Selective visceral and renal perfusion in thoracoabdominal aneurysm repair.

OBJECTIVE: Whether or not selective visceral and renal perfusion during thoracoabdominal aortic aneurysm (TAAA) repair has a protective effect on visceral and renal function remains unknown. The aim of this study was to clarify if selective perfusion has such an effect. METHODS: From May 1982 to December 1997, 82 consecutive patients underwent TAAA repair. Patients receiving hypothermic circulatory arrest or cooling of the kidney using Ringer's lactate solution were excluded, thus 73 patients were enrolled into this study. They were divided into three groups: those in whom selective visceral and renal perfusion was performed using a roller pump (n = 41), those in whom it was performed using a centrifugal pump with a reduced heparin regimen (n = 22) and those who underwent simple aortic clamping alone (n = 10). RESULTS: Serum creatinine, total bilirubin and alanine aminotransferase levels were elevated postoperatively in patients undergoing simple cross-clamp repair, but remained almost within normal limits in patients undergoing TAAA repair with selective visceral and renal perfusion. Urine output was more in selective perfused patients than in non-perfused patients. Renal dysfunction, defined by requirement of hemodialysis or by a serum level of creatinine above 3 mg/dl, occurred in four patients (10%) of the roller pump group and in two patients (9%) of the centrifugal pump group, while in four patients (40%) of the simple cross-clamping group. CONCLUSION: Our experience suggests that selective visceral and renal perfusion has a protective effect on hepato-renal function during TAAA repair.     

Selective intercostal arterial perfusion during thoracoabdominal aortic aneurysm surgery

BACKGROUND: This clinical study evaluated changes in motor evoked potentials (MEP) elicited by direct cerebral cortical stimulation and evoked spinal cord potentials (ESCPs) elicited by direct spinal cord stimulation during selective intercostal arterial perfusion for thoracoabdominal aortic aneurysm (TAAA) repair. We also determined the efficacy of this perfusion method for prevention of paraplegia. METHODS: Two kinds of ESCPs and MEPs were monitored during the prosthetic replacement step for TAAA surgeries. We performed selective intercostal arterial perfusion from the T7 intercostal artery to the L1 intercostal artery through a small piece of Dacron graft while monitoring spinal cord potentials in five cases of TAAA. RESULTS: The MEP amplitude decreased after clamping the aorta but quickly recovered after selective perfusion of intercostal arteries. Other spinal cord potentials did not change during the reconstruction of intercostal arteries. Postoperative paraplegia or parapalesis did not occur in any of the patients. CONCLUSIONS: Monitoring of MEPs during selective intercostal arterial perfusion was a useful adjunct to prevent postoperative paraplegia in TAAA surgery.     

Visceral and limb perfusion during thoracoabdominal aortic aneurysm repair

Patients undergoing thoracoabdominal aortic aneurysm repair are at high risk of operative morbidity and death. Aortic clamping and unclamping stresses the myocardium, interrupts visceral and limb perfusion, and leads to metabolic acidosis. Use of a simple technique to preserve distal perfusion during the period of aortic clamping may reduce perioperative morbidity. We describe a technique of visceral and limb perfusion that may reduce surgical risk in high-risk patients.     

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.(J Vasc Surg 1998;27:745-9.)     

Cold visceral perfusion improves early survival in patients with acute renal failure after thoracoabdominal aortic aneurysm repair

