Body Circulatory Arrest Research Articles

Visceral oxidative stress during antegrade cerebral perfusion and lower body circulatory arrest

Background: Antegrade cerebral perfusion (ACP) is the standard neuroprotection method in aortic surgery. Visceral ischemia during this modality brings out some controversies. We aimed to investigate the level of oxidative stress at the lower part of body during ACP.Methods: Thirty consecutive patients underwent elective ascending aorta and hemiarch repair with ACP (without distal perfusion) were enrolled to study. The patients were enrolled into two groups which were based on 50th percentile of ACP duration (15 patients in each group). Blood samples from inferior vena cava at the end of ACP were collected to assess oxidative stress with biochemical parameters such as lactate, advanced oxidative protein products (AOPP) and thiol levels. Clinical follow-up parameters regarding to visceral and spinal cord ischemia were recorded. There were no clinical complications at both groups.Results: Mean ACP duration for the study group was found to be 15 min (10–28 min). Lactate, AOPP, and thiol levels were found to be similar between two groups. Furthermore, correlation analysis revealed only low level of correlation between ACP duration and lactate levels. Renal and liver function tests were found to be similar between groups.Conclusions: Immediate parameters (such as lactate, AOPP, and thiol) that show alterations in response to oxidative stress were not affected by the duration of ACP. Therefore, ACP without distal perfusion may not be harmful when conducted for short duration.

Three-step method for transesophageal echocardiography-guided implantation of the frozen elephant trunk: how to prevent spinal cord injury.

Total aortic arch replacement using the frozen elephant trunk (FET) procedure has widely spread all over the world with more sophisticated devices. However, spinal cord injury is one of the most important complications, which limits the use of FET. In our hospital, 80 patients treated with FET had no spinal cord injury. There are three key points to avoid spinal cord injury, (1) The distal end of stent graft should be positioned up to the eighth thoracic vertebrae level; (2) the time for selective left subclavian artery perfusion and distal body circulatory arrest should be shortened within 60min; and (3) mean blood pressure should be maintained above 70mmHg. Especially, Key point (1) is the most important. The level of aortic valve, which locates around the seventh thoracic vertebrae level, is an appropriate benchmark. We implanted the stent graft with the use of transesophageal echocardiography guided three-step method.

Abdominal organ protection strategy for aortic arch aneurysm surgery.

Body temperature maintained during open distal anastomosis in patients who undergo aortic surgery has been showing an upward trend; however, a higher temperature may increase visceral organ and spinal cord injury. Distal perfusion may reduce abdominal organ injury, especially acute kidney injury (AKI). From 2009 to 2016, 56 patients who underwent ascending aortic and/or aortic arch surgery were enrolled. Open distal anastomosis was performed using one of three protection strategies: 1) systemic temperature of 25°C followed by selective cerebral perfusion (SCP) with lower body circulatory arrest (Group CA25, n=27); 2) systemic temperature of 28°C followed by SCP with lower body circulatory arrest (Group CA28, n=4); and 3) systemic temperature of 28°C followed by SCP with distal aortic perfusion (Group DP, n=25). During the postoperative course, levels of blood urea nitrogen, creatinine, liver enzymes, lactate dehydrogenase and lactate in Groups CA28 and CA25 were significantly higher than those in Group DP. AKI defined by the AKI Network occurred in 28 cases (50%) and 3 cases required permanent hemodialysis. AKI was significantly higher in Groups CA25 and CA28 than in Group DP (p=0.026). Mid-term follow-up showed that patients who developed postoperative AKI were more likely to suffer from cardiovascular events. Distal perfusion during open distal anastomosis reduced kidney and liver injury after thoracic aortic surgery despite an increased body temperature of up to 28°C. This strategy may be useful to prevent AKI, liver dysfunction, the need for hemodialysis and multiple organ failure and could improve mid-term results.

Moderate Hypothermic Circulatory Arrest (≥ 28°C) with Selective Antegrade Cerebral Perfusion for Total Arch Replacement with Frozen Elephant Trunk Technique.

