Controversy exists regarding the extent of proximal

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1 Does the Extent of Proximal or Distal Resection Influence Outcome for Type A Dissections? Marc R. Moon, MD, Thoralf M. Sundt III, MD, Michael K. Pasque, MD, Hendrick B. Barner, MD, Charles B. Huddleston, MD, Ralph J. Damiano, Jr, MD, and William A. Gay, Jr, MD Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri Background. The extent of proximal and distal aortic resection that should be performed for acute type A aortic dissections remains controversial. Methods. From 1984 to 1999, 119 patients underwent repair of an acute type A dissection. Distal resection was to the ascending aorta in 78 (66%) and hemiarch in 41 (34%) patients. Proximally, the aortic valve was preserved in 69 (58%) patients, 40 (34%) underwent composite valve grafting, and 10 (8%) underwent separate graft and valve replacement. Results. Operative mortality was higher for separate graft and valve (50% 16%) than for valve preservation (16% 5%) or composite grafts (20% 7%) (p < 0.05). Hemiarch replacement did not increase operative risk compared to distal reconstruction to the ascending aorta (17% 6% versus 22% 5%, p > 0.71). At 10 years, freedom from reoperation was 81% 7% and long-term survival was 60% 8%, but neither was related to the proximal or distal surgical technique (p > 0.15). Risk factors for late reoperation included a nonresected primary tear and Marfan syndrome (p < 0.05). Conclusions. An aggressive surgical approach, including a full root or hemiarch replacement, is not associated with increased operative risk and should be considered when type A dissections extensively involve the valve, sinuses, or arch. (Ann Thorac Surg 2001;71: ) 2001 by The Society of Thoracic Surgeons Controversy exists regarding the extent of proximal and distal aortic resection that should be performed for patients with acute type A aortic dissections. For example, arch replacement may potentially decrease the risk of late reoperation, but the extended distal resection may increase operative risk compared to standard reconstruction to the mid-distal ascending aorta. In addition, valve repair may be preferable to replacement when the dissection extends to the aortic root, but it remains unknown whether reconstruction below the sinotubular ridge predisposes the patient to proximal aneurysm formation or the need for valve replacement in the late postoperative period. In recent years, we have tended towards a more conservative proximal aortic approach, as have most centers, however, our approach to the distal aorta has become more aggressive. The purpose of the current investigation was to determine how the extent of proximal and distal aortic resection influenced operative morbidity and mortality, long-term survival, and the risk of late reoperation for patients with acute type A aortic dissections. Accepted for publication Oct 30, Address reprint requests to Dr Moon, Division of Cardiothoracic Surgery, Washington University School of Medicine, 3108 Queeny Tower, 1 Barnes- Jewish Plaza, St. Louis, MO ; moonm@ msnotes.wustl.edu. Material and Methods This retrospective review includes 119 consecutive patients who underwent surgical repair of an acute type A aortic dissection at Washington University Medical Center (Barnes-Jewish Hospital) from June 1984 through December 1999 by 18 different surgeons (see Appendix). Patients were contacted for follow-up by telephone during a 3-month closing interval ending February Cumulative long-term follow-up totaled 454 patientyears, and was 98% complete. There were 69 (58%) men and 50 (42%) women, with a mean age ( one standard deviation) of years (range, 21 to 88 years). For the 8 patients with Marfan syndrome, mean age was years (range, 21 to 46 years). Selected preoperative clinical patient characteristics are listed in Table 1. The most common underlying medical disorder was hypertension, present in 68% of patients. Four (3%) patients had previously undergone coronary artery bypass grafting (CABG) or aortic valve replacement (2 patients each). To compare the more recent surgical results with those in the early experience, three arbitrary time windows were defined: 1984 to 1988 (19 [16%] patients), 1989 to 1993 (39 [33%]), and 1994 to 1999 (61 [51%]). Fifteen (13%) patients experienced an intraoperative dissection while undergoing either CABG (11 patients) or a valve procedure (aortic 2, mitral 2). The location of the primary intimal tear was the ascending aorta in 103 (86%) patients, the arch in 9 (8%), and the descending thoracic aorta in 7 (6%). Preoperative complications were common, occurring in 72 (61%) patients, and are summarized 2001 by The Society of Thoracic Surgeons /01/$20.00 Published by Elsevier Science Inc PII S (00)

