Hypothermic circulatory arrest does not increase the risk of ascending thoracic aortic aneurysm resection.

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of a period of deep hypothermic circulatory arrest (DHCA) during elective replacement of the ascending thoracic aorta. SUMMARY BACKGROUND DATA: DHCA has been implemented in ascending thoracic aortic aneurysm resection whenever the anatomy or pathology of the aorta or arch vessels prevents safe or adequate cross-clamping. Profound hypothermia and retrograde cerebral perfusion have been shown to be neurologically protective during ascending aortic replacement under circulatory arrest. METHODS: The authors conducted a retrospective analysis of 91 consecutive patients who underwent repair of chronic ascending thoracic aortic aneurysms from 1986 to present. The authors hypothesized that patients undergoing DHCA with or without retrograde cerebral perfusion during aneurysm repair were at no greater operative risk than patients who received aneurysm resection while on standard cardiopulmonary bypass. RESULTS: There were no significant differences in hospital mortality, stroke rate, or operative morbidity between patients repaired on DHCA when compared to those repaired on cardiopulmonary bypass. CONCLUSIONS: DHCA with or without retrograde cerebral perfusion does not result in increased morbidity or mortality during the resection of ascending thoracic aortic aneurysms. In fact, this technique may prevent damage to the arch vessels in select cases and avoid the possible complications associated with cross-clamping a friable or atherosclerotic aorta.     

Effects of deep hypothermic circulatory arrest with retrograde cerebral perfusion on electroencephalographic bispectral index and suppression ratio

OBJECTIVE: No systematic study has been conducted to investigate effects of deep hypothermic circulatory arrest (DHCA) on electroencephalographic bispectral index (BIS) and suppression ratio (SR). Thus, the effects of DHCA were evaluated on BIS and SR. DESIGN: A prospective clinical study. SETTING: University hospital (single institute). PARTICIPANTS: Twenty consecutive patients undergoing thoracic aortic surgery using DHCA under narcotics-sevoflurane anesthesia. INTERVENTIONS: BIS and SR were monitored during cardiopulmonary bypass, simultaneously with nasopharyngeal temperature (NPT). MEASUREMENTS AND MAIN RESULTS: BIS decreased to 0 with induction of deep hypothermia and rose again with rewarming, although rates of BIS changes in response to cooling and rewarming varied widely among patients. Typically, BIS decreased slowly until NPT reached 26 degrees C during cooling and then it began to decrease rapidly and reached 0 at 17 degrees C, in inverse proportion to SR, which increased rapidly with deep hypothermia and reached 100% at 17 degrees C. When SR was 50% or more, BIS was determined by SR according to the expression: BIS = 50-SR/2. With rewarming, BIS rose again and returned to precooling baseline levels. Time to the beginning of the BIS recovery significantly correlated with duration of DHCA. CONCLUSIONS: With induction of deep hypothermia, BIS decreased in a biphasic manner to 0 at rates varying among patients. With rewarming, BIS rose again at rates extremely widely varying among patients. The rate of BIS recovery was related to duration of DHCA. BIS may be capable of conveniently tracing suppression and recovery of a part of cerebral electrical activity before, during, and after DHCA.     

Aortic arch replacement with proximal first technique.

