Surgical management of ascending and aortic arch disease: refined techniques with improved results

Coronary artery disease in aortic aneurysm and dissection

Coexisting coronary artery disease is a significant risk factor of untoward outcomes after surgical and endovascular aortic repair. This article reviewed the data, consensus, and remaining controversy about the diagnosis and management of coexisting coronary artery disease in the patients who require intervention for aortic aneurysm and dissection. It can be summarized as follows: (1) the current guidelines generally recommend the same diagnostic algorithm, including indications of coronary artery angiography, as one for non-surgical patients; (2) they also recommend the same indications of coronary revascularization; and (3) there are minor, but important, remaining issues regarding the details of management and surgical techniques most of which are still at the discretion of individual surgeons and institutions. Because it is not likely to get large-scale investigational data about these issues, the collection of individual experiences should be promoted in future scientific meetings to build up the consensus.

The effect of proximal anastomosis on the expansion rate of a dilated ascending aorta in coronary artery bypass surgery: a prospective study

Background:

This study was designed to determine the short- and long-term effects of proximal aortic anastomosis, performed during isolated coronary artery bypass grafting (CABG) in patients with dilatation of the ascending aorta who did not require surgical intervention.

Methods:

The study was performed on 192 (38 female and 160 male patients; mean age, 62.1 ± 9.2 years; range, 42–80 years) patients with dilatation of the ascending aorta who underwent CABG surgery between 1 June 2006 and 31 May 2014. In group 1 (n = 114), the saphenous vein and left internal mammarian artery grafts were used, and proximal anastomosis was performed on the ascending aorta. In group 2 (n = 78), left and right internal mammarian artery grafts were used, and proximal aortic anastomosis was not performed. Pre-operatively and in the first and third years postoperatively, the ascending aortic diameter was measured and recorded using transthoracic echocardiography at four different regions (annulus, sinus of Valsalva, sinotubular junction and tubular aorta).

Results:

A statistically significant difference was found between the groups for the number of grafts used and the duration of aortic cross-clamping and cardiopulmonary bypass. No significant intergroup difference was seen for the mean diameter of the ascending aorta (p > 0.05). Annual changes in the aortic diameter were found to be extremely significantly different in both groups (p = 0.0001). Mean values of the aortic diameter at the level of the sinotubular junction and tubular ascending aorta, mean aortic diameters (p = 0.002 and p = 0.0001, respectively), annual increase in diameter (p = 0.0001 and p = 0.0001, respectively), and mean annual difference in diameter (p = 0.0001 and p = 0.0001, respectively) at one and three years postoperatively were statistically significantly different between the groups.

Conclusion:

In patients with ascending aortic dilatation who did not require surgical intervention and who had proximal anastomosis of the ascending aorta and underwent only CABG, we detected statistically significant increases in the diameter of the sinotubular junction and tubular aorta up to three years postoperatively.

Novel suture technique for hemostatic aortic anastomosis: backstitch

Postoperative anastomotic suture line complications, such as hemorrhage and pseudoaneurysm, are often encountered in thoracic aortic surgery. To minimize these complications different anastomotic techniques have been developed. We hereby describe a new distal anastomotic technique, which involves positioning the graft inside the aorta at the distal end, reinforcing the suture line with an externally placed Teflon felt strip, and finishing the anastomosis with a circumferential and continued suture technique called "backstitch."

Postsurgical aortic false aneurysm: pathogenesis, clinical presentation and surgical strategy

Postsurgical aortic false aneurysm occurs in less than 0.5% of all cardiac surgical cases and its management is a challenge in terms of preoperative evaluation and surgical approach. Although infections are well recognized as risk factors, technical aspects of a previous operation may have a role in pseudoaneurysm formation. The risk factors and clinical presentation of pseudoaneurysms and the surgical strategy are revisited in this article.

