Deep Circulatory Arrest and Left Thoracotomy Approach Allow Open Repair of Chronic IIIb Dissection Associated to a Large Aortic Arch: A Case Series.

Thoracic aortic aneurysms evolving within a type IIIb chronic aortic dissection are mostly treated with the deployment of an endograft. However, several cases of dissecting aneurysms are associated with a significant dilatation of the aortic arch. These cases are usually managed in 2 steps: arch reconstruction or supra-aortic trunk debranching at first and a secondary graft deployment for the descending thoracic aorta. We present through this case series an alternative approach for this severe condition which consists in the replacement of the thoracic aorta from its hemi-arch to the distal thoracic or visceral aorta using a left thoracotomy. We deliberately neglected the remaining dissecting aorta if its diameter was below 45 mm, hypothesizing its nonevolution after repair. From 2012 to 2021, 9 patients have been treated for a thoracic aneurysm evolving after a IIIb chronic aortic dissection using a left thoracotomy and a 19°C circulatory arrest. Immediate postoperative results show no mortality or neurological disorders, and the 7 years follow-up for all of these 9 cases enlightened the absence of aneurysmal evolution especially for the distal anastomosis and the remaining dissected aorta. This work suggests that this direct approach strategy can definitively treat a thoracic dissecting aneurysm unsuitable for a simple endovascular treatment.

Enhancing Arterial Closure in Endovascular Aortic Procedures: The Efficacy of Echo-Guided ProGlide Technique.

BACKGROUND: Endovascular aortic surgery is increasingly becoming the standard treatment. Percutaneous access preclosing systems appear to be effective and notably the Proglide (PG). We aimed to prospectively assess the clinical effectiveness of combining ultrasound-guided femoral puncture with ultrasound-guided PG deployment. METHODS: Our single-center study consecutively included patients managed at a tertiary center from May to September 2023, undergoing endovascular aortic surgery. The placement of PG was performed under ultrasound guidance. Preoperative patient characteristics were evaluated using preoperative computed tomography scans. Clinical and technical success were defined, respectively, as the ability to achieve complete hemostasis confirmed by ultrasound 48 hr postprocedure and as the successful placement of a PG under ultrasound guidance contributing to final hemostasis. RESULTS: Twenty patients were included over a 6-month period, totaling 34 common femoral arteries (CFAs). Fourteen were male, with an average age of 72.8 ± 8.2 years. Among the 34 CFA, CFA had diameter of 12.05 ± 2.4 mm and a depth of 38.0 ± 13.4 mm. The mean introducer sheath diameter was 6.2 ± 1.5 mm with a sheath to femoral artery ratio of 0.54 ± 0.18. Successful Proglide placement under ultrasound guidance was achieved in 100% of cases. No PG failure occurred. Clinical and technical success were, respectively, of 95% and 100%. One small pseudoaneurysm was observed at 48 hr treated medically. No CFA access reintervention was required. CONCLUSIONS: The technique of ultrasound-guided PG deployment in aortic surgery is a safe and effective method for achieving hemostasis. It effectively prevents PG failures at a lower cost.

Anterograde Aortic Bypass Technique for Renal Preservation in Aneurysmal Repair With Horseshoe Kidney: A Novel Approach With Reduced Renal Ischemic Time.

The purpose of this article is to highlight an innovative technique in the surgical management of aortic aneurysms in the presence of a horseshoe kidney. The technique involves an anterograde aortic bypass from the distal thoracic aorta to the major renal artery with the primary advantage to a significant reduction in renal ischemia time.

Vascular Plug Embolization of a Superior Mesenteric Arteriovenous Fistula: Case Report and Literature Review of Endovascular Treatment.

