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Biomedical subjects

W Sandmann

Publications and source records attributed to W Sandmann.

At least 19 recordsLinked to original sources

[Reconstruction of the inferior vena cava for extended resection of malignant tumors].

OBJECTIVES: Malignant tumor invasion in the inferior vena cava (IVC) has for a long time been the limiting factor in the resection of retroperitoneal tumors. The clinical outcome in these patients depends on vascular surgical techniques, the central role of which is played by IVC reconstruction. METHODS: Within the last 7 years, 9,085 vascular reconstructive procedures were performed in our department. Six patients suffered from retroperitoneal invasion of tumor into the IVC. After tumor resection, the involved IVC segments were replaced by polytetrafluorethylene (PTFE) grafts to restore IVC continuity. In three patients, an adjunctive arteriovenous (AV) fistula was constructed. RESULTS: The graft patency after a mean follow-up of 30.2 months (range 1 to 79) was 83.3%. The only graft occlusion occurred in a patient without AV fistula. There were no perioperative deaths and no major complications demanding reoperation. CONCLUSION: In patients with tumor involvement of the IVC, clinical outcome depends on vascular surgical coprocedure. After resection of the IVC, a PTFE graft should be interposed in combination with an AV fistula. Anticoagulation and CT scan are recommended after 3 months before ligation of the AV fistula.

Adult↗

Carotid surgery in acute symptomatic patients.

OBJECTIVES: evaluation of urgent carotid artery surgery with new diagnostic techniques and changing surgical considerations at a university hospital. DESIGN, MATERIAL AND METHODS: prospective monitoring and assessment of outcome in 67 patients who underwent urgent carotid surgery because of symptomatic extracranial carotid artery involvement. Patients were examined via the stroke unit: duplex sonography was mandatory for diagnosis of extracranial carotid artery disease, as was proof of an open middle cerebral artery (MCA). Assessment of intracerebral damage followed CT or MR imaging procedures. Perioperative and surgical management was standardized. Neurological impairment was assessed pre-, postoperatively and at follow-up using the Rankin scale. "Urgent" was defined as "immediate" after the final diagnostic step had been performed. RESULTS: within a period of 26 months 67 symptomatic patients (58% stroke, 42% TIA) underwent urgent carotid surgery. Median time from admission to surgery was 2 days. In all but five cases flow through the ICA could technically be restored (93%). Thirty-day mortality was 3% and disease-related morbidity 13%. The one and two year survival rates were 92 and 90%, respectively. No ipsilateral recurrent stroke occurred during follow-up. CONCLUSIONS: clinical decision-making based on stratified diagnostic workup by means of extra- and intracranial as well as intracerebral hemodynamics using new imaging techniques may select patients who will benefit more from urgent surgery than from conservative management.

Acute Disease↗

Graft patency and clinical outcome of femorodistal arterial reconstruction in diabetic and non-diabetic patients: results of a multicentre comparative analysis.

OBJECTIVE: in diabetic patients with critical limb ischaemia (CLI) an inferior success rate following infrainguinal bypass surgery is quite often suggested. The aim of this retrospective analysis was, therefore, to evaluate the graft patency and, particularly, the clinical outcome at 1 year in diabetic compared with non-diabetic patients. MATERIAL AND METHODS: two hundred and eleven patients (diabetics 94; non-diabetics 117) with femorodistal reconstruction for CLI were studied. Groups were comparable with regard to the Fontaine classification, the distribution of vascular risk factors, graft material, distal anastomosis site, and the angiographic runoff grading. RESULTS: diabetes did not adversely affect graft function. For diabetics and non-diabetics primary cumulative patency rate at 1 year was found to be 66 and 56%, respectively (p=0.10) and a virtually identical limb salvage rate of 85 and 83% was achieved (p=0.76). With regard to healing of ischaemic foot ulcers a trend against diabetics was noted with a healing rate of 81% compared to 96% in non-diabetics at 1 year (p=0.067); gangrenous foot lesions could be equally remedied in 94% and in 87% among patients with and without diabetes (p=0.44). The survival rate of diabetics, however, was significantly lower with 78% at 1 year compared with 95% in non-diabetic patients (p=0.0004). CONCLUSIONS: our preliminary results support the view that infrainguinal bypass grafting can be safely done even in diabetics. Despite increased mortality in this group, liberal indication for reconstructive vascular surgery seems to be justified by favourable patency rates and clinical outcome in selected patients.