The optimal hypothermic level during circulatory arrest in aortic arch surgery remains controversial, particularly in frozen elephant trunk (FET) procedures. We describe herein our experience for total arch replacement with FET technique under moderate systemic hypothermic circulatory arrest (≥ 28°C) during selective antegrade cerebral perfusion. Between January 2009 and January 2016, 38 consecutive patients underwent elective total arch replacement for various aortic arch pathologies with FET technique using the E-vita Open hybrid prosthesis (Jotec GmbH, Hechingen, Germany). Selective unilateral or bilateral cerebral perfusion under moderate systemic hypothermic circulatory arrest (28.7°C ± 0.5°C) was used in all patients. Minimally invasive total arch replacement with FET via partial upper sternotomy was performed in 15 patients (39%) and in the remaining 23 patients (61%) via full sternotomy. Mean late follow-up was 3 ± 2 years and was 98% complete. Clinical data were prospectively entered into our institutional database. Cardiopulmonary bypass time accounted for 198 ± 58 minutes and the myocardial ischemic time 109 ± 29 minutes. Selective antegrade cerebral perfusion time was 55 ± 6 minutes. Lower body circulatory arrest time was 39 ± 11 minutes. Unilateral cerebral perfusion was performed in 31 patients (82%), and bilateral in 7 patients (18%). Intensive care unit stay was 4 ± 3 days. Thirty-day mortality was 5% (n = 2). Late survival at 3 years was 87 ± 3%. Two patients (5%) required reexploration for bleeding. Patients were discharged after a hospital length of stay of 7 ± 2 days. Postoperative permanent neurologic complication occurred in two patients (5%). Three patients (8%) experienced a transient neurologic disorder. New transient renal replacement therapy was necessary in three patients (8%). No spinal cord injury was noted. Our data suggest that moderate systemic hypothermic circulatory arrest (≥ 28°C) in combination with antegrade cerebral perfusion can safely be applied for total aortic arch replacement with FET and offers sufficient neurologic and visceral organ protection.

Selective Heart, Brain and Body Perfusion in Open Aortic Arch Replacement

Open aortic arch replacement is a complex and challenging procedure, especially in post dissection aneurysms and in redo procedures after previous surgery of the ascending aorta or aortic root. We report our experience with the simultaneous selective perfusion of heart, brain, and remaining body to ensure optimal perfusion and to minimize perfusion-related risks during these procedures. We used a specially configured heart–lung machine with a centrifugal pump as arterial pump and an additional roller pump for the selective cerebral perfusion. Initial arterial cannulation is achieved via femoral artery or right axillary artery. After lower body circulatory arrest and selective antegrade cerebral perfusion for the distal arch anastomosis, we started selective lower body perfusion simultaneously to the selective antegrade cerebral perfusion and heart perfusion. Eighteen patients were successfully treated with this perfusion strategy from October 2012 to November 2015. No complications related to the heart–lung machine and the cannulation occurred during the procedures. Mean cardiopulmonary bypass time was 239 ± 33 minutes, the simultaneous selective perfusion of brain, heart, and remaining body lasted 55 ± 23 minutes. One patient suffered temporary neurological deficit that resolved completely during intensive care unit stay. No patient experienced a permanent neurological deficit or end-organ dysfunction. These high-risk procedures require a concept with a special setup of the heart–lung machine. Our perfusion strategy for aortic arch replacement ensures a selective perfusion of heart, brain, and lower body during this complex procedure and we observed excellent outcomes in this small series. This perfusion strategy is also applicable for redo procedures.

Aortic arch surgery using selective antegrade cerebral perfusion and mild hypothermia

