Willem Wisselink

Endovascular repair versus open repair of ruptured abdominal aortic aneurysms: a multicenter randomized controlled trial.

Objective: Randomized comparison of endovascular repair (EVAR) with open repair (OR) in patients with a ruptured abdominal aortic aneurysm (RAAA). Background: Despite advances in operative technique and perioperative management RAAA remains fraught with a high rate of death and complications. Outcome may improve with a minimally invasive surgical technique: EVAR. Methods: All patients with a RAAA in the larger Amsterdam area were identified. Logistics for RAAA patients was changed with centralization of care in 3 trial centers. Patients both fit for EVAR and for OR were randomized to either of the treatments. Nonrandomized patients were followed in a prospective cohort. Primary endpoint of the study was the composite of death and severe complications at 30 days. Results: Between April 2004 and February 2011, we identified 520 patients with a RAAA of which 116 could be randomized. The primary endpoint rate for EVAR was 42% and for OR was 47% [absolute risk reduction (ARR) = 5.4%; 95% confidence interval (CI): −13% to +23%]. The 30-day mortality was 21% in patients assigned to EVAR compared with 25% for OR (ARR = 4.4% 95% CI: −11% to +20%). The mortality of all surgically treated patients in the nonrandomized cohort was 30% (95% CI: 26%–35%) and 26% (95% CI: 20% to 32%) in patients with unfavorable anatomy for EVAR, treated by OR at trial centers. Conclusions: This trial did not show a significant difference in combined death and severe complications between EVAR and OR. Mortality for OR both in randomized patients and in cohort patients was lower than anticipated, which may be explained by optimization of logistics, preoperative CT imaging, and centralization of care in centers of expertise.

Medium molecular weight pentastarch reduces reperfusion injury by decreasing capillary leak in an animal model of spinal cord ischemia

PURPOSE The medium molecular weight fraction of pentastarch (HES-Pz) has been shown to decrease reperfusion injury to myocardium and brain by reducing capillary leak. This study was undertaken to assess the effects of HES-Pz on neurologic function, microvascular permeability, and spinal cord infarction after temporary aortic cross-clamping in a rabbit model. METHODS In 30 New Zealand White rabbits, a snare occlusion device was placed around the infrarenal aorta and tunneled into a subcutaneous position. Animals were allowed to recover for 48 hours and were randomized into three groups. In each group, the infrarenal aorta was occluded by tightening the snare in the awake animal for 21 minutes. Immediately after unclamping, animals received an intravenous infusion of 4% of their estimated blood volume of one of the following solutions: normal saline solution (NS; group 1); 6% standard hydroxyethyl starch (HES), molecular weight 10 to 3400 kD (group 2); and 6% HES-Pz, molecular weight 100 to 1000 kD (group 3). During 5 days of observation, neurologic recovery was graded by an independent observer using the Tarlov scale. Animals were then killed and their spinal cords harvested for histologic examination using hematoxylin-eosin and 2,3,5-triphenyltetrazolium chloride staining. In a separate group of animals (n = 15), the occurrence of spinal cord capillary permeability after NS, HES, and HES-Pz infusions was evaluated by spectrophotometric analysis of extravasated Evans blue. RESULTS Complete paraplegia and marked histologic evidence of spinal cord cellular injury were seen in 90% of group 1 (NS) and in 78% of group 2 (HES). Treatment with HES-Pz (group 3) resulted in full neurologic recovery in 89% of animals (p < 0.05) and a threefold reduction of extravasated Evans blue compared with controls (p < 0.05). CONCLUSIONS These results indicate that microvascular hyperpermeability plays an important role in reperfusion injury to the spinal cord. Treatment with HES-Pz reduced the capillary permeability, neuron membrane injury, and incidence of paraplegia after reperfusion of ischemic spinal cord in a rabbit model.

Protecting the ischemic spinal cord during aortic clamping: The influence of selective hypothermia and spinal cord perfusion pressure

Abstract Purpose: We verified the hypothesis that selective deep hypothermia of the spinal cord during double thoracic aortic clamping can prevent postoperative paraplegia in dogs. Methods: Normal saline solution was circulated from the cisterna magna through an extracorporeal perfusion system consisting of a reservoir, a pump, and a heat exchanger, back into the subarachnoid space at the level of the medullary cone at a rate of 25 ml/min, starting 30 minutes before clamping, and ending after removal of the clamps. The thoracic aorta was cross-clamped below the left subclavian artery and above the diaphragm for a period of 45 minutes. Cerebrospinal fluid, intracranial, and central venous pressure and aortic pressure proximal, between, and distal to the clamps were continuously recorded. In five dogs, temperature of the circulating normal saline solution at the inflow level was maintained at 2° ±1.5° C (group 1), in five controls at 37° ±0.8° C (group 2). Five dogs underwent continuous cerebrospinal fluid drainage starting before clamping until sacrifice (group 3). Dogs were observed for up to 4 days, and neurologic function was graded by an independent observer with the Tarlov scale. Animals were then killed, and their spinal cords were prepared for microscopic examination. Results: Hemodynamic parameters were not significantly different between groups. All dogs in groups 2 and 3 were paraplegic with histologic evidence of spinal cord infarction. All animals in group 1 were neurologically normal without microscopic evidence of infarction ( p Conclusions: Selective deep hypothermia of the spinal cord prevents paraplegia after 45 minutes of double aortic clamping in dogs. Cerebrospinal fluid drainage was not effective in preventing paraplegia in this model. (J VASC SURG 1994;19:788-96.)