BACKGROUND: Deep hypothermic circulatory arrest (DHCA) without retrograde cerebral perfusion (RCP) has a strict time limit. We modified a surgical technique for anastomosis to shorten the period of DHCA and unilateral cerebral perfusion (UCP). METHODS: Between March 1993 and August 2001, retrospective analysis was done on 23 consecutive patients, who underwent aortic arch replacement with branches. The patients were divided into two groups: DHCA group and UCP group. The DHCA group, in which DHCA alone and without additional cerebral perfusion was performed, comprised of nine patients. Proximal aortic anastomosis was performed first during systemic cooling; then both the brachiocephalic artery and left carotid artery were reconstructed with the branches of the artificial graft during circulatory arrest; thereafter, cerebral and coronary perfusions were resumed. The UCP group, in which DHCA was not used but right hemisphere perfusion during deep hypothermia was performed when the origin of brachiocephalic artery was safely clamped, consisted of 14 patients. RESULTS: Mean time of DHCA was 18.8+/-4.2 minutes and that of right hemisphere perfusion time was 11.0+/-3.8 minutes, respectively. Twenty-one patients survived the surgery (91.3%), and two (8.7%) died during hospitalization. Transient cerebral complication occurred in four patients in the DHCA group and all recovered. Logistic regression analysis revealed that DHCA was the only parameter to significantly influence temporary neurological dysfunction. There was no other significant difference between the two groups. CONCLUSION: With our modified and simple surgical technique for aortic arch repair, we were able to successfully shorten the DHCA time and right hemisphere perfusion time. However, because DHCA was the only parameter to significantly influence temporary neurological dysfunction, some form of continuous cerebral perfusion at deep hypothermia may be a safer method to preserve cerebral function.     

Retrograde cerebral perfusion during thoracic aortic surgery and late neuropsychological dysfunction.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is commonly used in thoracic aortic surgery, ostensibly to provide metabolic support, maintain cerebral hypothermia and/or wash out particulate emboli. We tested the hypothesis that RCP would affect neuropsychological outcome in a clinical cohort. METHODS: Ninety-four patients undergoing elective thoracic aortic repairs requiring deep hypothermic circulatory arrest consented to participate in this study. These patients underwent preoperative neuropsychological evaluation and comprise the reference group. Fifty-six of these patients also underwent neuropsychological evaluation several weeks postoperatively, 12 of whom (21%) had RCP. The neuropsychological domains tested were attention, processing speed, memory, executive function, and fine motor function. A global assessment of impairment, negative neuropsychological outcome (NNO), was defined as a postoperative decrease in function in two or more neuropsychological domains for patients with at least three domains tested both pre- and postoperatively (n=48). The relationship of three potential predictors (RCP, cerebral ischemia time and patient age) to negative outcomes was analyzed using Wilcoxon two-sample tests, chi(2) tests, Mantel-Haenszel tests and multiple logistic regression. P<0.05 was considered significant. RESULTS: Memory dysfunction and NNO had strong associations with RCP. This effect remained significant when controlling separately for age and cerebral ischemia time. CONCLUSIONS: The effects of RCP are difficult to distinguish from those of age and prolonged cerebral ischemia time, because complex thoracic aortic repairs are associated with advanced age, prolonged cerebral ischemia and use of RCP. Despite this limitation, these preliminary data indicated that RCP had no beneficial effect (and most likely a negative effect) upon cognitive outcome.     

Cardiopulmonary bypass for thoracic aortic aneurysm: a report on 488 cases

Our objective was to investigate different cardiopulmonary bypass (CPB) techniques for thoracic aortic aneurysm retrospectively. Four hundred and eighty-eight patients with thoracic aortic aneurysm received surgical treatment. Total CPB was used routinely in 331 cases with ascending aortic aneurysm. When the aneurysm expanded to the aortic arch, brain protection was executed by adopting deep hypothermia circulatory arrest (DHCA) or DHCA combined with retrograde cerebral perfusion (RCP). Selected cerebral perfusion via carotid artery was used in three cases and separated upper and lower body perfusion in five cases. Left heart bypass was adopted for the surgeries of 157 cases with descending aortic aneurysm. In two of the cases, ventricular defibrillation could not be achieved, and then bypass was altered to separated upper and lower body perfusion to acquire satisfactory outcome. In the ascending aortic aneurysm group, DHCA time in the 17 patients was 10-63 minutes (mean 35.58 +/- 18.81 min), and DHCA +/- RCP time in 61 patients was 16-81 minutes (mean 43.43 +/- 17.91 min). Total mortality of aortic aneurysm surgery requiring full CPB was 5.4% (18/331), in which eight patients died in emergency operations. The total mortality of emergency operation was 11.9% (8/67). In the descending aortic aneurysm group, time of left heart bypass was 125.56 +/- 57.28 min, and the total mortality was 7% (11 of 157 patients). Three patients developed postoperative paraplegia. Techniques for extracorporeal circulation for surgery of the aorta are dependent on the nature of the disease and require a flexible approach to meet the specific anatomical challenge. The ability to alter the perfusion circuit to meet unexpected situations should be anticipated and planned for. In this series, we have varied our approach to perfusion techniques as required with acceptable outcome data as compared to the international literature.     

