate of 95%. This rendered long distal bypasses possible in patients who could not have been reconstructed with the reversed vein technique.

Aged↗
PubMedDate not supplied

A ruptured aortic aneurysm that "spontaneously healed".

A case of recovery after rupture of an abdominal aortic aneurysm without surgery is presented. The natural course of an abdominal aortic aneurysm is described by means of ultrasound examinations. The healing process after rupture is demonstrated with CT-scan. The question of whether all abdominal aneurysms should be resected is discussed.

Aged↗