INTRODUCTION: Despite advances in organ protection during thoracoabdominal aortic aneurysm (TAAA) repair, acute renal failure (ARF) remains a significant clinical problem, associated with increased morbidity and mortality. We studied outcome of ARF after TAAA repair in patients who underwent either warm or cold visceral perfusion. METHOD: Between 1991 and 2001 657 TAAA repairs were performed, of which 359 (55%) had either warm or cold visceral perfusion. Twelve patients with renal failure who had undergone preoperative dialysis were excluded from the study. Of the remaining 347 patients, ARF developed in 81 (23%) after TAAA repair. Forty-four (54%) of the 81 patients with ARF received cold visceral perfusion, and 37 (46%) patients received warm visceral perfusion. ARF was defined as either an increase of 1 mg/dL in serum creatinine (SCr) concentration per day for 2 consecutive days or dialysis requirement. Patient records were reviewed through hospital discharge. RESULTS: Twenty six (32%) of the 81 patients in whom ARF developed died, 17 of 37 (46%) patients in the warm perfusion group versus 9 of 44 (21%) patients in the cold perfusion group (P <.02). Median onset of ARF was on postoperative day 1 in both groups. Twenty-six of 81 (32%) patients recovered renal function, 10 of 37 (27%) patients in the warm perfusion group versus 16 of 44 (36%) patients in the cold perfusion group. Preoperative SCr concentration was predictive of recovery of renal function (odds ratio, 4.5 per mg/dL increase; P <.03) in patients who received either warm or cold visceral perfusion. CONCLUSIONS: ARF after TAAA repair remains a significant clinical problem. Recovery of renal function occurred in approximately one third of patients. Preoperative SCr concentration was the only significant determinant of recovered renal function. While cold visceral perfusion did not alter renal recovery, it significantly reduced hospital mortality.     

Impact of distal aortic and visceral perfusion on liver function during thoracoabdominal and descending thoracic aortic repair

Purpose: We examined the impact of distal aortic and visceral perfusion on liver function during thoracoabdominal and descending thoracic aortic repair. Methods: Between January 1991 and July 1996, 367 patients underwent thoracoabdominal and descending thoracic aortic repair. Baseline and postoperative total bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, fibrinogen, prothrombin time (PT), and partial thromboplastin time (PTT) were measured for 286 patients. We examined the impact of distal aortic and direct visceral perfusion on liver function–related clinical laboratory values. Univariate and multivariate statistical methods for categorical and continuous variables were used. Results: In categorical analysis, type II thoracoabdominal aortic aneurysm, history of hepatitis, and emergency presentation had a statistically significant multivariate association with abnormal laboratory values. In continuous-distributed multivariate data analysis, type II thoracoabdominal aortic aneurysm and visceral perfusion were statistically significant predictors of postoperative alkaline phosphatase, PT, and PTT. Type II aneurysms increased postoperative liver function–related laboratory values significantly above other aneurysm types (alkaline phosphatase, +114 IU, p < 0.0001; PT, +1.99 seconds, p < 0.02; PTT, +6.7 seconds, p < 0.03). Visceral perfusion was associated with a concomitant decrease (alkaline phosphatase, –101.2 IU, p < 0.0001; PT, –1.8 seconds, p < 0.07; PTT, –5.6 seconds, p < 0.02). Conclusions: Visceral perfusion negates the rise in postoperative liver function–related clinical laboratory values associated with type II thoracoabdominal aortic aneurysm repair. (J Vasc Surg 1998;27:145-53.)     

Spinal cord protection during thoracoabdominal aortic aneurysm repair; efficacy of distal aortic perfusion and segmental aortic clamping

Despite improvement in adjuncts for thoracoabdominal aortic aneurysms (TAAA) repairs, many devastating complications remains after the surgery. Our experience with these aneurysms has been reviewed in order to identify those methods at risk of major morbidity, as well as which further improvements required. During last 16 years, 53 consecutive patients were operated on TAAA. The mean age was 58 years. Twenty patients had dissecting aneurysms and 13 patients had had prior aortic surgery. A femoro-femoral bypass was used to maintain distal aortic perfusion in most patients. Reimplantation of intercostal or lumbar arteries under the multi-segmental aortic clamping is consistent in our technique. Motor evoked potentials (MEP) were measured to monitor spinal cord protection since 2000. The hospital mortality was 9.4% (5/53), 22.2% (2/9) for emergency operation and 15.4% (2/13) for patients with prior aortic surgery. The mortality for the first and elective operations was 3.2% (1/31). No any neurologic dysfunction was observed in all patients including the hospital deaths. In view of clinical results, our adjuncts and techniques are useful for prevention of spinal cord ischemia during the TAAA surgery.     

