Karl M. Dossche

Brain protection using antegrade selective cerebral perfusion: a multicenter study

BACKGROUND To evaluate the results of antegrade selective cerebral perfusion as a method of brain protection during surgery of the thoracic aorta and to determine predictors of hospital mortality and adverse neurologic outcome. METHODS Between October 1995 and March 2002, 588 patients underwent aortic surgery with the aid of antegrade selective cerebral perfusion. There were 334 men (56.8%); the mean age was 63.7 +/- 11.8 years. One hundred sixty-two patients (27.6%) underwent urgent operation. The separated graft technique was employed to reimplant the arch vessels in 230 patients (65.3%) of the 352 requiring aortic arch replacement. Associated procedures were performed in 254 patients (43.2%). One hundred twelve patients underwent elephant trunk procedure. The mean cerebral perfusion time was 67 +/- 37 minutes. RESULTS The overall hospital mortality rate was 8.7%. A logistic regression analysis revealed urgent operation, recent central neurologic event, tamponade, unplanned coronary artery revascularization and pump time to be independent predictors of hospital mortality (p < 0.05). The permanent neurologic dysfunction rate was 3.8%. A logistic regression analysis showed tamponade to be independent predictor of permanent neurologic dysfunction (p < 0.05). The transient neurologic dysfunction rate was 5.6%. Recent central neurologic event, tamponade, coronary disease, and aortic valve replacement were indicated as independent predictors of transient neurologic dysfunction by logistic regression (p < 0.05). CONCLUSIONS In our experience the utilization of antegrade selective cerebral perfusion resulted in encouraging results in terms of hospital mortality and brain complications. Neither the extent of the replacement nor the duration of the cerebral perfusion had an impact on hospital mortality and neurologic outcome.

The elephant trunk technique: operative results in 100 consecutive patients

OBJECTIVES To describe morbidity and mortality in patients undergoing the elephant trunk (ET) implantation as the first stage in the repair of their mega aorta and to assess determinants for the occurrence of complications. METHODS One hundred consecutive patients undergoing an ET implantation between 1984 and June 2001 were retrospectively analyzed. The ET was implanted as an extension of an isolated aortic arch (1%), an aortic valve replacement+ascending aorta+arch (14%), a root replacement+ascending aorta+arch (37%) and an ascending aorta+arch (48%). Indications for surgery were acute aortic dissection (1%), an inflammatory aneurysm (3%), chronic post-dissection (31%) or degenerative (65%) aneurysm. Marfan syndrome was present in six patients. For cerebral protection, we used isolated deep hypothermic circulatory arrest (7%), deep hypothermic circulatory arrest combined with uni- or bilateral antegrade cerebral perfusion (18%) or isolated uni- or bilateral antegrade cerebral perfusion (75%). Uni- and multivariate analysis was used. RESULTS There were no intraoperative deaths. Hospital mortality was 8%. The causes of death were cardiac in one, rupture of a remote aneurysm in three, tamponade in one and sepsis in three. After multivariate analysis, no single factor emerged as a risk factor for hospital mortality. Permanent and transient neurologic dysfunction occurred in 4 and 2%, respectively. Univariate analysis showed the operative period before 1990 (P=0.029) and emergency (P=0.018) as significant factors for postoperative neurologic dysfunction; after stepwise logistic regression analysis, only emergent operation retained significance (P=0.005). Permanent hoarseness, total atrioventricular block requiring pacemaker implantation and re-thoracotomy for bleeding occurred in 17, 2 and 30%, respectively. CONCLUSIONS The first step in the repair of a mega aorta, the implantation of an ET, can be performed with a low mortality and an acceptable morbidity. The risk of central neurologic damage is higher in emergency interventions.

Antegrade selective cerebral perfusion in operations on the proximal thoracic aorta.

