Long-term results of cryopreserved allografts in aortoiliac graft infections.

OBJECTIVE: Different graft materials have been proposed for in situ reconstruction in the setting of vascular graft infection (VGI). We analyzed the long-term outcomes after in situ aortoiliac reconstruction with cryopreserved allografts. METHODS: We performed a retrospective analysis of patients who had undergone in situ aortoiliac reconstruction with cryopreserved arterial allografts for VGI from 2000 to 2015. The end points were the perioperative and long-term mortality and graft-related complications, including stenosis, occlusion, pseudoaneurysm, and reinfection. RESULTS: A total of 33 patients (91% male) with a median age of 67 years (range, 53-83 years) had undergone in situ aortoiliac reconstruction with cryopreserved allografts. The 30-day mortality was 6% (n = 2); both deaths were related to the allograft (one early allograft-enteric fistula and one graft rupture). Another two patients had experienced early (≤30 days) graft-related events (one allograft-enteric fistula and one graft limb occlusion), for an early graft-related complication rate of 12% (n = 4). Of the 31 discharged patients, 13 (42%) had died after a median of 47 months (range, 2-97 months). The median follow-up for the 18 remaining patients was 96 months (range, 10-146 months). The estimated survival at 1, 3, and 5 years was 88%, 81%, and 66%, respectively. Nine patients (29%) had experienced at least one of the following graft-related events during follow-up, including graft stenosis requiring intervention in five (16%), graft occlusion in four (13%), pseudoaneurysm in three (10%), and reinfection in two patients (6%). The estimated freedom from any first graft-related event at 1, 3, and 5 years was 78%, 71%, and 62%, respectively. The estimated primary patency and primary assisted patency at 1 and 3 years was 87% and 79%, and 90% and 83%, respectively. CONCLUSIONS: In situ aortoiliac reconstruction with cryopreserved allografts to treat VGI was associated with relevant perioperative graft-related complications. Although the reinfection rate was acceptable, other graft-related complications were frequent in the long term, in particular, graft occlusion and stenosis.

Influences on the implementation of Mini-CEX and DOPS for postgraduate medical trainees' learning: A grounded theory study.

Introduction: In order for Mini-Clinical Evaluation Exercise (Mini-CEX) and Direct Observation of Procedural Skills (DOPS) to actually have a positive effect on trainees' learning, the way in which the tools are implemented is of key importance. However, there are many factors influencing their implementation. In this study, we aim to develop a comprehensive model of such factors. Methods: Using a constructivist grounded theory approach, we performed eight focus groups. Participants were postgraduate trainees and supervisors from three different specialties; all were experienced with Mini-CEX and/or DOPS. Data were analyzed for recurring themes, underlying concepts and their interactions using constant comparison. Results: We developed a model demonstrating how the implementation of Mini-CEX and DOPS for trainees' learning is influenced by 13 factors relating to four categories: organizational culture (e.g. value of teaching and feedback), work structure (e.g. time for Mini-CEX and DOPS, faculty development), instruments (e.g. content of assessment), and users (e.g. relationship between trainees and supervisors), and their interaction. Conclusions: We developed a complex model of influencing factors relating to four categories. Consideration of this model might support successful implementation and trainees' learning with Mini-CEX and DOPS.

Reality check: primary vascular access creation today.

INTRODUCTION: In Switzerland, the outcome of vascular access creation in the 4500 current dialysis patients is unknown, mainly because there is no prospective registry for patients undergoing vascular access surgery for renal replacement therapy. The aim of the study was to assess the quality of vascular access creation and to compare it with the current literature and guidelines, in order to define strategies to improve clinical outcome. METHODS: Retrospective single-centre study in a tertiary referral centre. All consecutive patients over 18 years of age undergoing primary vascular access creation between January 2013 and December 2014 were included. Follow-up data for at least 12 months were collected. RESULTS: During the study period, 365 patients had a surgical intervention for renal replacement therapy. A primary vascular access was created in 74 patients (20%), who were further analysed in our study: 63 (85%) had an arteriovenous fistula (AVF) and 11 (15%) an arteriovenous graft (AVG). The intervention-free survival (primary patency rate) of the primary vascular access at 1 year was 46% (95% confidence interval [CI] 33-58%) for AVF and 30% (95% CI 7-58%) for AVG, with a secondary patency rate at 1 year of 75% (95% CI 63-84%) for AVF and 50% (95% CI 18-75%) for AVG. Twenty-seven patients (36%) with primary vascular access underwent central venous catheter (CVC) placement (tunnelled or non-tunnelled) before the access creation. Thirty-seven (50%) patients had their first dialysis through a CVC. Thirty-one patients (42%) never received a CVC. CONCLUSIONS: The primary patency of vascular access was unexpectedly low, and the number of CVC requests unexpectedly high. In light of this, we consider it essential that centres creating vascular access should register their activities and compare their outcomes with current guidelines to check and improve clinical management. To facilitate this, there is an initiative starting in 2018 encouraging all Swiss vascular surgeons to provide data on vascular access interventions, including 1-year follow-up, in the national online registry "SwissVasc 2.0".