Hybrid debranching-endovascular repair of visceral patch aneurysm after thoracoabdominal aneurysm repair

A visceral patch aneurysm is a significant complication after extensive thoracoabdominal aneurysm repair, and open procedures to correct these lesions are associated with a high perioperative mortality. We report the case of a 6-cm visceral patch aneurysm occurring in a patient with a completely replaced descending and abdominal aorta that was successfully corrected by staged debranching and endovascular repair with a dedicated thoracic endograft. Hybrid procedures are a successful option to treat complex repairs in the reoperative setting. They have the potential to lower perioperative risk and enhance patient care.     

Fate of the visceral aortic patch after thoracoabdominal aortic repair.

OBJECTIVE: To analyse the fate of a visceral aortic patch (VAP) in patients that underwent thoracoabdominal aortic aneurysm (TAAA) repair. METHODS: We reviewed 204 consecutive patients (158 M, 46 F) treated for TAAA between 1988 and 2004. We performed VAP in 182 cases. Among the 149 survivors at 6 months, we followed 138 cases, mean follow-up 7 years (range 0.6-16 years). The mean graft diameter we used was 29mm (range 24-34mm) from 1988 to 1999 (83 patients), and 21.7mm (range 16-24mm) from 2000 to 2003 (55 patients). In 23% of cases we performed a separate bypass to the left renal artery. RESULTS: We observed 16 (12%) VAP dilatations (<5cm), 6 (4%) VAP aneurysms (>5cm) and one VAP pseudoaneurysm, at a mean time of 6 years after atherosclerotic TAAA was atherosclerotic repair. There were no VAP dilatations/aneurysms in the group of patients with separate left renal revascularization. Five VAP aneurysms were treated electively. In four cases the operation was performed with thoracophrenolaparotomy, in one case with a bilateral subcostal laparotomy. In all cases the visceral aorta was re-grafted. Reimplantation of a single undersized VAP was performed in one case, separate revascularization of visceral arteries was performed in the other four cases. Selective intraoperative hypothermic perfusion of visceral and renal arteries was used in all the patients. There was 1 perioperative death; 2 patients with preoperative renal failure required dialysis. The last VAP aneurysm has remained asymptomatic and stable at annual CT surveillance. The VAP pseudoaneurysm was successfully treated with an emergency thoracophrenolaparotomy and refashioning the left side suture line. CONCLUSIONS: Aneurysm of VAP is not uncommon in the patients operated on using larger grafts with a single VAP that includes the LRA (7.4%, 5/67 cases). Its treatment carries significant morbidity and mortality.     

Repair of recurrent visceral aortic patch aneurysm after thoracoabdominal aortic aneurysm repair with a branched endovascular stent graft

Aneurysmal degeneration of the visceral aortic patch is an uncommon late complication of surgical replacement of the thoracoabdominal aorta. We report on a 70-year-old woman who had undergone previous open thoracoabdominal aortic aneurysm repair and subsequent revision surgery for a visceral aortic patch aneurysm. The patient presented with a recurrent asymptomatic 60-mm-diameter visceral aortic patch aneurysm involving the celiac axis and superior mesenteric artery. The lesion was successfully treated with a custom-designed Zenith branched endovascular stent graft. The patient remains well at 12 months.     

Late patency of reconstructed visceral arteries after open repair of thoracoabdominal aortic aneurysm

Background

In the era of rising endovascular treatment of thoracoabdominal aortic aneurysms (TAAAs), the analysis of visceral vessel (VV) patency after open surgical repair is crucial to provide a future benchmark between these different approaches. This study reports the late outcomes of a single-center experience with open TAAA repair, focusing on the results of different techniques adopted for renal and splanchnic revascularization.

