Renal perfusion during complex aortic reconstruction: use of a radial-renal artery shunt.

Use a simple, expedient external shunt between the radial and renal arteries is described in two patients undergoing operation for abdominal aortic aneurysms involving the renal arteries. Such a shunt aided in preservation of postoperative renal function by allowing direct perfusion of the kidney during interruption of renal blood flow. Production of urine by the perfused kidney during clamping documented continued function during the period of renal artery occlusion. Other methods of renal protection during complex aortic reconstructions are discussed. Continuous perfusion of the kidney by means of such a shunt may be especially useful when a prolonged ischemic interval is anticipated, particularly if this involves a solitary kidney or a kidney with already diminished function preoperatively. Use of a larger cannula inserted into the brachial or axillary artery appears to be equally safe and simple and improves flow rates.

Recent experience with thoracoabdominal aneurysm repair.

Thoracoabdominal aneurysm repair was carried out in 55 patients during the period from January 1978 to June 1988. Considering the volume of experience and application of a routine for preoperative and intraoperative management, the experience was divided as follows: group 1 1978 to 1985 (26 patients) and group 2 1985 to 1988 (29 patients). Clinical features of the two groups differed only in the incidence of emergency operations (group 1 [6/18, 30%] vs group 2 [2/29, 8%]). Operative mortality in elective operations improved substantially in recent experience (group 1 [50%] vs group 2 [7.4%]). Significant reductions in total operative time, operative blood loss, and total aortic cross-clamping times paralleled and, in part, explained the improvement in overall surgical results seen in group 2 patients. Spinal cord injury occurred in 7.2% of the entire cohort. Nonfatal but major complications occurred in 25% of group 2 patients, with the most common being prolonged ventilatory assistance (12%). Current results with thoracoabdominal aneurysm repair both establish its safety and help to provide guidelines in selecting patients for elective repair.

Modification of the Haemonetics Cell Saver for optional high flow rate autotransfusion.

Intraoperative autotransfusion is a technique well-suited to major vascular surgery. It is most effective when salvage and reinfusion of shed blood can be accomplished at flow rates compatible with the degree of hemorrhage encountered in both elective and emergency procedures. Appropriate equipment modifications can render commercially available autotransfusion devices safer and more effective in the management of intraoperative blood loss. The Cell Saver, a device which concentrates and washes salvaged red blood cells, is limited in its potential as an autotransfusion device because of its slow reinfusion rate. A modification was devised which expands the flow capabilities of the Cell Saver and allows rapid reinfusion of autologous whole blood. The modified blood circuit has been employed in 10 major vascular cases with favorable results, thus demonstrating its efficacy in the management of massive hemorrhage during vascular repair. Guidelines for the safe and effective use of the modified unit are stressed.

Intraoperative autotransfusion in major vascular surgery.

The use of intraoperative autotransfusion provides a safe and cost-effective means of salvaging operative blood loss and reducing or eliminating the use of stored homologous bank blood with its inherent difficulties and risks. The risk of disease transmission or various reactions is minimized. Autotransfusion provides a readily available, more physiologic, and at times life-saving source of blood for patients with rare blood types or patients in whom time does not permit adequate cross-matching. This technique is acceptable to most sects of Jehovah's Witnesses, who normally refuse homologous blood. Our experience during the past six years with autotransfusion in major vascular surgery reveals a mean slavage equivalent to five units of blood loss, and avoidance of using any bank blood in almost half of elective patients. No significant problems occurred due to hemolysis, coagulation abnormalities, or particulate/air emboli, nor any morbidity or mortality specifically related to autotransfusion. We conclude that wider and more frequent use of autotransfusion technics is appropriate.

Regional hypothermia for prevention of spinal cord ischemic complications after thoracoabdominal aortic surgery: experience with epidural cooling.

