Extended Arch Resection in Acute Type A Aortic Dissection: PRO

Non-A non-B aortic dissection: A literature review

Non-A non-B aortic dissections are an infrequent occurrence and represent a small proportion of aortic dissections. Treating this life-threatening medical emergency often requires surgeons to undertake some one of the most challenging surgical or endovascular cases in medicine. This literature review aims to define and classify non-A non-B dissections, describe their epidemiology as well as their pathology. This review also aims to discuss the range of surgical techniques employed in their treatment and management and to investigate the patient outcomes associated with each technique.

Operative and Long-Term Outcomes After Curative Repair of Acute Dissection Involving the Proximal Aorta

BACKGROUND

The aim of the study was to evaluate operative and long-term results after acute type A aorta dissection (AAAD) operation, in which complete resection of all dissected aortic segments (curative repair) was achieved.

METHODS

Among 205 consecutive patients operated on between 2002 and 2014 because of AAAD were 88 patients (42.9%), in whom the dissection did not extend into the downstream aorta. The distal extension of the dissection ended before the origin of the innominate artery in 50 patients of the study cohort (56.8%) or extended throughout the arch, necessitating a total/subtotal arch replacement to achieve a curative distal repair in 38 remaining patients (43.2%). The aortic root was involved in 52 patients (59.1%) and was repaired using valve-sparing repair (31) or replacement with a valve composite graft (21). Combination of root and open arch surgery was reported in 46 patients (52.3%).

RESULTS

Thirty-day and in-hospital mortalities were 3.4% and 5.7%, respectively. Survival was estimated starting with the operation and was 81.9% ± 4.5% and 56.6% ± 8.7% at 5 and 10 years, respectively. No patient required reoperation on the aortic root and/or distal thoracoabdominal aorta; however 2 cardiac reoperations were unrelated to the primary surgical procedure. Moreover, the freedom of aortic and/or sudden/unknown death was 100%.

CONCLUSIONS

Curative aortic repair can be achieved in a relevant share of AAAD patients and is mostly limited by the distal extension of dissection. This kind of repair is advisable, whenever possible, because it can provide very low risk of aortic complications and/or reoperations over time.

Non-anatomical implantation of supra-aortic branches for customizing the standard form of Thoraflex™ hybrid prosthesis to a patient's anatomical requirements

Frozen elephant trunk technique represents a valuable therapeutic option for patients with extensive pathology of thoracic aorta. Thoraflex™ hybrid prosthesis (Vascutek, Terumo, Inchinnan, UK) is one of the commercially available devices in which a stent graft is combined with branched vascular tube mimicking the aortic arch anatomy. Owing to the sewing collar between the stented and unstented portions, this hybrid prosthesis offers a valuable addition to the surgical armamentarium for patients with huge thoracic aorta aneurysms, in whom the aortic diameter exceeds the diameter of available stent grafts. However, the standard factory form of the quadrifurcated arch prosthesis does not always fit to the patient's anatomy and demands a deviation from the anatomical anastomosing of the branches with the respective supra-aortic arteries. A technique of non-anatomical implantation of supra-aortic arteries for customizing the standard form of the Thoraflex prosthesis is described, which facilitates the surgery without limiting the functionality of this hybrid prosthesis.

Selective antegrade cerebral perfusion and mild (28°C-30°C) systemic hypothermic circulatory arrest for aortic arch replacement: results from 1002 patients

OBJECTIVES

The use of selective antegrade cerebral perfusion (ACP) makes deep hypothermia nonessential for aortic arch replacement. Consequently, a growing tendency to increase the body temperature during circulatory arrest with ACP has recently been reported from various institutions. However, very little is known about the clinical effect of different modes of ACP (unilateral vs bilateral) on neurologic morbidity. Also, the safe limits of this approach for spinal chord and visceral organ protection are yet to be defined.