Introduction: Arteriovenous fistula (AVF) rarely occurs in the portal venous system. Aetiologies include iatrogenic, surgical, and penetrating trauma of the abdomen. Clinical manifestations of superior mesenteric portal arteriovenous fistula (SMPAVF) are right heart failure, mesenteric ischaemia, or signs of portal hypertension. Report: The case of a 42 year old man with a history of Crohn's disease who had a delayed symptomatic mesenteric portal AVF, occurring 20 years after ileocecal resection, which was subsequently managed by endovascular approach is reported. The patient presented with post-prandial abdominal pain for almost one year, and dyspnoea New York Heart Association stage II. There were no signs of portal hypertension. Pre-operative contrast enhanced computed tomography showed a high flow SMPAVF, with a short and wide neck (9 mm × 16 mm) at the level of the last collateral of the superior mesenteric artery. It was associated with a large aneurysm of the mesenteric vein. Vascular plug embolisation (Amplatzer 18 × 18 mm, Abbott, Chicago, IL, USA) by femoral access allowed exclusion of the SMPAVF and preserved arterial flow in the distal collaterals. During follow up, the patient developed portal vein thrombosis and required therapeutic anticoagulation for six months. Discussion: In most cases, endovascular approaches are preferred in the management of SMPAVF. Endovascular approaches are based on minimally invasive techniques including embolisation (coiling or plug) and covered stenting. Vascular plug embolisation of SMPAVF is feasible and seems to be an effective technique, with the advantage of saving collaterals. Therapeutic anticoagulation should be considered post-operatively in cases with venous dilatation and reduced flow linked to exclusion of the AVF.

A Supraceliac Aortic Cross Clamping Model to Explore Remote Lung Injury and the Endothelial Glycocalyx.

BACKGROUND: We hypothesized that supraceliac aortic cross clamping could induce lung injury mediated by an inflammatory ischemia-reperfusion (IR) trigger. We aimed to characterize glycocalyx (GCX), a component of endothelial membrane, participating to remote lung injury. METHODS: Rats underwent supraceliac aortic cross clamping for 40 min and were sacrificed at 0, 3, 6, and 24 hr of reperfusion (n = 10/group). Each group was compared to sham (n = 6/group). GCX products (syndecan-1 [Sdc-1] and heparan sulfate [HS]), tumor necrosis factor-alpha (TNF-α), and interleukin-1ß (IL-1ß) were measured in plasma (enzyme-linked immunosorbent assay[ELISA]). Lungs were harvested for measurements of TNF-α, IL-1ß (polymerase chain reaction) and Sdc-1 (western blotting [WB]). Histologic lung injury scoring and pulmonary gravimetry were analyzed in a blinded manner. RESULTS: Plasmatic Sdc-1, HS, TNF-α, and IL-1ß reached peak levels at 3 hr. Levels were significantly higher in clamping groups than sham at 6 hr for Sdc-1, at 0 and 3 hr for HS, at 3 and 6 hr for TNF-α, and at 3 hr for IL-1ß. Lung TNF-α and Interleukin-1ß reached peak levels at 6 hr. Levels were significantly higher than sham at 6 and 24 hr for TNF-α and at 6 hr for IL-1ß. Lung Sdc-1 was lowest at 3 hr. Sdc-1 was not significantly different compared to sham at the different reperfusion times. At 3 hr, it was 0.27 ± 0.03 vs. 0.33 ± 0.02 (sham) (P = 0.09). Histopathologic scores at 6 and 24 hr were higher in clamping groups than sham. At 6 and 24 hr, it was higher for hemorrhage, polynuclear neutrophil (PNN) infiltration and intravascular leukocytes. Pulmonary edema was higher by gravimetry at 0 and 6 hr. CONCLUSIONS: Supra celiac aortic clamping causes early lung injury in relation with a systemic inflammatory response associated with altered GCX structure.

Post-EVAR Thrombus Density on Late Non-Contrast CT Scans Predicts Successful Aneurysm Exclusion.

PURPOSE: The incidence of type II endoleaks (ELII) after endovascular aneurysm repair (EVAR) ranges from 10-44%. Aneurysm thrombus density after EVAR could predict successful aneurysm exclusion. MATERIALS AND METHODS: Twenty-seven patients with an abdominal aortic aneurysm (AAA) who had a CT scan within the first 45 days (early group) post-surgery or after 7 months (late group) were included. Thrombus density was analyzed on non-contrast enhanced CT scans. RESULTS: A total of 5/13 (38%) patients in the early group had an ELII and 9/14 (64.3%) in the late group had a persistent ELII since surgery. In the early group, thrombus density was similar in patients with or without an ELII (mean: 39.9 ± 4.8 vs. 41.9 ± 3.4, p = 0.7; median: 38.7 ± 4.8 vs. 39.7 ± 3.1, p = 0.8). In patients with an ELII, there was no difference in thrombus density at 45 days and after 7 months (mean: 39.9 ± 4.8 vs. 40.2 ± 2.1, p = 0.9; median: 38.7 ± 4.8 vs. 38 ± 2.6, p = 0.9). In patients without an ELII, thrombus density was significantly higher at 45 days than after 7 months (mean: 41.9 ± 3.44 vs. 25.7 ± 2.0, p = 0.005; median: 39.7 ± 3.11 vs. 24.4 ± 1.5, p = 0.004). In patients with an ELII, thrombus density was significantly higher after 7 months than in patients without an ELII (mean: 40.2 ± 2.1 vs. 25.7 ± 2.0. p = 0.001; median: 38 ± 2.6 vs. 24.4 ± 1.5, p = 0.003). CONCLUSION: Low thrombus density after EVAR on late unenhanced CT scans predicts aneurysm exclusion.