Aged↗

Hemodynamically relevant hematuria several months after biopsy of a kidney graft: an unusual cause.

We report the case of a 52-year-old female patient, who after a complicated living donor kidney transplantation, underwent kidney biopsy for suspected rejection. Duplex scanning revealed a small, asymptomatic arteriovenous (AV) fistula which was assessed as being hemodynamically unimportant. During follow-up, several urinary tract infections occurred and recurrent short episodes of hematuria were attributed to cystitis, urethritis and urosepsis. Eight months later, the patient developed suddenly massive hematuria, tamponade of the urinary bladder and hemorrhagic shock as well as urosepsis. Duplex sonography showed a massive pseudoaneurysm in addition to the AV fistula. Arteriography confirmed the Duplex sonographic findings and embolization was performed after treatment of concomitant urosepsis. The fistula was closed completely and bleeding ceased. Although AV fistulas are rare complications of kidney biopsies and in most cases they remain asymptomatic, life-threatening hematuria can present several months after a biopsy due to the development of a pseudoaneurysm. Concomitant infectious complications of the urinary tract, bleeding disorders and other factors can be misleading during the assessment of the cause of gross hematuria. Regular Duplex sonographic follow-up examinations in patients with AV fistulas are advisable.

Aneurysm, False↗

[Long-term results after carotid reconstruction in patients with completed stroke caused by cerebrovascular occlusive disease].

UNLABELLED: Long-term results after carotid reconstruction in patients with completed stroke caused by cerebrovascular occlusive disease. BACKGROUND AND OBJECTIVE: In patients with completed stroke caused by cerebrovascular occlusive disease the reconstruction of high grade carotid artery stenosis is discussed as prophylaxis for prevention of recurrent stroke. The operative complications of all patients who underwent surgery for carotid occlusive disease in the Heinrich Heine University between 1990 and 1999 were evaluated in this study. PATIENTS AND METHODS: We present the results of 596 reconstructions in 537 patients (404 men, 133 women; mean age 64,5 plus minus 9,4 years). The operative technique of choice was thromboendarterectomy of the carotid bifurcation with vein-patch closure. RESULTS: A postoperative ipsilateral neurological deficit was observed in 41 patients (6,9 %): 4,7 % permanent, 2,2 % transitory. Thirtyeight percent of the permanent deficits appeared after reconstructions performed within six weeks after stroke and only 9 % after surgery between six and twelve weeks. The in-hospital mortality was 0,7 % for neurological and 1,0 % for cardiopulmonary complications. During long-term follow-up (mean follow-up time 50 plus minus 34 months) only 17 (3,7 %) of 462 patients, which could be evaluated, presented with a new neurological event for the reconstructed side. Fifty-eight percent had none or minimal neurological deficits. 115 Patients (24,0 %) died during follow-up. CONCLUSION: Even after completed stroke carotid reconstruction can be carried out successfully in selected patients with an acceptable complication rate in prophylaxis of recurrent stroke. In our retrospective study the optimal time for surgery seems to be between six and twelve weeks after stroke, but new imaging techniques may alter in the future the time window for operation in patients with an unstable neurological situation early after stroke. The reduction of social mobility and the high mortality in follow-up in correlation to patients without stroke are mostly related to accompanying severe cardiopulmonal risk factors.

Aged↗

[Survey of therapy of deep venous thrombosis among members of the German Society of Vascular Surgery].

