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.     

Mortality and neurologic morbidity after repair of traumatic aortic disruption

BACKGROUND: Traumatic disruption of the thoracic aorta frequently results in death before operative repair. The determinants of mortality after repair, however, are uncertain. In addition, intraoperative strategies for reducing the incidence of spinal cord injury remain controversial. METHODS: The records of 45 consecutive patients undergoing repair of traumatic disruption of the thoracic aorta at a single institution during a 9-year period were reviewed in a retrospective fashion. Patient age ranged from 15 to 81 years (mean age, 33.9 years). Twenty-two patients (49%) had multiple associated injuries, and 8 (18%) had isolated aortic injuries. Nine patients (20%) experienced preoperative hypotension (systolic blood pressure of less than 90 mm Hg). Repair was performed with partial bypass in 22 patients, a heparinized shunt in 2, and no distal perfusion (clamp and sew technique) in 21. RESULTS: Nine patient (20%) died after operation. Multivariate logistic regression analysis of preoperative and intraoperative variables identified advancing age and preoperative hypotension as independent predictors of operative death. The presence of associated injuries was not an independent predictor of operative death. All 4 patients with injuries proximal to the aortic isthmus died. Ten patients were excluded from analysis of spinal cord injury either because of preoperative neurologic deficit or because of death before postoperative evaluation. Six (17%) of the remaining 35 patients had development of paraplegia: 5 of the 15 patients having the clamp and sew technique, 1 of the 2 with a shunt, and 0 of the 18 patients with bypass (p < 0.05, clamp and sew versus bypass). In the clamp and sew group, patients in whom paraplegia developed had significantly longer aortic clamp times than those without neurologic injury (40.6 +/- 4.4 minutes versus 28.7 +/- 2.9 minutes, respectively; p < 0.05). CONCLUSIONS: Advancing age, preoperative hypotension, and perhaps injury location are important determinants of death after repair of traumatic disruption of the thoracic aorta. Adjunctive perfusion with partial bypass should be used during repair to reduce the incidence of spinal cord injury.     

The impact of diaphragm management on prolonged ventilator support after thoracoabdominal aortic repair

PURPOSE: The relationship of the division of the diaphragm during thoracoabdominal aortic repair to prolonged ventilator support has not been studied. The purpose of this study was (1) to determine whether preservation of diaphragm integrity has a significant effect on postoperative ventilator duration and (2) to elucidate other pulmonary risk factors related to thoracoabdominal aortic surgery and to study the relationship of these factors to the intact diaphragm technique. METHODS:Between February 1991 and January 1997, we repaired 397 descending and thoracoabdominal aortic aneurysms. Descending thoracic aneurysms were not included in the study because their repair does not include the diaphragm. A total of 256 patients participated in this study. The diaphragm was divided in 150 patients and left intact in 106 patients. Examined as potential risk factors were patient demographics, history and physical findings, aneurysm extent, urgency of the procedure, acute dissection, cross-clamp time, homologous and autologous blood product consumption, and adjunctive operative techniques. FEV1 also was considered in the 197 patients for whom preoperative spirometry was available. Prolonged mechanical ventilation was defined as ventilator support for >72 hours. Data were analyzed by univariate contingency table and multiple logistic regression methods. RESULTS: Increasing age (odds ratio [OR], 1.02/y; P <.02), current smoking (OR, 2.6; P <.0008), total cross-clamp time (OR, 1.0/min; P <.008), units packed red blood cells transfused (OR, 1.06/unit; P <.008), and division of the diaphragm (OR, 2.03; P <.02) were significant, independent predictors of prolonged ventilation. Sixty-seven percent of patients (71 of 106) whose diaphragms were preserved were extubated in <72 hours compared with 52% of patients (78 of 150) who underwent diaphragm division (OR, 0.53; P <.02). CONCLUSION: Independently of well known pulmonary risk factors, an intact diaphragm during thoracoabdominal aortic repair results in a higher probability of early ventilator weaning.     