Complex Vascular Revascularization in a Young Woman with Type 1 Neurofibromatosis.

We present an uncommon case of a 16-year-old woman with type 1 neurofibromatosis and renovascular hypertension due to bilateral renal stenosis associated with asymptomatic digestive artery stenosis. Our patient was treated by several autologous bypasses to the superior mesenteric artery and the left and right renal arteries. She had no postoperative complications and good clinical and imaging outcomes at 10 years. Furthermore, there are few data on the vascular impairment of this rare disease, thus justifying its presentation.

Protocol of supra-visceral aortic ischemic preconditioning for open surgical repair of thoracoabdominal aortic aneurysm : The EPICATA study (Evaluation of the Efficacy of Ischemic PreConditioning on morbidity and mortality in open ThoracoAbdominal Aortic surgery).

BACKGROUND: Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAA) is associated with a high pulmonary and renal morbidity rate. Ischemic preconditioning (IPC) is a mechanism of protection against the deleterious effects of ischemia-reperfusion. To our knowledge IPC has never been tested during OSR for TAA. METHODS: The primary objective of the study is to evaluate the efficacy of IPC during OSR for TAA with respect to acute kidney injury (AKI) according to KDIGO and pneumonia/prolonged ventilation-time during the first 8 postoperative days. The secondary objectives are to compare both arms with respect to cardiac complications within 48 h, renal and pulmonary complications within 21 days and mortality at 60 days. To assess the efficacy of IPC with respect to pulmonary and renal morbidity, a cox model for competing risks will be used. Assuming that the event occurs among 36% of the patients when no IPC is performed, the allocation of 55 patients to each arm should allow detecting a hazard ratio of at least 2.75 with a power of 80% when admitting 5% for an error of first kind. This means that 110 patients, enrolled in this multicenter study, may be randomised within 36 months of the first randomization. Randomization will be performed to allocate patients either to surgery with preconditioning before aortic cross clamping (Arm 1) or to surgery without preconditioning before aortic cross clamping (Arm 2). Randomization takes place during the intervention after intravenous injection of heparin, or after the start of femoral assistance. The procedure for IPC will be a supra-visceral thoracic aortic cross clamping for 5 min followed by an unclamping period of 5 min. This procedure will be repeated twice before starting thoracic aortic cross clamping needed to perform surgery. CONCLUSIONS: Our hypothesis is that ischemic preconditioning could reduce clinical morbidity and the incidence of lung damage associated with supra-visceral aortic clamping. TRIAL REGISTRATION: EPICATAStudy registered in ClinicalTrial.gov / number: NCT03718312 on Oct.24.2018 URL number.

Abdominal Aortic Aneurysm with Severe Chronic Heart Failure: Usefulness of Mechanical Hemodynamic Cardiac Support.

We present a case of abdominal aortic aneurysm open repair planned with temporary left ventricular support (Impella®) in a patient suffering from severe chronic heart failure. Only 1 single similar case was reported in the literature from 1974.

Early Postoperative Renal Dysfunction Predicts Long-Term Renal Function Degradation after Type IV Thoracoabdominal Aortic Aneurysm Surgical Repair.