INTRODUCTION: In the literature of the past 15 years, deep venous thrombectomy has been rarely described. The only indications reported for thrombectomy seem to be recurrent pulmonary embolisation and phlegmasia coerulea dolens. Many contraindications and severe complications are making decisions concerning thrombolysis very difficult. At present, anticoagulation therapy is preferred over fibrinolysis. There is no conclusive concept for the standardization of treatment for deep venous thrombosis. As a first step towards achieving this, it was necessary to know what therapy is performed in hospitals throughout Germany. METHODS: In 1999, we sent letters of enquiry to the members of the "Deutsche Gesellschaft für Gefässchirurgie". We wrote to 341 members (hospitals), and the information gained by means of a questionnaire was analysed and evaluated. RESULTS: We received answers from 39.9% (n = 136) of the members. In all, 69% of the hospitals had an independent vascular department. In 1999, 6,718 patients underwent treatment for deep venous thrombosis, on average, 51 patients per hospital. Overall, 7,665 therapies were performed in one year (15.9% thrombectomy, 18.6% fibrinolysis, and 65.5% only anticoagulation). Only 23.5% of the hospitals had their own data about the outcome of their patients. The patency rate was 71.8% for thrombectomy and 48.9% for fibrinolysis. A severe postthrombotic syndrome was seen in 6.2% after thrombectomy, in 8.1% after fibrinolysis, and in 10.4% after singular anticoagulation. CONCLUSION: At present, there is still no standardized concept for the treatment of patients with deep venous thrombosis. It seems that there are better results for some indications with thrombectomy than with other methods. For the establishment of a concept of treatment, a prospective randomised study is necessary.

Anticoagulants↗

[Surgical reconstruction of high grade carotid stenosis: a safe procedure?].

Carotid surgery is still controversial. Some large randomized trials have demonstrated the benefit of surgery in correlation to conservative treatment alone, but these positive results depend on how specific the diagnosis is and a low complication rate. This study presents the results of 2162 patients (male n = 1596 (74%), female n = 566 (26%), mean age 65 +/- 9 years), who underwent carotid surgery between 1990 and 1999. Forth-three percent of these patients had no ipsilateral neurological symptoms with high-grade carotid artery stenosis (Stage I). Thirty-eight percent appeared with prior ipsilateral TIA or PRIND--symptomatology (Stage II) and 19% suffered from stroke with persisting deficits (Stage IV). The operative technique of choice was thromboendarterectomy of the carotid bifurcation with vein-patch closure in 1967 patients (91%). In 1324 patients segmental resection of the internal carotid artery was performed. Carotid endarterectomies and other reconstructions for coronary artery disease including abdominal aortic aneurysm were combined during the same operation in 11% of the patients. The rate of postoperative ipsilateral neurological events was 4.1%. On the ontralateral side neurological symptoms appeared among 0.8%, and 0.4% of the patients had bilateral symptoms. Twenty patients (0.9%) died as a result of postoperative stroke. In relation to preoperative staging of the cerebrovascular occlusive disease in stage I, postoperative neurological symptoms appeared in 2.8% (mortality 0.6%), stage II in 5.7% (mortality 1.0%) and stage IV in 7.8% (mortality 1.2%) of the patients. These results confirm the importance of carotid reconstruction as a measure in the prevention of cerebral infarction in patients with asymptomatic or symptomatic high-grade carotid artery stenosis. The complication rate was lower than the data reported in the literature and the results were clearly better than under conservative treatment alone. In our opinion, the indication for carotid artery reconstruction should be made by a team of vascular surgeons, neurologists and neuroradiologists taking all patient-specific factors into consideration. Only by optimal patient selection and minimal complication rates will a significant benefit for the patient be achieved.

Aged↗

[Aortoiliac reconstruction after kidney transplantation. Strategies to avoid ischemic damage of the transplant].

INTRODUCTION: The rising life expectancy of patients undergoing kidney transplantation and the improvement in the function rate of the allografts have led to an increasing number of patients suffering from arteriosclerosis-related diseases of the aortoiliac arteries. In these particular cases, an interruption of the blood supply of the allograft is always necessary for operative repair of the aortic and iliac arteries. This means a high risk of ischemic damage to the transplanted kidney. PATIENTS AND METHODS: Between 1987 and 2000, 1,076 kidney transplantations were performed in our department. During this time, 14 reconstructive operations of the aortoiliac arteries were performed in 12 patients (6 women, 6 men, average age 55.2 (45-71) years). Operations were indicated in patients suffering from occlusive disease with imminent extremity or allograft loss, and symptomatic or asymptomatic aneurysms with a maximum diameter of more than 4 cm. In patients presenting with thoracoabdominal (1) and abdominal aortic aneurysms (3), protection of the transplanted kidney was performed by axilloiliac or axillofemoral bypass. Hypothermic flush-perfusion of the allograft containing PGE1 and heparin was performed in seven of nine operations for occlusive disease. RESULTS: None of the patients presented with a permanent decrease in kidney function, six patients showed temporary creatinine elevation, and in nine patients creatinine levels at discharge were lower than they were preoperatively. None of the patients died. CONCLUSION: Reviewing all reported methods of allograft protection, we recommend a three-step strategy including sequential clamp technique (ischemia < 30 min.), hypothermic flush-perfusion (ischemia < or = 60 min.), and temporary axilloiliac/femoral shunt (ischemia > 60 min), depending on the expected renal ischemia time.