Simultaneous coronary artery bypass grafting and abdominal aneurysm repair decreases stay and costs

BACKGROUND: Patients with large (> or = 5.0 cm) abdominal aortic aneurysms (AAA) frequently have marked associated coronary artery disease. We hypothesized that a single operation for coronary artery bypass grafting (CABG)/AAA would provide equivalent, if not improved, patient care while decreasing postoperative length of stay and hospital costs compared with staged procedures. METHODS: Eleven patients to date have undergone a combined procedure at our institution. Ten underwent CABG followed by AAA repair, whereas one patient received an aortic valve replacement before aneurysm repair. We performed a retrospective analysis comparing the postoperative length of stay and hospital costs for this single procedure to a combined cohort of 20 randomly selected patients who either received AAA repair (n = 10) or standard CABG (n = 10) during the same time period. RESULTS: No operative mortality has been reported. There were no episodes of neurologic deficit or cardiac complication after these procedures. The postoperative length of stay was significantly decreased for the CABG/AAA group compared with the combined postoperative length of stay for the AAA plus CABG group (7.44+/-0.88 days versus 14.10+/-2.00; p = 0.012). Total hospital costs were also significantly decreased for the CABG/AAA group compared with total hospital costs for the AAA plus CABG group ($22,941+/-$1,933 versus $34,076+/-$2,534; p = 0.003). CONCLUSIONS: A single operation for coronary revascularization and AAA repair is safe and effective. Simultaneous CABG and AAA repair substantially decreases postoperative length of stay and hospital costs while avoiding possible interim aneurysm rupture and repeat anesthesia.     

Strategies to prevent neurologic deficit based on motor-evoked potentials in type I and II thoracoabdominal aortic aneurysm repair

PURPOSE: Motor-evoked potentials (MEPs) were monitored during thoracoabdominal aortic aneurysm (TAAA) repair to assess spinal cord ischemia and evaluate the subsequent protective strategies to prevent neurologic deficit. METHODS: Between January 1996 and December 1997, 52 consecutive patients with type I (n = 24) and type II (n = 28) TAAA underwent surgery (mean patient age, 60 years; range, 21-78 years). The surgical protocol included left heart bypass, cerebrospinal fluid drainage, and monitoring transcranial myogenic MEPs. When spinal cord ischemia was detected, distal aortic pressure and mean arterial pressure were increased. By means of sequential crossclamping, MEPs were used to identify critical intercostal or lumbar arteries. RESULTS: Reproducible MEPs could be recorded in all patients, and spinal cord ischemia was detected within 2 minutes. During distal aortic perfusion, 14 patients (27%) showed rapid decrease in the amplitude of MEPs to less than 25% of baseline, indicating spinal cord ischemia, which could be corrected by increasing distal aortic pressure. The mean distal aortic pressure to maintain adequate cord perfusion was 66 mm Hg; however, it varied among individuals between 48 and 110 mm Hg. In 24 patients (46%), MEPs disappeared after segmental clamping and returned after reattachment of intercostal arteries. In 9 patients (17%), MEPs disappeared completely, but no intercostal arteries were found. After aortic endarterectomy, 6 or 8 mm Dacron grafts were anastomosed to intercostal arteries, and MEPs returned after reperfusion. Using this aggressive surgical approach based on MEPs, no early or late paraplegia occurred in this series. CONCLUSION: Monitoring of MEPs is an effective technique to assess spinal cord ischemia. Operative strategies based on MEPs prevented neurologic deficits in patients treated for type I and II TAAA.     

Differential expression of heat shock proteins in normal and failing human hearts