Effects of deep hypothermic circulatory arrest on outcome after resection of ascending aortic aneurysm

BACKGROUND: Aneurysm of the ascending aorta is a common finding especially in patients with aortic valve diseases. The aim of this study was to analyze early and midterm outcome in patients operated on for aneurysm of the ascending aorta with or without the use of deep hypothermic circulatory arrest (DHCA). METHODS: Between January 1996 and December 2000, 133 of 410 patients with thoracic aortic pathology were operated on for an aortic aneurysm limited mainly to the ascending aorta. Early and midterm outcomes were assessed and quality of life (QOL) evaluated using the Short-Form 36 Health Survey Questionnaire (SF-36). RESULTS: Sixty patients (group 1) were operated on with DHCA and 73 patients (group 2) without DHCA. In-hospital mortality was identical in both groups (9.6% versus 6.7%; p = not significant) whereas postoperative transient neurologic events were significantly more frequent in group 1 (6.7% versus 0%; p < 0.05). Midterm clinical outcome was not different between groups but QOL showed significant impairment in daily functional physical and emotional activity in group 1 patients compared with group 2 and an age-matched standard population. CONCLUSIONS: The risk of transient neurologic complications is significantly increased with the use of DHCA and QOL is impaired without benefits in the long-term outcome especially among older patients.     

Correlation between age and vital organ function following deep hypothermic circulatory arrest

BACKGROUND: We investigated the correlation bet-ween perioperative variables such as patients' age and vital organ function after operation on thoracic aorta using deep hypothermic circulatory arrest (DHCA). METHODS: Ninety-five patients who underwent replacement of thoracic aorta under DHCA for acute or chronic aortic dissection and aortic aneurysm, and survived more than 10 days were divided into group I (age less than 60, n=17), group II (between 60 and 69, n=39), and group III (over 70, n=39). Concomitant procedures such as aortic root replacement and coronary artery bypass grafting were performed in 9, 4, and 1 patients in group I, II, and III, respectively. Postoperative pulmonary, renal, and hepatic function within 10 days were compared. Correlation between other perioperative variables and organ function was also investigated among all 95 patients. RESULTS: Postoperative pulmonary, renal, and hepatic function in group III was not significantly inferior to those in groups I and II. The operation time, and amount of red blood cells and fresh frozen plasma used during operation, were significantly greater in group I, which showed an intimate correlation to significant elevation of hepatic enzymes. CONCLUSIONS: Although lower functional reserve of vital organs in the elderly patients was predicted, they showed an acceptable functional recovery after operation with DHCA. Other perioperative variables such as operation time and blood transfusion showed a negative impact on postoperative hepatic function.     

Major clinical outcomes in adults undergoing thoracic aortic surgery requiring deep hypothermic circulatory arrest: quantification of organ-based perioperative outcome and detection of opportunities for perioperative intervention

OBJECTIVE: The purpose of this study was to describe clinical outcome after adult thoracic aortic surgery requiring standardized deep hypothermic circulatory arrest (DHCA), to determine mortality and length of stay, neurologic outcome, cardiorespiratory outcome, and hemostatic and renal outcome after DHCA. DESIGN: Retrospective and observational. SETTING: Cardiothoracic operating rooms and intensive care unit (ICU). PARTICIPANTS: All adults requiring thoracic aortic repair with DHCA. INTERVENTIONS: None. The study was observational. MAIN RESULTS: The cohort size was 110. All patients received an antifibrinolytic. The mortality rate was 8.2%. The mean length of stay was 6.8 days (ICU) and 14.0 days (hospital). The incidence of stroke was 8.1% and postoperative delirium was 10.9%. The rate of postoperative atrial fibrillation was 43.6%; 19.1% required postoperative mechanical ventilation longer than 72 hours. Chest tube drainage was 931 mL for the first 24 hours. Postoperative dialysis was required in 1.8% of patients. Renal dysfunction occurred in 40% to 50% of patients, depending on the definition. CONCLUSIONS: The protocol for DHCA at the authors' institution is associated with superior or equivalent perioperative outcomes to those reported in the literature. This study identified the need for further quantification of the clinical outcomes after DHCA in order to prioritize outcome-based hypothesis-driven prospective intervention in DHCA.     