Increased pulmonary capillary permeability and extravascular lung water after major vascular surgery: effect on radiography and ventilatory variables

Introduction: We decided to investigate the pathogenesis of pulmonary ventilatory and radiographic abnormalities in patients after major vascular surgery. Patients and methods: Sixteen mechanically ventilated patients without heart failure were studied, within 3 h after major abdominal surgery. We measured extravascular lung water, intrathoracic, global end‐diastolic and pulmonary blood volumes, 67Ga‐transferrin pulmonary leak index and ventilatory and radiographic variables. The latter allowed computation of the lung injury score as a measure of lung injury. Results: The extravascular lung water was elevated (>7 mL kg−1) in 5 of 16 patients, while the pulmonary leak index was elevated in 11 patients and a supranormal extravascular lung water was associated with a high pulmonary leak index and higher extravascular lung water relative to intrathoracic blood volume or pulmonary blood volume. Patients were arbitrarily divided into those with a lung injury score >1 and ≤1, and only differed in the factors composing the score as well as in extravascular lung water divided by pulmonary blood volume. A lung injury score >1 was associated with a longer duration of mechanical ventilation. Conclusion: Our data suggest that mild, subclinical, pulmonary oedema is relatively common after major vascular surgery, mainly caused by increased pulmonary capillary permeability in the absence of overt heart failure. However, permeability oedema only partially contributes to postoperative lung injury score and need for mechanical ventilation, suggesting a major contribution by atelectasis.

Cine MRI assessment of aortic aneurysm dynamics before and after endovascular repair.

Purpose: To evaluate stent-graft and aneurysm wall motions during the cardiac cycle using cine magnetic resonance imaging (MRI) to identify mechanisms of long-term failure of endovascular aneurysm repair (EVAR). Methods: Prior to and after EVAR in 7 patients with abdominal aortic aneurysms (AAA), 12 MRI images per cardiac cycle were acquired in transverse, sagittal, and coronal planes of the aneurysm. Two independent observers blinded to the aim of the study manually traced stent-graft and aneurysm wall contours. Translation was defined as the maximal displacement of the contours in the peak-systolic image compared to the end-diastolic image. Aneurysm wall motions before and after repair were compared. Stent-graft and aneurysm configuration changes during the cardiac cycle were evaluated. The relation between translation and the degree of angulation of the stent-graft was calculated. Results: The anteroposterior translation of the aneurysm decreased from a median 1.05 mm (range <0.5–1.29) before EVAR to within pixel size (<0.5 mm) after EVAR (p=0.04). The cranial-caudal translation of the aneurysm increased from a median 1.01 mm (range <0.5–1.51) before to 1.69 mm (range 1.1–1.99) after EVAR (p=0.02). In 4 stent-grafts, bending during cardiac systole was observed at the site of maximal angulation of the device. In transverse sections, 2-dimensional pulsatile wall motion of the aneurysm was 0.25 cm2 (range 0.07–0.29) before and 0.17 cm2 (range 0.07–0.42) after EVAR (p=0.79). No pulsatility of the stent-graft itself was observed. The correlation coefficient between angulation of the stent-graft and the increase in cranial-caudal translation after EVAR was 0.67 (p>0.05). Conclusions: After EVAR, increased longitudinal translation of both the aneurysm and stent-graft was observed, indicating downward pulling forces at the proximal fixation site. Secondly, increased bending was seen at the site of maximal angulation, which implies a risk of metal fatigue and fabric damage at sites of stent-graft angulation.

Thoracic sympathectomy for digital ischemia : A summary of evidence

BACKGROUND Thoracic sympathectomy is used in the management of a variety of upper limb disorders. We have analyzed the evidence for thoracic sympathectomy in the management of digital ischemia. METHODS We reviewed the English literature between 1980 and 2010. Our analysis included reports with the clinical end points of relief, recurrence of symptoms or healing of ulcers, or both. Primary Raynaud disease (PRD) and secondary Raynaud phenomenon (SRP) were analyzed separately. RESULTS An initial postoperative positive effect was reported in 92% of PRD patients and in 89% of SRP patients. Long-term beneficial effect was 58% for PRD and 89% for SRP. Ulcer healing or improvement was achieved in 95%. CONCLUSIONS The available evidence suggests that thoracic sympathectomy has a role in the treatment of severe PRD and SRP, albeit with better results in SRP patients than in PRD patients. In case of digital ulceration, thoracic sympathectomy may maximize tissue preservation or prevent amputation.