A technique for regional hypothermic protection of spinal cord with epidural cooling during thoracoabdominal aneurysm (TAA) repair has been applied in over 100 patients. Elevation of cerebrospinal fluid pressure during the infusion is the principle technical limitation of the technique. When compared to institutional historic controls, patients treated with epidural cooling had a significant reduction in spinal cord ischemic complications. In patients treated for elective Types I, II, III TAA with epidural cooling, spinal cord complications have been reduced to the 3% range.

Regional hypothermia with epidural cooling for spinal cord protection during thoracoabdominal aneurysm repair.

Several techniques have been developed and clinically applied to reduce the spinal cord ischemia complications that follow thoracoabdominal aortic aneurysm (TAA) repair. Hypothermia as a protective adjunct is a concept that has been used throughout the evolution of cardiac and central aortic surgery. Because experimental regional hypothermic perfusion delivered directly to the epidural or intrathecal space showed protective effects against cord injury, we developed and applied a method for providing regional cord hypothermia with epidural cooling during TAA repair. This review describes the technical considerations with epidural cooling and the clinical results obtained in our experience.

Video teleconferencing with realistic simulation for medical education.

This report describes how realistic patient simulation can be used with video teleconferencing to conduct long-distance clinical case discussions with realistic re-enactments of critical events. By observing what appears to be a real procedure unfolding in real time, it is intended that audience members will better learn and appreciate the lessons from conferences. A commercially available mannequin simulator and video teleconferencing technology were used in nine sessions between a free-standing simulation center and different conference sites throughout the U.S. Transmission was via high-speed telephone lines. In each conference, a clinical scenario was simulated on a screen. Audience members asked questions of a live simulated "patient" and family and later advised the care team on routine treatments and management of urgent clinical problems that arose during management of the mannequin simulator in a highly realistic clinical setting. Ninety-eight percent of respondents from one audience of 150 (response rate 60%) judged the quality of the presentation as "very good or excellent." In response to the statement that "the educational value of the presentation was much greater than that of a standard case conference," 95% scored 4 or 5 on a five-point Likert scale (where 5 is highest agreement). While all conferences were conducted successfully, there were instances of technical challenge in using teleconferencing technology. Technical information about the teleconferencing system and scenario preparation, contingency planning for failures, and other details of using this new teaching modality are described. Although audiences were enthusiastic in their response to this approach to clinical case conferences, further study is needed to assess the added value of interactive simulation for education compared to standard conference formats.

Epidural cooling for regional spinal cord hypothermia during thoracoabdominal aneurysm repair.

PURPOSE: We investigated the feasibility of achieving regional hypothermia of the spinal cord with an infusion of iced (4 degrees C) saline solution administered into an epidural catheter while monitoring cerebral spinal fluid (CSF) temperature in eight patients undergoing thoracic or thoracoabdominal aneurysm resection. METHODS: As part of the anesthetic management, an epidural catheter was placed at T11-12, and a subarachnoid thermistor catheter was placed at L3-4. Approximately 30 minutes before aortic cross-clamping, iced (4 degrees C) saline solution was infused into the epidural catheter until CSF temperature decreased to approximately 25 degrees C. The infusion was then adjusted to maintain this temperature until the aorta was unclamped. The subarachnoid catheter was also used to measure CSF pressure and provide for CSF drainage. Surgery was performed in all patients with a clamp-and-sew technique with selective intercostal vessel reattachment. RESULTS: Infusion of a mean volume of 489 ml (range 80 to 1700 ml) of iced saline solution into the epidural space before aortic cross-clamping led to a decrease in mean CSF temperature to 26.9 degrees C (range 25 degrees to 28.8 degrees C) in 15 to 90 minutes. During cross-clamping and aortic replacement the mean CSF temperature was maintained between 25.2 degrees to 27.6 degrees C and, with discontinuation of the infusion, returned to within 1 degrees C of body core temperature by the end of the procedure. Body core temperature was not significantly affected by the epidural infusion. Mean CSF pressure increased during the epidural infusion but could be reduced by removing saline solution from the epidural space. No postoperative neurologic deficits were observed. CONCLUSION: Epidural cooling appears to be a satisfactory method of achieving regional spinal cord hypothermia in patients requiring resection of thoracic or thoracoabdominal aortic aneurysms.