2 Ann Thorac Surg MOON ET AL 2001;71: TREATMENT OF TYPE A DISSECTION 1245 Table 1. Preoperative Clinical Characteristics Variable No. (%) Hypertension 81 (68) Coronary artery disease 24 (20) Diabetes mellitus 11 (9) Chronic renal insufficiency 11 (9) Pulmonary disease 16 (13) Peripheral vascular disease 10 (8) History of cerebrovascular accident 11 (9) Previous cardiac operation 4 (3) Marfan syndrome 8 (7) History of smoking 70 (59) Table 3. Cross-Clamp and Cardiopulmonary Bypass Times for the Different Combinations of Proximal and Distal Surgical Techniques a Variable Ascending only (min) Hemiarch (min) Cross-clamp time Valve preservation Separate graft and valve Composite valve-graft CPB time Valve preservation Separate graft and valve Composite valve-graft a Values are mean standard deviation. in Table 2. The most common complication was aortic insufficiency, which was moderate-to-severe in 40% of patients. Operative Techniques Although there was substantial variability in the specific operative techniques used among the 18 surgeons during this 16-year period, the following reflected the general operative approach. All patients underwent median sternotomy and total cardiopulmonary bypass (CPB) with femoral artery cannulation. A segment of the ascending aorta, containing the area of most severe injury and intimal tear (if present), was resected and replaced with a tubular prosthetic graft. The primary intimal tear was resected in 108 (91%) patients. The primary tear was not resected in 3 out of 9 (33%) patients with arch tears nor in any of the 7 patients with primary tears beyond the arch. In most cases, Teflon-felt strips were used liberally for a sandwich-type reinforcement of the proximal and distal anastomoses. At the discretion of the operative surgeon, profound hypothermic circulatory arrest was employed in 88 (74%) patients with a core (bladder) temperature of 17 2 C (range, 13 C to 28 C). Circulatory arrest was more common in the later rather than earlier time periods: 11% prior to 1989, 74% from 1989 to 1993, and 93% after 1993 ( p 0.001). Proximally, the aortic valve was preserved in 69 (58%) patients, 40 (34%) underwent composite valve graft (CVG) replacement with reimplantation of the coronary arteries or CABG if the ostia were damaged, and 10 (8%) Table 2. Preoperative Complications Variable No. (%) Cardiogenic shock 22 (18) Rupture/tamponade 25 (21) Aortic insufficiency (moderate or severe) 43 (40) Malperfusion syndrome 28 (24) Peripheral 17 (14) Visceral 7 (6) Coronary 6 (5) Neurologic (central) 7 (6) Paralysis or paresis 4 (3) CPB cardiopulmonary bypass. underwent separate aortic graft and valve (GV) replacement. Aortic valve preservation was more common in the later rather than earlier time periods: 37% prior to 1989, 44% from 1989 to 1993, and 74% after 1993 ( p 0.001). The distal extent of aortic resection was the ascending aorta in 78 (66%) patients and hemiarch in 41 (34%). For ascending replacement only, the distal anastomosis was performed to the mid-distal aorta either with the crossclamp in place (30 patients) or with circulatory arrest and an open-distal technique (48 patients). While circulatory arrest is not required to replace only the ascending aorta, it was employed in most patients in the later time periods to avoid the potential late complications of clamp trauma and to allow a more secure distal anastomosis. For hemiarch replacement, the prosthetic graft was cut obliquely and sewn into the concavity (lesser curve) of the aortic arch (extended to the left subclavian orifice) with circulatory arrest and an open-distal technique. Hemiarch replacement was more common in the later rather than earlier time periods: 5% prior to 1989, 31% from 1989 to 1993, and 46% after 1993 ( p 0.004). Circulatory arrest times were higher with hemiarch replacement (42 15 minutes) than in the 48 patients who underwent ascending replacement only with an opendistal technique (34 15 minutes) ( p 0.02). The aortic cross-clamp (myocardial ischemia) and CPB times are summarized in Table 3. Of note, aortic cross-clamp and CPB times were longer for patients who underwent CVG replacement. Data Analysis Surgical outcome was measured in terms of operative morbidity (neurologic complications, reexploration for bleeding), operative mortality, late survival, and the rate of late reoperation. Neurologic complications included permanent cerebral vascular accident (CVA), transient ischemic attacks (TIA), and delirium or prolonged coma (greater than 24 hours). Operative mortality included any death that occurred during the initial hospitalization or within 30 days of operation for discharged patients. Long-term survival data included death from all causes. Continuous data are reported as mean one standard