BackgroundMany studies have shown the benefits of deep hypothermia on cerebral protection during arch surgery; however this has a deleterious effect on endothelial function, coagulation & renal functions. Our aim from this study was to show that we could achieve cerebral protection by using selective antegrade cerebral perfusion (SACP) and mild hypothermia, hence avoiding the side effects of deep hypothermia. MethodsIn this retrospective analytical study, the computerised database was interrogated retrospectively to identify all patients who underwent full arch or hemi-arch replacement with the utilisation of open distal anastomosis technique. The cases retrieved were operated on between August 2003 and September 2013, in the Lancashire cardiac center, Blackpool Victoria Hospital. The main indication of surgery was based on size criteria. A total of 73 patients were identified for inclusion in the study. All patients had SACP along with a period of lower body circulatory arrest at mild systemic hypothermia. 22 patients including 9 (40.9%) men underwent full arch replacement (Group A) and 51 had hemi-arch replacement which included 43 (66.7%) men (Group B). ResultsThe arch group (Group A) had no neurological complications. In the hemi-arch group (Group B), 2 patients (3.9%) had cerebrovascular events but there were no cases of paraplegia. Temporary hemofiltration was required in 1 patient (4.5%) in Group I and 2 patients (3.9%) in Group II. Further, 2 patients (9.1%) in the arch group and 3(6%) in the hemi-arch group had renal dysfunction not needing dialysis. Mean ICU stay was 2 days (±6.5 days) in the arch group and 1 day (±13.9 days) in the hemi-arch group. Overall there were 4 in-hospital deaths including 2 (9.1%) in the arch group and 2 (3.9%) in the hemi-arch group. There was no significant statistical difference between the two groups. ConclusionThe study showed outcomes comparable to other previous larger studies and adds to the available evidence in favour of this approach.

Surgical outcomes for acute type A aortic dissection with aggressive primary entry resection.

An entry located at aortic arch in acute type A aortic dissection (AAAD) is uncommon. It remains controversial whether or not aggressive primary entry resection should be routinely performed in such patients. We have adopted an aggressive strategy of entry site resection, including total arch replacement (TAR) in patients with arch tears. The purpose of this study was to investigate the efficacy of our surgical management approach, using aggressive primary entry resection. Between January 2000 and December 2014, we retrospectively reviewed the records of 334 patients with AAAD who underwent emergent surgery. The mean age was 67 ± 13 years (range, 20-95 years). Ninety-five patients (28%) presented with shock vital status, and 84 patients (25%) manifested malperfusion of branched arteries. Primary entry resection was achieved in 95% of patients under an aggressive surgical strategy [hemiarch replacement for 173 (52%) patients and TAR for 161 (48%) patients] concomitant with 22 coronary artery bypass grafts and 38 root replacements. Ninety-six percent of hospital survivors (298/311) were followed for a median of 39 months (range, 0-179 months). Operation, cardiopulmonary bypass, cardiac arrest, antegrade cerebral perfusion and lower body circulatory arrest times were 447 ± 170, 236 ± 93, 112 ± 74, 115 ± 81 and 54 ± 18 min, respectively. The 30-day mortality rate was 5.4%. The in-hospital mortality rate was 8.4% (6.9% at our hospital). Incidences of postoperative permanent neurological dysfunction, tracheotomy and newly permanent haemodialysis were 6.9, 8 and 2%, respectively, with no spinal cord injuries observed. Complete false lumen thrombosis was achieved in 57% of patients as visualized by postoperative computed tomography angiography. After 3, 5 and 10 years, overall survival rates were 81, 74 and 65%, respectively, and the percentages of patients free from downstream dissection-related reoperation were 89, 86 and 80%, respectively. Multivariable analysis demonstrated that the risk factors for downstream aortic reoperation were patent false lumen, residual primary entry tear and connective tissue disorder. The surgical outcomes following aggressive treatment of AAAD are satisfactory. False lumen thrombosis can be achieved in a relatively high proportion of patients using this technique, resulting in a low rate of subsequent downstream aortic reoperations.

Adventitial inversion technique for type A aortic dissection distal anastomosis

ObjectiveAnastomosis in dissected aorta management remains challenging. The patent false lumen of remnant aorta influences the growth of the residual aorta after hemiarch replacement. We evaluated the beneficial effect of adventitial inversion technique for distal anastomotic reinforcement of hemiarch replacement in acute type A aortic dissection. MethodsFrom 2006 to 2014, 90 patients with DeBakey type I aortic dissection who underwent hemiarch replacement for acute type A aortic dissection management at the National Cerebral and Cardiovascular Center were retrospectively analyzed. Patients were divided according to the technique used: the adventitial inversion technique in group A and the original Sandwich method with Teflon felt in group S. Surgical variables and aortic morphology from distal aortic anastomosis were evaluated by computed tomography after surgery. ResultsThe mean follow-up time was 2.2 ± 2.1 years with a follow-up rate of 91.1%. Cardiopulmonary bypass time was 208.2 ± 93.9 minutes in group A and 220.6 ± 93.9 minutes in group S; lower body circulatory arrest time was 51.6 ± 10.2 minutes in group A and 54.5 ± 17.8 minutes in group S. No significant differences were observed between groups. The overall hospital mortality rate was 10.0%. Postoperative false lumen thrombosis rate at proximal descending aorta on enhanced delayed phase computed tomography was significantly higher in group A than in group S. ConclusionsThe adventitial inversion technique may facilitate thrombotic closure of the distal false lumen in acute type A aortic dissection management by hemiarch replacement.

