Wim J. Morshuis

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.

Acute Aortic Dissection Complicating Pregnancy

BACKGROUND Acute aortic dissection occurring during pregnancy represents a lethal risk to both the mother and fetus. Our purpose was to study the prevalence, treatments, and outcome of this rare problem and to suggest therapeutic guidelines. METHODS During the past 12 years, 6 pregnant women were admitted with an acute aortic dissection. Four had a type A and 2 had a type B dissection (Stanford classification). RESULTS Two of the 4 patients with a type A dissection underwent a combined emergency operation consisting of first cesarean section and then ascending aortic repair. Cesarean section was carried out 5 days after the emergency procedure on the aorta in the third patient, and 16 weeks later in the fourth patient. All 4 fetuses were delivered alive. One fetus died 6 days later, but the other 3 are alive and well at long-term follow-up. Of the 2 patients with a type B dissection, 1 was operated on for celiac ischemia; the other was treated medically. In both cases the fetus died in utero. There were no maternal deaths in either group. CONCLUSIONS Cesarean section with concomitant aortic repair is recommended for pregnant women with a type A dissection, depending on the gestational age. The maternal hemodynamic status will determine the sequence of the two procedures. Medical treatment is advised for patients with a type B dissection, but surgical repair is indicated if complications such as bleeding or malperfusion of major side branches occur.

Durability of aortic valve preservation and root reconstruction in acute type A aortic dissection

BACKGROUND The aim of this study was to determine the durability of aortic valve preservation and root reconstruction in type A aortic dissection with involvement of the aortic root. METHODS From November 1976 to February 1999, 246 patients underwent surgical treatment for acute type A aortic dissection at our institution. In 121 patients (49%), all with acute type A dissection and aortic root involvement, the aortic valve was preserved and one or more of the sinuses of Valsalva were reconstructed. The mean age of this group was 59 +/- 11 years and 70 (58%) were men. Thirty patients (25%) were operated in cardiogenic shock. Criteria for aortic root reconstruction were technical feasibility and surgeon preference. Techniques used for reconstruction were valve resuspension in all patients and additional reinforcement of the aortic root with Teflon (L.R. Bard, Tempe, AZ) felt (n = 21), gelatin-resorcinol-formaldehyde-glue (GRF-glue, Fii, Saint-Just-Malmont, France) (n = 103), or fibrinous glue (Tissu-col, Immuno AG, Vienna, Austria) (n = 5). Mean follow-up was 43.5 +/- 46 months. RESULTS The operative mortality was 21.5% (n = 26). Actuarial survival was 72% +/- 4%, 64% +/- 5%, and 53% +/- 6% at 1, 5, and 10 years, respectively. Median aortic regurgitation in patients with retained native aortic valve at follow-up was 1+. All root reoperations included aortic valve replacement (n = 12). Freedom from aortic root reoperation was 95% +/- 2% at 1 year, 89% +/- 4% at 5 years, and 69% +/- 9% at 10 years. The incidence of aortic root reoperation was 23%, 11%, and 40%, respectively, when Teflon felt, GRF-glue, and fibrinous glue were used for root reconstruction. Multivariate Cox proportional hazard analysis revealed the use of fibrinous glue (RR = 8.7; p = 0.03) as well as the presence of an aortic valve annulus more than 27 mm (RR = 4.2; p = 0.04) as independent risk factors for aortic root reoperation. CONCLUSIONS Aortic valve preservation in acute type A dissection provides relatively durable results. The use of fibrinous glue for root reconstruction seems to compromise the long-term durability of the repair compared with Teflon felt and GRF-glue. A dilated aortic annulus requires a more extensive root procedure.

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.

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.

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.

Long-term outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a single institution experience.

OBJECTIVE Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is the first treatment of choice with good short-term results. Only limited data are available concerning the long-term outcome after PEA. The purpose of this study is to evaluate the long-term survival and functional outcome after PEA with nearly 10 years experience. METHOD In the period of December 1998 and December 2007 120 patients with CTEPH were referred to the St Antonius Hospital (Nieuwegein, The Netherlands) of whom 72 underwent PEA. The clinical data are collected retrospectively. RESULTS In-hospital mortality was (5/72) 6.9%. Since 2004 one patient died in the hospital (1/38, 2.9%). Two patients died during long-term follow-up with a median observation of 3 years. The overall 1-, 3- and 5-year survival rates were 93.1%, 91.2% and 88.7% respectively. Prior to surgery patients were in New York Heart Association functional class III (58) and IV (14) with a mean pulmonary vascular resistance of 572+/-313 dynes s cm(-5). The following data were compared before and after operation: mean pulmonary artery pressure (mPAP) decreased from 42+/-11 to 22+/-7 mmHg (p=0.0001), NT-pro BNP improved from 1527+/-1652 to 160+/-3 pg/ml (p=0.0001), 6 min walk distance (6MWD) from 359+/-124 to 518+/-11 m (p=0.0001), and almost all patients returned to functional class I or II (p=0.0001). CONCLUSION Pulmonary endarterectomy for patients with CTEPH has shown a dramatic improvement of clinical status with excellent long-term survival.

The influence of nitrous oxide to supplement fentanyl/low-dose propofol anesthesia on transcranial myogenic motor-evoked potentials during thoracic aortic surgery

OBJECTIVE Intraoperative monitoring of myogenic motor evoked potentials to transcranial electrical stimulation (tc MEPs) is a new method to assess the integrity of the motor pathways. The authors studied the effects of 50% nitrous oxide (N2O) and a low-dose propofol infusion on tc MEPs paired electrical stimulation during fentanyl anesthesia with partial neuromuscular blockade. DESIGN Cross-over study. SETTING St Antonius Hospital, Nieuwegein, The Netherlands. PARTICIPANTS Ten patients scheduled to undergo surgery on the thoracoabdominal aorta were studied; 6 women aged 54 to 69 years and 4 men aged 68 to 77 years. INTERVENTIONS After achieving a stable anesthetic state and before surgery, tc MEPs were recorded during four 15-minute periods: (I) air/oxygen (O2; F(I)O2 = 50%); propofol target blood concentration, 0.5 microg/mL; (II) N2O/O2 (F(I)O2 = 50%); propofol target blood concentration, 0.5 microg/mL; (III) N2O/O2 (F(I)O2 = 50%; propofol target blood concentration, 1.0 microg/mL; and (IV) air/O2 (F(I)O2 = 50%); propofol target blood concentration, 1.0 microg/mL. MEASUREMENTS AND MAIN RESULTS Tc MEPs were recorded from the right extensor digitorum communis muscle and the right tibialis anterior muscle. The right thenar muscle was used for recording the level of relaxation; the T1 response was maintained at 40% to 70% of the control compound muscle action potential. There was no significant difference in onset latency among the four phases. The addition of N2O and doubling the target propofol infusion to 1.0 microg/mL resulted in a 40% to 50% reduction of tc MEP amplitude recorded in the extensor digitorum communis muscle and tibialis anterior muscle (p < 0.01). During each phase, tc MEPs could be elicited and interpreted, except in one patient, in whom no tc MEPs could be elicited in the leg because of technical problems. CONCLUSION The data indicate that tc MEP monitoring is feasible during low-dose propofol, fentanyl/50% N2O in 02 anesthesia and partial neuromuscular blockade.