3 1246 MOON ET AL Ann Thorac Surg TREATMENT OF TYPE A DISSECTION 2001;71: deviation, and clinically important ratios with 70% confidence limits. Actuarial survival estimates were calculated using the Kaplan-Meier method and compared using the log-rank test (Primer of Biostatistics 4.0, McGraw-Hill, New York, NY). Variability of the actuarial estimates was expressed as one standard error of the mean. Freedom from reoperation estimates were also determined using the actual, or cumulative incidence, method of analysis, which takes into account the competing hazard risk of death when calculating the probability of reoperation. Continuous data were compared between groups using analysis of variance and the Student-Newman-Keuls test. Univariate analysis (chisquared test) and multivariate stepwise regression analysis were used to determine the preoperative and intraoperative risk factors that were significant, independent predictors of operative morbidity and mortality, longterm survival, and the need for late reoperation (Sigma- Stat 2.03, SPSS Inc, Chicago, IL). Twenty-five variables were analyzed: age, year of operation, gender, race, hypertension, diabetes, coronary artery disease, pulmonary disease, cerebrovascular disease, peripheral vascular disease, chronic renal insufficiency, cigarette smoking, Marfan syndrome, previous cardiac operation, preoperative malperfusion syndrome, cardiogenic shock, aortic insufficiency, cardiac tamponade, DeBakey classification (I, extends beyond ascending; II, limited to ascending), intraoperative dissection, circulatory arrest, primary tear location, primary tear resected, and proximal and distal surgical technique. Results Operative Morbidity Reexploration for bleeding was necessary in 16 (13% 3%) patients, but was not influenced by either the proximal ( p 0.90) or distal ( p 0.56) surgical technique. Multivariate regression analysis identified three factors to be independent predictors for reexploration for bleeding: 1) nonresected primary tear ( p 0.004); 2) preoperative malperfusion syndrome ( p 0.02); and 3) Marfan syndrome ( p 0.02). Neurologic complications (including delirium or coma beyond 24 hours) were common, occurring in 38 (32% 4%) patients. Permanent CVA occurred in 5 (4% 2%) patients, TIA in 3 (3% 1%), and prolonged delirium or coma in 30 (25% 4%). Neurologic complications were unrelated to the proximal ( p 0.72) and distal ( p 0.28) surgical technique. Multivariate regression analysis identified two factors to be independent predictors for neurologic complications: 1) preoperative malperfusion syndrome ( p 0.02); and 2) intraoperative dissection ( p 0.003). Seven patients developed acute renal failure requiring dialysis, and 2 patients developed mediastinitis. Operative Mortality The operative mortality rate was 20% 4% (24 out of 119 patients). The causes of operative death were multisystem organ failure (7 patients), left ventricular failure (5), Fig 1. Long-term survival estimates following repair of type A aortic dissection for all patients (including operative deaths) and for operative survivors. The numbers of patients at risk at 1, 5, 10, and 15 years are indicated. postoperative bleeding (5), cerebrovascular accident (4), and rupture (3) of the distal aorta at 3, 6, and 29 days postoperatively. The operative mortality rate did not differ significantly between the three time periods: 21% 10% from 1984 to 1988, 18% 6% from 1989 to 1993, and 21% 5% from 1994 to 1999 ( p 0.91). Operative mortality did not increase with hemiarch replacement (17% 6%) compared to distal reconstruction to the ascending aorta (22% 5%) ( p 0.71). However, operative mortality was influenced by the extent of proximal resection, being higher for separate GV replacement (50% 16%) than for either valve preservation (16% 5%) or CVG replacement (20% 7%) ( p 0.05). Multivariate regression analysis identified five factors to be independent predictors of operative mortality: (1) proximal surgical technique ( p 0.002); (2) preoperative malperfusion syndrome ( p 0.02); (3) preoperative