Assessment of spinal cord integrity during thoracoabdominal aortic aneurysm repair

BACKGROUND: Monitoring motor-evoked potentials (MEPs) is an accurate technique to assess spinal cord integrity during thoracoabdominal aortic aneurysm (TAAA) repair, guiding surgical strategies to prevent paraplegia. METHODS: In 210 consecutive patients with type I (n = 75), type II (n = 103), and type III (n = 32) TAAA surgical repair was performed using left heart bypass, cerebrospinal fluid drainage, and MEPs monitoring. RESULTS: Reliable MEPs were registered in all patients. The median total number of patent intercostal and lumbar arteries was five. After proximal aortic crossclamping, MEP decreased below 25% of base line in 72 patients (34%) indicating critical spinal cord ischemia, which could be corrected by increasing distal aortic pressure. By using sequential clamping it appeared that in 43% of type I and II cases spinal cord circulation was supplied between T5 and L1, and 57% between L1 and L5. In type II and III cases cord perfusion was dependent upon lower lumbar arteries in 16% and pelvic circulation in 8%, necessitating reattachment of these segmental arteries. In 9% of patients critical ischemic MEP changes occurred without visible arteries, requiring aortic endarterectomy and selective grafting. One patient suffered early paraplegia and 2 delayed, and 2 patients had temporary neurologic deficit (5 of 210; 2.4%). CONCLUSIONS: In patients with TAAA, blood supply to the spinal cord depends upon a highly variable collateral system. Monitoring MEPs is an accurate technique for detecting cord ischemia, guiding surgical tactics to reduce neurologic deficit (2.4%).     

Importance of intercostal artery reattachment during thoracoabdominal aortic aneurysm repair

Purpose: We studied the relationship of neurologic deficit to ligation, reimplantation, and preexisting occlusion of intercostal arteries to determine which arteries and consequent management are most critical to outcome in thoracoabdominal aortic aneurysm repair. Methods: From February 1991 to July 1996, 343 patients with thoracoabdominal aortic aneurysms underwent repair by one surgeon. In this study, only Crawford types I, II, and III (n = 264) were considered. Of these, 110 (42%) were type I, 116 (44%) type II, and 38 (14%) type III. The adjuncts of distal aortic perfusion and cerebrospinal fluid drainage were used in 164 patients (62%). Data were analyzed by contingency table and by multiple logistic regression. Results: Early neurologic deficit occurred in 23 patients (8.7%), and late deficit in 10 patients (3.8%). Neurologic deficit in patients with at least one reimplantation and no ligation of arteries T11 or T12 occurred in 19 of 147 (12.9%). Neurologic deficit for occlusion of the same arteries occurred in 11 of 111 (9.9%), whereas for ligation of T11 and T12 neurologic deficit occurred in three of six (50%; reimplantation, p < 0.03; occlusion, p < 0.006). In addition, reimplantation of intercostal arteries T9 or T10 was significantly associated with reduced late neurologic deficit in multivariate analysis (p = 0.05). No other intercostal artery status was associated with modification of the neurologic deficit rate. Multivariate analysis showed type II aneurysms and acute dissections to be significantly associated with an increased risk of postoperative neurologic deficit (p < 0.0009, 0.002, respectively). Adjuncts were protective (p < 0.007), most often in types II and III (14.1% neurologic deficit in type II with adjunct, 35.3% without; 0% in type III with adjunct, 20% without). Conclusions: Patients with patent arteries at the T11/T12 level have highly variable outcomes depending on whether the arteries are reattached or ligated. Our data suggest that reimplantation of thoracic intercostal arteries T11 and T12 is indicated when these arteries are patent. Reimplantation of T9 and T10 lowers the risk of late neurologic deficit, probably by decreasing the spinal cord's vulnerability to changes in blood and cerebrospinal fluid pressure in the days after surgery. Adjuncts lower overall risk and provide adequate time for targeted intercostal artery reimplantation. (J Vasc Surg 1998;27:58-68.)     

