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H J Buchardt Hansen

Publications and source records attributed to H J Buchardt Hansen.

17 recordsLinked to original sources
PubMed1988

Quantitative assessment of carotid artery disease by continuous wave and pulsed multigated Doppler--prospective comparison with angiography.

We have evaluated the use of a Doppler system combining continuous wave (CW) and pulsed multigated Doppler (PD) for quantification of internal carotid artery (ICA) stenoses. The peak systolic frequency (PF), obtained with the CW technique was used for identification of lesions exceeding 50% stenosis. Thereafter, with the PD technique, the spectral broadening index (SBI) was calculated from a sample volume located in the area of highest forward velocity (PD), and this SBI was used to discriminate normal from diseased vessels. Results were compared with arterial digital subtraction angiography. For assessment of greater than or equal to 50% stenoses we obtained an overall accuracy of PF (CW) of 90%. The use of SBI (PD) for discriminating normal from diseased vessels resulted in an accuracy of 86% (sensitivity 93%, specificity 74%). The combination of CW and PD achieved an overall agreement of 77% (kappa = 0.676 +/- 0.053). It is concluded that the combination of CW and pulsed multigated Doppler is accurate in the diagnosis of even minor ICA stenoses. For exclusion of disease, imaging combined with flow information seems necessary.

Adult↗
PubMed1988

Haemodynamic evaluation of the cerebral circulation by periorbital Doppler examination and cerebral blood flow (CBF) measurement in carotid artery disease.

To assess the haemodynamic significance of an internal carotid artery (ICA) stenosis, angiography or direct ultrasound examination should be supplemented by indirect physiologic testing of the collateral circulation. Among the tests proposed, we used the periorbital flow direction, assessed by Doppler technique, and cerebral blood flow reactivity to vasodilation, by i.v. xenon-133 technique, in 35 patients before carotid endarterectomy. The results were related to the actual perfusion pressures, measured during surgery in the distal ICA. All 15 patients with normal orthograde periorbital flow had normal cerebral blood flow (CBF) vasoreactivity and no, or only minor, reduction in ICA perfusion pressure. Of the 20 patients with inverted flow, 12 had normal and 8 had abnormal CBF reactivity. These 8 patients proved to have significantly lower cerebral perfusion pressures, as compared with the remaining 12 patients with inverted periorbital flow (p less than 0.001), who in turn had lower perfusion pressures than the 15 patients with orthograde flow (p less than 0.005). Based on these results, we suggest periorbital Doppler examination as a haemodynamic adjunct to direct ICA visualization. A normal orthograde flow will most certainly rule out any severe pressure reduction. By measuring CBF at rest and following vasodilation in cases with inverted flow, most patients with severe reduction in cerebral perfusion pressure may be identified.

Adult↗
PubMed1988

Middle cerebral artery occlusion in presence of low perfusion pressure increases infarct size in rats.

A model was set up in order to evaluate the importance of hemispheric perfusion pressure when the middle cerebral artery (MCA) is occluded in anaesthetized rats. In 6 animals the internal carotid artery (ICA) was occluded prior to ipsilateral MCA occlusion; in 17 animals the MCA only was occluded; 6 animals underwent the same preparation, but the vessels were left unoccluded. Four days after surgery the infarct volume was measured with a computerized image analyser. The infarcted areas were significantly larger in the ICA + MCA occluded group compared with the MCA occluded group (p less than 0.005), which in turn had larger infarcts than the sham-operated animals (p less than 0.001). These results indicate that patients with hypoperfusion, due to severe ICA stenosis and impaired collateral blood supply, are at higher risk of developing major stroke, when embolism into a cerebral artery occurs, as compared to patients with no, or only minor, reduction in hemispheric perfusion pressure.

Animals↗
PubMed1987

Carotid endarterectomy in patients with occlusion of the contralateral carotid artery. Perioperative risk and late results.

Recent reports on the outcome of carotid endarterectomy in patients with contralateral occlusion have been conflicting. Therefore, we reviewed 51 cases identified, among 675 consecutive carotid endarterectomies. A perioperative mortality of 2% and a permanent morbidity rate of 16% was observed. Compared with a complication rate of about 5% previously reported from this institution, this clearly indicates contralateral carotid occlusion as a major risk factor in carotid surgery. Though not statistically significant, patients with severely reduced cerebral perfusion pressure (CPP) had suffered more severe strokes when compared to patients with only minor reduction in CPP. In addition, the internal carotid artery blood flow following endarterectomy was significantly higher in the low pressure group (P less than 0.02). No patients were lost during follow-up, for a mean of 34 months. The cumulative five-year survival rate was 74%, not significantly different from the expected survival of an age and sex matched population. During the period of follow-up 16 patients experienced new neurologic symptoms, in six (2 strokes and 4 TIA's) referable to the hemisphere ipsilateral to operation and in 10 (2 strokes and 8 TIA's) referable to the contralateral hemisphere. The five-year stroke rate was 16%. This together with the observed survival rate indicated a better-than-expected course in this group of patients with severe cerebrovascular atherosclerosis.

