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Biomedical subjects

M A Enzler

Publications and source records attributed to M A Enzler.

At least 19 recordsLinked to original sources
PubMed2002

Severe potential consequences of delayed diagnosis in patients with hip claudication.

Delayed diagnosis in patients with hip claudication can lead to severe consequences. We report on patients with ischaemic hip claudication which had primarily been attributed to coxarthrosis. One patient went through a variety of treatments including hip arthroplasty. The second patient had a life-threatening abdominal aortic aneurysm (AAA) which remained undiagnosed. Orthopaedic surgeons should maintain a high degree of suspicion for vascular disease. Moreover, we strongly advocate that all men over 60 years old who seek medical advice for whatever reason should be screened once for AAA by ultrasonography.

Aortic Aneurysm, Abdominal↗
PubMed2002

[Endovascular therapy of aneurysms of the abdominal aorta: report of 4,291 patients of the Eurostar Register].

BACKGROUND: The Eurostar project is a multicentred database of the outcome of endovascular repair of infra-renal aortic aneurysms. From 1996 to March, 2002, 113 European centres of vascular surgery have contributed. The purpose of this article is to review the medium term (up to 7 years) results of endovascular aneurysm repair as reported to Eurostar. PATIENTS AND METHODS: Patients intended for endovascular aneurysm repair were notified to the Eurostar Data Registry Centre before treatment in order to eliminate bias due to selective reporting. The following data was collected on all patients: (1) their demographic details and the anatomical characteristics of their aneurysms, (2) details of the endovascular device used, (3) procedural complications and the immediate outcome, (4) results of contrast enhanced CT imaging at 1, 3, 6, 12, 18 and 24 months after operation and at yearly intervals thereafter, (5) all adverse events. Life table analysis was performed to determine the cumulative rates of: (1) death from all causes, (2) secondary intervention. RESULTS: By March 2002, pre- and postoperative data of 4291 patients had been registered. The median duration of follow-up was 12 mo (range 0-96). Successful deployment was achieved in 97.8% of the patients with a perioperative (30 day) mortality of 2.4%. Early conversion to open repair occurred in 1.3%. Late rupture of the aneurysm occurred in 35 patients. The significant factors were endoleaks, graft migration and kinking. Late conversion to open repair occurred at an annual rate of approximately 2%. Risk factors (indications) for late conversion were endoleaks, graft migration and kinking. CONCLUSIONS: Endovascular repair of infra-renal aortic aneurysms using the first and second-generation devices that predominated in this study is associated with a risk of early or late failure of 3% per year, based upon an analysis of observed primary endpoints of rupture and conversion.

Adult↗
PubMed1996

The influence of gender on the outcome of arterial procedures in the lower extremity.

OBJECTIVES: To determine the outcome of arterial reconstructive procedures, we audited retrospectively peripheral bypass grafts and endarterectomies performed between 1982 and 1990. MATERIALS AND METHODS: 1005 peripheral arterial procedures were performed in 862 lower limbs in 782 patients. 62% of the limbs were critically ischaemic. The procedures include 565 bypasses, 346 endarterectomies and 94 combinations of both. 30% of the patients were women. Follow-up information was obtained from practitioners in charge of post-hospital care by questionnaires. Factors potentially affecting patency were investigated by multivariate analysis and patency rates were calculated by life-tables. MAIN RESULTS: Overall secondary patency was 61% at one year and 35% at 5 years. Bypasses and endarterectomies in women yielded lower patency rates than in men (49% vs. 67% at 1 year, p < 0.001). The relative risk of failure in women as compared to men was 1.30. The risk of failure was further increased by "redo" surgery (relative risk 1.51), diabetes (1.40), critical ischaemia (1.34) and crural procedures (1.34). CONCLUSIONS: Secondary patency rates were significantly lower in women than in men. This is in agreement with some other studies, although gender has gained little attention as a risk factor in vascular surgery.

Aged↗
PubMed1996

Long-term function of vascular access for hemodialysis.