METHODS

Between January 2000 and January 2011, 1002 consecutive patients underwent aortic arch repair during ACP (unilateral, 673; bilateral, 329) with mild systemic hypothermia (30°C ± 2°C; range, 26°-34°C) at 2 centers in Germany. The mean patient age was 62 ± 14 years, 663 patients (66%) were men, and 347 patients (35%) had acute type A dissection. Hemiarch replacement was performed in 684 patients (68%), and 318 (32%) underwent total arch replacement.

RESULTS

The cardiopulmonary bypass time accounted for 158 ± 56 minutes and the myocardial ischemic time, 101 ± 41 minutes. Isolated ACP was performed for 36 ± 19 minutes (range, 9-135). We observed new postoperative permanent neurologic deficits in 28 patients (3%; stroke in 25 and paraplegia in 3) and transient neurologic deficits in 42 patients (4%). All 3 cases of paraplegia occurred in patients with acute type A dissection and a broad range of ACP times (24, 41, and 127 minutes). A trend was seen toward a reduced permanent neurologic deficit rate after unilateral ACP (P = .06), but no difference was seen in the occurrence of transient neurologic deficits (P = .6). Overall, the early mortality rate was 5% (n = 52). Temporary dialysis was necessary primarily after surgery in 38 patients (4%). When corrected for the unequal distribution of type A dissection, neurologic morbidity, early mortality, and the need for temporary dialysis were independent of the duration of ACP and were not affected by unilateral versus bilateral ACP.

CONCLUSIONS

Current data suggest that ACP and mild systemic hypothermic circulatory arrest can be safely applied to complex aortic arch surgery even in a subgroup of patients with up to 90 minutes of ACP. Unilateral ACP offers at least equal brain and visceral organ protection as bilateral ACP and might be advantageous in that it reduces the incidence of embolism arising from surgical manipulation on the arch vessels.

Mild-to-moderate hypothermia in aortic arch surgery using circulatory arrest: a change of paradigm?

OBJECTIVES

Antegrade cerebral perfusion makes deep hypothermia non-essential for neuroprotection; therefore, there is a growing tendency to increase the body temperature during circulatory arrest with selective brain perfusion. However, very little is known about the clinical efficacy of mild-to-moderate hypothermia for ischemic organ protection during circulatory arrest. The aim of this study was to evaluate the safety and efficiency of mild-to-moderate hypothermia for lower-body protection during aortic arch surgery with circulatory arrest and antegrade cerebral perfusion.

METHODS

Between January 2005 and December 2009, a total of 347 patients underwent non-emergent arch surgery. In all patients, the systematic cooling was adapted to the expected time of circulatory arrest, and cerebral perfusion was performed at a constant blood temperature of 28 °C. There were 40 cardiac or aortic re-operations, 312 patients had concomitant aortic valve or root surgery, and 10 patients had replacement of the descending aorta. All examined data were collected prospectively.

RESULTS

The duration of circulatory arrest and the deepest rectal temperature were 18±11 min (range, 6-70 min) and 31.5±1.6 °C (range, 26.0-35.0 °C) for all 347 patients, and 34±12 min (range, 17-70 min) and 29.9±1.7 °C (range, 26.0-34.6 °C) for 77 patients having total/subtotal arch replacement. The maximum serum lactate level on the first postoperative day was, on average, 2.3±1.2 mmol l(-1). In the statistical analysis, no association between the duration of temperature-adapted circulatory arrest and lactate, creatinine, or lactate dehydrogenase levels after surgery could be demonstrated. The 30-day mortality was 0.9%. Permanent neurological deficit or temporary dysfunction occurred in three (0.9%) and eight (2.3%) patients, respectively. No paraplegia and no hepatic failure were reported; however, mesenteric ischemia occurred in one patient with severe stenosis of the celiac and upper mesenteric arteries. Temporary dialysis was necessary primarily after surgery in five patients. All of them underwent hemiarch replacement only, and four patients had an increased creatinine level before surgery.

CONCLUSION

Systemic mild-to-moderate hypothermia that is adapted to the duration of circulatory arrest is a simple, safe, and effective method of organ protection and can be recommended in routine aortic arch surgery with circulatory arrest and cerebral perfusion.