异丙酚对体外循环中脑氧代谢的影响

目的：探讨异丙酚对体外循环（ＣＰＢ）各阶段脑氧及乳酸代谢的影响。方法：选择心内直视手术病人３１例，随机分为异现酚组（Ａ组）１６例，对照组（Ｂ组）１５例。分别于ＣＰＢ前、降温及３３℃和３０℃，低温期，复温至３０℃和３３℃以及ＣＰＢ后１５分钟七个时点动脉，颈内静脉血气及乳酸值（ＬＡ）并计算脑摄氧率（Ｏ２Ｅｘｔ）及动脉－颈内静脉乳酸差值。     

The incidence of transient neurologic dysfunction after ascending aortic replacement with circulatory arrest

BACKGROUND: Transient neurologic dysfunction (TND) namely postoperative confusion, delirium, and agitation after aortic operation, particularly after deep hypothermic circulatory arrest (DHCA), remains an underestimated adverse event in the early outcome of these patients. Although no influence on long-term outcome has been reported so far, this entity markedly affects the early outcome and leads to prolonged intensive care unit and hospital stay. METHODS: Between January 1997 and January 2003, 160 consecutive patients (130 type A dissections [81%] and 30 elective atherosclerotic aneurysms [19%]) had surgical repair with DHCA for a thoracic aortic aneurysm limited to the ascending aorta. From those, 40 patients (25%) underwent DHCA alone, whereas in 13 patients (8%) antegrade cerebral perfusion and in 103 patients (64%) retrograde cerebral perfusion was used for further brain protection. RESULTS: The overall incidence of TND was 18% (28 of 160) with a significant association between duration of circulatory arrest and the incidence of TND (13.8% in DHCA < 30 minutes versus 37.9% in DHCA > 40 minutes; p < 0.05). Furthermore the severity of TND was directly associated with the duration of circulatory arrest and age. In contrast, however, the use of retrograde cerebral perfusion had no influence on the incidence of TND, (p < 0.05). Intensive care unit stay as well as hospital stay were prolonged in the patients with TND (intensive care unit 14.3 +/- 14.2 days versus 10.8 +/- 13.7 days, p < 0.05; hospital stay 15.6 +/- 10.1 days versus 11.4 +/- 7.9 days, p < 0.05). CONCLUSIONS: Duration of DHCA, regardless of whether retrograde cerebral perfusion was used, was the most important predictor of the incidence of transient neurologic dysfunction in patients who had replacement of the ascending thoracic aorta. The occurrence of TND leads to impaired functional recovery as well as prolonged intensive care unit and hospital stay.     

Quality of life after interventions on the thoracic aorta with deep hypothermic circulatory arrest.

OBJECTIVE: Assessment of quality of life (QL) in patients undergoing major surgical procedures is of increasing interest. We focused on surgery of the thoracic aorta requiring deep hypothermic circulatory arrest (DHCA). Aim of this study was to assess QL after thoracic aortic surgery with DHCA, using the Short Form 36 Health Survey (SF-36) questionnaire. METHODS: Between 01/94 and 12/99 212 (59.1%) out of a total of 359 interventions on the thoracic aorta were performed under DHCA, with an early mortality of 13.7% (28 patients). During an average follow-up of 3.2+/-1.3 years, 27 patients died (15.2%) and five patients (2.8%) were lost. A total of 145 patients (81.9%) had a complete follow-up. RESULTS: 125 of the 145 SF-36 questionnaire handed out were answered correctly (86.2%). In relation to a standard population (z=0), the most important deficits were found in physical function (z=-0.53) and role limitations because of physical health (z=-0.42). Good results were found regarding the aspect of pain (z=0.28), social functioning (z=0.02) and vitality (z=-0.02). Overall QL in patients having been operated for aortic aneurysm was better than for patients with acute type A-dissection. CONCLUSION: Despite restrictions in physical functioning and role limitation because of physical health, QL in patients after interventions on the thoracic aorta with DHCA is fairly good and, for patients being operated for aortic aneurysm, comparable to an age-matched standard population. Patients having being operated electively for aortic aneurysm enjoyed a better QL than patients having been operated emergently for acute type A dissection.     