Carotid Artery Diseases↗
PubMed1987

"Femoro-distal bypass--a worthwhile procedure?".

Infrapopliteal vascular reconstruction was undertaken in 63 patients with limb threatening ischaemia. Graft materials used were reversed autogenous saphenous vein in 33 patients, umbilical vein in 23 patients, composites of saphenous and umbilical vein in six patients, and a Solcograft in one patient. At the end of the first month 13 grafts were non-functioning, and eight of these patients had an amputation performed. Cumulative 3-year limb salvage and patency rates were 69% and 35%, respectively. Cumulative patency rates of saphenous and umbilical vein grafts were equal, and neither the indication for operation nor the preoperative ankle-arm pressure index correlated to graft failure. In total, twenty-two major amputations were performed, 16 below or through the knee, and six above-knee. The conclusion is that vascular reconstructive surgery for limb threatening distal disease is a valuable procedure.

Arterial Occlusive Diseases↗
PubMed1987

Four years' results of a prospective, randomized clinical trial comparing polytetrafluoroethylene and modified human umbilical vein for below-knee femoropopliteal bypass.

Polytetrafluoroethylene (PTFE) (Gore-Tex) and human umbilical vein (Biograft) arterial grafts were compared for below-knee femoropopliteal bypass grafting in a prospective randomized clinical trial. One hundred five patients (105 limbs) entered the trial. Seventy-six percent suffered from rest pain, ulceration, or gangrene. The median postoperative ankle-arm blood pressure index was 0.36. Twenty-three limbs had three patent tibial arteries, 46 limbs had two tibial arteries, 31 limbs had one patent artery, and five limbs had isolated popliteal segments. Thirty-four percent were repeat operations. Fifty-five patients were allocated to receive PTFE grafts and 50 to receive human umbilical vein grafts. The two groups were comparable as to preoperative risk factors and operative and postoperative treatment. During the first 4 years (maximum 1609 days) 40 PTFE grafts and 24 umbilical veins occluded. At 1 year the PTFE patency rate was 53% and at 4 years was 22%. For umbilical vein the corresponding figures were 74% and 42% (p = 0.005, Gehan test). During follow-up the incidence of PTFE failure was on the average 2.1 times higher than that of umbilical vein failure (95% confidence limits 1.2 to 3.4).

Aged↗
PubMed1987

Surgical treatment of anuria caused by renal artery occlusion. Case report.

A patient with anuria caused by renal artery occlusion is presented. Revascularization was performed 42 days after onset of renal failure, and resulted in complete normalization of kidney function. The case demonstrates that surgical treatment of prolonged renal artery occlusion with subsequent return of renal function is possible.

Aged↗
PubMed1985

Late results after surgical treatment of renovascular hypertension. A follow-up study of 122 patients 2-18 years after surgery.

During the period 1963-1980, 122 patients were operated on for renovascular hypertension at surgical department D, vascular section, Rigshospitalet, Copenhagen. Seventeen patients, with a median age of 24 years, had fibromuscular hyperplasia and 95 patients, with a median age of 48 years, had atherosclerosis. Twenty-four of the latter had bilateral renal artery lesions and 71 had unilateral disease. Ten patients had various other causes of renovascular hypertension. Operative mortality was 4.9%, decreasing to two per cent in the last 8 years. At discharge, 71% of the patients were normotensive without medication, 18% were improved, and 11% were unimproved. At follow-up in 1982, the actuarial 10-year survival rates for patients with unilateral and bilateral atherosclerotic disease were 65% and 48%, respectively. There was no difference between survival rates for patients with fibromuscular hyperplasia and an age- and sex-matched, population. Sixty-nine patients were reexamined with a median follow-up of 9 years. Of the survivors with atherosclerosis, 87% benefitted from the operation: 50% were normotensive without medication and 37% were improved. Of patients with fibromuscular hyperplasia, 93% benefitted from operation: 79% were normotensive and 14% were improved. The results support the value of surgery in patients with renal fibromuscular hyperplasia and to the long-term benefits of surgical treatment of patients with atherosclerotic renovascular disease.

Adolescent↗
PubMed1985

Human umbilical vein for vascular access in chronic hemodialysis.

Since 1979 we have used human umbilical vein graft as the ultimate vascular access for hemodialysis in patients with chronic renal failure. In 24 patients 33 graft fistulas were performed. Several complications were encountered. Among these infection was the most serious, occurring in seven grafts. All these grafts were removed and never used for hemodialysis. Thrombosis occurred 25 times, and five grafts were lost because of this, whereas 20 grafts had successful thrombectomy and continued to function. Aneurysm formation occurred four times, two grafts were lost. Stenosis was seen in three cases, one graft was lost. In the material 26 grafts were used for hemodialysis and a median function time of 8.5 months was obtained. At the end of the observation period 10 grafts were open, eight were used for hemodialysis, two were not used because of successful transplantation. The umbilical vein graft is an acceptable alternative as vascular access where conventional methods of fistula formation have been exhausted.