OBJECTIVE: To predict spinal cord ischemia after endovascular stent graft repair of descending thoracic aortic aneurysms, temporary interruption of the intercostal arteries (including the aneurysm) was performed by placement of a novel retrievable stent graft (Retriever) in the aorta under evoked spinal cord potential monitoring. METHODS: From February 1995 to October 1997, endovascular stent graft repair of descending thoracic aortic aneurysms was performed in 49 patients after informed consent was obtained. In 16 patients with aneurysms located in the middle and distal segment of the descending aorta, the Retriever was placed temporarily before stent graft deployment. The Retriever consisted of two units of self-expanding zigzag stents connected in tandem with stainless steel struts. Each strut was collected in a bundle fixed to a pushing rod, and the stent framework was lined with an expanded polytetrafluoroethylene sheet. The Retriever was delivered beyond the aneurysm through a sheath and was retracted into the sheath 20 minutes later. A stent graft for permanent use was deployed in patients whose predeployment test results with the Retriever were favorable. Evoked spinal cord potential was monitored throughout placement of the Retriever and stent grafting until the next day. RESULTS: The Retriever was placed in 17 aneurysms in 16 patients. There were no changes in amplitude or latency of evoked spinal cord potential records obtained before or during Retriever placement. After withdrawal of the Retriever, all aneurysms were excluded from circulation immediately after permanent stent grafting. There were no changes in evoked spinal cord potential, nor were neurologic deficits seen after stent graft deployment in any patient. CONCLUSIONS: These results suggest that predeployment testing with the Retriever under evoked spinal cord potential monitoring is promising as a predictor of spinal cord ischemia in candidates for stent graft repair of thoracic aortic aneurysms.     

Cardiac function is a risk factor for paralysis in thoracoabdominal aortic replacement

PURPOSE: We studied factors that influence paralysis risk, renal function, and mortality in thoracoabdominal aortic replacement. METHODS: We prospectively collected preoperative demographic and intraoperative physiologic data and used univariate and multivariate analyses to correlate this data with risk factors for paralysis. A mathematical model of paraplegia risk was used to study the efficacy of paraplegia reduction strategies. We analyzed preoperative and operative factors for paralysis risk, renal function, and mortality for 217 consecutive patients surgically treated from 1984 through 1996 for 176 thoracoabdominal and 41 thoracic aneurysms at the University of Wisconsin Hospital and Clinics. No patient had intercostal reimplantation or assisted circulation. One hundred fifty patients (group A) received cerebrospinal fluid drainage (CSFD) and low-dose naloxone (1 microg/kg/hour) as adjuncts to reduce the risk of paralysis. Sixty-seven patients (group B) did not receive CSFD and naloxone. RESULTS: Seventeen deficits occurred in 205 surviving patients: 5 of the 147 in group A (expected deficits = 31) and 12 of the 58 in group B (expected deficits = 13) (p < 0.001). In a multivariate logistic regression model, acute presentation, Crawford type 2 aneurysm, group B membership, and a decrease in cardiac index with aortic occlusion remained significant risk factors for deficit (p < 0.0001). By odds ratio analysis, group A patients had 1/40th the risk of paralysis of group B. The only significant predictor of postoperative renal function was the preoperative creatinine level (p < 0.0001); renal revascularization significantly improved renal function. The mortality rate was 1.6% (2) for patients undergoing elective treatment and 21% (19) for patients who had acute presentations. Acute presentation, age, and the preoperative creatinine level were found to be significant factors for operative mortality in a logistic regression model (p < 0.001) and defined a group at high risk for death. CONCLUSIONS: CSFD and low-dose naloxone significantly reduce the paralysis risk associated with thoracoabdominal aortic replacement. A decrease in the cardiac index with aortic occlusion is a previously unreported variable that defines a subset of patients at higher risk for paralysis.     

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). CONCLUSION: 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.     

Abdominal and thoracoabdominal aortic aneurysm

Most abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms (TAAA) are asymptomatic and are found on physical exam or incidentally during radiological studies for other indications. These aneurysms are repaired primarily because their risk of rupture increases geometrically as the size exceeds 5 cm. The potential morbidity of intraoperative visceral and spinal ischemia involved with TAAA repair may be reduced with various adjunctive maneuvers.     

Identification and analysis of the regulatory region R&R* with the cnf1 gene encoding the cytotoxic necrotizing factor type 1 that closely links to the lux regulon of Vibrio fischeri