Combination of alpha-stat strategy and hemodilution exacerbates neurologic injury in a survival piglet model with deep hypothermic circulatory arrest

BACKGROUND: The optimal pH strategy and hematocrit during cardiopulmonary bypass with deep hypothermic circulatory arrest (DHCA) remain controversial. We studied the interaction of pH strategy and hematocrit and their combined impact on cerebral oxygenation and neurological outcome in a survival piglet model including monitoring by near-infrared spectroscopy (NIRS). METHODS: Thirty-six piglets (9.2+/-1.1 kg) underwent DHCA under varying conditions with continuous monitoring by NIRS (pH-stat or alpha-stat strategy, hematocrit 20% or 30%, DHCA time 60, 80, or 100 minutes). Neurological recovery was evaluated daily. The brain was fixed in situ on postoperative day 4 and a histological score (HS) for neurological injury was assessed. RESULTS: Oxygenated hemoglobin (HbO2) and total hemoglobin signals detected by NIRS were significantly lower with alpha-stat strategy during cooling (p < 0.001), suggesting insufficient cerebral blood supply and oxygenation. HbO2 declined to a plateau (nadir) during DHCA. Time to nadir was significantly shorter in lower hematocrit groups (p < 0.01). Significantly delayed neurologic recovery was seen with alpha-stat strategy compared with pH-stat (p < 0.05). The alpha-stat group had a worse histological score compared with those assigned to pH-stat (p < 0.001). Neurologic impairment was estimated to be over 10 times more likely for animals randomized to alpha-stat compared with pH-stat strategy (odds ratio = 10.7, 95% confidence interval = 3.8 to 25.2). CONCLUSIONS: Combination of alpha-stat strategy and lower hematocrit exacerbates neurological injury after DHCA. The mechanism of injury is inadequate cerebral oxygenation during cooling and a longer plateau period of minimal O2 extraction during DHCA.     

主动脉弓置换术后急性肾损伤发生的危险因素分析

目的探讨在深低温停循环（DHCA）下行主动脉弓置换术后发生急性肾损伤（AKI）的危险因素。方法回顾性分析2004年1月至2008年12月期间首都医科大学附属北京安贞医院139例行主动脉弓置换术患者的临床资料,依术后是否发生AKI将139例患者分为两组,肾功能正常组（n=91）：男69例,女22例;年龄41.30±13.37岁;AKI组（n=48）：男39例,女9例;年龄57.67±9.56岁。观察两组患者的临床资料,包括术前左心室射血分数（LVEF）、左心室内径、升主动脉直径、肾功能、体外循环时间、主动脉阻断时间、停循环时间等指标的改变,采用单因素和logistic多因素回归分析导致患者术后发生AKI和死亡的危险因素。结果 139例患者中术后发生AKI48例（34.53%）,其中行连续性肾脏替代治疗（CRRT）17例（12.23%）,发生呼吸衰竭27例（19.42%）,脑部并发症29例（20.86%）,包括暂时性脑损害26例,永久性脑损害3例。住院死亡14例（10.07%）,其中死于心力衰竭4例,多器官功能衰竭9例,多发性脑梗死1例。肾功能正常组死亡3例（3.30%）,AKI组死亡11例（22.92%）,两组病死率比较差异有统计学意义（P=0.011）。随访118例,随访时间5~56个月,平均随访42个月,失访7例。随访期间死亡7例,其中死于心力衰竭3例,脑卒中2例,死亡原因不明2例。logistic回归分析结果显示：术前血肌酐〉132.60μmol/L（OR=1.042,P=0.021）和术后发生呼吸衰竭（OR=2.057,P=0.002）是导致主动脉弓置换术后发生AKI的独立危险因子。结论主动脉弓置换术后AKI的发生率较高,是手术死亡的危险因素,应加强围术期肾功能保护。     