OBJECTIVES: To compare the outcome of autogenous arteriovenous fistulas (AVF) with interposition graft fistulas for hemodialysis access. DESIGN: Retrospective clinical study. SETTING: Department of Surgery, Zurich University Hospital. METHODS: Primary and secondary patency rates were calculated by life tables. Factors potentially affecting patency were studied by comparison of life tables using the log rank test. MAIN RESULTS: From 1980 to 1992, 414 patients were operated on for long-term vascular access. 720 fistulas were created including 429 AVF and 291 interposition grafts (150 bovine xenografts, 69 PTFE grafts, 59 sheep collagen grafts, 10 autologous and 1 homologous vein grafts). Secondary patency rates after 1 and 3 yr were 74/64% in AVF, 56/24% in bovine xenografts, 58/40% in PTFE grafts and 71/45% in sheep collagen grafts. The latter performed not significantly worse than AVF. Primary and secondary patency rates were significantly lower in women.

Adolescent↗
PubMed1994

A new approach to in vivo testing of vascular grafts?

We present an novel approach to in vivo testing of vascular grafts. Seven grafts of two different materials, each with an inner diameter of 5 mm, were joined together to form a bundle, the ends of which were joined to connecting segments with an inner diameter of about 15 mm. The device was then implanted into the abdominal aorta of an experimental animal. After surgery, the animal was followed by CT scan at regular intervals to assess patency of each individual graft. The model features an increased number of grafts per animal with standardized anastomoses and hemodynamic conditions, but it needs modification to lower its thrombogenic potential.

Anastomosis, Surgical↗
PubMed1993

[Suggestion for differential use of graft materials in peripheral bypass operations].

Autologous great saphenous vein (AGSV) is admittedly the best graft for infrainguinal arterial reconstructions. It remains controversial, though, whether it should preferably be used "in situ" or "reversed". Even more controversial is the use of non-autologous grafts. Some authors prefer PTFE grafts for primary reconstructions in order to preserve the AGSV for secondary peripheral bypass or aortocoronary bypass procedures. We have reviewed recent studies comparing different graft materials. Several prospective studies show no significant difference between patency rates of "in situ" or "reversed" AGSV grafts in any position. We therefore feel that both methods are equivalent. In suprageniculate femoro-popliteal bypasses non-autologous grafts perform nearly as well as AGSV according to several studies. There preferential use seems justified, because many patients will ultimately need a secondary repair which has a dramatically higher patency when performed with AGSV. In infrageniculate femoro-popliteal bypasses AGSV does clearly better, but the use of non-autologous material may be justified under certain conditions. For femoro-crural bypasses there is no alternative so far to autologous veins. In patients without adequate AGSV alternate vein sources including the opposite leg and the arms should be used and veno-venous anastomoses should be made to construct conduits of adequate length. Some studies compare various non-autologous graft materials. Below the inguinal ligament, polytetrafluoroethylene seems to be todays standard. This is challenged by some recent results which need further confirmation.

Bioprosthesis↗
PubMed1992

[Acute ischemia of the lower extremity in an adolescent with Crohn disease].

The authors report a case with a rare form of peripheral ischaemia. A 25-year-old man with Crohn's disease suffers from sudden ischaemia of his right leg. There is no evidence of entrapment of the popliteal artery, of arterial embolism or Buerger's disease. Thrombocytosis in combination with hypercoagulability as described previously in patients with Crohn's disease seems to be the most probable cause. - In this case percutaneous transluminal thrombectomy and thrombolysis were more successful than surgical thrombectomy using balloon catheters.

Adolescent↗
PubMed1991

Valve disruption for in situ vein bypass: use of a new technique.

Following its introduction in 1960, the in situ bypass technique has gradually gained acceptance among vascular surgeons. This can be explained, in part, by the lack of a reliable method for rendering vein valves incompetent. Several instruments developed by Skagseth and Hall, Leather and Karmody, and others have been used. Although most are relatively easy to use, one common drawback is the difficulty in controlling rotation of the cutting blade. This is due to insufficient torsional rigidity of the shaft and the lack of a blade plane indicator. Edwards, in 1936, described the consistent orientation of vein valves, whose margins are always parallel to the overlying skin surface. This knowledge facilitates complete midline incision of the valve cusps, provided that the surgeon is able to control the cutting blade. With this fact in mind, we have developed a new set of instruments. They feature satisfactory torsional rigidity, as well as blade plane indicators at the handle. For the endoscopist, the blade plane is made visible by a mark at the tip of each instrument. Precision-manufactured of stainless steel and welded with laser technology, the instruments are suitable for multiple use, which we consider an advantage from an economic, as well as an ecological viewpoint.

