Treatment of acute aortic arch dissection

Spontaneous retrograde dissection of ascending aorta from descending thoracic aorta - a case review

A 56-year-old man with sudden onset chest pain, absent right lower limb pulses and ECG changes suggestive of inferior ST elevation MI underwent coronary angiogram through the right radial artery with a view to primary percutaneous coronary intervention (PCI). The left coronary angiogram demonstrated severe proximal stenotic disease in the left anterior descending and circumflex coronary arteries, but the right coronary artery could not be selectively cannulated. An ascending aortogram to visualise the right coronary artery not only failed to demonstrate it, but revealed, instead, a dissection flap in the ascending aorta, arch and descending thoracic aorta, with moderately severe aortic regurgitation. At operation, the patient was found to have an acute dissection of the ascending aorta, arch and descending aorta with an entry tear in the descending aorta below the left subclavian artery origin. Triple coronary artery bypass grafting with re-suspension of the aortic valve, supracoronary replacement of the ascending aorta and hemiarch and transaortic repair of the descending aortic tear was performed. The patient made an uncomplicated recovery, with the re-appearance of right limb pulses. A postoperative magnetic resonance (MR) scan revealed complete thrombosis of the false channel in the residual arch and a considerably shrunken false channel in the descending aorta and no aortic regurgitation.

Retrograde dissection of the ascending aorta from the descending aorta has been reported infrequently in the past. We believe the scale of the problem has been underestimated because of the failure to adopt open distal anastomosis routinely in the past and, hence, failure to inspect the arch and the descending aorta routinely, particularly when the intimal tear was not identified in the ascending aorta. Retrograde dissection of the ascending aorta from an intimal tear in the descending aorta, when identified as such, has been managed, either on the principle of exclusion of the tear in the descending aorta by various elephant trunk procedures and their variants or, alternatively, on the principle of excision of the tear by extended one-stage aortic replacement, usually combined with an elephant trunk procedure. Neither of these procedures is widely adopted, owing to procedural, institutional and outcome considerations. We describe a transaortic repair of the intimal tear in the descending aorta with supracoronary interposition graft replacement of the ascending aorta and hemiarch with excellent clinical and radiological result. We also review the diagnostic and therapeutic approaches to this incompletely understood lethal disease.

Congenital Heart Surgery Nomenclature and Database Project: aortic aneurysm, sinus of Valsalva aneurysm, and aortic dissection

The extant nomenclature for aortic aneurysms, sinus of valsalva aneurysms, and aortic dissections is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. Classification was based on morphology, histology, anatomic location, etiology, and acuity. A comprehensive database set is presented that is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented that will allow for data sharing that would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Extended aortic replacement in acute dissection by the separated elephant trunk technique

BACKGROUND

Extensive aortic replacement in acute dissection is currently not a widely accepted method of treatment.

METHODS

We developed a safe method for extended aortic repair including the aortic arch in type A acute dissection, and describe here its application in 5 cases. This method was based on a modification of the elephant trunk method and several other strategies. Most of the procedures were carried out under simple hypothermic circulatory arrest.

RESULTS

All patients recovered within 2 days without recurrent nerve injury. One patient suffered from unilateral upper arm palsy due to severe innominate dissection. Patients were all discharged and early postoperative computed tomography (CT) showed thrombotic obliteration around the elephant trunk. Follow-up CT after 4 to 18 months confirmed that thromboexclusion proceeded down to the distal end of the elephant graft in 1 patient and to the diaphragmatic level in 3 patients. Total obliteration was observed in the remaining 1 patient.

CONCLUSIONS

This technique enables extended aortic repair in acute dissection with no increase in morbidity, and effectively promotes thromboexclusion of the dissected lumen to a wider extent than conventional methods.

Extended aortic replacement for acute type A dissection with the tear in the descending aorta

OBJECTIVE

There has been controversy as to the selection of surgical treatments for acute type A dissection with the tear in the descending thoracic aorta, a subtype of acute aortic dissection in which the limited tear is located distal to the left subclavian artery but the dissection extends retrogradely to the ascending aorta.

METHODS

Total replacement of the ascending aorta and aortic arch was performed in 12 patients with acute type A dissection with the tear in the descending thoracic aorta between March 1991 and the end of September 1995. The indications for total replacement of the ascending aorta and aortic arch were cardiac tamponade, acute aortic regurgitation, cerebral ischemia, and dilatation of the ascending aorta. The operation was performed with the aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion, and open distal anastomosis. The surgical procedure used was total replacement of the ascending aorta and aortic arch with a graft provided with three limbs accompanied by resection of the intimal tear in the descending thoracic aorta.

RESULTS

Hospital death occurred in two patients (16.7%). In both, death was due to dissection/related complications of renal/mesenteric ischemia. The other 10 patients have had uneventful postoperative courses over a mean period of 24 months.

CONCLUSIONS

Total replacement of the ascending aorta and aortic arch accompanied by resection of an intimal tear distal to the left subclavian artery seems to be justified in selected patients with acute type A dissection with the tear in the descending thoracic aorta.

Significance of distal false lumen after type A dissection repair

Fifty-eight patients underwent repair of acute type A dissection between 1986 and 1992. Follow-up aortogram, computed tomographic scan with contrast, magnetic resonance imaging scan, or a combination of these tests was available in 38 patients with preoperatively patent distal false lumens. All distal anastomoses were constructed with the open technique during a period of circulatory arrest. There were 25 suture and 13 intraluminal graft anastomoses. Patency of the distal false lumen was found in 47.3%. Use of the intraluminal graft for the distal anastomosis decreased patency, although not significantly (4/13, 30% versus 14/25, 56%; p = 0.14). The direction of flow into the false lumen was antegrade in 11 of 24 (45.8%) of sutured anastomoses and 0 of 9 intraluminal graft anastomoses (p < 0.01). Actuarial survival at 5 years for patients with closed distal false lumen was 95% +/- 4.8% versus 76% +/- 15% for patients with patency of the distal false lumen (p = not significant). Event-free survival at 5 years for both groups was 84% +/- 8.3% (closed false lumen) and 63% +/- 13.5% (patency of distal false lumen; p = not significant). This experience indicates that in the treatment of acute type A dissections, operative strategy and anastomotic technique play a role in reducing the incidence of patency and related complications of the distal false lumen.