Activation of a Neutrophil-Derived Inflammatory Response in the Airways During Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is believed to cause postoperative lung dysfunction. To more closely examine the inflammatory processes occurring in the airways during CPB, we serially measured inflammatory mediators, with the assistance of a new bronchoscopic microsample probe, in 11 patients undergoing repair of aortic arch aneurysms. Epithelial lining fluid (ELF) and arterial blood were sampled simultaneously after induction of anesthesia, at the time of pulmonary reperfusion, and at the end of surgery. A decrease in the PaO2/FiO2 ratio was observed at the end of surgery (P = 0.029). Although the ELF concentrations of interleukin (IL)-8, IL-6, and neutrophil elastase had increased significantly at the end of surgery (median = 23,200, 1818, and 12,900 microg/mL, respectively), they did not correlate with the degree of hypoxemia. Neutrophil elastase increased significantly at the time of pulmonary reperfusion, before IL-8 and IL-6, and independently of blood transfusions. At the end of surgery, IL-6 in ELF correlated with total blood transfusion volume (rho = 0.731, P = 0.011). These results indicate that a neutrophil-derived inflammatory response is activated in the airway in the early phase of CPB.

Time and Risk Analysis for Acute Type A Aortic Dissection Surgery Performed by Hypothermic Circulatory Arrest, Cerebral Perfusion, and Open Distal Aortic Anastomosis

BACKGROUND

Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion, and open distal anastomosis are important stages of surgical management and cerebral protection for acute type A dissections. Among the factors that influence survival are the transfer time to hospital from the onset of symptoms, in-hospital transfer time to operation, organ malperfusion, preoperative risk factors, and intraoperative variables. The aim of this study was to analyze time and risk factors during surgical management.

METHODS

Between September 1996 and March 2002, a total of 26 patients with acute type A aortic dissection were operated. Sixteen patients (61.5%) were male and mean age was 49 ( 13.1 years (range: 26-68). The diagnosis was based on clinical examination, telecardiography, transthoracic echocardiography, computerized tomography, and angiography. Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion and open distal anastomosis were used during the procedures. Operative techniques were as follows: supracoronary ascending aortic replacement (17 patients), aortic root and ascending aortic replacement with flanged composite grafting technique (5 patients), replacement of ascending aorta and hemiarcus (1 patient), aortic root and ascending aortic replacement with modified Bentall technique (1 patient), replacement of ascending aorta and arcus (1 patient), and total arcus replacement with elephant trunk technique and modified Bentall procedure (1 patient).

RESULTS

The early postoperative mortality rate within the first 30 days was 26.9%, and the late postoperative mortality rate was 15.8%. Two patients (7.7%) developed major neurological complications during the postoperative period. Time to admission, durations of total circulatory arrest, cross-clamp, cardiopulmonary bypass, and intubation were longer, and postoperative blood loss was greater in patients who died during early postoperative period, although the differences did not reach statistical significance. Duration of total circulatory arrest was longer in patients who developed neurological dysfunction compared to patients without this complication; this difference also did not reach statistical significance.

CONCLUSIONS

Total circulatory arrest, cerebral perfusion, and open distal anastomosis are reliable options in the surgical management of acute type A aortic dissections. With open distal anastomosis aortic arcus can be evaluated, distal anastomosis can be performed more easily, and postoperative neurological recovery is hastened. In the present study, although statistical significance could not be reached due to limited sample size, the time to admission, durations of total circulatory arrest, cross-clamp, and cardiopulmonary bypass, and the amount of postoperative chest output seem to influence postoperative survival.

Total aortic arch grafting via median sternotomy using integrated antegrade cerebral perfusion

BACKGROUND

In aortic arch grafting, antegrade cerebral perfusion prolongs the safe time of arch exclusion. However, there are the problems of cerebral embolism and distribution of the cerebral perfusion. We describe and analyze mortality and cerebral complications in patients undergoing total arch grafting using our refined technique.

METHODS

Between June 1994 and March 2002, 100 consecutive patients underwent total arch grafting through median sternotomy. There were 49 atherosclerotic aneurysms and 51 aortic dissections. Fifty-four patients were operated on an emergency basis because of rupture or acute type A dissection. We conducted total arch grafting using hypothermic antegrade cerebral perfusion from every cervical vessel. Carbon dioxide gas was added to the cerebral perfusion in order to inhibit the increase in the cerebral vascular resistance during hypothermic cerebral perfusion.