Renal failure after thoracoabdominal aortic surgery.

PURPOSE: Renal failure remains a common and morbid complication after complex aortic surgery. This study was performed to identify perioperative factors that contribute to postoperative renal failure. METHODS: The perioperative outcomes of 183 patients who underwent thoracoabdominal aortic surgery with supraceliac clamping were reviewed. During the interval from Jan. 1987 to Nov. 1996, thoracoabdominal aneurysm repair was performed in 154 patients (type I, 49 patients [27%]; type II, 21 patients [11.5%]; type III, 55 patients [30%]; type IV, 29 patients [16%]), suprarenal abdominal aortic aneurysm repair in 17 patients (9%), and visceral/renal revascularization procedures in 12 patients (6.5%). Intraoperative management included thoracoabdominal aortic exposure and clamp-and-sew technique with renal artery cold perfusion whenever the renal arteries were accessible (79% of cases). RESULTS: Relevant clinical features included preoperative hypertension (85%), diabetes mellitus (8%), single functioning kidney (10%), recent intravenous contrast injection (34%), renal insufficiency (creatinine level greater than 1.5 mg/dl; 24%), and emergent operation (19%). Acute renal failure, defined as both a doubling of serum creatinine level and an absolute value greater than 3.0 mg/dl, occurred in 21 patients (11.5%), of whom five required hemodialysis (2.7%). Variables associated with this complication included a preoperative creatinine level greater than 1.5 mg/dl (p = 0.004) and a total cross-clamp time greater than 100 minutes (p = 0.035). The operative mortality risk (within 30 days; 8%) was significantly increased with renal failure (odds ratio, 9.2; 95% confidence interval, 2.6 to 33; p < 0.005). CONCLUSIONS: Renal failure, although uncommon in contemporary practice, greatly increases the risk of early death after thoracoabdominal aortic surgery. The overall incidence of renal failure and dialysis requirement in the present series compare favorably with those reported using other operative techniques, specifically partial left heart bypass and distal aortic perfusion. These data suggest that patients who have preoperative renal insufficiency are prone to postoperative renal failure. Furthermore, regional hypothermic perfusion and minimal clamp times are important elements in the prevention of renal failure after thoracoabdominal aortic surgery.

Mesenteric shunting decreases visceral ischemia during thoracoabdominal aneurysm repair.

PURPOSE: A technique to decrease visceral ischemic time during thoracoabdominal aneurysm (TAA) repair is reported. METHODS: A 10 mm Dacron side-arm graft is attached to the aortic prosthesis and positioned immediately distal to the planned proximal thoracic aortic anastomosis. On completion of the anastomosis, a 16 to 22 Fr perfusion catheter is attached to the side-arm graft and inserted into the orifice of the celiac axis or superior mesenteric artery. The cross-clamp is then placed on the aortic graft distal to the mesenteric side-arm graft. Pulsatile arterial perfusion is thus established to the visceral circulation while intercostal anastomoses or reconstruction of celiac, superior mesenteric, and right renal arteries is performed. Visceral ischemic time and the rise in end-tidal Pco2 after reconstruction of the visceral vessels in patients with mesenteric shunting was compared with a control group matched for aneurysm extent and treated immediately before use of the mesenteric shunt technique. RESULTS: Between July and Oct, 1996, the technique was applied in 15 patients undergoing type I, II, or III TAA repair with a clamp and sew technique. The mean decrease in systolic arterial pressure was 12.5 +/- 8.5 mm Hg, with a concomitant rise in end-tidal Pco2 (mean, 6.9 +/- 5.8 mm Hg), after perfusion was established through the mesenteric shunt. Mean time to establishment of visceral perfusion through the shunt was 25.5 +/- 4.4 minutes; the resultant decrement in visceral ischemic time averaged 31.3 minutes (i.e., until celiac, superior mesenteric, and right renal arteries were reconstructed). Compared with controls, patients with shunts had a significantly decreased (6.9 +/- 5.8 versus 21.6 +/- 8.4 mm Hg; p = 0.0003) rise in end-tidal CO2 on completion of visceral vessel reconstruction. CONCLUSIONS: In-line mesenteric shunting is a simple method to decrease visceral ischemia during TAA repair, and it is adaptable to clamp and sew or partial bypass and distal perfusion operative techniques.

