Cüneyt Köksoy

Mortality and paraplegia after thoracoabdominal aortic aneurysm repair: a risk factor analysis

BACKGROUND Recent recommendations regarding thoracoabdominal aortic aneurysm (TAAA) management have emphasized individualized treatment based on balancing a patients calculated risk of rupture with their anticipated risk of postoperative death or paraplegia. The purpose of this study was to enhance this risk-benefit decision by providing contemporary results and determining which preoperative risk factors currently predict mortality and paraplegia after TAAA surgery. METHODS Risk factor analyses based on data regarding 1,220 consecutive patients undergoing TAAA repair from 1986 through 1998 were performed using multiple logistic regression with step-wise model selection. RESULTS The 30-day mortality rate was 4.8% (58 of 1,220) and the incidence of paraplegia was 4.6% (56 of 1,206). For elective cases, predictors of operative mortality included renal insufficiency (p = 0.0001), increasing age (p = 0.0005), symptomatic aneurysms (p = 0.0059), and extent II aneurysms (p = 0.0054). Extent II aneurysms (p = 0.0023) and diabetes (p = 0.0402) were predictors of paraplegia. CONCLUSIONS These risk models may assist in decisions regarding elective TAAA operations. For patients who are acceptable candidates, contemporary surgical management provides favorable results.

Morbidity and mortality after extent II thoracoabdominal aortic aneurysm repair

BACKGROUND Surgical repair of Crawford extent II thoracoabdominal aortic aneurysms (TAAAs) carries substantial risk for morbidity and mortality. The purpose of this study was to analyze the results of a large consecutive series of extent II TAAA repairs and identify factors that influence morbidity and survival. METHODS Of 1,415 consecutive patients who underwent TAAA operations over a 13-year period, 442 (31.2%) had extent II repairs. Data from a prospectively maintained database were analyzed to determine which factors were associated with death and major complications. RESULTS The operative mortality was 10.0% (44 patients). Postoperative complications included paraplegia/paraparesis in 33 patients (7.5%), pulmonary complications in 158 (35.7%), and renal failure in 69 (15.9%). Multivariable analysis revealed that renal insufficiency (odds ratio [OR] 2.6), increasing age (OR 1.1/year), and increasing red blood cell transfusion requirements (OR 1.1/U) were predictors for mortality; renal insufficiency (OR 2.8) and peptic ulcer disease (OR 9.3) were predictors of renal failure; and rupture (OR 6.3) was a predictor of paraplegia. Left heart bypass was an independent protective factor against paraplegia (OR 0.4). CONCLUSIONS This contemporary experience demonstrates acceptable levels of morbidity and mortality in this high-risk group. Left heart bypass was found to provide protection against paraplegia in these patients.

Renal perfusion during thoracoabdominal aortic operations: cold crystalloid is superior to normothermic blood

BACKGROUND Renal failure remains a common complication of thoracoabdominal aortic aneurysm repair. The purpose of this randomized clinical trial was to compare two methods of selective renal perfusion--cold crystalloid perfusion versus normothermic blood perfusion--and determine which technique provides the best kidney protection during thoracoabdominal aortic aneurysm repair. METHODS Thirty randomized patients undergoing Crawford extent II thoracoabdominal aortic aneurysm repair with left heart bypass had renal artery perfusion with either 4 degrees C Ringers lactate solution (14 patients) or normothermic blood from the bypass circuit (16 patients). Acute renal dysfunction was defined as an elevation in serum creatinine level exceeding 50% of baseline within 10 postoperative days. RESULTS One death occurred in each group. One patient in the blood perfusion group experienced renal failure requiring hemodialysis. Ten patients (63%) in the blood perfusion group and 3 patients (21%) in the cold crystalloid perfusion group experienced acute renal dysfunction (p = 0.03). Multivariable analysis confirmed that the use of cold crystalloid perfusion was independently protective against acute renal dysfunction (p = 0.02; odds ratio, 0.133). CONCLUSIONS When using left heart bypass during repair of extensive thoracoabdominal aortic aneurysms, selective cold crystalloid perfusion offers superior renal protection when compared with conventional normothermic blood perfusion.

Management of Thoracic Aortic Graft Infections

BACKGROUND We reviewed our experience managing patients with thoracic aortic graft infections to evaluate their clinical characteristics and outcomes of treatment. METHODS Records of 20 consecutive patients with thoracic aortic graft infections managed over a 7 year period were retrospectively reviewed. Current follow-up status was obtained for all survivors. RESULTS; Nineteen patients (95%) underwent surgical treatment. Graft excision and in situ replacement were performed using Dacron grafts (10/19, 53%) or cryopreserved homografts (5/19, 26%). Three pseudoaneurysms were managed by debridement and primary repair. Although 30 day postoperative survival was 89% (17/19), in-hospital mortality occurred in 8 patients (42%). Infected thoracoabdominal aortic grafts were universally fatal. Of 6 patients with infected composite valve grafts, both patients who received new composite valve grafts died and all 4 who received homografts survived (p = 0.067). CONCLUSIONS Infections involving thoracic aortic grafts continue to carry a high mortality rate, especially in patients with polymicrobial infections, thoracoabdominal aortic graft infections, and composite valve graft infections. Use of homografts in the latter situation may improve outcome.

