Selective Cerebral Perfusion Via Innominate Artery in Aortic Arch Replacement Without Deep Hypothermic Circulatory Arrest

Ideal intensive care unit course following comprehensive stage II in hypoplastic left heart syndrome

Comprehensive stage II is the advanced surgical part of the staged treatment of a newborn with hypoplastic left heart syndrome (HLHS) palliated initially by a Giessen-Hybrid approach. We report an almost ideal course following comprehensive stage II operation with focus on postoperative intensive care strategy. Following a short introduction of the postnatally performed Giessen-Hybrid approach, in which the surgical part is focused on bilateral pulmonary banding and duct stenting as well as manipulation of the atrial septum is postponed to transcatheter approach, it should be emphasized, that the quality of inter-stage I is eminently important for the success of the following comprehensive stage II. Furthermore, the interplay of the responsible surgeon, anesthesiologist, cardiologist and intensivist is mandatory for working as a team with a similar pathophysiological background. Presupposed a sophisticated surgical and anesthesiologic management, the immediate post-operative intensive care is crucial for the patient's final outcome, not only in terms of mortality but even morbidity (long-term neurological condition). Detailed treatment strategies are presented by pathophysiological reasonable hypotheses and the current pharmacological knowledge. Aiming to improve systemic and regional oxygen delivery and lowering oxygen consumption, as a sine qua none for a favorable patient's outcome.

Fifteen-year single center experience with the "Giessen Hybrid" approach for hypoplastic left heart and variants: current strategies and outcomes

Presented is a retrospective outcome study of a 15-year single institutional experience with a contemporary cohort of patients with hypoplastic left heart syndrome and complex that underwent a "Giessen Hybrid" stage I as initial palliation. Hybrid approach consisting of surgical bilateral pulmonary artery banding and percutaneous duct stenting with or without atrial septum manipulation was developed from a rescue approach to a first-line procedure. Comprehensive Aristotle score defined pre-operative condition. Fifteen-year follow-up mortality is reported as occurring within the staged univentricular palliation or before and after biventricular repair. Hybrid stage I was performed in 154 patients; 107 should be treated by single ventricle palliation, 33 by biventricular repair (BVR), 7 received heart transplantation, and 7 were treated by comfort care, respectively. Overall 34 children died. The Aristotle score (mean value 18.2 ± 3) classified for univentricular circulations in newborns did not have statistical impact on the outcome. Two patients died during stage I (1.2%), and the interstage I mortality was 6.7%, and stage II mortality 9%, respectively. Stage III was up to now performed in 57 patients without mortality. At 1 year, the overall unadjusted survival of HLHS and variants was 84% and following BVR 89%, respectively. The Fifteen-year survival rate for HLHS and variants was 77%, with no significant impact of birth weight of less than 2.5 kg. In conclusion, Hybrid stage I fulfilled the criteria of life-saving approach. In our institution, Hybrid procedure replaced Norwood-staged palliation with a considerable mid- and long-term survival rate. Considering interstage mortality close surveillance is mandatory.

Right axillary and femoral artery perfusion with mild hypothermia for aortic arch replacement

Objectives

Aortic arch replacement is associated with increased mortality and morbidity especially in acute type-A aortic dissection. Although hypothermic circulatory arrest with selective antegrade cerebral perfusion has been widely used because of its excellent cerebral protection, its optimal perfusion characteristics are unknown. The present study investigates clinical results obtained after perfusion method modification and temperature management during cardiopulmonary bypass (CPB).

Methods

Between July 2010 and August 2012, 16 consecutive adult patients (mean age 50.0 yr ± 14.1 yr, range 25 yr to 73 yr, 12 males, 4 females) who presented with acute Stanford type-A aortic dissection underwent aortic arch replacement (total arch, n = 11; hemiarch, n = 5) under mild hypothermia (31.1°C ± 1.5°C) with right axillary and femoral artery perfusion.

Results

The mean CPB time was 201 min ± 53 min, and the mean myocardial ischemic time was 140 min ± 42 min. The mean selective cerebral perfusion time was 80 min ± 16 min, and the mean lower-body circulatory arrest time was 20 min ± 13 min. No patient death occurred within 30 post-operative days. The following details were observed: new post-operative permanent neurologic deficit in 1 patient (6.3%), temporary neurologic deficit in 2 patients (12.5%), acute renal dysfunction (creatinine level > 230 umol/L) in 3 patients (18.8%) and mechanical ventilation > 72 h in 5 patients (31.2%).

Conclusions

Aortic arch replacement for acute type-A aortic dissection under mild hypothermia with right axillary and femoral artery perfusion could be safely performed in the patient cohort.