Thoracoabdominal aneurysm repair: perspectives over a decade with the clamp-and-sew technique.

OBJECTIVES: Experience over a decade with thoracoabdominal aortic aneurysm (TAA) repair using a clamp-sew technique was reviewed to compare overall results with alternative operative methods. SUMMARY BACKGROUND DATA: Controversy continues as to the optimal technique for TAA repair, with frequent contemporary emphasis on bypass-distal perfusion methods. Proponents of this technique claim improved results compared to those of historic control subjects in the parameters of operative mortality, postoperative renal failure, and lower extremity neurologic deficit. METHODS: Over the interval from 1987 to 1996, 160 TAA repairs (type I, 32%; type II, 15%; type III, 34%; and type IV, 19%) were performed in 157 patients with a mean age of 70 years and a male-to-female ratio of 1/1. Clinical features included ruptured TAA (10%), urgent operation (22.5%), and aortic dissection (18%). Operative management used a clamp-sew technique with regional hypothermia for spinal cord (epidural cooling, since 1993) and renal protection. Variables associated with the endpoints of operative mortality or major morbidity, particularly spinal cord injury, were assessed with Fisher exact test and logistic regression; late survival was estimated with the Kaplan-Meier method. RESULTS: In-hospital mortality was 9% and was associated with operation for rupture (p < 0.005) or other acute presentation (p < 0.001). After multivariate analysis, the postoperative complication renal failure (relative risk, 6.5 [95% confidence interval, 1.8-23.6, p = 0.004]) and significant spinal cord injury (relative risk, 16.5 [95% confidence interval, 3.2-83.2, p = 0.001]) were associated independently with operative mortality. Paraparesis-paraplegia occurred in 7%, an incidence significantly (p < 0.001) less than that (18.7%) predicted for this cohort from published models. Variables associated (univariate analysis) with this complication included TAA rupture (p < 0.0001), other acute presentation or dissection (p < 0.001), prolonged (>6 hours) operation (p < 0.04), and excessive (>3 L) transfusions (p < 0.02). Operation for acute presentation or dissection (relative risk, 7.9 [95% confidence interval, 1.7-37.7, p = 0.009]) and prolonged surgery [relative risk, 7.5 [95% confidence interval, 1.5-35.3, p = 0.01]) retained independent association with paraplegia-paraparesis after multivariate analysis. Dialysis was needed in 2.5%. Late survival at 1 and 5 years was 86 +/- 2.9% and 62 +/- 5.8%, respectively. CONCLUSIONS: These data compare favorably with those from contemporary reports using other operative strategies and do not support routine adoption of bypass-distal perfusion as the preferred technique for TAA repair.

Epidural cooling for spinal cord protection during thoracoabdominal aneurysm repair: A five-year experience.