Risk factors for acute kidney injury in aortic arch surgery with selective cerebral perfusion and mild hypothermic lower body circulatory arrest.

Previous studies have reported a high incidence of acute kidney injury (AKI) after thoracic aortic surgery. However, the incidence of AKI in patients undergoing total arch replacement (TAR) with selective cerebral perfusion (SCP) and mild hypothermic lower body circulatory arrest (mild HLBCA) with a tympanic temperature of 25°C remains unknown. We studied AKI incidence and associated risk factors, as defined by the Acute Kidney Injury Network (AKIN). We examined 116 consecutive patients with aortic arch aneurysm undergoing non-emergency TAR. Our surgical method is standardized to use systemic cooling of the tympanic membrane temperature to 25°C for circulatory arrest, followed by SCP and myocardial protection by cold blood cardioplegia. Anastomoses were sequentially constructed at the distal arch, the proximal root, the left sub-clavian artery, the left carotid artery and the right brachiocephalic artery. Bladder temperature was generally around 30°C at the start of lower body circulatory arrest (mild HLBCA) until reperfusion of the distal aorta. The incidence of AKI was investigated, with multivariate analysis of its risk factors. The mean operation time, cardiopulmonary bypass (CPB) time, mild HLBCA time and SCP time were 270.6 ± 72.5, 151.0 ± 46.4, 53.1 ± 20.1 and 99.0 ± 28.4 min, respectively. Hospital mortality occurred in 2 cases (1.7%). AKI occurred in 50 cases (43.1%); of which, 2 cases required renal replacement therapy (RRT). However, AKI had subsided in 44 cases by discharge. For contemporary perspective, the incidence of AKI was 32.8% in off-pump coronary bypass grafting and 38.9% in aortic valve replacement. Multivariate analysis of risk factors for AKI identified chronic kidney disease (CKD) (eGFR <60 ml/min/1.73 m(2)) and mild HLBCA time >60 min. Our method of TAR was associated with low mortality and low rate of kidney injury by discharge. However, prolonged mild HLBCA and preoperative CKD might need additional consideration.

In situ total aortic arch replacement for infected distal aortic arch aneurysms with penetrating atherosclerotic ulcer

We present a series of patients who underwent in situ total aortic arch replacement for infected distal aortic arch aneurysms. Between 2002 and 2013, 9 patients with infected distal aortic arch aneurysms underwent total aortic arch replacement using antegrade selective cerebral perfusion. There were 4 male and 5 female patients with a mean age of 72.7±9.0 years. All patients had penetrating atherosclerotic ulcer in the distal aortic arch, which formed saccular aneurysms. Four patients had preoperative hoarseness. Maximum preoperative white blood cell count was 10,211±4375/μL, and mean serum C-reactive protein concentration was 12.7±7.2 mg/dL. Causative microorganisms were identified by blood culture or aortic wall culture and were as follows: Candida albicans, Pseudomonas aeruginosa, Edwardsiella tarda, Streptococcus dysgalactiae, Listeria monocytogenes, Staphylococcus aureus (2 cases), and unknown (2 cases). Radical debridement with in situ total aortic arch replacement was performed in all patients, followed by the omental flap grafting in 7 patients. All surgery was performed on an urgent or emergency basis. Average cardiopulmonary bypass time and lower body circulatory arrest time were 199.7±50.7 minutes and 66.6±13.8 minutes, respectively. There was no in-hospital mortality, but 1 patient died of asphyxia 5 months after hospital discharge. Freedom from recurrence of infection was 100%. Surgical treatment with the combination of radical debridement with in situ total aortic arch replacement using antegrade selective cerebral perfusion and omental flap grafting was a reliable procedure for the treatment of infected distal aortic arch aneurysms.

Frozen elephant trunk surgery using the E-vita open plus prosthesis.