BACKGROUND To determine the factors that influence hospital death and neurologic complications after surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. METHODS From May 1989 through April 1997, 106 patients underwent surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. Mean age was 64.0 +/- 11.5 years. Unilateral antegrade cerebral perfusion was used in 37 patients (35%), bihemispheric antegrade cerebral perfusion in 69 patients (65%). Mean antegrade cerebral perfusion time was 50.5 +/- 20.5 minutes. Indication for surgery was atherosclerotic aneurysm in 60 (56.5%) patients, postdissection aneurysm in 26 (24.4%), acute type A dissection in 16 (15.1%), other in 4 (4.0%). RESULTS Hospital mortality was 8.5% (n = 9; 70% CL: 5.8%-11.2%). Independent predictors of hospital mortality were rethoracotomy (odds ratio 5.7, p = 0.02), postoperative temporary (odds ratio 17.3, p = 0.02) or permanent (odds ratio 7.5, p = 0.03) neurologic dysfunction, postoperative dialysis (odds ratio 9.9, p = 0.008). Bilateral antegrade selective cerebral perfusion had a favorable impact on hospital mortality (odds ratio 0.08, p = 0.007). Temporary neurologic dysfunction occurred in 3.8% of patients (n = 4; 70% CL: 2.0%-5.6%); preoperative hemodynamic instability (odds ratio 14.8, p = 0.05) and perioperative technical problems (odds ratio 22.2, p = 0.033) were independent determinants of temporary neurologic dysfunction. Permanent central neurologic damage occurred in 5.4% of patients (n = 6; 70% CL: 3.2%-7.6%). Preoperative hemodynamic instability (odds ratio 18.9, p = 0.009) and approach through a left thoracotomy (odds ratio 9.4, p = 0.031) were significant predictors of permanent neurologic damage. CONCLUSIONS Hospital mortality is affected significantly by the choice of technique used for antegrade cerebral perfusion. The incidence of both temporary and permanent postoperative central neurologic damage is influenced by preoperative hemodynamic instability. Duration of cerebral perfusion had no influence on the postoperative neurologic outcome.

Endovascular stent-grafting for descending thoracic aortic aneurysms

OBJECTIVE Endoluminal placement of covered stent-grafts emerges as a less-invasive alternative to open surgical repair of thoracic aortic aneurysms (TAA). The present report describes our experience with endovascular stent-grafting in the treatment of descending TAA. METHODS From 1997 to 2001, 28 descending TAAs were treated in 27 patients (17 male, mean age 70 years) by endovascular stent-grafting. The aneurysms (mean diameter, 6.6 cm) had diverse causes, but the majority were due to atherosclerosis (71%). They were predominantly localized in the proximal (32%), central (39%), and distal part (22%) of the descending thoracic aorta. In two patients (7%), the entire thoracic aorta was treated. Preliminary subclavian-carotid artery transposition was performed in five patients. AneurX (n=6), Talent (n=9), and Excluder (n=13) stent-grafts were used. In 13 cases (46%), multiple stents were necessary for complete aneurysm exclusion. RESULTS In 27 of 28 cases (96%), the endovascular stent-grafts were successfully deployed. In one patient, stent dislocation into the aneurysm required open surgical repair in a subsequent procedure. There was no operative mortality. None of the patients developed paraplegia or paraparesis. No distal embolization occurred. After a median follow-up of 21 months (range, 1-49 months), there was one non-related late death. There was no aneurysm rupture. Maximal aneurysm diameter either remained stable or decreased slightly over time in all but one patient with evidence of an endoleak. Endoleaks occurred in eight patients (29%) during follow-up. In five of them the endoleaks sealed spontaneously, whereas in two patients a distal extension was inserted. CONCLUSIONS Endovascular repair of descending TAAs is a promising less-invasive alternative to open repair. Extended follow-up is necessary to determine its definite efficacy in the longer term.

Reoperations on the ascending aorta and aortic root: pitfalls and results in 134 patients

BACKGROUND This analysis was performed to evaluate the results of reoperations on the ascending aorta and aortic root. METHODS All reoperations (n = 134) on the aortic root and ascending aorta performed between February 1981 and April 1998 were retrospectively analyzed. Indications for reintervention were a true or false aneurysm (35%), acute dissection (3.0%), aortic valve stenosis and/or insufficiency (23.1%), prosthetic valve endocarditis (32.8%), and combinations (4.5%). The principal reoperations performed were aortic root replacement (composite graft, freestyle, aortic allograft, or pulmonary autograft) in 116 patients, ascending aortic replacement in 10 patients, and closure of a false aneurysm in 5 patients. Results were analyzed using univariate statistical methods. RESULTS Hospital mortality was 6.6% (8 patients). Univariate predictors of hospital death were preoperative functional class III or IV (p = 0.02), an interval of less than 6 months between the primary and actual operation (p = 0.02), preoperative creatinine level of more than 200 micromol/L (p = 0.001), acute aortic dissection (p = 0.001), intraoperative technical problems (p = 0.001), and postoperative dialysis (p = 0.001). Freedom from repetitive reoperation was 99% at 1 year and 98% at 5 and 10 years. CONCLUSIONS Reoperations on the aortic root and ascending aorta can be performed with an early mortality which is very acceptable.

Allograft aortic root replacement in prosthetic aortic valve endocarditis: a review of 32 patients.

