Kurt Tiesenhausen

N-Terminal Pro-brain Natriuretic Peptide Identifies Patients at High Risk for Adverse Cardiac Outcome after Vascular Surgery

Background:Preoperative N-terminal pro-BNP (NT-proBNP) is independently associated with adverse cardiac outcome but does not anticipate the dynamic consequences of anesthesia and surgery. The authors hypothesized that a single postoperative NT-proBNP level provides additional prognostic information for in-hospital and late cardiac events. Methods:Two hundred eighteen patients scheduled to undergo vascular surgery were enrolled and followed up for 24–30 months. Logistic regression and Cox proportional hazards model were performed to evaluate predictors of in-hospital and long-term cardiac outcome. The optimal discriminatory level of preoperative and postoperative NT-proBNP was determined by receiver operating characteristic analysis. Results:During a median follow-up of 826 days, 44 patients (20%) experienced 51 cardiac events. Perioperatively, median NT-proBNP increased from 215 to 557 pg/ml (interquartile range, 83/457 to 221/1178 pg/ml; P < 0.001). The optimum discriminate threshold for preoperative and postoperative NT-proBNP was 280 pg/ml (95% confidence interval, 123–400) and 860 pg/ml (95% confidence interval, 556–1,054), respectively. Adjusted for age, previous myocardial infarction, preoperative fibrinogen, creatinine, high-sensitivity C-reactive protein, type, duration, and surgical complications, only postoperative NT-proBNP remained significantly associated with in-hospital (adjusted hazard ratio, 19.8; 95% confidence interval, 3.4–115) and long-term cardiac outcome (adjusted hazard ratio, 4.88; 95% confidence interval, 2.43–9.81). Conclusion:A single postoperative NT-proBNP determination provides important additional prognostic information to preoperative levels and may support therapeutic decisions to prevent subsequent structural myocardial damage.

The European experience with vascular injuries

The rich and diverse heritage of the management of vascular injuries in the 45 independent European countries prevents the authors from revealing a uniform picture of the European experience, but some trends are clearly emerging. In countries with a low incidence of penetrating trauma and increasing use of interventional vascular procedures, the proportion of iatrogenic vascular trauma exceeds 40% of all vascular injuries, whereas on other parts of the continent, armed conflicts are still a major cause of vascular trauma. National vascular registries, mostly in the Scandinavian countries, produce useful, nationwide data about vascular trauma and its management but suffer still from inadequate data collection. Despite a relatively low incidence of vascular trauma in most European countries, the results are satisfactory, probably in most cases because of active and early management by surgeons on call, whether with vascular training or not, treating all kinds of vascular surgical emergencies. In some countries, attempts at developing a trauma and emergency surgical specialty, including expertise in the management of vascular injuries, are on their way.

AORTODUODENAL FISTULA : A LATE COMPLICATION OF INTRALUMINAL EXCLUSION OF AN INFRARENAL AORTIC ANEURYSM

During recent years, considerable clinical experience has been gained with endoluminal stent-graft procedures. Several studies have shown promising results up to a period of 4.5 years. However, long-term follow-up studies are still limited. Late endoleaks caused by stent-graft migration, disconnection of single components in modular stent-grafts, and limb thrombosis have been observed as long-term complications. We report a case in which a migrated and kinked bifurcated stent-graft caused an aortoduodenal fistula 20 months after stent-graft insertion. To our knowledge, such a complication has not been reported before.

Treatment of Acute Aortic Type B Dissection with Stent-Grafts

AbstractPurpose: To evaluate the feasibility of endoluminal stent-grafts in the treatment of acute type B aortic dissections. Methods: In five patients with acute aortic type B dissections, sealing of the primary intimal tear with an endoluminal stent-graft was attempted. Indication for treatment was aneurysm formation in two patients and persistent pain in three patients. One of the latter also had an unstable dissection flap compromising the ostium of the superior mesenteric artery. The distance from the intimal tear to the left subclavian artery was <0.5 cm in four patients, who had typical type B dissections. In one patient with an atypical dissection the distance from the primary tear to the left subclavian artery was 4 cm. This patient had no re-entry tear. Talent tube grafts (World Medical Manufacturing Cooperation, Sunrise, FL, USA) were used in all patients. Results: Stent-graft insertion with sealing of the primary tear was successful in all patients. The proximal covered portion of the stent-graft was placed across the left subclavian artery in four patients (1× transposition of the left subclavian artery). Left arm perfusion was preserved via a subclavian steal phenomenon in the patients in whom the stent-graft covered the orifice of the left subclavian artery. The only procedural complication we observed was an asymptomatic segmental renal infarction in one patient. In the thoracic aorta thrombosis of the false aortic lumen occurred in all patients. In one patient the false lumen of the abdominal aorta thrombosed after 4 weeks; in the other three patients the status of the abdominal aorta remained unchanged compared with the situation prior to stent-graft insertion. As a late complication formation of a secondary aneurysm of the thoracic aorta was observed at the distal end of the stent-graft 3 months after the primary intervention. This aneurysm was treated by coaxial insertion of an additional stent-graft without complications. Conclusion: Endoluminal treatment of acute type B aortic dissections seems to be an attractive alternative treatment to surgical repair. Thrombosis of the false lumen of the thoracic aorta can be induced if the primary tear is sealed with a stent-graft. This could protect the dissected thoracic aorta from delayed rupture.

Endovascular treatment of proximal arsastomotic aneurysms after aortic prosthetic reconstruction

AbstractPurpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudo-aneurysms. Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8–15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n=1), bifurcated graft (n=s1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed. Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft. Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

Complications in endoluminal repair of abdominal aortic aneurysms.