BACKGROUND: We determined that cold blood cardioplegia and intermittent ventricular fibrillation with ischemia were associated with similar enzyme and myocardial protein leakage in a randomized, prospective study of 40 patients. We have continued to use both methods in our unit, according to surgeons' preference. METHODS: In our database we have reviewed 1,923 patients who have undergone first-time elective or urgent coronary artery bypass grafting from January 1992 to May 1997. RESULTS: Five hundred seventy-eight patients underwent coronary artery bypass grafting with cold blood cardioplegia and 1,345 had ventricular fibrillation and aortic cross-clamping. The preoperative factors were virtually identical. Intraoperative differences were only those inherent to the two techniques: temperature and cross-clamp time. Mortality was 2.5% for ventricular fibrillation and aortic cross-clamping arrest and 2.1% for cardioplegia (p=0.55 by chi2 test). There was a higher use of the intraaortic balloon pump in the ventricular fibrillation and aortic cross-clamping group (2.4% versus 1.0%; p=0.04), but no other differences in outcome were detected. CONCLUSIONS: A truly randomized trial to demonstrate which technique is superior is impractical at this level of difference because it would require 37,000 patients to avoid a beta error. We have to base our practice on the retrospective data available. Each technique has its merits in practice, which are discussed.     

Surgical treatment of thoracoabdominal aortic aneurysms]

Between February, 1981, and April, 1989, 20 patients underwent surgical treatment of thoracoabdominal aortic aneurysms. Most of the patients were operated under temporary external bypass. For Group I and III aneurysms without reconstruction of renal arteries, a modified Crawford's graft inclusion technique was employed to shorten abdominal visceral ischemic time. This modification consists of (1) using adjuncts to perfuse the distal aorta during aortic clamp, (2) starting the first anasistomosis from the distal end of the graft, and (3) shifting the distal aortic clamp on the graft after completing the anastomosis in order to restore abdominal visceral circulation as soon as possible. For Group III and IV aneurysms with reconstruction of renal arteries as well as celiac and superior mesenteric arteries, a modified DeBakey's procedure was employed. This modification consists of (1) using the spiral opening method, (2) doing end-to-end anastomosis at the proximal aortic site, and (3) maintaining the circulation of abdominal organs and spinal cord by using adjuncts during the anastomosis of the proximal end. There were one operative death and two hospital deaths. Paraplegia developed in two cases, one of which was a ruptured case. Renal dysfunction was not found in any case. The survivors were followed from 5 to 103 months, and there was no late death. The results suggest that our modified procedures for thoracoabdominal aortic aneurysms are useful and reliable ones.     

Reoperation after repair of type A and B dissecting aneurysm

BACKGROUND: In the late postoperative period after repair of an aortic dissection or dissecting aneurysm, reoperations may be required. The interval to reoperation, size and location of intimal tear, and results of reoperation were evaluated. METHODS: Between January 1982 and April 1997, 138 patients underwent surgery for Stanford type A (90 patients) or type B (48 patients) dissections of the aorta. The entire aorta was evaluated in postoperative follow-up by computed tomography and magnetic resonance imaging for 6 months to 15 years. Reoperations were performed in 14 (10.1%) patients with changes in the aneurysms at the site of the initial repair or in the distal aorta. Selective cerebral perfusion or retrograde cerebral perfusion with deep hypothermia was used in the repair of the ascending, arch, and distal arch aneurysms. Reoperations included aortic root reconstruction (n=3), resection of a pseudoaneurysm (n=1), and replacement of the ascending aorta (n=1), arch (n=5), descending aorta (n=2), thoracoabdominal aorta (n=1), or abdominal aorta (n=1). Secondary reoperations were performed in four patients (replacement of the arch [n=2], thoracoabdominal aorta and abdominal aorta). Consequently two patients had subtotal aortic replacements. The aneurysms were caused by an anastomotic leak, a new intimal tear following aortic cross-clamping, a second intimal tear in the distal arch or abdominal aorta, and Marfan syndrome. RESULTS: Two patients (2/18 11.1%) died of bleeding or low output syndrome. Two patients died of graft infection or prosthetic valve infection 3 months after surgery respectively. CONCLUSIONS: 1) The surgical results of reoperation for type A and B dissections were good. 2) Close postoperative follow-up of the patent false lumen in the entire aorta was necessary. 3) At the initial operation, total resection of the intimal tear in the aortic arch in low-risk patients reduced the risk of reoperation.     