The use of an aortoiliac side-arm conduit to maintain distal perfusion during thoracoabdominal aortic aneurysm repair

Thoracoabdominal aneurysm repair continues to be associated with a significant risk of operative complications, many of which are related to the prolonged period of aortic cross clamping inherent in the procedure. A variety of adjuvant techniques have been used in attempts to decrease morbidity, including atriofemoral extracorporal bypass, subarachnoid drainage, epidural cooling, and preliminary axillofemoral bypass. Herein is described a method to maintain distal perfusion with a side-arm conduit, originating from the most proximal aspect of the aortic graft and terminating on the left iliac artery. The technique has the potential to minimize hemodynamic instability while decreasing the period of pelvic and lower extremity ischemia and simplifying reattachment of aortic branch vessels. This method provides another option that can be considered in these technically demanding operative procedures.     

Individual temperature management during thoracoabdominal aortic aneurysm repair using separate perfusion of upper and lower torso

We report thoracoabdominal aortic aneurysm repair using separate perfusion of upper and lower torso that can control temperature of each organ individually. This novel modality can maintain mild hypothermic organ perfusion in upper torso and protect the heart under empty beating, while lower torso is further cooled to protect the spinal cord and visceral organs. Therefore this technique may be useful for patients with heart disease who require complex reconstruction of the intercostal arteries or visceral branches. We used this technique successfully in a patient who has a history of surgical repair of the aortic arch and the abdominal aorta. A 70-year-old male who had a history of abdominal aortic aneurysm repair and aortic arch aneurysm repair using stented elephant trunk underwent Crawford's type II thoracoabdominal aortic aneurysm repair. Three pairs of the intercostal arteries and 4 visceral branches were reconstructed using this technique successfully.     

Functional outcome after thoracoabdominal aortic aneurysm repair

OBJECTIVE: Repair of thoracoabdominal aortic aneurysms (TAAAs) is performed for the improvement of long-term survival and the preservation of function. The determination of functional outcome and the identification of predictors of survival and functional recovery after TAAA repair are key to proper patient selection. METHODS: This retrospective review of clinical data was performed in an academic medical center. The demographics, Crawford aneurysm type (I-18, II-33, III-22, IV-28), preoperative risk factors, operative characteristics, and postoperative complications and outcomes were recorded from the medical records for 101 consecutive patients who underwent TAAA repair (58 elective and 43 urgent/emergent). Functional status and living situation at hospital discharge and 12 months after discharge were determined from follow-up examination records or telephone contact with surviving patients. The patients then were categorized into "good" (survival, home, discharge to rehabilitation center, ambulatory) or "bad" (death, discharge to or residence in a long-term care facility, non-ambulatory) outcomes. RESULTS: The postoperative mortality rate was 17.8% (10% in elective cases and 28% in urgent cases), and significant postoperative complications occurred in 77% of the cases (pulmonary complications in 41%, renal complications in 28%, and cord injury in 12%). The mean length of stay was 22.8 + 23.6 days, and at discharge, 80% of the patients were sent to home or rehabilitation and 20% were sent to long-term care facilities. At 1 year, 15 additional patients had died. All but two patients who had been initially discharged to rehabilitation had returned home, but only two patients who had been discharged to long-term care facilities had returned home and both were nonambulatory. Therefore, the survival rate at 1 year was 67%, and only 52.4% of the patients had a "good" outcome at 1 year (survival rate was 78% and rate of "good" outcome was 63% in patients who underwent elective TAAA repair). Independent predictors of postoperative death and "bad" outcome were age more than 75 years, preoperative heart disease, duration of visceral ischemia, use of left atrial femoral bypass graft, postoperative renal dysfunction, and number of organs failing after surgery. CONCLUSION: Survival and good functional outcome after TAAA repair is significantly less common than expected and is primarily predicted with intraoperative factors and postoperative complications. Improved operative techniques and limitation of visceral ischemia reperfusion injury may improve outcome after TAAA repair.