Central Nervous System Protection in Cardiac Surgery

Neurological dysfunction and stroke following cardiac surgery and thoracic surgery requiring hypothermic circulatory arrest is a well-defined problem. The original studies in CABG patients identified risk factors, such as prior stroke and lower educational level. There is older evidence suggesting that higher perfusion pressures during cardiopulmonary bypass are helpful. Hyperthermia during rewarming on cardiopulmonary bypass and postoperative hyperthermia have been associated with adverse cognitive outcomes. Glucose management intraoperatively remains controversial, but most now advocate for moderate glucose control using insulin, if required. The subset of patients having thoracic aortic surgery requiring periods of aortic discontinuity are particularly problematic. A cerebral protection strategy should be determined, and this may include hypothermic circulatory arrest, selective cerebral perfusion, or retrograde cerebral perfusion. All of these techniques have been associated with good surgical outcomes, but there is little information on cognitive outcomes of thoracic aortic surgery.

Incomplete Circle of Willis and Right Axillary Artery Perfusion

BACKGROUND

The aim of our anatomic study was to assess whether the commonly used method of perfusion through the right axillary artery is sufficient in providing uniform distribution of blood to both hemispheres of the brain in patients undergoing surgery of the aortic arch. We considered that critical arteries to examine are anterior and left posterior communicating arteries of the circle of Willis because the absence or insufficiency of either one would drastically endanger perfusion to the left hemisphere of the brain. The existence and the diameters of these arteries were studied.

METHODS

The material was collected as a part of normal forensic medicine autopsies. The anatomy of the cerebral arteries of 87 deceased individuals was assessed by angiography and permanent silicone casts. A new classification was created for this study. According to a recent observation in the literature we defined the minimum threshold of arterial diameter that allows cross flow to be 0.5 mm. We also repeated analyses using 1 mm as a threshold, which has also been recommended.

RESULTS

In our material 22% of the anterior communicating arteries and 46% of the left posterior communicating arteries were missing. In this anatomic population the perfusion to the left hemisphere might have been insufficient in 14% of the patients at a threshold of 0.5 mm and in 17% at a threshold of 1 mm.

CONCLUSIONS

When the right axillary artery is used for perfusion, the circulation to the contralateral hemisphere seems to be good for most patients undergoing operations of the aortic arch, but additional means of brain protection are still needed.

Methods of cerebral protection in surgery of the thoracic aorta

During the last decade, a considerable increase in the number of operations on the thoracic aorta has been observed. Although patient's outcomes have improved considerably, this surgery is still associated with significant morbidity and mortality due to neurological complications. Various methods have been proposed and widely used as means to protect the brain from ischemic damage. This review summarizes the principal methods of cerebral protection, describes the advantages and disadvantages of each method and their impact on patient outcomes, and discusses the different surgical techniques proposed to minimize the risk of cerebral injuries.

Aortic Arch Replacement Using a Trifurcated Graft: Simple, Versatile, and Safe

BACKGROUND

Hypothermic selective antegrade cerebral perfusion during aortic arch replacement may prevent adverse neurologic sequelae. It can be provided via balloon-tipped catheters or a branched graft sewn to the brachiocephalic vessels. We report a consecutive series of total arch replacement using a trifurcated graft.

METHODS

From September 1999 through October 2004, 109 patients underwent nonemergent total arch replacement using this technique. The graft, placed during a period of hypothermic circulatory arrest, was used for selective cerebral perfusion during the arch reconstruction.

RESULTS

Adverse outcomes were seen in 9 (8.3%) patients: hospital death in 5 (4.6%), and stroke in 5 (4.6%). Transient neurologic dysfunction was noted in 6 (5.5%) patients. Mean duration of hypothermic circulatory arrest was 31.2 +/- 6.6 minutes and selective cerebral perfusion was 65.3 +/- 20.9 minutes. Reoperation for bleeding was required in 3 (2.8%) patients and prolonged intubation in 15 (13.8%). Median intensive care unit stay was 3 days (interquartile range 2-4; range, 1 to 108) and hospital stay was 9 (interquartile range 8-15; range, 5 to 108).

CONCLUSIONS

The trifurcated graft technique results in low rates of perioperative mortality, temporary neurologic dysfunction, and stroke. It may reduce cerebral embolization as it requires no instrumentation of the aortic arch to establish selective cerebral perfusion and, although it mandates hypothermic circulatory arrest to place the graft, this interval is reliably brief enough to fall within accepted safe limits. This strategy leaves no residual arch tissue behind, and allows placement of an elephant trunk proximal to one or more arch vessels if anatomically indicated.