Impact of retrograde cerebral perfusion with posterolateral thoracotomy on distal arch aneurysm repair

BACKGROUND: Repair of distal aortic arch aneurysms is difficult to accomplish through a median sternotomy or left thoracotomy, and stroke and respiratory disorders often become lethal complications with the use of circulatory arrest. We investigated the use of retrograde cerebral perfusion with a posterolateral thoracotomy in the repair of distal arch aneurysms. METHODS: Thirty-eight patients underwent repair of a distal arch aneurysm. They were divided into three groups according to the method of surgical repair used. Sixteen patients (group I) underwent proximal anastomosis of the graft with the use of an aortic cross-clamp. Eight patients (group II) underwent open proximal anastomosis with the use of retrograde cerebral perfusion (oxygenated blood perfusion through a superior vena cava cannula) and a median sternotomy and anterolateral thoracotomy. Fourteen patients (group III) also underwent open anastomosis with the use of retrograde cerebral perfusion (cerebral perfusion through blood returned to the right atrium with the patient in the Trendelenburg position) and a posterolateral thoracotomy. RESULTS: The operative mortality rate in group I was 25.0%; 4 of 16 patients died of stroke, myocardial infarction, and intestinal necrosis. In group II, 3 of 8 patients (37.5%) died of respiratory failure and aortic dissection. In group III, only 1 of 14 patients (7.1%) died, as a result of heart failure. CONCLUSIONS: The use of retrograde cerebral perfusion with a posterolateral thoracotomy is an alternative method that minimizes the risk of stroke and respiratory failure during distal aortic arch operations.     

Effects of depletion of leukocytes and platelets on cardiac dysfunction after cardiopulmonary bypass

BACKGROUND: This study examined the effects of the depletion of leukocytes and platelets from circulated blood on cardiac function after cardiopulmonary bypass in 37 patients who underwent coronary artery bypass grafting or aortic valve replacement. METHODS: Leukocytes and platelets were removed continuously using a blood cell separator, beginning immediately after the start of the operation and ending 1 hour after the release of the aortic cross-clamp in 19 patients (LPD group), but not in the remaining 18 patients (control group). Blood cell counts and levels of thromboxane B2, 6-keto-prostaglandin F1alpha, leukocyte elastase, complements C3a and C4a, thrombin-antithrombin III complex, and D-dimer were determined periodically during and after the operation. The cardiac index, the difference between the central and peripheral core temperatures, and the doses of catecholamines and vasodilators required to support the circulation in the early postoperative period also were assessed. RESULTS: Leukocyte and platelet counts and levels of leukocyte elastase, thromboxane B2, thromboxane2/6-ketoprostaglandin F1alpha, thrombin-antithrombin III complex, and D-dimer were significantly lower in the LPD group than in the control group before and after the release of the aortic cross-clamp and during the perioperative period. There were no significant differences in the levels of 6-keto-prostaglandin F1alpha or complements C3a and C4a between the two groups. The catecholamine dose was significantly lower in the LPD group than in the control group (1.1 +/- 2.5 versus 5.0 +/- 5.2 mg/kg, respectively). Fewer patients required the use of nitroprusside as a vasodilator in the LPD group than in the control group (1/19 versus 12/18, respectively). CONCLUSIONS: The depletion of leukocytes and platelets using a blood cell separator prevents the deterioration of cardiac function after cardiac operations using cardiopulmonary bypass.     

Operative results after the Cox/maze procedure combined with a mitral valve operation