BACKGROUND This study was conducted to evaluate allograft aortic root replacement in the setting of complicated prosthetic valve endocarditis with extensive annular destruction. METHODS From January 1990 through March 1996, 32 patients diagnosed with complicated prosthetic valve endocarditis underwent allograft root replacement. Mean age was 58.3 +/- 13.2 years; 23 patients were men. Mean preoperative New York Heart Association functional class was 3.4. Staphylococcus epidermidis (50%) and Enterococcus faecalis (19%) were the predominant causative microorganisms. Annular abscesses were found in 26 patients (81%), aortic-mitral discontinuity in 14 patients (43%), and left ventricular-aortic discontinuity in 11 patients (34%). A cryopreserved allograft was used in 31 patients (97%) and a fresh antibiotic-treated allograft was used in 1 patient (3%). Mean aortic cross-clamp time was 150 +/- 29 minutes. Mean duration of the postoperative antibiotic treatment was 38.5 +/- 11.8 days. RESULTS There were three operative deaths (9.4%); causes of death were multiorgan failure in 2 patients (6.2%) and low cardiac output in 1 patient (3.2%). Six patients (18%) had complete heart block (4 patients already before the operation), 3 patients (9.4%) had temporary respiratory insufficiency, and 1 patient (3.2%) needed temporary hemodialysis. Mean follow-up was 37.4 +/- 22.4 months. Two late deaths occurred: 1 patient had recurrent endocarditis, leading to a false aneurysm, and died at reoperation; another patient died of lung cancer. Actuarial 5-year survival was 87.3% (70% confidence interval, 76.8% to 97.8%); actuarial 5-year freedom from recurrent endocarditis was 96.5% (70% confidence interval, 90.0% to 100%). CONCLUSIONS Allograft aortic root replacement is a valuable technique in the complex setting of prosthetic valve endocarditis with involvement of the periannular region. Mortality and morbidity are low.

Impact of left heart bypass on the results of thoracoabdominal aortic aneurysm repair.

BACKGROUND This study evaluated the role of left heart bypass on the results of thoracoabdominal aortic aneurysm (TAAA) operations. METHODS Two hundred fifty-eight patients had surgical repair of a thoracoabdominal aortic aneurysm between 1981 and 1998 using the inlay technique. Simple cross-clamping was used in 47.7% and left heart bypass (atriodistal) in 52.3%. Further surgical technique was identical: liberal intercostal or lumbar artery reimplantation, cerebrospinal fluid drainage (since 1989), administration of a renal cooling solution, permissive mild hypothermia, and no pharmacologic protection. Both univariate and multivariate analysis were used. RESULTS The hospital mortality rate was 10.1% overall: 14.6% in the cross-clamp group, and 5.9% in the bypass group (p = 0.02). The risk of hospital death increased with aneurysm rupture (odds ratio 5.6) and when the patient needed postoperative dialysis (odds ratio 7.5). The use of left heart bypass had a mild protective effect on hospital death (odds ratio 0.56). The incidence of postoperative renal failure requiring dialysis was 8.3% overall: 10.9% in the cross-clamp group, and 5.9% in the bypass group (p = 0.16). After multivariate analysis, a longer operative procedure (odds ratio 1.01 per minute) and a longer reappearance time of blue dye in the urine (odds ratio 1.05 per minute) increased the risk of dialysis, whereas the use of atriodistal bypass reduced that risk (odds ratio 0.08). Paraplegia or paraparesis occurred in 10.9% of patients overall: 13.2% in the cross-clamp group, and 8.8% in the bypass group (p = 0.27). After logistic regression, rupture increased the risk of paraplegia or paraparesis (odds ratio 3.2) and dissection reduced it (odds ratio 0.23). CONCLUSIONS The use of atriodistal bypass is beneficial in patients who had thoracoabdominal aortic aneurysm repair. Hospital mortality rates, postoperative dialysis, and paraplegia/paraparesis were reduced.

A 23-year experience with composite valve graft replacement of the aortic root.

BACKGROUND This is a retrospective study of early and long-term results of composite valve graft replacement of the aortic root. METHODS AND RESULTS Between July 1974 and July 1997, 244 patients underwent aortic root replacement with a composite valve graft. Mean age was 54+/-15 years. The inclusion technique was used in 178 patients (73.0%), the open technique in 65 (26.5%), and the Cabrol II technique in 1 patient (0.5%). Hospital mortality was 7.8% (70% confidence limit, 6.1% to 9.5%). Independent determinants of hospital mortality were preoperative creatinine level more than 150 micromol/L (p = 0.04), prolonged cardiopulmonary bypass time (p = 0.006), intraoperative technical problems (p = 0.048), and year of operation (p = 0.015). Follow-up was 99.6% complete, median 96 months (range, 2 to 256 months). Fifty-seven patients (25.3%; 70% confidence limit, 22.4% to 28.2%) died during follow-up. Cumulative survival at 5, 10, and 20 years was 76%, 62%, and 33%. Independent risk factors for late death were postoperative complications (p = 0.027), technique for coronary reattachment (p = 0.028), and concomitant aortic arch operation (p = 0.01). Twenty patients (8.8%; 70% confidence limit, 7.0% to 10.6%) underwent reoperation on the aortic root. Estimated freedom from reoperation for pseudoaneurysms at 3 years was 96% in the inclusion group and 94% in the open group (p = 0.236). CONCLUSIONS Aortic root replacement with a composite valve graft can be performed with low hospital mortality and morbidity. Pseudoaneurysms did occur in the inclusion group, but also in the open group.