PURPOSE: We developed and applied a method for providing regional spinal cord hypothermia with epidural cooling (EC) during thoracoabdominal aneurysm (TAA) repair. Preliminary results indicated significant reduction in spinal cord ischemic complications (SCI), compared with historical controls, and a 5-year experience with EC was reviewed. METHODS: From July 1993 to September 1998, 170 patients with thoracic aneurysms (n = 14; 8.2%) or TAAs (types I and II, n = 83 [49%]; type III, n = 66 [39%]; type IV, n = 7 [4.1%]) were treated with EC. An earlier aneurysm resection was noted in 44% of patients, an emergent operation was noted in 20% of patients, and an aortic dissection was noted in 16% of patients. The EC was successful (mean cerebrospinal fluid [CSF] temperature at cross-clamp, 26.4 +/- 3 degrees C) in 97% of cases, with all 170 patients included in an intention-to-treat analysis. The operation was performed with a clamp/sew technique (98% patients) and selective (T(9) to L(1) region) reimplantation of intercostal vessels. Clinical and EC variables were examined for association with operative mortality and SCI by means of the Fischer exact test, and those variables with a P value less than.1 were included in multivariate logistic regression analysis. RESULTS: The operative mortality rate was 9.5% and was weakly associated (P =.07) with SCI; postoperative cardiac complications (odds ratio [OR], 35. 3; 95% CI, 5.3 to 233; P <.001) and renal failure (OR, 32.2; 95% CI, 6.6 to 157; P <.001) were the only independent predictors of postoperative death. SCI of any severity occurred in 7% of cases (type I/II, 10 of 83 [12%]; all other types, 2 of 87 [2.3%]), versus a predicted (Acher model) incidence of 18.5% for this cohort (P =. 003). Half the deficits were minor, with good functional recovery, and devastating paraplegia occurred in three patients (2.0%). Independent correlates of SCI included types I and II TAA (OR, 8.0; 95% CI, 1.4 to 46.3; P =.021), nonelective operation (OR, 8.3, 95% CI, 1.8 to 37.7; P =.006), oversewn T(9) to L(2) intercostal vessels (OR, 6.1; 95% CI, 1.3 to 28.8; P =.023), and postoperative renal failure (OR, 23.6; 95% CI, 4.4 to 126; P <.001). These same clinical variables of nonelective operations (OR, 7.7; 95% CI, 1.4 to 41.4; P =.017), oversewn T(9) to L(2) intercostal arteries (OR, 9.7; 95% CI, 1.5 to 61.2; P =.016), and postoperative renal failure (OR, 20.8; 95% CI, 3.0 to 142.1; P =.002) were independent predictors of SCI in the subgroup analysis of high-risk patients, ie, patients with type I/II TAA. CONCLUSION: EC has been effective in reducing immediate, devastating, total paraplegia after TAA repair. A strategy that combines the neuroprotective effect of regional cord hypothermia, avoiding the sacrifice of potential spinal cord blood supply, and postoperative adjuncts (eg, avoidance of hypotension, CSF drainage) appears necessary to minimize SCI after TAA repair.

Transperitoneal versus retroperitoneal approach for aortic reconstruction: a randomized prospective study.

A prospective, randomized study was conducted to compare the retroperitoneal versus transperitoneal approach for elective aortic reconstruction. One hundred thirteen patients (transperitoneal = 59, retroperitoneal = 54) were randomized between March 1987 and October 1988. In addition, to assess the changing course of patients undergoing aortic reconstruction similar data were gathered retrospectively on a group of 56 patients undergoing aortic reconstruction by the same surgeons performed via a transperitoneal approach in 1984 to 1985. Randomized patients were identical in age, male to female ratio, smoking history, incidence and severity of cardiopulmonary disease, indication for operation, and use of epidural anesthetics. Details of operation including operative and aortic cross-clamp times, crystalloid and transfusion requirements, degree of hypothermia on arrival at the intensive care unit, and perioperative fluid and blood requirements did not differ significantly for patients undergoing transperitoneal versus retroperitoneal reconstruction. Respiratory morbidity, as assessed by percent of patients requiring postoperative ventilation, deterioration in pulmonary function tests, and the incidence of respiratory complications, was identical in randomized patients. Other aspects of postoperative recovery including recovery of gastrointestinal function, the requirement for narcotics, metabolic parameters of operative stress, the incidence of major and minor complications, and the duration of hospital stay were similar for randomized patients undergoing transperitoneal and retroperitoneal reconstruction. When compared to retrospectively reviewed patients having aortic reconstruction, randomized patients undergoing transperitoneal and retroperitoneal operations had highly significant (p less than 0.001) reductions in postoperative ventilation, transfusion requirements, and length of hospital stay. Such trends were all independent of transperitoneal versus retroperitoneal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular effects of midazolam and thiopentone for induction of anaesthesia in ill surgical patients.