Key points for patient safety in dialysis access.

For more than 15 years, patient safety has been an issue in different domains of medicine. There is evidence for this subject and also a great need for information. First, we should be familiar with the basic terminology such as the relationship between adverse events and errors, and understand the variations of error. In patient management, besides skills and knowledge (evidence-based medicine), the ability (competence) of healthcare professionals to act and react in unexpected situations is key to prevent and treat adverse events. Not only healthcare professionals should be involved in the process but also healthy people in a way that they understand and patients in a way that they are actively involved. This paper will show how a more general view of patient safety can and should be implemented in the daily work of caregivers dealing with dialysis access in different aspects. A key factor to advance in this subject is to be open-minded and sensualized for this topic. The reader should get an idea of how an institution can create a culture of safety.

Simulation in vascular access surgery.

In the last years, simulation training has become widespread in different areas of medicine due to social expectations, political accountability and professional regulation. Different types of simulators allow to improve knowledge, skills, communication and team behavior. Simulation sessions have been proven to shorten the learning curve and allow education in a safe environment. Patients on dialysis are an expanding group. They often suffer from several comorbidities and need complex surgical procedures with regard to their dialysis access. Therefore, education in evidence-based algorithms is as important as teaching of practical skills. In this chapter, we are presenting an overview of available dialysis access training modalities. We are convinced that simulation will become more important in the near future and has a substantial impact on strategies to improve aspects of patient safety.

Team training to establish a safety culture in dialysis access surgery.

Operating room (OR) team safety training and learning in the field of dialysis access is well suited for the use of simulators, simulated case learning and root cause analysis of adverse outcomes. The objectives of OR team training are to improve communication and leadership skills, to use checklists and to prevent errors. Other objectives are to promote a change in the attitudes towards vascular access from learning through mistakes in a nonpunitive environment, to positively impact the employee performance and to increase staff retention by making the workplace safer, more efficient and user friendly.

Careful and safe vascular access creation.

Morbidity and mortality are significant in hemodialysis patients, and every vascular access (VA) is prone to complications - some more, some less. The risk of complications rises from arteriovenous fistulae to arteriovenous grafts and peaks in nontunneled central lines. Strategies to achieve complete evaluation of the patient and precise planning mark the start of successful VA creation. Furthermore, preoperative considerations include safety checklists, team time-out procedures, and antibiotic prophylaxis. Intraoperative technical features and postoperative aspects of documentation and surveillance schemes complete careful and safe VA creation.

Patient safety in dialysis access: education and research.

Today, a growing activity to improve patient safety in all domains of medicine is reality. This chapter deals with patient safety research in general, but is also about strategies to implement this evidence in the daily clinical work treating patients on dialysis. Good clinical research practice has been well established for some years. In the domain of dialysis access, further basic, clinical, epidemiological and health service research will be important to further improve patient safety as a whole.

Self-made pericardial tube graft: a new surgical concept for treatment of graft infections after thoracic and abdominal aortic procedures.

BACKGROUND: The aim of this study was to evaluate a new surgical concept for the treatment of graft infections after operation or endovascular treatment of thoracic, thoracoabdominal, and abdominal aortic diseases. METHODS: Between 2004 and 2011, 15 patients (mean age 72 ± 10 years, 87% men) with prosthetic graft or endovascular graft infection were treated with complete removal of the infected prosthetic material, extensive debridement of the surrounding tissues, and orthotopic vascular reconstruction with self-made xenopericardial tube grafts constructed from a patch. Perioperative and long-term outcomes were evaluated. RESULTS: Perioperative mortality was 27% (n = 4). All deaths were due to multiorgan failure resulting from uncontrolled septicemia from the local infectious process. Mean observational follow-up was 24 months (5 to 83 months). Control computed tomographic scans showed normal findings at the operative site in all patients. Antibiotic treatment was continued for a mean of 6 months. Freedom from reinfection was 100%. Freedom from reoperation was also 100%. CONCLUSIONS: Treatment of graft infections after operation or endovascular treatment of thoracic, thoracoabdominal, and abdominal aortic diseases by complete removal of the infected prosthetic material and extensive debridement as well as orthotopic vascular reconstruction using self-made xenopericardial tube grafts as neoaortic segments provides excellent results with regard to durability and freedom from reinfection and reoperation. This new concept is an additional alternative to cryopreserved homografts that extends the armamentarium for treating patients with these highly complex conditions.

[Surgical options in the treatment of chronic venous ulcers]. / Chirurgische Therapieoptionen beim chronisch venösen Ulcus cruris.