Equipment Design↗
PubMed1991

Tunnelling instruments for vascular grafts: problems and solutions.

When autologous veins or vascular prostheses are implanted for bypass operations or haemodialysis, the use of an appropriate tunnelling device is extremely helpful. In order to avoid perigraft haemorrhage and allow undelayed graft incorporation, the tunneller should match the diameter of the implant. Interchangeable shafts of various lengths and blunt tips of various diameters are prerequisites for a versatile instrument. Most instruments on the market have an important drawback: the handle is welded to one end of the shaft thus preventing "bi-directional" use. We have therefore developed a modified tunneller that can be used equally well in either direction. The connection between shaft and handle affords torsional rigidity and thus allows precise guidance during insertion. The handle can be attached to both ends of the shaft. Thus, for example, in a femoro-popliteal bypass, the distal anastomosis can be constructed first, followed by the introduction of the tunneller from the knee to the groin. As a next step the tip and handle are interchanged and the graft is passed from the knee to the groin. When a haemodialysis shunt with a PTFE-loop is inserted, the bidirectional use of the tunneller makes it possible to insert the graft with a smooth curve into the smallest possible cavity. Thus, the new instrument set called the "Bi-directional Tunneller" is more versatile and easier to use than other tunnellers presently available.

Anastomosis, Surgical↗
PubMed1991

[Mid-term results of our first 53 "in situ" bypasses].

The "in situ" bypass technique was adopted by our group in 1986. A total of 53 "in situ" bypasses were carried out until June 1989. The worst symptoms were incapacitating claudication, rest pain or ischemic necrosis, each in about one third of the patients. The site of the distal anastomosis was the popliteal artery below the knee in 40 instances, the peroneal artery in 7 and other infrapopliteal vessels in 6. Valve incisions were performed uneventfully with re-usable instruments featuring a sharp-edged blade and an indicator for rotation control of the blade ("Insitutom RG"). Vein branches were located mostly by angiography, but residual arterio-venous fistula remained a vexing problem. In the beginning they were ligated under local anaesthesia. Later on they were dealt with successfully using transluminal embolization. Patients were last examined in July 1990 when the follow-up time ranged from 12 to 51 months. 5 patients had died and 5 were lost to follow-up. Patency rates were evaluated according to the life-table method. They were gratifying for femoro-popliteal bypasses with 87% after one year and 83% after two and three years. Femoro-tibial-peroneal bypasses performed below average, but their number was too small to draw conclusions.

Adult↗
PubMed1989

["Bidirectional tunneler": an improved tunneler and shunt instrument for vascular surgery].

When autologous veins or vascular prostheses are implanted for bypass operations or hemodialysis shunts, the use of an appropriate tunneling device is recommended. In order to avoid perigraft hemorrhage and allow undelayed graft incorporation, the tunneler should match the diameter of the implant. Interchangeable shafts with various lengths and blunt tips of various diameters are prerequisites for versatile applicability. The tunneling instrument designed by Kelly and Wick was until now the most versatile on the market. Its main drawback is a handle that is welded to one end of the shaft thus preventing "bi-directional" use. We therefore developed a modified "Bi-directional Tunneler". Its handle can be attached to both ends of the shaft and allow at the same time torsional rigidity for directional guiding. Thus, e.g. in a femoro-popliteal bypass, the distal anastomosis can be accomplished first, followed by the introduction of the "Bi-directional Tunneler" from the knee to the groin. In a further step the tip and handle are interchanged and the graft is also passed from the knee to the groin. Thus, the "Bi-directional Tunneler" offers hitherto unknown versatility in bypass as well as in hemodialysis shunt surgery.

Arteriovenous Shunt, Surgical↗
PubMed1987

A double-blind clinical trial of prophylactic cloxacillin in open fractures.

In 100 patients with first-, second-, and third-degree open fractures, a randomized, double-blind study was carried out to compare prophylactic cloxacillin and placebo. Prophylaxis was started preoperatively and continued for 10 days. The standard fracture treatment consisted of operative stabilization, mostly by means of plates or external fixators. In the cloxacillin group two infections were observed as compared to 12 in the control group. This difference was significant.

Adolescent↗