Is Extended Arch Replacement for Acute Type A Aortic Dissection an Additional Risk Factor for Mortality

BACKGROUND We report our experience with surgery for acute type A aortic dissection with involvement of the aortic arch. METHODS From January 1986 to December 2001, 277 patients underwent surgery for acute type A aortic dissection. In 70 patients (25.3%), surgery was extended into the aortic arch: hemiarch and total arch replacement in 53 (75.7%) and 17 (24.3%) patients, respectively. Deep hypothermic circulatory arrest was used in 19 patients, antegrade selective cerebral perfusion in 38, and combined deep hypothermic circulatory arrest with antegrade selective cerebral perfusion in 13. RESULTS Operative mortality was 18.6% (13/70) after extended replacement into the arch versus 21.7% (45/207) after surgery limited to the ascending aorta (p = 0.62). Multivariate analysis did not reveal significant risk factors for operative mortality. Postoperatively, 5 patients (8.1%) had a new postoperative cerebral vascular accident (CVA). Multivariate analysis showed an earlier date of operation as the only independent determinant for a new postoperative CVA (p = 0.0162, RR = 0.80/year, 95% CI = 0.67 to 0.96). None of the patients, operated on with antegrade selective cerebral perfusion, had a new cerebral deficit. Comparing the different methods of cerebral protection, multivariate risk analysis revealed antegrade selective cerebral perfusion as a significant protective factor against new postoperative CVA (p = 0.0110, OR = 0.12, 95% CI = 0.02 to 0.61). Survival at 5 and 10 years was 66.6.5% and 40.0%, respectively, after replacement of the aortic arch versus 68.7% and 57.7%, respectively, after replacement of the ascending aorta (p = 0.96). Freedom from aortic arch reoperation was 96.3% at 5 and 77.0% at 10 years versus 86.6% and 75.1% in both groups, respectively (p = 0.21). CONCLUSIONS Extended replacement into the aortic arch during surgery for acute type A dissection does not influence early and late results. The best cerebral protection seems to be obtained with antegrade selective cerebral perfusion.

Bilateral antegrade selective cerebral perfusion during surgery on the proximal thoracic aorta

OBJECTIVE To assess risk factors for hospital death and neurologic outcome after surgery on the proximal thoracic aorta using moderate hypothermic circulatory arrest and bilateral antegrade selective cerebral perfusion. METHODS From October 1995 through June 1999, 163 patients with a mean age of 63+/-11 years underwent surgery using bilateral antegrade selective cerebral perfusion. Degenerative aneurysms (55%) and acute type A dissection (28%) were the predominant indications for operation. Forty-six (28%) operations were considered as emergency procedure. Twenty-four (15%) procedures were reoperations. RESULTS Mean ASCP time was 48+/-20 min. Hospital mortality was 8.6% (n=14; 70% confidence limit (CL): 6.4-10.8%). Univariate risk factors for hospital mortality were acute type A dissection (P=0.003), central neurologic damage <24 h before the operation (P=0.000), preoperative hemodynamic instability (P=0.034), and rethoracotomy for any cause (P=0.036). Logistic regression analysis identified central neurologic damage <24 h (P=0.006, odds ratio 14) as an independent risk factor. Temporary neurologic damage occurred in 3.8% (n=6; 70% CL: 2.3-5.3%) of patients. Logistic regression analysis indicated preoperative hemodynamic instability (P=0.003, odds ratio 13) as an independent risk factor. Perioperative permanent central neurologic damage was reported in another 3.8% (n=6; 70% CL: 2.3-5.3%) patients. Acute type A dissection (P=0.018, odds ratio 8) and the non-use of a midline sternotomy (P=0.049, odds ratio 8) were retained as independent risk factors. CONCLUSION Hospital mortality and perioperative neurologic complications are not significantly influenced by the duration of antegrade selective cerebral perfusion. Overall complication rate is low.