Surgery offers several options in prevention of chronic venous insufficiency and its sequelae. Both the operation on veins with valve dysfunction to reduce reflux and the elimination of obstruction in thrombosed veins aim for the reduction of venous hypertension. Elevated venous pressure, impairment of cutaneous capillaries and a chronic inflammatory process result in sclerosis of skin and subcutaneous tissue and might proceed to the fascia resulting in a chronic compartment syndrome. Non- healing chronic venous ulcers under conservative therapy for more than three months may be treated by vein-surgery, local wound care therapy like shaving and negative pressure treatment and if necessary by lowering of elevated intracompartimental pressure by fasciotomy or even fasciectomy.

Aortitis following percutaneous aortic side branch embolization prior to endovascular repair of infrarenal aortic aneurysm.

PURPOSE: To report two cases of life-threatening aortic infection after percutaneous endovascular coil embolization prior to endovascular abdominal aortic aneurysm (AAA) repair (EVAR). CASE REPORT: Two 76-year-old patients were readmitted 5 days and 3 weeks, respectively, after technically successful percutaneous coil embolization of aortic side branches in advance of scheduled EVAR. In the first patient, the right hypogastric artery, the inferior mesenteric artery (IMA), and a lumbar artery had been embolized, whereas in the second patient only the right hypogastric artery and the IMA had been occluded. On admission, both patients presented with severe abdominal pain. Investigations revealed acute aortic infection in both patients, combined with substantial AAA enlargement in one. Open surgical infrarenal aortic replacement was performed using homografts, and antibiotic therapy was initiated. After uneventful recovery, both patients were asymptomatic, had intact aortic homografts, and showed no evidence of infection after 12 and 18 months of follow-up, respectively. CONCLUSION: Endovascular infections are a potentially serious complication following percutaneous coil embolization of major aortic branches. Early diagnosis and dedicated therapy are mandatory. Immediate resection of the infected aorta and replacement with homografts in association with prolonged antibiotic treatment showed good midterm results.

Effects of low abdominal blood flow and dobutamine on blood flow distribution and on the hepatic arterial buffer response in anaesthetized pigs.

Low cardiac output impairs the hepatic arterial buffer response (HABR). Whether this is due to low abdominal blood flow per se is not known. Dobutamine is commonly used to increase cardiac output, and it may further modify hepatosplanchnic and renal vasoregulation. We assessed the effects of isolated abdominal aortic blood flow changes and dobutamine on hepatosplanchnic and renal blood flow. Twenty-five anesthetized pigs with an abdominal aorto-aortic shunt were randomized to 2 control groups [zero (n = 6) and minimal (n = 6) shunt flow], and 2 groups with 50% reduction of abdominal blood flow and either subsequent increased abdominal blood flow by shunt reduction (n = 6) or dobutamine infusion at 5 and 10 microg kg(-1) min(-1) with constant shunt flow (n = 7). Regional (ultrasound) and local (laser Doppler) intra-abdominal blood flows were measured. The HABR was assessed during acute portal vein occlusion. Sustained low abdominal blood flow, by means of shunt activation, decreased liver, gut, and kidney blood flow similarly and reduced local microcirculatory blood flow in the jejunum. Shunt flow reduction partially restored regional blood flows but not jejunal microcirculatory blood flow. Low-but not high-dose dobutamine increased gut and celiac trunk flow whereas hepatic artery and renal blood flows remained unchanged. Neither intervention altered local blood flows. The HABR was not abolished during sustained low abdominal blood flow despite substantially reduced hepatic arterial blood flow and was not modified by dobutamine. Low-but not high-dose dobutamine redistributes blood flow toward the gut and celiac trunk. The jejunal microcirculatory flow, once impaired, is difficult to restore.

Bilateral leg ischemia due to descending aortic dissection: combined treatment with femoro-femoral cross-over bypass and unilateral aorto-iliac stenting.

We report a case of aorto-iliac occlusion due to descending aortic dissection treated initially with femoro-femoral cross-over bypass and secondarily with unilateral aorto-iliac stenting because of progression of the dissection. A 75-year-old man presented with acute ischemia of the right leg. CT revealed occlusion of the right iliac artery due to descending aortic dissection with a clotted false lumen. Three days after femoro-femoral cross-over bypass, ischemia of both legs developed and angiography demonstrated occlusion of the infrarenal aorta and left common iliac artery. Two overlapping stents were deployed in these vessel segments. Completion angiography confirmed successful recanalization with adequate distal flow and good patency of the cross-over bypass. Peripheral pulses were restored and the patient's symptoms were alleviated. Combined treatment with cross-over bypass and endovascular recanalization may be considered as a viable alternative to open aortic surgery in selected cases of complicated aorto-iliac dissection with bilateral leg ischemia.