RESULTS

Hospital mortality was 4%. The causes of death were dysarrhythmia (n = 1), mesenteric necrosis (n = 1), and preoperative cardiac arrest (n = 2). On univariate analysis, preoperative shock and concomitant cardiac procedures were risk factors for hospital death. The rate of postoperative neurologic damage was 5%. Two patients suffered from cerebral infarction. Temporary neurologic dysfunction occurred in 3 patients. On univariate analysis, emergency surgery was a risk factor for postoperative neurologic damage. On multivariate analysis, there was no significant independent predictor of hospital mortality and neurologic damage. Actuarial survival at 96 months was 66.4 +/- 9.1%, and freedom from aortic accidents (reoperation, rupture, and cholesterol embolism) was 74.9 +/- 7.9%.

CONCLUSIONS

The early- and long-term results of total arch grafting using integrated antegrade cerebral perfusion were found to be satisfactory.

Aortic root replacement versus aortic valve replacement: a case-match study

BACKGROUND

There is increasing evidence that patients with aortic valve disease and dilatation of the ascending aorta are at risk for later dissection or rupture of the aortic wall when the dilated ascending aorta is not replaced or reinforced at the time of aortic valve replacement. In order to find out whether the more complex surgical procedure of aortic root replacement carries a higher early or late postoperative risk than isolated aortic valve replacement, we conducted a matched-pair study with patients of both groups.

METHODS

Between June 1993 and August 1998, 100 consecutive patients with aortic valve disease and ectasia/aneurysm of the ascending aorta underwent replacement of the aortic valve and the ascending aorta with a CarboSeal composite graft (CarboSeal; Sulzer Carbo-Medics Inc, Austin, TX). Identical bileaflet valve prostheses (CarboMedics; Sulzer CarboMedics Inc, Austin, TX) were implanted during the same time period in 928 patients for aortic valve disease. On the basis of various preoperative clinical variables 100 patients with aortic valve replacement were matched to the 100 patients with replacement of the aortic root. The duration of follow-up for both groups was similar with 37 + 17 months (range, 9 to 70) for the CarboSeal group and 38 + 14 months (range, 13 to 65) for the CarboMedics group. Survival and morbidity were calculated by Kaplan-Meier analysis and risk-adjusted mortality was evaluated by multivariate analysis in a Cox regression model.

RESULTS

The early postoperative mortality of 1% in the CarboSeal group and 4% in the CarboMedics group was insignificantly different. Although the overall survival rate at 5 years was lower (60.7% vs 86.3%; p = 0.13) in the CarboSeal group, the freedom from cardiac mortality and valve-related morbidity was similar in the two groups.

CONCLUSIONS

Replacement of the ascending aorta and aortic valve can be performed with similar operative risk, valve-related morbidity, and late cardiac mortality as isolated aortic valve replacement.

One-stage thoracic aortic aneurysm treatment and coronary artery bypass grafting

OBJECTIVE

The treatment of thoracic aortic aneurysm accompanied by ischemic heart disease presents a surgical challenge and has up to now shown a high hospital mortality rate. This report discusses the factors contributing to improved results in these cases.

METHODS

We conducted a retrospective analysis of the records of 24 consecutive patients who had undergone replacement of thoracic aorta with combined coronary artery bypass grafting (CABG) between May 1991 and October 1998. Fifteen patients received total arch replacement (Arch-with-CABG Group), and the other 9 patients received the Bentall operation (Bentall-with-CABG Group). These results were compared with those patients who had undergone replacement of the thoracic aorta without CABG (Without-CABG Group).

RESULTS

In the combined CABG groups, the overall operative mortality rate was 16.7%. In comparison with the Arch-without-CABG Group, there was a significantly longer cardiopulmonary bypass time and longer selective cerebral perfusion time in the Arch-with-CABG Group. However, no significant difference was observed in postoperative complications between the two groups. In addition, there was no significant difference in either actuarial survival or the cardiac-event-free rate at 5 years between the replacement of thoracic aorta with- and without-CABG Groups (83.1% vs. 90.4%, and 78.5% vs. 77.7%, respectively). No reoperation and no late death were observed during the follow-up period (mean 21.3 months).

CONCLUSIONS

We concluded that replacement of the thoracic aorta combined with CABG can be carried out safely, and that revascularization for coronary artery disease is useful for preventing any occurrence of cardiac event.