BACKGROUND: Type IV thoracoabdominal aortic aneurysm surgical repair is often complicated by postoperative acute kidney injury. The aim was to evaluate early renal injury influence on long-term renal function. METHODS: All type IV thoracoabdominal surgical repair performed between January 2000 and January 2014 in our tertiary hospital were included in this retrospective observational study. All procedures were performed through a retroperitoneal approach with at least suprarenal aortic cross-clamping. Cold Ringer Lactate was used to perfuse the kidneys. Serum creatinine (Scr.) and glomerular filtration rate (GFR) were recorded preoperatively, daily until discharge and at least annually during follow-up. Postoperative renal dysfunction was classified using the RIFLE score. Predictors of long-term renal decline were identified by logistic regression and a Cox model. RESULTS: Of total, 80 patients were included. Aortic clamping level was suprarenal (10%), supramesenteric (37%) or supracoeliac (53%). Ischemic durations were 29 ± 9 min for the gastrointestinal tract and the right kidney, 54 ± 28 min for the left kidney. Three patients died postoperatively. At discharge, 31 (38.8%) patients did not have a postoperative renal impairment (RIFLE-), compared with 49 (61.2%) who had a renal dysfunction (RIFLE+). GFR was 89 ± 29 ml/min vs 68 ± 37 ml/min, respectively (P < 0.01). In the RIFLE + group, Scr. was increased by x1.5 (Risk) for 22 patients, x2 (Injury) for 19 patients, and ×3 (Failure) for 8 patients. Mean follow-up was 59 months. Eighteen patients died, and 2 patients started permanent dialysis at 46 and 118 months during follow-up. The only predictive factor of long-term GFR degradation was a postoperative GFR below 45 ml/min (OR: 16.5; 95%; P < 0.001). CONCLUSIONS: Postoperative renal dysfunction was a frequent complication, associated with long-term renal function degradation.

Rupture of a Totally Occluded Abdominal Aortic Aneurysm.

Totally occluded aortic aneurysm is a rare pathology. The medical history and the evolution are unknown. We present a case of a regularly followed up 60-year-old man with chronic thrombosed aneurysm, presenting with mycotic acute rupture. As an original treatment, the patient was treated by aortic ligation without distal revascularization. A literature review from 1974 to 2015 enhances the contemporary understanding of the pathology, by exploring the thrombus interaction, pressure, and the wall shear stress. The literature review confirms the poor prognosis and concludes of a necessary closer follow-up for chronic occluded aneurysm.

Long-term Outcomes after Transplant Renal Artery Stenosis Surgery.

The occurrence of transplant renal artery stenosis (TRAS) ranges from 1 to 23% and is associated with resistant hypertension, volume overload, graft dysfunction, and poor long-term graft and patient survival. Enhancing graft availability with expanded criteria donors results in the transplantation of kidneys with atherosclerotic arteries, increasing the risk of vascular complications. Although endovascular management is the first-line strategy in this context, in some patients, surgery has to be considered. We report the experience and long-term follow-up of TRAS surgery in a French kidney transplantation center. Between 2004 and 2009, 10 patients with postoperative TRAS, considered unfit for an endovascular procedure by a multidisciplinary team, were addressed for surgery. Mean time from transplantation to surgery was 139.8 ± 136.4 days. Clinical indications were oliguria, anuria, or acute decrease in urine output (n = 5), resistant hypertension (n = 4), and persistence of a decreased allograft function (n = 1). Imaging-revealed ostial stenosis is associated with external iliac artery stenosis (n = 3) or early bifurcation (n = 2), and kinking (n = 5). Revascularization techniques consisted in a great saphenous vein bypass (n = 5) and internal iliac artery anastomosis (n = 5). In the postoperative period, there was no graft loss, but 2 patients required hemodialysis during the first week. Mean follow-up was 9.8 ± 2.1 years. One patient lost his graft 10.3 years after transplantation due to chronic rejection, and 1 patient needed endovascular dilation. There was no graft loss at 5 years. Blood pressure was controlled in all patients. Surgical intervention for TRAS is safe and effective on graft survival and graft function and has to be considered for patients unsuitable for endovascular repair.

Operated descending thoracic and thoracoabdominal atherosclerotic aortic aneurysm prognosis.

BACKGROUND: The long-term survival of patients treated from descending thoracic aneurysm (DTA) is well known, more than those treated from a thoracoabdominal aortic aneurysm (TAAA). Moreover, studies are rarely focused on the aneurysmal etiology and include both degenerative and post dissecting aneurysms. The aim of this study is to compare the long-term survival of patients operated from DTA or TAAA due to degenerative atherosclerosis. METHODS: Thirty-nine atherosclerotic aneurysm patients were operated between January 2007 and July 2015 at Rouen University Hospital. Eighteen DTA patients were operated by TEVAR and 21 TAAA patients (8 type I and 13 type III) by open approach. The main endpoint was remote survival patients. RESULTS: Overall, the initial population was similar in the two groups. However, one third of DTA were treated in context of emergency for painful aneurysm versus 9.5% of patients with TAAA (P=0.066). Survival median of 18 DTA was 18 months (1-68). Survival median of 21 TAAA followed was 66 months (1-91). Survival in both groups was statistically different with the log-rank test (P=0.044). CONCLUSIONS: Long-term prognosis of atherosclerotic DTA may be worse than that of TAAA's. This retrospective study reflects experience in the management of DTA and TAAA in a single-center. Prospective data in patients treated with endovascular procedures for DTA or TAAA, with fenesterated or branched endoprosthesis, are warranted to confirm these results.