Adolescent↗
PubMed1985

Umbilical vein bypass in patients with severe lower limb ischemia: a report of 121 consecutive cases.

In 112 patients with severe ischemia of the lower limb and without a suitable saphenous vein, 99 femoropopliteal and 22 femorodistal bypass procedures were performed with the modified human umbilical vein (Biograft, Meadox Medicals Inc., Oakland, N.J.). Seventy-eight percent of the operations were performed for limb salvage. In the remaining 22% the indication was severe disabling claudication. Forty-nine percent of the patients had previously undergone arterial reconstruction of the extremity in question. In 36% the distal anastomosis was to the popliteal artery above the knee, in 46% to the popliteal artery below the knee, and in 18% to one of the crural arteries. It was mandatory to perform an additional proximal reconstruction in 38% of the extremities. The observation time ranged from 6 to 60 months, with a mean of 24 months. Two patients died within the first month. The overall cumulative patency rate calculated by the life table method was 67.7% at 1 year, 61.2% at 2 years, and an unchanged 56.6% at 3 to 5 years. The cumulative patency rate in the limb salvage group was higher (58.6%) than the patency rate of the grafts implanted for claudication (46.5%, not significant). Graft patency decreased the more peripherally the distal anastomosis was situated, but we could demonstrate neither a significant relationship between graft patency and runoff nor any prognostic significance in the peroperatively measured flow values. Limb salvage calculated by the life table method was 86% at 1 year and 75.4% at 5 years. It is concluded that the umbilical vein graft is an acceptable alternative for bypass grafting in patients without a suitable autogenous vein.

Aged↗
PubMed1985

Ischemic colitis complicating reconstruction of the abdominal aorta.

A review of 23 patients with ischemic colitis after surgical treatment of the abdominal aorta disclosed a pathogenetic heterogeneous finding. Ligation of the inferior mesenteric artery, abolished collateral blood supply or nonocclusive low flow state, or both, was a common feature. An incidence of 0.5 per cent was revealed for full-thickness necrosis. The mortality was 70 per cent since diagnosis was made first since perforation and peritonitis had occurred. On the basis of these findings vital prophylactic measures and diagnostic possibilities are discussed herein.

Aged↗
PubMed1983

A randomized clinical trial of PTFE versus human umbilical vein for femoropopliteal bypass surgery. Preliminary results.

PTFE (Goretex) and modified human umbilical vein (Biograft) vascular grafts were compared in femorodistal popliteal artery bypass surgery in a randomized clinical multicentre trial. During 18 months 104 patients (104 limbs) entered the trial. Twenty-five patients suffered from claudication, 54 suffered rest pain and 25 patients had ulceration or gangrene. The median preoperative ankle-arm blood pressure index was 0 . 34. Twenty-three limbs had 3 patent tibial arteries, 45 limbs had 2 tibial arteries, 31 limbs had 1 tibial artery while 5 limbs had an isolated popliteal segment. Thirty-six of the operations were redo-operations. Fifty-four patients were allocated to PTFE and 50 to umbilical vein. During follow-up (maximum 650 days) 24 PTFE grafts occluded against 12 umbilical veins. The 1-year patency rate was 40 per cent in the PTFE group against 75 per cent in the umbilical vein group (P = 0 . 014, Gehans test). During the first year the PTFE failure rate was on average 3 . 1 times higher than that of the umbilical vein.

Aged↗
PubMed1976

Abdominal angina. Results of arterial reconstruction in 12 patients.

Twelve patients suffering from abdominal angina have been operated upon with revascularization of the superior mesenteric artery. Preoperatively, all had the classical symptoms: postprandial pain, wieght loss and abnormalities of the stools. The surgical procedure of choice was endarterectomy with patch grafting; in two cases a vein by-pass have been used. In general, it will be sufficient to reconstruct one artery, even with two or three of the mesenteric arteries afflicted. Peroperative measurements of pressure gradients and flow may guide in choice of procedure. Two patients died postoperatively, both had additional extensive reconstruction of the aorta and the renal arteries. The remaining 10 patients were all relieved of their symptoms after the operation and gained considerably in weight. They were followed over 25 months in mean. During the period of observation 2 patients have died from other diseases. The good longterm results after arterial reconstruction in contrast to the poor prognosis without operation call for early diagnosis and surgical treatment. The difficulties involved with the diagnosis of abdominal angina are discussed and a functional diagnostic test is proposed.

Adult↗