Antegrade selective cerebral perfusion combined with deep hypothermic circulatory arrest on cerebral circulation: comparison between pulsatile and nonpulsatile blood flows.

PURPOSE: In aortic arch surgeries, antegrade selective cerebral perfusion (SCP) combined with deep hypothermic circulatory arrest (DHCA) has been recently widely used in institutions as one of the most reliable methods for cerebral protection. However, some studies reported a 3.7-9.3% incidence of postoperative cerebral complications. To perform antegrade SCP more safely, we sought to examine the impact of pulsatile flow perfusion during DHCA on cerebral tissue metabolism, focusing on physiological effects of pulsatile flow perfusion. MATERIALS AND METHODS: Sixteen pigs were divided into 2 groups. In each group, antegrade SCP combined with DHCA was conducted. During circulatory arrest, for SCP, a pulsatile flow (group P) and a nonpulsatile flow (group N) were used. We compared results between group P and group N. Jugular venous oxygen saturation (SjO(2)) and cerebral tissue oxygen partial pressure (PtO(2)) were measured at baseline, and continuously throughout the extracorporeal circulation. Hematocrit (Ht), and concentrations of S-100 protein and CK-BB in blood and the cerebrospinal fluid (CSF) were measured at baseline (before the beginning of extracorporeal circulation), following SCP, and after rewarming. Following rewarming, each brain under perfused fixation was removed, and histopathological examinations were conducted using Kluver-Barrera and Tunnel staining methods, electron micrograph. RESULTS: SjO(2) was found to be within normal ranges until after SCP, but decreased with rewarming in both groups. In Group N, changes in SjO(2) were significant, with a decrease to < or =50%. In Group N, concentrations of S-100 protein and CK-BB in CSF after SCP and after rewarming were significantly higher than those in Group P. The time needed for rewarming to 36 degrees C in Group P was shorter than that in Group N. CONCLUSION: Our results suggest that the pulsatile flow circulation method shows cerebral protection effects with increasing blood flow in small cerebral tissues. In addition, it is effective for improving the imbalance between oxygen supply and demand, especially in the process of rewarming from hypothermic conditions. This method seems to be useful as an adjunct in hypothermic circulatory arrest procedures.     

Cerebral oxygen desaturation monitoring during off-pump coronary artery bypass grafting

BACKGROUND: The evaluation of cerebral perfusion during off-pump coronary bypass grafting (OPCAB) has not been clarified. The aim of this study was to investigate the predictive value of neurobiochemical markers of brain damage and cerebral perfusion with respect to the neuropsychological outcomes after OPCAB. METHODS: Ten patients (4 males and 6 females) underwent OPCAB. All patients were performed brain CT preoperatively and 7 days postoperatively. We excluded the patients with cerebralvascular disease from this study. A 5.5 Fr oximetric catheter was placed in the jugular bulb, and we measured continuously SjO2 and mean arterial blood pressure during OPCAB. Venous serum level of neuron specific enolase (NSE) was measured preoperatively and 24 hours after skin closure. RESULTS: There was correlation between mean blood pressure and SjO2 during anastomoses. The mean blood pressure during anastomoses of left anterior descending coronary artery (LAD), circumflex coronary artery (Cx), right coronary artery (RCA) were 68.6 +/- 12.9 mmHg, 60.9 +/- 9.3 mmHg, 64.1 +/- 14.1 mmHg. The SjO2 during anastomoses of LAD, Cx, RCA were 57.3 +/- 10.9%, 48.6 +/- 9.8%, 57.7 +/- 18.2%. There is tendency that the SjO2 during anastomosis of Cx was lower than others. No patients died, and there was no permanent neurologic deficit. Postoperatively, 2 patients had abnormal high NSE level. CONCLUSION: Intraoperative continuous cerebral oxygen desaturation monitoring seems to be useful monitor for neuropsychological outcomes after OPCAB.     