cardiogenic shock ( p 0.008); (4) hypertension ( p 0.04); and 5) intraoperative dissection ( p 0.04). Long-Term Survival Of the 95 early survivors, there were 24 late deaths, and 2 patients were lost to follow-up. Mean follow-up was months, with 2 patients alive 15 years after standard ascending aortic replacement without circulatory arrest. Actuarial survival rates (including operative deaths) for all patients were 76% 4% at 1 year, 64% 5% at 5 years, and 48% 7% at 10 years (Fig 1). When operative deaths were excluded, long-term survival was 96% 2% at 1 year, 80% 5% at 5 years, and 60% 8% at 10 years (Fig 1), but did not differ significantly between the various proximal ( p 0.22) and distal ( p 0.39) surgical techniques (Fig 2). Multivariate regression analysis identified three factors to be independent predictors of late death: (1) earlier year of operation ( p 0.001); (2) increased age ( p 0.02); and (3) intraoperative dissection ( p 0.02). Risk of Late Reoperation Nine (9% 3%) operative survivors underwent 11 late reoperations with a reoperative mortality rate of 9%

4 Ann Thorac Surg MOON ET AL 2001;71: TREATMENT OF TYPE A DISSECTION %. One patient underwent revision of a CVG for a pseudoaneurysm at the root. Five patients underwent thoracoabdominal aortic replacement for aneurysmal dilatation of the distal aorta. None of the 34 patients who survived hemiarch replacement required anterior reoperation. In contrast, 5 of 61 (8% 4%) patients who survived initial reconstruction to the ascending aorta required anterior reoperation for aneurysmal dilatation of the residual distal ascending aorta and arch. In actuarial terms, freedom from reoperation was 95% 2% at 1 year, 92% 3% at 5 years, and 81% 7% at 10 years (Fig 3). Using the actual (cumulative incidence) method of analysis, freedom from reoperation increased slightly to 95% 2% at 1 year, 93% 5% at 5 years, and 87% 8% at 10 years (Fig 3). Freedom from reoperation was independent of the extent of proximal surgical resection ( p 0.36) (Fig 4A). There was a trend towards improved freedom from reoperation with hemiarch replacement, but the difference did not reach statistical significance ( p 0.15) (Fig 4B). Multivariate regression analysis identified two factors to be independent predictors of late reoperation: 1) nonresected primary tear ( p 0.05); and 2) Marfan syndrome ( p 0.001). Fig 2. Long-term survival estimates for operative survivors following: (A) aortic valve preservation, composite valve-graft (CVG), or separate graft and valve (GV) replacement; and (B) distal reconstruction to the ascending aorta or hemiarch. The numbers of patients at risk are indicated. Comment Proximal Surgical Technique: Aortic Valve Preservation or Replacement? Historically, some surgeons have felt that there was increased risk with radical root replacement, such that conservative root repair or separate GV replacement was preferred for acute dissections, however, recent reports have not found this to be the case. Lytle, Sabik, and colleagues [1, 2] from the Cleveland Clinic reported similar mortality rates with CVG (22% 8%), separate GV replacement (20% 13%), and root reconstruction (13% 4%) ( p 0.30). The Mount Sinai group reported good results in 19 patients with CVG compared to 54 patients with valve preserving reconstruction [3]; operative mortality (16% versus 13%) and morbidity were similar, and event-free survival appeared better with CVG at 9 years (88% 22% versus 19%). In the current series, operative mortality was 20% 7% for CVG and 16% 5% for root reconstruction, consistent with previous reports [1 7]. However, operative mortality was substantially higher with separate GV replacement (50% 16%) ( p 0.05). For patients with a bicuspid aortic valve and ascending aortic aneurysm (dissections excluded), we recently reported similar operative mortality and long-term survival with CVG and separate GV replacement [8]. Therefore, in the current series, it is difficult to explain why the operative mortality rate was higher with separate GV replacement, since the deaths in this group did not appear to be the direct result of the procedure itself. There has certainly been a bias towards CVG at our institution, however, we do feel that a dissection that damages the valve, such that it needs to be replaced, has Fig 3. Freedom from reoperation estimates following repair of type A aortic dissection for all operative survivors using the actuarial and actual (cumulative incidence) methods of analysis. The number of patients at risk are indicated.