The cardiovascular effects of midazolam (0.15 mg kg-1) and thiopentone (3.0 mg kg-1) were compared during induction of anaesthesia in 20 American Society of Anesthesiologists class III patients. In patients given thiopentone (N = 11), cardiac output, mean arterial pressure, heart rate, and systemic vascular resistance all decreased significantly over the course of the study period; mean right atrial pressure rose slightly, and stroke volume remained the same. Patients receiving midazolam (N = 9) experienced similar haemodynamic changes which were significant relative to baseline only for the fall in mean arterial pressure and the rise in mean right atrial pressure at ten minutes. There were no significant differences between the two groups. Midazolam thus appears to be at least as acceptable an induction agent as thiopentone in ill patients, from a haemodynamic point of view.

Comparative cardiovascular effects of midazolam and thiopental in healthy patients.

Midazolam, a water-soluble benzodiazepine that is shorter-acting, more potent, and less irritating to veins than diazepam, has been suggested for use for induction of anesthesia. The cardiovascular effects of an induction-sized dose (0.25 mg/kg) of midazolam in A.S.A. class I or II surgical patients (N = 11) sedated with morphine and N2O-O2 were compared in a double-blind fashion with a similar group of patients (N = 9) receiving thiopental (4.0 mg/kg). Consistent with earlier studies, patients given thiopental experienced downward trends from base line in mean arterial pressure, stroke volume, cardiac output, and heart rate; mean right atrial pressure increased slightly, whereas systemic vascular resistance did not change. Induction of anesthesia with midazolam was associated with more gradual and less pronounced hemodynamic alteration; the only significant changes from base line were decreases in mean arterial pressure 5 and 10 minutes after injection. When the two groups were compared, no significant differences were found. Midazolam is, then, as acceptable for induction of anesthesia as thiopental from a hemodynamic point of view in A.S.A. class I and II patients.

Coagulation changes during thoracoabdominal aneurysm repair.

PURPOSE: The cause of coagulopathic hemorrhage during thoracoabdominal aneurysm (TAA) repair has not been well defined in human studies. We investigated changes in the coagulation system associated with supraceliac versus infrarenal cross-clamping to address this critical issue. METHODS: Blood levels of fibrinogen, the prothrombin fragment F1.2, D-dimer, and factors II, V, VII, VIII, IX, X, XI, and XII were analyzed in 19 patients with TAAs and four patients with abdominal aortic aneurysms (AAAs) at: (A) induction; (B) 30 minutes into supraceliac (TAA) or infrarenal (AAA) clamping; (C) 30 minutes after release of supraceliac or infrarenal clamps; and (D) immediately after surgery. Preoperative and intraoperative variables, including but not limited to aneurysm type, pathologic findings, comorbid conditions, clamp times, volume and timing of blood products, and clinical outcome, were prospectively recorded. Significance was determined by analysis of variance, Student's t test, and univariate linear regression. RESULTS: Levels of fibrinogen and factors II, V, VIII, VIII, IX, X, XI, and XII decreased (p < 0.05) at time B versus time A and returned to near baseline by time D. D-dimer and F1.2 increased starting at time B and reached significance (p < 0.05) by time D. Data points were compared for the TAA and AAA groups. Although AAA groups demonstrated a trend to factor activity reduction and increased fibrinolysis, the effect was much less pronounced than in TAA and did not approach significance. No correlation of coagulation change with clamping time was present; however, visceral clamping times were all less than 65 minutes (mean, 44 minutes). Blood and factor replacement was initiated after time B. Univariate regression analysis of factor level versus total blood replacement demonstrated a significant (p < 0.04) correlation between the reduction in the levels of factors II, V, VII, VIII, X, and XII, and the increase in the level of D-dimer at time B and subsequent total blood replacement. CONCLUSIONS: Thoracoabdominal aneurysm repair is associated with a reduction in clotting factor activity and an increase in fibrinolytic function, which occurs after placement of the supraceliac clamp. Explanations include visceral ischemia or a greater and longer ischemic tissue burden as the likely cause of coagulation alterations. Total blood replacement during TAA procedures was correlated to the degree of factor reduction and fibrinolysis at the time of visceral cross-clamping. An aggressive approach to early blood component replacement and to coagulation monitoring could lessen blood loss during TAA repair and avoid potentially disastrous bleeding complications.