Aged↗

Systemic and local antibiotic prophylaxis in the prevention of prosthetic vascular graft infection: an experimental study.

AIM: to determine if local, in addition to systemic antibiotic prophylaxis (compared to that provided by systemic prophylaxis alone) provides additional benefit in terms of reducing graft infection. METHODS: gelatin-sealed Dacron grafts were interposed in the infrarenal aorta of 36 mongrels and inoculated with 1 ml of a S. aureus suspension. Group 1 (control group) received no prophylaxis and were inoculated with 1 ml containing 10(9)cfu/ml. Group 2 (n=6) received systemic prophylaxis (1 g cephamandole) and were inoculated with 10(5) cfu/ml (n=3) or 10(7) cfu/ml (n=3). Group 3 received systemic prophylaxis (1 g cephamandole) and were inoculated with 109 cfu/ml. Group 4 received systemic prophylaxis (2 g cephamandole) and were inoculated with 10(9)cfu/ml. In group 5 and 6 grafts were soaked in a rifampicin solution before use and inoculated with 10(9) cfu/ml. Group 5 received no systemic prophylaxis and group 6 received systemic prophylaxis (1 g cephamandole). Grafts were harvested at 2 weeks, and peritonitis, perigraft abscess, anastomotic disruption and graft occlusion recorded. Swabs were taken of the graft, the perigraft tissues and the peritoneal fluid. Graft segments were incubated in broth medium. RESULTS: inoculation with 10(9) cfu/ml ensured graft infection. Systemic or local prophylaxis alone failed to prevent graft infection. Only systemic and local antibiotic prophylaxis provided significant better results than no prophylaxis at all (p<0.01) and local prophylaxis alone (p<0.05). However, total "graft sterility" was not achieved as bacteriologic analysis of the graft segments showed low bacterial counts (<10 bacteria/graft) in 5 of 6 grafts. CONCLUSION: local and systemic prophylaxis provided more protection as demonstrated by the significant decrease in the incidence of "overt" graft infection. Total "graft sterility" cannot be expected in the case of an overwhelming bacterial challenge.

Animals↗

Gene expression profiles in the acutely dissected human aorta.

OBJECTIVES: heritable connective tissue abnormalities and arterial hypertension may predispose to aortic dissection. This study evaluates gene expression profiles in the acutely dissected human aorta. DESIGN, MATERIALS AND METHODS: Atlas Human Broad Arrays I, II, and III (Clontech) were used to compare gene expression in acutely dissected (6 patients) and normal ascending aortas (6 multiorgan donors). The tissues were also compared macroscopically. RESULTS: of 3537 genes analysed, 1250 (35%) were expressed in aortic tissue. For statistical analysis we focused on 627 genes, which had an intensity>0.95 of the mean patients or controls. Dissected and adjacent macroscopically intact aorta displayed similar gene expression patterns. On the contrary, 66 genes were expressed significantly different in dissected aorta, compared with undiseased control aorta of multiorgan donors. Genes, predominantly upregulated in dissection, are involved in inflammation, in extracellular matrix proteolysis, in proliferation, translation and transcription. Predominantly downregulated genes code for extracellular matrix proteins, adhesion proteins and cytoskeleton proteins. CONCLUSION: our results demonstrate for the first time the complexity of the dissecting process on a molecular level. The ultimate dissection seems to be the dramatic endpoint of a long-lasting process of degradation and insufficient remodelling of the aortic wall. Altered patterns of gene expression suggest a pre-existing structural failure of the aortic wall, resulting in dissection.

Acute Disease↗

[The acute mesenteric ischemia - not understood or incurable?].