Clinical vignette The frozen elephant trunk (FET) procedure is a hybrid therapy available for the treatment of patients with extensive diseases of the thoracic aorta. This approach combines surgical graft replacement of the aortic arch with stent-grafting of the descending thoracic aorta using a covered stent. Different prostheses have been developed for carrying out this surgery, including the commercially available E-vita open plus prosthesis (Jotec Inc., Hechingen, Germany). This hybrid prosthesis is composed of a distal nitinol-covered stent-graft sutured to a proximal woven polyester tube graft (Figure 1). During lower body circulatory arrest and antegrade selective cerebral perfusion (ASCP), the E-vita open plus prosthesis is antegradely deployed into the descending thoracic aorta through the open aorta, while the proximal graft segment is sutured to the distal aortic stump and used to replace the aortic arch. As shown in the video entitled “FET surgery using the E-vita open plus prosthesis”, this manuscript describes our surgical FET approach with ASCP in detail. The video illustrates the surgical treatment of a 75-year-old man who had previously undergone a Bentall procedure and myocardial revascularization for a DeBakey type 1 acute aortic dissection. The patient was admitted to our hospital 4 years later, at which time computer tomography (CT) angiogram showed a pseudo aneurysm at the distal anastomosis measuring 63 mm, and a residual DeBakey type 1 chronic dissection with severe false lumen dilatation at the proximal descending thoracic aorta (61 mm) (Figure 2).

Reply to Luehr and Etz

We appreciate the comments from Luehr and Etz [1] on our recent article reporting on selective cerebral perfusion (SCP) under mild hypothermic lower body circulatory arrest (CA) [2]. The purpose of our study was to provide clinical information from this creative surgical procedure based on our own experiences and valuable past studies. As Luehr and Etz commented, the greatest concern raised over mild hypothermic lower body CA relates to spinal cord damage. The safe time limit for CA under mild hypothermia for protection of the spinal cord is unknown. However, a number of clinical studies and graduated exploration by surgeons have gradually delineated a safety margin [2–6]. In research into spinal cord ischaemic damage, it is impossible to perform an experimental study. The only option therefore is to accumulate valuable and precious information from pioneer surgeons and clinical data. In the early stage of 2001–2004, we used deeper cooling to a bladder temperature of <20°C. We did not make a sudden change to the current temperature strategy. We sought to improve our skills in the relevant surgical techniques and used valuable past studies, as an investigate resource, and gradually raised the minimum temperature at the time of CA. As our clinical presentation was based on these efforts and valuable past studies, we hope that readers will give serious attention to the data and seek to learn from them. As Luehr and Etz pointed out, the estimated safe ischaemic interval for the spinal cord (50 min at 32°C, 75 min at 28°C) is accepted among surgeons worldwide. We recognize that the safety limit is based on the status of CA without SCP. We inserted SCP cannulae into all three arch vessels and perfused using three separate pumps, and achieved blood backflow from the intercostal arteries inside the descending aorta. Although the origin of this blood backflow is unknown and the vascular network in the vertebral artery, mammary artery, intercostal artery and spinal artery was not clarified, we think that the backflow may contribute to the protection of the spinal cord. We, therefore, think that if threefold SCP is performed, the safe ischaemic interval may be longer than that mentioned previously (50 min at 32°C, 75 min at 28°C). As a final comment, the only thing that the surgeon can do in this challenging research area is to strive for small improvements by following the valuable efforts of pioneer researchers.

Moderate-to-mild hypothermia may not be sufficient to protect the spinal cord during aortic arch surgery