Concomitant replacement of the aortic root and aortic arch with or without secondary thoracoabdominal aorta replacement

OBJECTIVES

Extensive aortic replacement, such as concomitant aortic root and arch replacement, thoracoabdominal aortic repair, and complete thoracic aorta replacement, remains controversial. We studied surgical morbidity and mortality in patients undergoing concomitant aortic root and arch replacement, and those undergoing secondary replacement of the thoracoabdominal aorta after this preceding procedure.

SUBJECTS AND METHODS

Between January, 1987 and March 1999, 21 patients (mean age: 52 years) underwent concomitant aortic root and arch replacement involving 3 surgical procedures--aortic root replacement with composite graft and arch (n = 12), aortic root replacement with valve sparing and arch (n = 4), or aortic root replacement with composite graft and arch and elephant trunk (n = 5).

RESULTS

Overall hospital mortality was 4.8%. Six patients (mean age: 42 years) underwent secondary thoracoabdominal aorta replacement after the concomitant root and arch procedure. The mean time until secondary surgery was 9.5 months. There was 1 hospital death.

CONCLUSION

Concomitant replacement of the aortic root and arch, or secondary replacement of the thoracoabdominal aorta after concomitant root and arch replacement can be conducted with low surgical morbidity and mortality.

Replacement of the aortic valve and ascending aorta with a valved stentless composite graft: technical considerations and early clinical results

BACKGROUND

Replacement of the aortic valve and the ascending aorta with a conduit consisting of a mechanical valve and a Dacron tube has become a fairly common procedure. Commercially available conduits employing xenografts are rarely used for the same purpose, because if a reoperation becomes necessary due to degeneration of the valve prosthesis, usually the entire conduit must be replaced. A composite graft with a stentless valve, such as we describe in this article, avoids this problem, because in case of reoperation only the valve cusps need to be resected and the tube graft may be left in place.

METHODS

Surgical technique of replacement of the aortic valve and the ascending aorta with a stentless composite graft and early results of the procedure are presented.

RESULTS

Hemodynamics of the graft soon after surgery were excellent, with an average systolic gradient of 8 mm Hg and no regurgitation across the valve. There were two reoperations for bleeding in the early postoperative period.

CONCLUSIONS

The stentless composite graft we describe provides excellent hemodynamics, has no need for anticoagulation, and is expected to offer a benefit in case of reoperation.

Predictors of adverse outcome and transient neurological dysfunction after ascending aorta/hemiarch replacement

BACKGROUND

This study was undertaken to determine predictors of adverse outcome and transient neurological dysfunction after replacement of the ascending aorta with an open distal anastomosis.

METHODS

All 443 patients (300 male, median age 63) undergoing replacement of the ascending aorta with an open distal anastomosis between 1986 and 1998 were included in the analysis. The ascending aorta alone was replaced in 190 (42.9%); 253 (57.1%) also had proximal arch replacement. Median hypothermic circulatory arrest (HCA) time was 25 minutes (range 12 to 68). Either death or permanent neurological dysfunction were considered adverse outcome (AO).

RESULTS

Adverse outcome occurred in 11.5% (51 of 443) of patients overall: in 7.4% of elective (20 of 269) or urgent (4 of 54) operations, but in 17% (19 of 113) of emergencies. Multivariate analysis of the group as a whole revealed that significant (p < 0.05) independent preoperative predictors of AO were age greater than 60 [odds ratio (OR) 2.2], hemodynamic instability (OR 2.7), and dissection (OR 1.9). For the 435 operative survivors, procedural variables predictive of AO were contained rupture (OR 2.8) and HCA time (OR 1.03/min). When only the 271 elective patients were analyzed separately, the need for a concomitant procedure (p = 0.009, OR 3.6) and HCA time (p = 0.002, OR 1.06/min) were the only predictors of AO in multivariate analysis. Transient neurological dysfunction (TND) occurred in 86 of 392 patients (22%). Significant predictors of TND for all patients without AO were age (OR 1.06/y), HCA time (OR 1.04/min), coronary artery disease (OR 2.2), hemodynamic instability (OR 3.4), and acute operation (OR 2.2). Survival of discharged patients was 93% at 1 year and 83% at 5 years.

CONCLUSIONS

Early elective operation and shorter HCA time during ascending aorta/hemiarch surgery will reduce both AO and TND.