BACKGROUND: There have been few reports on postoperative morbidity and mortality analyses after concomitant mitral valve operation and the Cox/maze procedure. METHODS: Between April 1993 and August 1995, 87 consecutive patients with chronic atrial fibrillation underwent a mitral valve operation and concomitant Cox/maze procedure at Iwate Medical University. The patients were divided into the replacement group (n = 31) and repair group (n = 56) according to the method of mitral valve replacement. Our initial experience with the combined operative procedures is presented along with the operative mortality and morbidity rates. Univariate analysis on preoperative and intraoperative variables affecting early mortality and morbidity is carried out retrospectively. RESULTS: Total cardiopulmonary bypass time in all patients was 177.2 +/- 70.1 minutes. Total aortic cross-clamp time was 121.7 +/- 30.8 minutes. Total intensive care unit stay was 5.3 +/- 7.9 days. The average intubation period was 55.5 +/- 187.6 hours. The intensive care unit stay and the intubation period of the replacement group were longer than those of the repair group. There were four operative deaths among the 87 patients (4.6%). All repair group patients survived operation, whereas 4 replacement group patients died after operation. In all patients, the New York Heart Association functional class was higher (p = 0.028) in those who died than in those who survived. The overall restoration rate from atrial fibrillation was 79.5% (66 of 83 survivors). Seventeen patients (20.5%) had persistent atrial fibrillation postoperatively. Sick sinus syndrome occurred in 7 patients (8.4%). In the repair group, the restoration rate was 76.8%, whereas in the replacement group it was 85.2% for the survivors. CONCLUSIONS: The Cox/maze procedure can be combined with a mitral valve operation with acceptably low operative risk. Analysis of risk factors of early mortality revealed that the type of mitral valve operation (replacement versus repair) and higher preoperative New York Heart Association functional class were associated with mortality. Long-term results from this combined procedure should be clearly demonstrated before its universal acceptance.     

A case report of a successful surgery for thoracoabdominal aortic aneurysm under partial cardiopulmonary bypass with selective perfusion of major abdominal branches

A 69-year-old man showed gradually developing thoracoabdominal aortic aneurysm (TAAA) after coronary artery bypass grafting. The patient underwent graft replacement of TAAA uneventfully under partial cardiopulmonary bypass with selective perfusion of major abdominal branches. The major abdominal branches and two pairs of intercostal arteries were reconstructed. The patient showed no organ failure or spinal damage postoperatively. Partial cardiopulmonary bypass with selective perfusion of abdominal branches successfully protected both the visceral organs and the spinal cord from ischemia in a TAAA surgery.     

Technical advances in the surgical management of thoracoabdominal aortic aneurysms]

Thoracoabdominal aortic aneurysmectomy ranks among the major cardiovascular surgical procedures. During the last two decades perioperative results have improved to the point that surgery should be discussed in the vast majority of patients seen with a thoracoabdominal aortic aneurysm. This progress is largely attributable to a variety of technical improvements including: aortic reconstruction using the graft inclusion technique, usually with direct reattachment of aortic branches to the prosthetic graft; distal aortic perfusion; selective use of deep hypothermic circulatory arrest in anatomically complex situations; preoperative visualization of arterial blood supply to the spinal cord using selective arteriography of intercostal and lumbar arteries. Current perioperative mortality is around 10% whereas the spinal cord complication rate is between 5% and 20% according to clinical and anatomical conditions. Future efforts should concentrate on the prevention of spinal cord complications.     

A randomized study of the influence of perfusion technique and pH management strategy in 316 patients undergoing coronary artery bypass surgery. I. Mortality and cardiovascular morbidity

The impact of perfusion technique and mode of pH management during cardiopulmonary bypass has not been well characterized with respect to postoperative cardiovascular outcome. METHODS: This double-blind, randomized study comparing outcomes after alpha-stat or pH-stat management and pulsatile or nonpulsatile perfusion during moderate hypothermic cardiopulmonary bypass was undertaken in 316 patients undergoing coronary artery bypass operations. RESULTS: Cardiovascular morbidity and mortality were not affected by pH management, and the incidence of stroke (2.5%) did not differ between groups. Overall in-hospital mortality was 2.8%, eight of the nine deaths occurring in the nonpulsatile group (5.1% versus 0.6%; p = 0.018). The incidence of myocardial infarction was 5.7% in the nonpulsatile group and 0.6% in the pulsatile group (p = 0.010), and use of intraaortic balloon pulsation was significantly more common in the nonpulsatile group (7.0% versus 1.9%; p = 0.029). The overall percentage of patients having major complications was also significantly higher in the nonpulsatile group (15.2% versus 5.7%; p = 0.006). Duration of cardiopulmonary bypass, age, and use of nonpulsatile perfusion all correlated significantly with adverse outcome. CONCLUSIONS: Use of pulsatile perfusion during cardiopulmonary bypass was associated with decreased incidences of myocardial infarction, death, and major complications.     