In this review the technical and systemic complications occurring during endoluminal repair of abdominal aortic aneurysms are summarized. According to the data in the literature the technical success-rate of the endoluminal procedure should be >90% and the overall complication-rate <10%. It should be differentiated between complications which have an adverse effect on the outcome of the procedure, and technical problems, which complicate the procedure but do not affect the outcome. The majority of the technical problems can be solved endoluminally. The 30-day mortality rate should be in the same range as elective open surgical repair. One major factor influencing the immediate results is the experience of the interventional team.

Osteomyelitis of the Spine and Abscess Formation in the Left Thigh after Stent-Graft Implantation in the Superficial Femoral Artery

Purpose: To present a rare case of abscess formation around a covered stent in the superficial femoral artery. Methods and Results: Two weeks after balloon dilation of a left superficial femoral artery (SFA) occlusion, during which a Hemobahn covered stent had been placed to treat dissection, a 77-year-old nondiabetic male developed intolerable pain and swelling of his left thigh. An abscess had formed around the stent, which was patent; intravenous antibiotic therapy quelled the symptoms, and the patient discontinued his oral antibiotic regimen weeks after discharge. General septicemia ensued. Acute lower limb ischemia and excruciating back pain prompted readmission. The SFA stent-graft occlusion required femoropopliteal bypass; the abscess and spondylodiskitis that had developed in the T12 and L1 vertebrae responded to intravenous antibiotics. The patient is without signs of infection at 6 months. Conclusions: Local and systemic infections associated with intraluminal prostheses are rare, and prophylactic antibiotic therapy is not commonly employed. Balloon- or device-induced arterial injury may expose the arterial wall to bacterial colonization, suggesting that patients receiving lengthy stents or experiencing arterial injury during angioplasty should receive antibiotics as a precautionary measure.

Endovascular Treatment of Mycotic Aortic Pseudoaneurysms with Stent-Grafts

Mycotic aortic aneurysms remain a therapeutic challenge, especially in patients who are not suitable for open surgery. Endovascular treatment with stent-grafts in this indication is still disputed. Between January 2002 and January 2006, six patients with mycotic aneurysms of the thoracoabdominal or abdominal aorta were admitted to our department. All patients were male, aged 57–83 years (mean, 74.6 years). The mycotic aneurysms were diagnosed on the basis of clinical signs of infection, on CT, and, in four cases, on a positive blood culture. In all patients the mycotic aortic aneurysms were treated endovascularly by stent-graft implantation. Technical and clinical success was achieved in all patients. There was no in-hospital or 30-day mortality. In the follow-up period (range, 2–47 months) four patients died of cancer, cardiac failure, or unknown cause (one case). Two patients are still alive with nearly complete regression of the aneurysms. We conclude that treatment of mycotic aortic aneurysms with stent-grafts may be an alternative in selected patients.

Access recirculation in a native fistula in spite of a seemingly adequate access flow

True access recirculation (AR) measured by ultrasound dilution technique is usually absent in well-working shunts. It occurs with low access flows (Qa). High access flow rates are assumed to prevent AR. Two major exceptions to these rules are known: presence of intra-access strictures and inadvertently reversed blood lines. We present an additional exception in which true access recirculation occurred in a native arteriovenous (AV) fistula with correct placement of bloodlines. Surprisingly, access blood flow exceeded pump blood flow (Qb) almost threefold. The situation was clarified by a magnetic resonance angiogram showing a collateral forming a functional loop. This loop led to true access recirculation in one branch, although overall blood flow through both branches appeared to be adequate. The different findings in this shunt over time give insight into the often complex pathophysiology of native fistulae. This case proves that seemingly adequate access flow does not necessarily prevent access recirculation in native AV fistulae. We suggest monitoring both access flow and recirculation in hemodialysis accesses on a regular basis.

Die Behandlung infrarenaler Aortenstenosen mittels transluminaler Angioplastie und Stent

Zusammenfassung Vom 1.4.1996 bis 30.6.1998 wurden 7 Patienten im Alter von 61–85 Jahren mit arteriosklerotisch bedingten, symptomatischen infrarenalen Aortenstenosen mittels transluminaler Angioplastie und primärer Implantation eines Palmaz-Stents behandelt. Simultan wurde in einem Fall eine Thrombendarterektomie der A. iliaca externa mit Profundaplastik, in einem weiteren Fall eine Angioplastie mit Stentimplantation der A. iliaca communis durchgeführt. Der technische sowie klinische Erfolg war in allen Fällen gegeben. In einem Beobachtungszeitraum von median 23 (7–33) Monaten kam es zu keinem Verschluß oder klinischer Restenose. Die transluminale Angioplastie mit Stentimplantation bei segmentalen abdominellen Aortenstenosen stellt ein wenig invasives und sicheres Verfahren mit guten Langzeitergebnissen dar.Abstract Seven patients, aged 61–85 years with symptomatic infrarenal aortic stenosis caused by arteriosclerosis, were treated with transluminal angioplasty and primary implantation of a Palmaz stent, between 1 April 1996 and 30 June 1998. In one case, a thrombendarteriectomy of the external iliac artery with profundaplsty, in another, angioplasty with stent implantation of the common iliac artery was performed simultaneously. The procedures were technically and clinically successful in all cases. During a mean observation period of 23 months (minimum 7 months, maximum 33 months) no obstruction or clinical restenosis occurred. Transluminal angioplasty with stent implantation in segmentary abdominal aortic stenosis represents a less invasive and safe technique with good long-term results.