Real-time cerebral monitoring using multichannel near-infrared spectroscopy in total arch replacement.

Multichannel near-infrared spectroscopy (NIRS) could detect change in the regional cerebral oxygenation by following animated pictures of oxy-hemoglobin (OxyHb), deoxy-hemoglobin (DeoxyHb) and total hemoglobin in operations for three surgical cases of thoracic aortic aneurysm with selective cerebral perfusion (SCP). Simultaneously measured jugular venous oxygen saturation (SjO2) showed no change in parallel to OxyHb or DeoxyHb of NIRS. It was concluded that SjO2 represented the entire rather than the local findings of the cerebral oxidative metabolism. Assessment of the intra cranial oxidative metabolism using a multichannel NIRS provided real-time information about the efficacy of SCP, while SjO2 had a comprehensive limited value. The animation enabled the detection of regional hypoperfusion visually and instantly during SCP. This multichannel NIRS was a new real-time monitoring method and was useful to prevent cerebral neurological complication due to hypoperfusion during SCP.     

Protective effect of sivelestat sodium (Eraspol) on postoperative lung dysfunction in patients with type A acute aortic dissection: a pilot study

AIM: The authors evaluated the protective effect of sivelestat sodium on postoperative lung dysfunction in patients with type A acute aortic dissection who underwent aortic arch surgery with cardiopulmonary bypass (CPB) under deep hypothermia with circulatory arrest (DHCA). METHODS: Twelve patients with type A acute aortic dissection who underwent aortic arch replacement under CPB with DHCA and were pretreated with or without sivelestat sodium (sivelestat group, N.=7 patients; control group, N.=5 patients) were observed. The ratio of arterial oxygen tension to inspired oxygen fraction (P/F ratio) was measured as a parameter of pulmonary function before and after operation. The number of white blood cells was also counted as an index of inflammatory reaction before and after the operation. RESULTS: The P/F ratio decreased significantly after operation in the control group. However, the P/F ratio was unchanged between before and after operation in the sivelestat group. The number of white blood cells tended to increase after operation in the control group, whereas it decreased significantly after operation in the sivelestat group. CONCLUSION: The present study demonstrated the protective effect of sivelestat sodium on postoperative lung injury in patients with acute type A aortic dissection undergoing aortic arch surgery under CPB with DHCA.     

Systemic temperature and paralysis after thoracoabdominal and descending aortic operations

HYPOTHESIS: Systemic temperature influences the development of neurologic deficits after aortic surgery. DESIGN: Retrospective case-comparison study of prospectively collected data. SETTING: Tertiary referral center. PATIENTS AND INTERVENTIONS: We examined spinal cord injury according to mild passive hypothermia (mean temperature, 36.5 degrees C; n = 25), moderate active hypothermia (temperature range, 29 degrees C-32 degrees C; n = 76), or profound hypothermia (temperature, <20 degrees C; n = 31) for complex repairs in 132 patients. Aortic dissection was present in 67 patients (51%), 41 (31%) had leaks or rupture, 39 (30%) were reoperations on the descending thoracic aorta, and 27 (20%) had concurrent arch and/or ascending thoracic aortic repairs. MAIN OUTCOME MEASURE: Occurrence of permanent and transient deficits. RESULTS: Five patients (3.8%) had permanent deficits. One (4.0%) of the 25 patients underwent mild hypothermia, 3 (3.9%) of the 76 patients who underwent moderate hypothermia, and 1 (3.2%) of the 31 patients who underwent profound hypothermia (P =.70). Reversible deficits occurred in 7 patients (total 32%) who underwent mild hypothermia, 2 patients (total 6.6%) underwent moderate hypothermia, and 1 (total 6.5%) underwent profound hypothermia (P =.004). Six were delayed neurologic deficits. Independent predictors were intercostal ischemic time (P =.02), mild hypothermia (P =.004), and no cerebrospinal fluid drainage (P =.05). The total 30-day survival was 92.4% (122 of 132 patients). The only multivariable predictor of death was acuity of surgery (namely, emergent, urgent, or elective) (P =.06). CONCLUSIONS: Moderate or profound hypothermia resulted in fewer transient neurologic deficits. Thus, we recommend active cooling and cerebrospinal fluid drainage for most patients, and profound hypothermia for patients undergoing complex repairs and reoperations.     