Effect of Ischemia/Reperfusion as a Systemic Phenomenon on Anastomotic Healing in the Left Colon

Intestinal ischemia/reperfusion provokes a local inflammatory response leading to a systemic inflammatory state. In this study we aimed to assess the effects of intestinal ischemia/reperfusion injury on anastomotic healing in the left colon with an intact vascular supply. A total of 94 Wistar albino rats were divided into three groups: sham-operated control (group I, n= 25), 30 minutes of intestinal ischemia/reperfusion (group II, n= 40), and 7-day allopurinol pretreatment and intestinal ischemia/reperfusion (group III, n= 29). After the reperfusion experiment, a segmental left colon resection and anastomosis were done. On postoperative days 3 and 7 anastomotic bursting pressure, anastomotic and operative complications, and intraabdominal adhesions were assessed. Mortality rates were 1/25, 16/40, and 4/29 for groups I, II, and III, respectively (p= 0.001). There was no difference among the groups for wound and anastomotic healing parameters evaluated by macroscopic criteria. On postoperative day 7 the mean bursting pressures were 220.3 ± 18.5, 162.0 ± 21.0, and 213.9 ± 24.7 for groups I, II, and II, respectively (p= 0.000). Significantly dense adhesions were found in group II (p= 0.000). Allopurinol pretreatment prevented the effects of ischemia/reperfusion on anastomotic healing of the left colon. Intestinal/ischemia reperfusion causes impairment of anastomotic healing of the left colon. In addition to remote organ effects, reperfusion injury may affect anastomotic healing in the viscera with an intact vascular supply.

Direct trocar insertion versus veress needle insertion in laparoscopic cholecystectomy

BACKGROUND Direct insertion of the trocar is an alternative method to Veress needle insertion for the creation of pneumoperitoneum. The safety of direct disposable shielded trocar insertion for the creation of pneumoperitoneum was assessed by comparing with Veress needle insertion during laparoscopic cholecystectomy (LC). METHODS One thousand five hundred patients undergoing LC with pneumoperitoneum were included in this study. In 470 patients the Veress needle insertion technique was used, and in 1,030 patients direct trocar insertion technique was used. Patients having indications for open trocar insertion were excluded from the study. RESULTS Complication rate was significantly higher in the Veress needle group (14% versus 0.9%; P <0.01), and the two major complications, gastric perforation and iliac artery laceration, were also encountered in this group. CONCLUSIONS Our results suggest that with a lower complication rate, direct insertion of the disposable trocar is a safe alternative to Veress needle insertion technique for the creation of pneumoperitoneum. Such an approach has further advantages such as less cost/instrumentation and rapid creation of pneumoperitoneum.

Intestinal Ischemia and Reperfusion Impairs Vasomotor Functions of Pulmonary Vascular Bed

OBJECTIVE To investigate the effects of intestinal ischemia and reperfusion (I/R) on the pulmonary vascular endothelium and smooth muscle. SUMMARY BACKGROUND DATA Respiratory failure is an important cause of death and complications after intestinal I/R. Although the mechanism of respiratory failure in this setting is complex and poorly understood, recent studies of lung injury suggest that endothelial dysfunction may play a significant role. METHODS A rat model of acute lung injury was studied after 60 minutes of superior mesenteric arterial occlusion followed by either 120 or 240 minutes of reperfusion. The pulmonary vasomotor function was examined in isolated lungs perfused at a constant flow rate. RESULTS Sixty minutes of intestinal ischemia followed by 120 or 240 minutes of reperfusion led to a significant reduction in the ability of the pulmonary vasculature to respond to angiotensin II, acetylcholine, and calcium ionophore but not to nitroglycerin. The vasoconstriction response to N(G)-nitro-L-arginine methyl ester, which is a measure of basal nitric oxide release, was diminished in the 240-minute reperfusion group. Intestinal I/R was also associated with pulmonary leukosequestration and increased pulmonary microvascular leakage. CONCLUSIONS Basal and agonist-stimulated release of nitric oxide from the pulmonary vascular endothelium and the ability of pulmonary smooth muscle to contract in response to angiotensin II were impaired by intestinal I/R. Such functional impairment in both pulmonary vascular endothelium and smooth muscle may contribute to the alveolocapillary dysfunction and pulmonary hypertension found in acute lung injury after intestinal I/R.

Brachiobasilic versus brachiocephalic arteriovenous fistula: a prospective randomized study.