We read with great interest the article by Suzuki et al. [1] regarding antegrade selective cerebral perfusion (SCP) with lower body circulatory arrest (LBCA) at moderate body core temperatures of 30–32°C. We agree with the authors that antegrade SCP, utilizing deep hypothermic circulatory arrest (21–27°C) to safeguard the protection of the visceral end-organs and the spinal cord, has become the most efficient neuroprotective strategy during transverse aortic arch repair over the past decades. However, as described by the authors, antegrade SCP is being increasingly utilized in combination with progressively increasing body core temperatures [1], a trend culminating in the advocation of moderate-to-mild temperatures (up to 35°C) and even normothermia [2]. Suzuki et al. report on their technique of total aortic arch repair in a contemporary series of 105 patients using a quadrifurcated Dacron graft. The authors proclaim that they routinely aim for deeper body core temperatures (25°C) to ensure lower body-organ protection when LBCA is expected to exceed a duration of 30 min. However, the authors also state that in ‘almost all cases... the core temperature was still 30–32°C’ with a mean LBCA time of 58 ± 22 min in the reported series [1]. This progressive approach may bear potential risks for the non-perfused organs in case of prolonged operation times—apparently not only in case of unexpected technical problems (as documented by an average of 58 min of LBCA) [3, 4]. The authors also admit that they are not familiar with the safe limits of spinal cord ischaemic tolerance during distal circulatory arrest at mild hypothermia. In fact, the ischaemic tolerance of the spinal cord and the visceral organs has not yet been clearly defined, and is therefore not well recognized in clinical practice. A consensus paper of the EACTS Vascular Domain is currently underway to address this issue. However, with regard to recent experimental data, the safe ischaemic interval for the spinal cord—utilizing the currently available state—of—the—art adjuncts for intraoperative neuroprotection—may be estimated as follows [2, 5]:

Selective cerebral perfusion with mild hypothermic lower body circulatory arrest is safe for aortic arch surgery

The antegrade selective cerebral perfusion (SCP) technique, which extends the safe time limit for arch surgery, has now gained acceptance. However, neither the optimal hypothermic temperature nor the optimal SCP flow rate has been clearly determined. From January 2008 to February 2012, a total of 105 patients underwent total arch replacement under a single surgeon (A.T.) at Shiga Medical University Hospital. The patients were 85 males and 20 females with a mean age of 73 years (range 41-88). The cause of the aneurysm was atherosclerosis in 90 patients and dissection in 15. Eighty-one patients with chronic lesion underwent elective surgery and 24 underwent emergent surgery. Univariate analysis of postoperative neurological dysfunction and early mortality was performed. The mean operation time, cardiopulmonary bypass (CPB) time, coronary ischaemic time, lower body circulatory arrest (CA) time and SCP time were 277 ± 83 min, 164 ± 40 min, 92 ± 33 min, 58 ± 22 min and 95 ± 28 min, respectively. Thirty-day mortality occurred in 1 ruptured emergent case (1%). Hospital mortality (>30 days) occurred in 3 cases (3%), 2 due to multisystem organ failure following emergent rupture and the other to cerebrovascular accident in an elective surgery case. Permanent neurological dysfunction (PND) occurred in 3 patients (3%) and temporary neurological dysfunction (TND) also in 3 patients (3%). SCP under mild hypothermia can be safely applied to aortic arch surgery and is associated with a low rate of hospital mortality and morbidity. However, prolonged SCP time is associated with incidences of postoperative neurological deficit.

Clinical and biochemical outcomes for additive mesenteric and lower body perfusion during hypothermic circulatory arrest for complex total aortic arch replacement surgery

Surgical repair of transverse aortic arch aneurysms frequently employ hypothermia and antegrade cerebral perfusion as protective strategies during circulatory arrest. However, prolonged mesenteric and lower limb ischemia can lead to significant lactic acidosis and end organ dysfunction, which remains a significant cause of post-operative morbidity and mortality. We report our experience with additive warm mesenteric and lower body perfusion (1-3 L/min, 30°C) in addition to continuous cerebral and myocardial perfusion in 5 patients who underwent total aortic arch replacement with trifurcated head vessel re-implantation and distal elephant trunk reconstruction. Concomitant surgical procedures included re-operations (2), aortic root operations (2), coronary artery bypass (2) and descending thoracic aortic replacement (1). Serum lactate levels demonstrated a rapid decline from a peak 9.9 ± 2.6 post circulatory arrest to 3.4 ± 2.0 in the intensive care unit (ICU). The lowest serum bicarbonate levels were 19.3 ± 3.5 mmol/L, intra-operatively, which normalized to 28.4 ± 2.4 mmol/L on return to the ICU. The lowest pH levels were 7.25 ± 0.10, corrected to 7.43 ± 0.04 on return to the ICU. Mean cardiopulmonary bypass and aortic cross-clamp times were 361 ± 104 and 253 ± 85 minutes, respectively. Mean cerebral and lower body circulatory arrest times were 0 (0) and 50 ± 35 minutes, respectively. The mean time required for systemic rewarming was 95 ± 66 minutes. There were no in-hospital mortalities and no patient experienced any neurological, mesenteric, renal or lower limb ischemic complications. Two patients required mechanical ventilation >24 hours, and one patient returned for reoperation for bleeding. Median intensive care unit and total hospital lengths of stay were 5 and 16 days, respectively. Our results suggest early serum lactate clearance, normalization of acidosis, and metabolic recovery when utilizing a simultaneous cerebral perfusion and warm body protection strategy for complex aortic arch surgery. This additive perfusion strategy may attenuate visceral and lower body ischemia that normally develops during periods of deep hypothermic circulatory arrest.