5 1248 MOON ET AL Ann Thorac Surg TREATMENT OF TYPE A DISSECTION 2001;71: % 13% for aortic valve replacement, and 98% 2% and 73% 13% for valve resuspension [10]. In the current report, freedom from reoperation was 91% 5% at 5 and 10 years for patients undergoing aortic valve preservation, but only one of these reoperations was for valve replacement. Patients with AI were more likely to undergo valve replacement at the initial operation than those without AI (56% versus 34%), although the trend has been towards valve preservation in recent years for both groups. If the sinuses of Valsalva are not involved, and the AI is secondary to dilatation at the sinotubular ridge, we currently prefer valve repair instead of replacement in acute and chronic dissections. Freedom from reoperation is acceptable, even in patients with AI preoperatively, and the risk of reoperative root surgery appears to be relatively low [5, 7, 9 13]. Fig 4. Actuarial freedom from reoperation following: (A) aortic valve preservation, composite valve-graft (CVG), or separate graft and valve (GV) replacement; and (B) distal reconstruction to the ascending aorta or hemiarch. The numbers of patients at risk are indicated. more than likely weakened the sinuses as well. In Kouchoukos and associates classic series of aortic root replacement, he noted that annuloaortic ectasia was very common in patients with dissections, and felt that a more aggressive resection was associated with a decrease in serious bleeding compared to reconstruction of the sinuses when the dissection extensively involved the root [9]. The current data demonstrate that CVG replacement did not significantly increase operative morbidity or mortality, and can be performed safely for patients with an acute type A dissection. We, therefore, prefer CVG to separate GV replacement if the valve or sinuses are involved. In addition, since CVG did not increase morbidity and mortality or impair long-term survival, we advocate CVG for patients with annuloaortic ectasia, Marfan syndrome, and for patients in whom there is significant cusp pathology, including bicuspid valves. In the Stanford-Duke cooperative series of type A dissections complicated by aortic insufficiency (AI), freedom from reoperation at 5 and 10 years was 100% and Distal Surgical Technique: Ascending, Hemiarch, or Total Arch Replacement? In the current series, freedom from reoperation at 2 years was 91% 4% for ascending only and 97% 3% for hemiarch replacement, 89% 5% and 97% 3% at 5 years, respectively, and 76% 8% and 97% 3% at 10 years, consistent with previous reports [4, 14, 15]. Intimal tears or fenestrations at intercostal or visceral branches result in a patent false lumen in many patients, which may lead to aneurysmal dilatation in the thoracoabdominal aorta. However, while 5 of 10 late reoperations in the ascending only group were necessary because of progression of disease in the residual distal ascending aorta and arch, none of the patients undergoing hemiarch replacement required an anterior reoperation. Clearly, hemiarch replacement does not eliminate the need for late reoperation on the distal thoracoabdominal aorta, but it can eliminate the risk of aneurysmal dilatation of the distal ascending aorta that remains following classic reconstruction to the ascending aorta. In addition, a subsequent operation via the left chest can easily reach the previous graft, eliminating the potential risk of a third operation to treat the arch. The Stanford group has shown that mortality does not increase for patients in whom the intimal tear was not resected [6, 16]. In the current report, we found no significant difference in early mortality (19% 4% versus 27% 14%; p 0.82) or long-term survival (10-year: 61% 8% and 52% 23%; p 0.40) either with or without resection of the primary tear. However, multivariate analysis identified nonresection of the primary tear and Marfan syndrome to be independent predictors of late reoperation. Therefore, our current practice in acute type A dissection is to extend the distal aortic resection using the hemiarch technique if the primary tear resides within the arch, and for all patients with Marfan syndrome. We do not perform total arch replacement in these patients, reserving this technique for chronic dissections with aneurysmal dilatation of the arch or descending aorta [17]. We believe that aggressive hemiarch replacement can accomplish much the same objective in the acute setting with considerably less risk.