Pulmonary endarterectomy: an alternative to circulatory arrest and deep hypothermia: mid-term results.

BACKGROUND: The current surgical technique for pulmonary endarterectomy (PEA) involves the use of deep hypothermia and circulatory arrest at 18 degrees C (DHCA). Our experience started in 2004 when we decided to use an original alternative strategy which consists of avoiding deep hypothermia and subsequent circulatory arrest by using moderate hypothermia at 26 degrees C, and maintaining a bloodless field. This can be achieved by means of negative pressure in the left heart chambers and appropriate pump flow modulation in order to maintain the mixed venous oxygen saturation (SVO(2)) higher than 65%. MATERIALS AND METHODS: From June 2004 to June 2007, 40 consecutive patients were operated on in our department with this strategy. The aim of this article is to report the early results for all patients and the complete six-month follow-up for 30 subjects who have reached this end-point at the time of writing. The mean temperature during extracorporeal circulation was 25.9 degrees C; core temperature was lowered to 21 degrees C in only one patient and an 8 min DHCA was performed in order to complete the PEA. RESULTS: Two patients died (6.6%): one on the third postoperative day due to myocardial infarct, requiring an ECMO implantation. The other patient died from septic shock. The six-month follow-up, performed in all other patients, included clinical and hemodynamic evaluation. Pulmonary vascular resistance (PVR) decreased from 793.5+/-284 dyn/cm/s(-5) to 286+/-143 (p=0.000). A comparable reduction of mean pulmonary arterial pressure and an increase of cardiac output were also observed. Conclusions: The results confirm that adequate removal of pulmonary artery obstructive lesions can also be achieved with an operative procedure that avoids or reduces the use of DHCA while allowing a bloodless field during PEA interventions. This technique may limit the well known adverse effects of DHCA due to organ hypoperfusion, improving the postoperative recovery of the patients.     

Evaluation of cerebral oxygen balance during normothermic cardiopulmonary bypass using jugular oxygen saturation

BACKGROUND: Previous studies suggest that normothermic cardiopulmonary bypass(CPB) impairs cerebral oxygen balance. We studied the effect of normothermic CPB on cerebral oxygen balance evaluated by continuous measurement of oxygen saturation in the jugular vein (SjO2). METHODS: Eleven patients undergoing coronary artery bypass grafting with normothermic CPB were studied. A 4 Fr oxymetry catheter was inserted into the internal jugular bulb for SjO2 monitoring. We measured mean arterial pressure (MAP), SjO2 and hemoglobin (Hgb) concentration at five time points-1) pre CPB, 2) 3) 4) 5, 30, 60 min after the onset of CPB, respectively, 5) 5 min after the end of CPB. RESULTS: MAP decreased significantly 30 min (47 +/- 9 mmHg) and 60 min (48 +/- 9 mmHg) after the onset of CPB compared with the pre CPB (80 +/- 14 mmHg) value. Hgb also decreased significantly 5 min (7.8 +/- 1.1 g x dl(-1)) and 30 min (7.1 +/- 1.0 g x dl(-1)) and 60 min (7.1 +/- 0.8 g x dl(-1)) after the onset of CPB compared with the pre CPB (11 +/- 1.0 g x dl(-1)) value. However, SjO2 showed no significant change throughout the study period. No significant correlation was observed between MAP and SjO2. CONCLUSIONS: Cerebral oxygen balance assessed by SjO2 was not impaired during normothermic CPB, and was unaffected by hypotension and hemodilution.