Advantages of the L-incision approach comprising a combination of left anterior thoracotomy and upper half-median sternotomy for aortic arch aneurysms

Although surgical outcomes of total arch replacement have improved, the strategy for extended arch aneurysms remains controversial. We have applied the L-incision approach (combination of left anterior thoracotomy and upper half-median sternotomy) for total arch replacement for single-stage repair of extensive arch aneurysms. We retrospectively reviewed the operative outcomes of patients who underwent total arch or extended total arch replacement for degenerative aneurysms from 1999 to 2010. Operations were performed via median sternotomy in 47 patients (M group) and the L-incision approach was used in 38 patients (L group). Through the L-incision approach, we were able to complete distal anastomosis below the pulmonary hilus. The L-incision approach has advantages of reducing selective antegrade cerebral perfusion and lower body circulatory arrest times compared with the M group. Recurrent laryngeal nerve palsy and renal dysfunction were less frequent in the L group than those in the M group. Respiratory dysfunction and wound infection were similar between the groups. Hospital mortalities were 5.3% in the L group and 6.4% in the M group. The L-incision approach has similar or better postoperative outcomes compared with the median sternotomy approach. This approach could be useful for single-stage extended total arch replacement with relatively low risk.

Effect of retrograde perfusion with autologous blood through inferior vena cava on MDA and SOD in serum, liver and kidney during moderate hypothermic lower body circulatory arrest in pigs

Objective To study the effect of retrograde perfusion through the inferior vena cava(IVC) during moderate hypothermic lower body circulatory arrest on malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in the serum,liver and kidney of pigs.Methods Twenty healthy pigs were randomly divided into two groups: group A had moderate hypothermic lower body circulatory arrest for 90 min,group B had moderate hypothermic lower body circulatory arrest and retrograde perfusion through IVC at the same time.SOD activities and MDA contents in the serum,liver and kidney were analyzed before retrograde perfusion(T1),1 h after circulatory arrest(T2),and 1 h(T3),3 h(T4),and 5 h(T5) after reperfusion.Results There were no significant differences in SOD activities and MDA contents in the serum,liver or kidney between the two groups at T1(P0.05).Serum MDA contents were increased and the SOD activities were decreased in both groups at T3,T4,and T5,with the changes in group B being significantly small than those in group A(P0.05).MDA contents in the liver and kidney in group A were significantly higher and the SOD activities were significantly lower than those in group B at T2-T5(P0.05).Conclusion Retrograde perfusion with autologous blood through IVC can partly alleviate the ischemic-reperfusion injury of liver and kidney during moderate hypothermic lower body circulatory arrest in pigs,showing a protective effect on the hepatic and renal function.

Open arch reconstruction in the endovascular era: Analysis of 721 patients over 17 years