Routine Continuous Cold Perfusion of the Kidneys during Elective Juxtarenal Aortic Aneurysm Repair

OBJECTIVES Surgical treatment of JAAs (juxtarenal aortic aneurysms) requires suprarenal aortic cross-clamping, causing temporary renal artery occlusion. We implemented a standardized protocol of hypothermic renal perfusion for all elective JAA operations. DESIGN Retrospective study. MATERIALS AND METHODS Over a period of 6 years, 23 consecutive patients received a 300ml bolus followed by an infusion (20ml/minute) of cold (4 degrees C) saline to each kidney during suprarenal aortic clamping. We assessed outcome in terms of rise in serum creatinine, new onset of dialysis and mortality. RESULTS None of the patients suffered from postoperative acute renal failure and in-hospital mortality was zero. Five patients did not show any rise in serum creatinine level, whereas in the others rises were <25% in comparison with the admission level, except for one patient (38%). Postoperative rise in serum creatinine level was not related to renal ischemia time (Spearman rank correlation=0.24, p=0.27), preoperative renal function, total aortic clamping time or renal re-implantation. There were no renal complications at 6 months. CONCLUSIONS Our results suggest that a standardized strategy to apply renal hypothermia during the ischemic period of elective JAA surgery may reduce postoperative renal failure.

Intravenous glutamine supplementation enhances renal de novo arginine synthesis in humans: a stable isotope study

BACKGROUND Arginine plays a role in many different pathways in multiple cell types. Consequently, a shortage of arginine, caused by pathologic conditions such as cancer or injury, has the potential to disturb many cellular and organ functions. Glutamine is the ultimate source for de novo synthesis of arginine in humans via the intestinal-renal axis. Therefore, we hypothesized that parenteral glutamine supplementation may stimulate the interorgan pathway of arginine production. OBJECTIVES The objectives were to quantify arginine production from its precursor glutamine and to establish the contribution of the kidneys to de novo synthesis of arginine in patients receiving intravenous supplementation of glutamine dipeptide during major abdominal surgery. DESIGN Whole-body and renal metabolism of glutamine, citrulline, and arginine was assessed by stable isotope techniques in 7 patients receiving a perioperative supplement of intravenous alanyl-glutamine (0.5 g · kg(-1) · d(-1)). RESULTS Plasma glutamine, citrulline, and arginine concentrations increased significantly in patients receiving intravenous glutamine dipeptide. At whole-body level, 91% of total citrulline turnover was derived from glutamine, whereas 49% of whole-body citrulline turnover was used for de novo synthesis of arginine. The kidneys were responsible for 75% of whole-body arginine production from citrulline. CONCLUSIONS Glutamine and citrulline are important sources for de novo arginine synthesis. The kidneys are the main production site for endogenous arginine. After comparison of these results with previous similar studies, our data suggest that an intravenous glutamine supplement doubles renal arginine production from citrulline. This trial was registered at www.trialregister.nl as NTR2914.

Carotid Artery Dynamics during Head Movements: A Reason for Concern with Regard to Carotid Stenting?

Purpose: To evaluate carotid artery mobility patterns during head movements following carotid angioplasty/stenting (CAS). Methods: In 7 patients (all men; mean age 69 years, range 65–76) who had undergone unilateral CAS, 3D time-of-flight magnetic resonance angiography was performed, visualizing both carotid arteries in 5 different head positions (neutral, turned left and right, and bent forward and backward). Maximum intensity projection reconstructions were obtained to measure angulation at the proximal and distal stent junction. Configuration changes of the stented section of the carotid artery and the unstented contralateral artery were judged. Secondly, transverse sections at the level of the carotid bifurcation and at the skull base were used to calculate torsion shear in the common and internal carotid arteries (CCA, ICA) during turned left and right head position. Results were expressed as median (range). Results: In neutral head position, maximal angulation at the distal stent junction was 34.3° (32.3°–55.6°). With the head bent forward, this angulation changed to 47.6° (42.6°–85.2°, p=0.028) and when bent backward to 26.5° (25.0°–48.7°, p=0.027). In all patients, configuration changes of the stented sections were absent. The contralateral unstented side showed diffuse configuration changes without specific angulation at one location. With the head turned left and right, the CCA on the stented side was subjected to 28.6° (13.6°–53.7°) and 24.9° (2.0°–50.6°) of torsion shear, respectively. Torsion of the ICA was subsequently 18.1° (12.7°–40.5°) and 15.2° (2.9°–69.4°). Conclusions: Following carotid stenting, sharp ICA angulations that are aggravated by forward bending of the head occur at the distal stent junction. The stented section of the carotid artery shows complete lack of flexibility despite highly flexible features of the stents ex vivo. Both the CCA and ICA are subjected to considerable torsion shear with the head turned left and right. This shear is not accommodated by the current stent designs.

Cost‐effectiveness and cost–utility of endovascular versus open repair of ruptured abdominal aortic aneurysm in the Amsterdam Acute Aneurysm Trial

Minimally invasive endovascular aneurysm repair (EVAR) could be a surgical technique that improves outcome of patients with ruptured abdominal aortic aneurysm (rAAA). The aim of this study was to analyse the cost‐effectiveness and cost–utility of EVAR compared with standard open repair (OR) in the treatment of rAAA, with costs per 30‐day and 6‐month survivor as outcome parameters.