Safety and cost-effectiveness of MIDCABG in high-risk CABG patients

BACKGROUND: Myocardial revascularization without cardiopulmonary bypass has been proposed as a potential therapeutic alternative in high-risk patients undergoing coronary artery bypass grafting. To evaluate this possibility we compared 15 high-risk (HR) patients in whom minimally invasive direct coronary artery bypass grafting was used as the method of revascularization with 41 consecutive patients who underwent conventional coronary artery bypass grafting during 1 month. METHODS: Patients undergoing myocardial revascularization without cardiopulmonary bypass were significantly older than their low-risk (LR) counterparts (72.2 +/- 11.6 versus 63.3 +/- 9.7 years, p = 0.006). The demographic profile for HR versus LR patients was as follows: female patients, 60.0% versus 26.8%, p = 0.02; diabetes, 20.0% versus 24.4%, p = 0.7; prior stroke, 33.3% versus 7.4%, p = 0.03; chronic obstructive pulmonary disease, 60.0% versus 9.8%, p < 0.0001; peripheral vascular disease, 33.3% versus 12.2%, p = 0.03, congestive heart failure, 26.6% versus 9.8%, p = 0.09; impaired left ventricular (ejection fraction < 0.40), 40.0% versus 17.0%, p = 0.07; urgent operation, 86.6% versus 46.3%, p < 0.0001; and redo operation, 20.0% versus 0%, p = 0.003. RESULTS: There were no deaths in the HR group and one death in the LR group. The average intensive care unit stay was 1.1 +/- 0.5 days in HR patients versus 1.6 +/- 1.6 days in LR individuals (p = 0.2), and the average hospital stay was 6.1 +/- 1.8 versus 7.3 +/- 4.4 days, respectively (p = 0.3). We used an acuity risk score index developed by the Adult Cardiac Care Network of Ontario to predict outcome in the HR group. The expected intensive care unit stay in HR patients was 4.1 +/- 1.2 days (versus the observed stay of 1.1 +/- 0.5 days, p < 0.0001), and the expected hospital stay was 12.5 +/- 1.5 days (versus the observed stay of 6.1 +/- 1.8 days, p < 0.0001). The expected mortality in the HR group was 6.1% versus 0%, p = 0.3. A cost regression model was used to examine predicted versus actual cost (in Canadian dollars) for the HR patient cohort (based on Ontario Ministry of Health funding). The expected cost for the HR cohort would have been $11,997 per patient. In contrast, the average cost for these 15 patients was $5,997 per patient, an estimated cost saving of 50%. CONCLUSIONS: Myocardial revascularization without cardiopulmonary bypass appears to be a safe and cost-effective therapeutic modality for HR patients requiring myocardial revascularization.     

Traumatic aortic rupture: diagnosis and management

BACKGROUND: Traumatic aortic rupture is a relatively uncommon lesion that presents the cardiothoracic surgeon with unique challenges in diagnosis and management. To address controversial aspects of this disease, we reviewed our experience. METHODS: The study was performed by retrospective chart review. RESULTS: Forty-two patients with traumatic thoracic aortic ruptures were managed between January 1988 and June 1997. Nine arrived without vital signs and died in the emergency department. Admission chest radiographs were normal in 3 patients (12%) and caused significant delays in diagnosis. Four of 30 patients admitted with vital signs had rupture before thoracotomy and died. Twenty-six underwent aortic repair. In 1 patient repair was performed with simple aortic cross-clamping, whereas a second was managed with a Gott shunt. The remaining 24 patients had repair with partial left heart bypass. In 1 patient hypothermic circulatory arrest was required. Two patients (7.7%) died. There were no cases of new postoperative paraplegia in the bypass group. There was no morbidity directly attributable to the administration of heparin for cardiopulmonary bypass. CONCLUSIONS: In a discrete group of patients with traumatic rupture of the aorta, the rupture will become complete during the first few hours of hospital admission; aggressive medical treatment with beta-blockade and vasodilators in the interval before the operation is an essential aspect of management. Active distal circulatory support with partial left-heart bypass provides the optimal means of preventing spinal cord ischemia during repair of acute traumatic aortic rupture.