6 Ann Thorac Surg MOON ET AL 2001;71: TREATMENT OF TYPE A DISSECTION 1249 Limitations The current series was a retrospective, nonrandomized comparison of the surgical results of 18 different surgeons using a variety of techniques over a 16-year period. Although we attempted to account for factors that changed during this time period, surely there were issues that were not reflected in the multivariate analysis. In general, while the surgical principles among the surgeons were similar, there was variability in the way each surgeon performed each specific operation. None of the surgeons performed more than one-fifth of the operations. However, we feel that the diversity in this study may better predict the expected outcome for a given surgeon in practice than does a similar series from a single surgeon or from a center in which dissections are directed toward specific surgeons. We included intraoperative dissections in the current report, and while the iatrogenic etiology is different than a spontaneous dissection, we feel that the treatment strategy is analogous. Multivariate analysis identified intraoperative dissection as an independent predictor of neurologic complications, operative mortality, and late death. Therefore, while the treatment was similar to spontaneous dissections, intraoperative dissections were associated with a substantially worse prognosis. For all patients, the rate of CVA and TIA ( hard neurologic endpoints) was similar to that previously reported by other investigators [6, 14]. However, using the strict criteria of delirium or prolonged coma greater than 24 hours, neurologic complications were common (32% 4%). In our experience, it often takes a few days for these patients to wake up fully following such an event, especially if they are elderly. In conclusion, an aggressive surgical approach to the treatment of patients with acute type A aortic dissections, including a full root or hemiarch replacement, is not associated with increased operative risk. If the sinuses of Valsalva are not involved and AI is secondary to dilatation at the sinotubular ridge, the aortic valve should be preserved. However, CVG rather than separate GV replacement should be performed for patients with uncorrectable pathology of the valve itself. Circulatory arrest should be employed in all cases with an open-distal anastomosis to minimize the risk of reoperation. Hemiarch replacement may also be performed without significant incremental risk and may reduce the risk of reoperation if the arch is involved. References 1. Lytle BW, Mahfood SS, Cosgrove DM, Loop FD. Replacement of the ascending aorta. Early and late results. J Thorac Cardiovasc Surg 1990;99: Sabik JF, Lytle BW, Blackstone EH, McCarthy PM, Loop FD, Cosgrove DM. Long-term effectiveness of operations for ascending aortic dissections. J Thorac Cardiovasc Surg 2000; 119: Ergin MA, McCullough J, Galla JD, Lansman SL, Griepp RB. Radical replacement of the aortic root in acute type A dissection. Indications and outcome. Eur J Cardiothorac Surg 1996;10: Galloway AC, Colvin SB, Grossi EA, et al. Surgical repair of type A aortic dissection by the circulatory arrest-graft inclusion technique in sixty-six patients. J Thorac Cardiovasc Surg 1993;105: Bachet JE, Termignon J, Dreyfus G, et al. Aortic dissection. Prevalence, cause, and results of late reoperations. J Thorac Cardiovasc Surg 1994;108: Fann JI, Smith JA, Miller DC, et al. Surgical management of aortic dissection during a 30-year period. Circulation 1995; 92(Suppl 2): von Segesser LK, Lorenzetti E, Lachat M, et al. Aortic valve preservation in acute type A dissection. Is it sound? J Thorac Cardiovasc Surg 1996;111: Sundt TM, Mora BN, Moon MR, Bailey MS, Pasque MK, Gay WA. Options for repair of a bicuspid aortic valve and ascending aortic aneurysm. Ann Thorac Surg 2000;69: Kouchoukos NT, Wareing TH, Murphy SF, Perrillo JB. Sixteen-year experience with aortic root replacement. Results of 172 operations. Ann Surg 1991;214: Fann JI, Glower DD, Miller DC, et al. Preservation of aortic valve in type A aortic dissection complicated by aortic regurgitation. J Thorac Cardiovasc Surg 1991;102: Pessotto R, Santini F, Pugliese P, et al. Preservation of the aortic valve in acute type A dissection complicated by aortic regurgitation. Ann Thorac Surg 1999;67: Mazzucotelli JP, Deleuze PH, Baufreton C, et al. Preservation of the aortic valve in acute aortic dissection. Long-term echocardiographic assessment and clinical outcome. Ann Thorac Surg 1993;55: Westaby S, Katsumata T, Freitas E. Aortic valve conservation in acute type A dissection. Ann Thorac Surg 1997;64: David TE, Armstrong S, Ivanov J, Barnard S. Surgery for acute type A aortic dissection. Ann Thorac Surg 1999;67: Heinemann M, Laas J, Jurmann M, Karck M, Borst HG. Surgery extended into the aortic arch in acute type A dissection. Indications, techniques, and results. Circulation 1991;84(Suppl 3): Yun KL, Glower DD, Miller DC, et al. Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted? J Thorac Cardiovasc Surg 1991;102: Moon MR, Miller DC. Aortic arch replacement for dissection. Op Tech Thorac Cardiovasc Surg 1999;4: Appendix: Operative Surgeons Clarence S. Weldon, MD; James L. Cox, MD; Thomas L. Spray, MD; Nicholas T. Kouchoukos, MD; R. Morton Bolman, MD; Thomas B. Ferguson, Sr, MD; William G. Marshall, MD; Michael K. Pasque, MD; T. Bruce Ferguson, Jr, MD; Michael Rosenbloom, MD; Thomas H. Wareing, MD; Charles B. Huddleston, MD; Bill B. Dailey, MD; Thoralf M. Sundt, MD; William B. Gay, MD; Scott H. Johnson, MD; Hendrick B. Barner, MD; and Marc R. Moon, MD. INVITED COMMENTARY Moon and colleagues from Washington University School of Medicine reviewed 119 patients over a 15-year period who underwent surgical repair of acute type A aortic dissection. They asked the very appropriate question whether or not the extent of proximal or distal aortic resection would alter short-term and long-term out by The Society of Thoracic Surgeons /01/$20.00 Published by Elsevier Science Inc PII S (01)02433-X