Recent advancements in thoracic endovascular aortic repair, such as branched endografts or hybrid debranching/thoracic endovascular aortic repair, have extended the option of endoluminal therapy into the realm of the aortic arch. A contemporary assessment of open arch repair to provide long-term data for comparative analysis for these newer therapies is timely, warranted, and presented in this article. Since the inception of our thoracic endovascular aortic repair program in 1993, 721 patients (mean age of 59.3 years, 68.9% were male) have undergone median sternotomy and open arch reconstruction with hypothermic circulatory arrest. Extended arch repair was performed in 42.7% with construction of bypasses to the innominate (296 patients), left carotid (216 patients), and subclavian (75 patients) arteries or elephant trunk procedures (42 patients). Concomitant aortic valve or aortic root replacement was required in 403 patients, and root reconstruction was required in 222 patients. Retrograde (641 patients) or antegrade (400 patients) cerebral perfusion was used for neuroprotection during hypothermic circulatory arrest. The operative procedure was urgent or emergency in 316 patients (43.8%) and included repair of type A dissection in 284 patients (39.3%). A total of 111 patients (15.4%) had undergone prior cardiac surgery. Primary outcomes in this study were early and late mortality. Follow-up was 100% complete (mean, 52.6 months). Thirty-day morbidity included death (36 patients [5%]), stroke (34 patients [4.7%]), and permanent dialysis (14 patients [1.9%]). Independent predictors of early mortality included advancing age, prolonged bypass times, and impaired ejection fraction (all P < .05). Actuarial survival at 10 years was 65%. Independent predictors of late mortality included advancing age, prolonged lower body circulatory arrest times, and increasing creatinine (all P < .05). By Kaplan-Meier analysis, 10-year survival was significantly reduced after operative procedures for type A dissection (non-type A 69.1% vs type A 58%, P = .003). Freedom from aortic reoperation (any segment) was 72.6% at 10 years. Open aortic arch repair can be accomplished with excellent early and late results. These outcomes provide objective data for comparison and suggest that newer endovascular therapies should be evaluated first in high-risk groups, such as those with advanced age or impaired renal function before broader application in all patients.

Safety of Mild Hypothermic Circulatory Arrest with Selective Cerebral Perfusion

Although hypothermic circulatory arrest with antegrade selective cerebral perfusion is used for cerebral protection, optimal perfusion characteristics are still unclear. Between May 2006 and March 2008, 26 patients (mean age, 68.9 years; 14 males) underwent thoracic aortic repair with mild hypothermic circulatory arrest (34.3 degrees C +/- 1.9 degrees C) and antegrade selective cerebral perfusion (30 degrees C) for various indications including 16 acute type A aortic dissections. Mean cerebral perfusion rate was 21.1 +/- 4.3mL kg(-1) min(-1). Non-elective operations were carried out in 16 (61.5%) cases. Operative procedures were ascending aortic replacement in 16 patients, hemiarch replacement in 4, and total arch replacement in 6. Cardiopulmonary bypass time was 209 +/- 61 min, cardiac ischemic time was 141 +/- 45 min, cerebral perfusion time was 81 +/- 67 min, and lower body circulatory arrest time was 65 +/- 22 min. Mean rectal temperature drifted to 30.6 degrees C +/- 1.3 degrees C. There was 1 (3.8%) hospital death due to rupture of a residual descending thoracic aneurysm. One patient needed reexploration for bleeding, and 2 (7.7%) suffered permanent neurologic dysfunction. No postoperative spinal cord dysfunction was observed. Mild hypothermic circulatory arrest with antegrade selective cerebral perfusion could be performed safely in our patient population.

Evolution of Cardiopulmonary Bypass

At the end of the Second World War, the devastation of many cities in Europe, combined with the problems of reconstruction and loss of financial support, had brought European medical research to a halt. On the other hand, in the United States the war brought about an enormous amount of scientific research through the development of nuclear weapons, the mass production of penicillin, early computers, and a variety of other technological advances, some of which were eventually put to use by medical investigators. In the immediate postwar years, Congress began 3 decades of generous funding for medical research and education through the National Institutes of Health and the Public Health Service. In the 1920s and 1930s, medical research money had been scarce, but after the war there was a flood of money. The National Institutes of Health budget for medical research in 1945 was $180 000. By 1947, it was increased to $4 000 000, in 1950 to $46 000 000, and in 1974 to $1 billion.1 By 2008, the total budget just for the Heart, Lung, and Blood Institute was almost $3 billion. Since colonial times, it had been customary for young American physicians to spend postgraduate time in Vienna, Berlin, London, or Paris. Now the opposite was true. It became important for a young European physician to have worked for a year or so in a US medical center. The world center for medical education and research had shifted from Europe to the United States. Postwar medical progress was also stimulated by several other programs. The Hill-Burton act of 1946 provided funds for community hospital upgrades and construction. Initially this bill provided $75 million per year for 5 years. It was a matching plan in which local hospitals were required to raise two thirds of the new …