A 30-Minute Supraceliac Aortic Clamping in the Rat Causes Death Due to an Inflammatory Response and Pulmonary Lesions.

BACKGROUND: The treatment of thoracoabdominal aortic aneurysms through an open approach has general and pulmonary consequences of multiple etiologies. Our assumption was that the supraceliac aortic clamping needed for this operation causes a systemic inflammatory response associated with a pulmonary attack. METHODS: We developed a model of 30-min supraceliac aortic clamping in Wistar rats weighing 300 g. After 90 min of reperfusion, the rats were sacrificed. The effects on the digestive tract wall were analyzed by measurement of the mucosal thickness/total thickness ratio. The effects on the mesenteric endothelial function were determined by an ex situ measurement of the arterial pressure/volume curves (third branch). The systemic consequences of the procedure were analyzed by dosing tumor necrosis factor alpha (TNFα), interleukin (IL)1ß, and IL10 in the blood. The pulmonary consequences were analyzed by the measurement of macrophages, polymorphonuclear neutrophils (PNs), T lymphocyte infiltration, pulmonary apoptosis (TUNEL) and active caspase 3. The experimental scheme included 20 rats with ischemia-reperfusion (IR) and 20 control rats. An analysis of survival was carried out on 20 other rats (10 IR and 10 controls). RESULTS: The results were expressed as average ± standard error of the mean. The statistical tests were Student's t-test and Mann-Whitney test. This visceral IR model decreased the ratio of the thickness of the intestinal mucosa compared with that of the control rats (0.77 ± 0.008 vs. 0.82 ± 0.009 [P < 0.001]). This local effect was not accompanied by any mesenteric endothelial dysfunction (P = 0.91). On a systemic level, IR increased TNFα (37.9 ± 1.5 vs. 28.2 ± 0.6 pg/mL; P < 0.0001), IL1ß (67.1 ± 9.8 vs. 22.5 ± 5.6 pg/mL; P < 0.001), and IL10 (753.3 ± 96 vs. 3.7 ± 1.7 pg/mL; P < 0.0001). As regards the lungs, IR increased the parenchymal cellular infiltration by macrophages (6.8 ± 0.8 vs. 4.5 ± 0.4 cells per field; P < 0.05) and PNs (7.4 ± 0.5 vs. 6.2 ± 03 cells per field; P < 0.05). There was no increase in the pulmonary cellular apoptosis measured by TUNEL (P = 0.77) or in the caspase 3 activity (P = 0.59). The mortality of the visceral IR rats was 100% at 36 hr vs. 0% in the animals without IR. CONCLUSIONS: This work showed that the inflammatory response to visceral IR had systemic and pulmonary effects which always results in the death in the rat.

Low baseline and subsequent higher aortic abdominal aneurysm FDG uptake are associated with poor sac shrinkage post endovascular repair.