Clinical experience with epidural cooling for spinal cord protection during thoracic and thoracoabdominal aneurysm repair.

PURPOSE: This report summarizes our experience with epidural cooling (EC) to achieve regional spinal cord hypothermia and thereby decrease the risk of spinal cord ischemic injury during the course of descending thoracic aneurysm (TA) and thoracoabdominal aneurysm (TAA) repair. METHODS: During the interval July 1993 to Dec. 1995, 70 patients underwent TA (n = 9, 13%) or TAA (n = 61) (type I, 24 [34%], type II, 11 [15%], type III, 26 [37%]) repair using the EC technique. The latter was accomplished by continuous infusion of normal saline (4 degrees C) into a T11-12 epidural catheter; an intrathecal catheter was placed at the L3-4 level for monitoring of cerebrospinal fluid temperature (CSFT) and pressure (CSFP). All operations (one exception, atriofemoral bypass) were performed with the clamp-and-sew technique, and 50% of patients had preservation of intercostal vessels at proximal or distal anastomoses (30%) or by separate inclusion button (20%). Neurologic outcome was compared with a published predictive model for the incidence of neurologic deficits after TAA repair and with a matched (Type IV excluded) consecutive, control group (n = 55) who underwent TAA repair in the period 1990 to 1993 before use of EC. RESULTS: EC was successful in all patients, with a 1442 +/- 718 ml mean (range, 200 to 3500 ml) volume of infusate; CSFT was reduced to a mean of 24 degrees +/- 3 degrees C during aortic cross-clamping with maintenance of core temperature of 34 degrees +/- 0.8 +/- C. Mean CSFP increased from baseline values of 13 +/- 8 mm Hg to 31 +/- 6 mm Hg during cross-clamp. Seven patients (10%) died within 60 days of surgery, but all survived long enough for evaluation of neurologic deficits. The EC group and control group were well-matched with respect to mean age, incidence of acute presentations/aortic dissection/aneurysm rupture, TAA type distribution, and aortic cross-clamp times. Two lower extremity neurologic deficits (2.9%) were observed in the EC patients and 13 (23%) in the control group (p < 0.0001). Observed and predicted deficits in the EC patients were 2.9% and 20.0% (p = 0.001), and for the control group 23% and 17.8% (p = 0.48). In considering EC and control patients (n = 115), variables associated with postoperative neurologic deficit were prolonged (> 60 min) visceral aortic cross-clamp time (relative risk, 4.4; 95% CI, 1.2 to 16.5; p = 0.02) and lack of epidural cooling (relative risk, 9.8; 95% CI, 2 to 48; p = 0.005). CONCLUSION: EC is a safe and effective technique to increase the ischemic tolerance of the spinal cord during TA or TAA repair. When used in conjunction with a clamp-and-sew technique and a strategy of selective intercostal reanastomosis, EC has significantly reduced the incidence of neurologic deficits after TAA repair.