PURPOSE: Despite surgical research and progress, the high mortality of acute intestinal ischemia seems to be improved insignificantly over the past fifty years. In this study we analyzed the specific diagnostic and therapeutic problems of the disease in order to improve further management of acute mesenteric ischemia. METHODS: From 1979 until 2000 64 patients (female 31, male 33) with a mean age of 64 (30-89) years underwent operation for primary intestinal ischemia at our institution. All medical and surgical records and imaging studies were reviewed retrospectively. Follow up consisted of clinical examination and duplex sonography. RESULTS: Only in 26 patients (41 %) a preoperative diagnostic work-up including angiography 12 and CT 14 was performed, whereas in 42 cases the intestinal ischemia was diagnosed during surgical exploration. Intestine malperfusion was caused primarily by venous thrombosis in 9 cases (14 %) and by arterial occlusive disease in 55 cases (86 %). Arterial disorders consisted of arterial thrombosis in 19 cases (30 %), arterial embolism in 18 cases (28 %), aortic or mesenteric artery dissection in 10 cases (15 %), non occlusive disease (NOD) in 5 cases (8 %), trauma 3 cases (5 %). Five different therapeutic strategies were applied: group I: Intestinal resection: 24 patients, anastomotic insufficiency 5 (39 %), mortality 11 (46 %), group II: intestinal artery revascularization: 5 patients, secondary patency rate 80 %, mortality 40 %, GROUP III: Intestinal artery revacularization and perfusion with Ringer's solution: 11 patients, mortality 8 (73 %), group IV intestinal artery revascularization and intestinal resection: 3 patients, mortality 100 %, group V intestinal artery revascularization and perfusion and intestinal resection: 3 patients, mortality 33 %. A second look operation was performed in 29 cases (40 %) and displayed malperfusion in 72 %. Only 21 of 64 patients survived the acute intestinal ischemia (in hospital mortality was 67 %). Delayed diagnostic and operation caused higher mortality (interval 10 hours: mortality 59 %, interval 37 hours mortality; 71 %, p = 0,06). Follow up after 61 (4-72) months of 21 patients (100 %) could be achieved. Ten patients (48 %) had meanwhile died, 5 patients (50) % as consequence of mesenteric ischemia, the others of unrelated reasons. Eleven patients are still alive without clinical signs of intestinal ischemia. CONCLUSIONS: Early diagnosis before hospitalisation and in-hospital (arteriography) and operation are essential to improve the outcome of patients with acute intestinal ischemia. To avoid short bowel syndrome bowel resection should be combined with mesenteric revascularization. Resection of malperfused bowel should be done cautiously and should be followed automatically by second look operations. Special expertise and good team work of visceral and vascular surgeons are required to achieve better therapeutic results.

Acute Disease↗

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke.

OBJECTIVE: The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings. METHODS: This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis. RESULTS: The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks. CONCLUSION: Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

Aged↗

[Simultaneous surgical intervention for occlusion of the internal carotid artery and coronary disease--reasonable or high-risk combination?].

BACKGROUND AND OBJECTIVE: Carotid artery stenosis as risk factor for postoperative stroke after cardiac surgery is confirmed in recent publications. Nevertheless indications for combined procedures in carotid occlusive disease and coronary artery disease are discussed controversely in the literature. Based on our own experiences since 1992 the risk factors are reviewed. PATIENTS AND METHODS: The data of 104 patients (80 male, 24 female, age 67 +/- 7 years), with 106 combined operations performed between 1992 and 1999, were evaluated retrospectively. 36% of the patients had symptomatic and 64% had asymptomatic carotid artery stenosis. RESULTS: Seven patients (6.6%) developed postoperative neurological deficits. One patient (1.0%) died as result of a stroke. In three patients a stroke occurred in the ipsilateral hemisphere, whereas two of three patients with cerebral infarction in the contralateral hemisphere had no significant carotid artery stenosis on this side. One patient had multiple bilateral embolism. Cardiac complications occurred in seven patients (6.6%). The inhospital mortality for non-stroke related complications was 3.8%, the total mortality 4.8%. CONCLUSION: From our experiences the combined approach for carotid artery occlusive disease and coronary artery disease can be recommended in selected patients. The rate of complications seems to be lower than in staged procedures. The spontaneous course of the disease can be improved and the patient is spared a second operation.

Aged↗