PURPOSE: The growth phases of medically treated abdominal aortic aneurysms (AAA) are frequently associated with an 18F-fluorodesoxyglucose positron emission tomography (FDG-PET) pattern involving low baseline and subsequent higher FDG uptake. However, the FDG-PET patterns associated with the endovascular aneurysm repair (EVAR) of larger AAA are presently unknown. This study aimed to investigate the relationship between serial AAA FDG uptake measurements, obtained before EVAR and 1 and 6 months post-intervention and subsequent sac shrinkage at 6 months, a well-recognized indicator of successful repair. METHODS: Thirty-three AAA patients referred for EVAR (maximal diameter: 55.4 ± 6.0 mm, total volume: 205.7 ± 63.0 mL) underwent FDG-PET/computed tomography (CT) before EVAR and at 1 and 6 months thereafter, with the monitoring of AAA volume and of a maximal standardized FDG uptake [SUVmax] averaged between the axial slices encompassing the AAA. RESULTS: Sac shrinkage was highly variable and could be stratified into three terciles: a first tercile in which shrinkage was absent or very limited (0-29 mL) and a third tercile with pronounced shrinkage (56-165 mL). SUVmax values were relatively low at baseline in the 1st tercile (SUVmax: 1.69 ± 0.33), but markedly increased at 6 months (2.42 ± 0.69, p = 0.02 vs. baseline). These SUV max values were by contrast much higher at baseline in the 3rd tercile (SUVmax: 2.53 ± 0.83 p = 0.009 vs. 1st tercile) and stable at 6 months (2.49 ± 0.80), while intermediate results were documented in the 2nd tercile. Lastly, the amount of sac shrinkage, expressed in absolute values or in percentages of baseline AAA volumes, was positively correlated with baseline SUVmax (p = 0.001 for both). CONCLUSION: A low pre-EVAR FDG uptake and increased AAA FDG uptake at 6 months are associated with reduced sac shrinkage. This sequential FDG-PET pattern is similar to that already shown to accompany growth phases of medically treated AAA.

Below-The-Knee Angioplasty for Critical Limb Ischemia: Results of a Series of 157 Procedures and Impact of the Angiosome Concept.

BACKGROUND: To evaluate the long-term clinical results of below-the-knee percutaneous transluminal angioplasty (BTK-PTA) with or without stenting, in patients with critical limb ischemia (CLI), and to determine factors affecting clinical results including the role of the angiosome concept. METHODS: All patients undergoing primary BTK-PTA from January 2007 to December 2011 were included. Primary patency, assisted patency, limb salvage, survival, and wound healing were assessed using the Kaplan-Meier method. Predictors of patency, limb salvage, survival, and wound healing, including the role of the angiosome theory, were determined using multivariate models. RESULTS: A total of 157 procedures were performed in 139 patients with CLI (Rutherford IV 10.8%; Rutherford V-VI 89.2%). Mean age was 74.2 years and 68.3% were men; 60% had diabetes and 31% renal insufficiency. PTA was confined to the infrapopliteal segment alone in 53.5% of cases. Technical success was 87.9%. Stents were placed in 42.6% of cases. The mean follow-up was 14.7 months (range, 1-67 months). Four-year primary and secondary patency were 51% and 61%, respectively. Limb salvage at 4 years was 68.8%. Complete wound healing was 52% at 4 years. Positive predictors of survival were the absence of renal insufficiency (P < 0.0001) and technical success (P = 0.029). Target vessel occlusion of >50% was a negative predictor of limb salvage (P = 0.0072). Positive predictors of wound healing were technical success (P = 0.0067), the absence of renal insufficiency (P < 0.0001) and continuity between a leg artery and a foot artery (P = 0.02). CONCLUSIONS: BTK-PTA can be performed with favorable long-term results in patients with limited longevity. Secondary interventions may be necessary to maintain target vessel patency. In our experience, the angiosome concept had no impact on clinical success.

Passive Temporary Visceral Shunt from the Axillar Artery as an Adjunct Method during the Open Treatment of Thoracoabdominal Aortic Aneurysm.

BACKGROUND: Distal aortic retrograde perfusion systems like the left heart bypass or femoro-femoral extracorporeal circulation are the methods of reference for organ protection during direct approaches to thoracoabdominal aortic aneurysms. The aim of this work was to evaluate the use of a passive arterial shunt to reduce visceral ischemia during aortic operations when occlusive diseases of the iliac arteries make distal aortic retrograde perfusion inappropriate. METHODS: Ten patients affected by a Crawford type III thoracoabdominal aneurysm (TAA) were operated on between January 2013 and January 2015 with the use of a temporary shunt inserted onto the left axillar artery that allows visceral perfusion immediately after the aorta is opened. The operation was performed after a single dose of heparin (50 UI/kg). The sera lactate levels were measured 2 hr after the last aortic clamp was removed and compared with those obtained from a group of 19 patients operated on for a Crawford type IV TAA during the same period without any arterial shunt. RESULTS: Neither mortality nor paraplegia occurred. The sera lactate levels were lower in the group of patients operated on for a type III TAA (2.57 ± 1) than for a type IV TAA (3.68 ± 1) (P < 0.01, Student's t-test). CONCLUSION: This method was effective for low mesenteric ischemia, easy to perform, and did not require high doses of anticoagulants.