BACKGROUND The most recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend that the order of preference for arteriovenous fistula (AVF) placement is the radial-cephalic primary AVF, followed by the secondary brachiocephalic (BC) and, if either of these is not viable, then brachiobasilic (BB) AVF should be fashioned. However, there is limited prospective data comparing technical and clinical outcomes of these two approaches. The purpose of our study was to compare outcome, patency, and complication rates in these two autogenous upper arm AV accesses. METHODS Between December 2003 and and January 2007, patients (61 male, 39 female) who have lost more distal AVFs were enrolled in the study. After preoperative duplex mapping, patients with patent both basilic and cephalic veins greater than 3 mm of diameter were randomized into BCAVF and BBAVF groups, each group consisting of 50 patients. All procedures were performed under local anesthesia as one-stage procedures. Follow-up data were prospectively collected. Kaplan-Meier analysis was used to calculate primary and secondary patency rates. Univariate and multivariate Cox-regression analysis was used to find risks for the occurrence of thrombosis. RESULTS Baseline demographics, clinical characteristics, and preoperative history dialysis access were comparable between groups with the exception of the fact that mean caliber of the basilic veins were larger (4.51 +/- 0.93 mm vs 3.90 +/- 0.1 mm; P = .002). The mean duration of operation was significantly shorter in the BC group compared with the BB group (P < .001). There was no significant difference in the thirty day mortality, wound complications, 24 hour thrombosis, postoperative hemorrhage, maturation, and time to maturation between the groups. Mean follow-up was 43.2 +/- 1.8 months. Primary patency at 1 and 3 years of follow-up was 87% and 81% for the BC group and 86% and 73% for the BB group (P = .7) Secondary patency at one and three year follow-up was 87% and 70% for the BC group and 88% and 71% for the BB group, respectively (P = .8). Twenty-eight patients (28%) in the BC (18 patients) and BB (10 patients) group died with a patent fistula during the follow-up period (P = .18). Multivariate analysis revealed that use of dominant arm increased the risk of fistula failure. CONCLUSION We conclude that brachiobasilic and brachiocephalic AVF are equally effective alternatives; however, a longer and demanding operation with BB AVF construction should be considered.

Role of integrins and intracellular adhesion molecule-1 in lung injury after intestinal ischemia-reperfusion

BACKGROUND We tested the hypothesis that lung injury after intestinal ischemia-reperfusion (IR) requires the activation of CD11/CD18 glycoprotein complex and its ligand, intracellular adhesion molecule-1 (ICAM-1), on pulmonary endothelial surface. METHODS Rats were assigned to one of six groups including sham operation, intestinal IR (60/120 min) and IR plus treatment with one of the following monoclonal antibodies against CD11a, CD11b, CD18, and ICAM-1. Pulmonary microvascular permeability, neutrophil accumulation, and expression of adhesion molecules were evaluated. RESULTS Intestinal IR resulted in lung injury characterized by a marked increase in microvascular permeability, neutrophil accumulation and upregulated expression of leukocyte integrins and ICAM-1. The increase in pulmonary microvascular permability and neutrophil accumulation elicited by intestinal reperfusion was effectively prevented by administration of blocking antibodies against ICAM-1, CD11, and CD18. CONCLUSIONS These results indicate that adhesion molecules contribute to the lung injury after intestinal IR. Immunoneutralization of certain of these adhesion molecules may prevent intestinal IR-induced lung injury.

Reperfusion injury delays healing of intestinal anastomosis in a rat

BACKGROUND Revascularization of ischemic bowel may induce further local tissue damage due to reperfusion injury. Therefore, we aimed to investigate the effect of ischemia-reperfusion injury on the healing of intestinal anastomosis in experimental models. METHODS One hundred and two male Wistar rats were divided into three groups: a control group (group I, n = 23); an ischemia group (group II, n = 32), in which only the superior mesenteric artery (SMA) was occluded for 30 minutes; and a profound ischemia group (group III, n = 47), in which SMA was occluded as well as collateral vessels for 30 minutes. The pulsations were seen to return to marginal vessels and the bowels began to appear pinker and healthier in all groups following the restoration of arterial flow. Then, all animals underwent a 3-cm ileal resection and primary anastomosis, 10 cm proximal to the ileocecal valve. Within each group, animals were anesthetized either on the third or seventh postoperative days. Abdominal wound healing, intraabdominal adhesions, anastomotic complications, anastomotic bursting pressure measurements, and bursting site were recorded. RESULTS Statistically significant differences were detected in intraperitoneal adhesion scores in group II and III (P <0.001). Anastomotic dehiscence was found in 2 of 23 (9%) in group I, 5 of 32 (16%) in group II, and 16 of 47 (34%) in group III (P <0.001). On the third and seventh days, the median bursting pressures of the anastomosis were determined to be 42 mm Hg and 250 mm Hg in group I, 46 and 253 in group II, and finally 19 and 90 mm Hg in group III (P <0.01). The burst occurred at the anastomoses in all animals tested on the third postoperative day, none in group I, 4 (28%) in group II, and 8 (67%) in group III on the seventh postoperative day (P <0.005). CONCLUSION The present study demonstrated that ischemia-reperfusion impairs anastomotic healing. Despite the fact that the intestines are well perfused and viable after revascularization, one must bear in mind that intestinal reperfusion may compromise anastomotic healing.