Selective cerebral perfusion during operation for aneurysms of the aortic arch: a reassessment.

Thirty-two consecutive patients with thoracic aortic aneurysms who required aortic arch reconstruction were operated on with the aid of extracorporeal circulation and selective cerebral perfusion between January 1986 and August 1990. For selective cerebral perfusion, blood was infused into both the innominate and left common carotid arteries at a rate of 10 mL.kg-1.min-1 using a single roller pump separately from the systemic circulation. In 9 patients treated before March 1987, the operations were performed without open aortic anastomosis (group 1), whereas in 23 patients treated from March 1987 onward we used open aortic anastomosis (group 2). The extracorporeal circulation and cardiac arrest times were significantly longer in group 2, but there was no significant difference in the cerebral perfusion time. Early death occurred in 1 patient in group 1 and 2 in group 2. No serious cerebrospinal neurological complications occurred in either group, and there were similar rates of postoperative hepatic and renal dysfunction in both groups. The present data suggest that selective cerebral perfusion and open aortic anastomosis are useful methods for thoracic aortic aneurysm operation requiring complex repair of the aortic arch.     

Surgical treatment of aneurysm of the ductus arteriosus in the adult

Aneurysm of the ductus arteriosus is rare, however, reports on this lesion have increased recently with the progress of thoracic aortic surgery in Japan. We report 3 male cases aged 58, 59, 73 years. Aneurysms and total aortic arch were replaced by artificial graft through median sternotomy using selective cerebral perfusion in 2 cases. Through left posterolateral thoracotomy using deep hypothermia with circulatory arrest, proximal descending thoracic aorta including the aneurysm was replaced in 1 case. Their postoperative courses were uneventful. Surgery for this lesion is safe and various surgical approaches and circulatory supporting methods can be selected depending on the size of aneurysm and associated lesions.     

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.     

Total arch replacement using prior selective cerebral perfusion

Prior selective cerebral perfusion is the method whereby selective cerebral perfusion and systemic perfusion start almost simultaneously, and the arch vessels are clamped. Cerebral circulation is isolated from systemic circulation to avoid cerebral embolization owing to detachment of atherosclerotic material from the aorta, caused by the "sandblasting" effect of high-velocity jets of blood exiting the aortic canula. Twenty-seven consecutive patients underwent total arch replacement for degenerative aortic arch aneurysm using prior selective cerebral perfusion from 1992 to 2001. Surgical death (within 1 month after operation) was 2 cases (7.4%), in-hospital death was 5 cases (18.5%). Systemic circulatory arrest time is almost equal to the time which distal anastomosis takes. The time was 81.4 +/- 24.3 minutes. Selective cerebral perfusion time was 194.9 +/- 30.9 minutes. Extracorporeal circulation time was 280.6 +/- 55.3 minutes. The time for emergence from anesthesia was 6.0 +/- 2.7 hours. Permanent neurologic dysfunction which was thought to occurred within 48 hours after surgery was noted in 1 case (3.7%). Postoperative survival at 8 years was 73.3%. There was 1 arch aneurismal related accident. Prior selective cerebral perfusion may be useful for avoiding cerebral embolization.     

Surgery for thoracic aortic aneurysms involving the distal arch through a left thoracotomy

Surgical outcome for thoracic aortic aneurysms involving the distal arch via a left thoracotomy using retrograde cerebral perfusion combined with profound hypothermic circulatory arrest was reviewed. Twelve patients with a atherosclerotic aortic aneurysm between 1994 and 1997 were involved. A proximal aortic anastomosis was made by means of an open aortic technique. For the first four patients, oxygenated arterial blood from cardiopulmonary bypass was perfused retrogradely through a venous cannula positioned into the right atrium. In the last eight cases, venous blood provided by a low-flow perfusion of the lower half body via the femoral artery, which was still oxygen-saturated, was circulated passively in the brain in a retrograde fashion with the descending aorta clamped. Prosthetic replacement was done between the distal arch and the proximal descending aorta in 6 patients and from the distal arch to the entire descending thoracic aorta in 6 patients. The median duration of hypothermic circulatory arrest and continuous retrograde cerebral perfusion was 36 minutes and 33 minutes respectively. The overall outcome was satisfactory without early mortality--all patients survived, although an octogenarian died of respiratory failure 1 year postoperatively. Another octogenarian with a ruptured aneurysm developed delay of meaningful consciousness, and other two patients with a severely atherosclerotic aneurysm suffered permanent neurological dysfunction (stroke) presumably due to an embolic episode. The safe and simple combination of profound hypothermic circulatory arrest, retrograde cerebral perfusion, and open aortic anastomosis protects the brain adequately and produces satisfactory results in surgery for aortic aneurysms involving the distal arch through a left thoracotomy.     

Endovascular stent-grafting through the aortic arch: an alternative approach for distal arch aortic aneurysm

BACKGROUND: Endovascular stent-grafting is an innovative procedure; we have developed a novel approach to treat distal arch aortic aneurysm through a small incision in the aortic arch. METHODS: Eight patients with thoracic aortic aneurysms were treated with an endovascular stent-graft that was introduced into the thoracic aorta through a small incision in the aortic arch. Of these patients, 7 had distal arch aortic aneurysms, and 1 had chronic aortic dissection of Stanford type B. Four of these patients had received concomitant coronary artery bypass grafting, and 1 patient had undergone tricuspid valvular annuloplasty. The stent-graft was introduced into the distal arch aorta and descending aorta through a small incision in the aortic arch, under selective cerebral perfusion and hypothermic circulatory arrest. RESULTS: The selective cerebral perfusion time ranged from 52 to 86 minutes (mean, 68 minutes) and the operating time from 289 to 422 minutes (mean, 318 minutes). There was no endoluminal leakage into the aneurysm. Seven patients survived and were discharged, but 1 patient suffered a cerebral infarction and died during the follow-up period. CONCLUSIONS: Placing an endovascular stent-graft through the aortic arch is an acceptable alternative treatment for distal arch aortic aneurysms.     

Antegrade selective cerebral perfusion during surgery of the thoracic aorta: risk analysis

Objective: To determine independent predictors of neurologic outcome and hospital mortality after surgery of the thoracic aorta using moderate hypothermic circulatory arrest and antegrade selective cerebral perfusion. Methods: Between November 1996 and June 2000, 96 consecutive patients (69 men, 27 women; mean age 63±10 years) underwent operations on the thoracic aorta with the aid of moderate hypothermic circulatory arrest and antegrade selective cerebral perfusion. Sixty-four patients were operated on electively (66.7%), 32 emergently (33.3%). Indications for surgery were: type A acute dissection in 30 patients (31.3%), chronic aneurysm in 66 (68.8%). Seventeen patients (17.7%) had undergone previous aortic/cardiac surgical procedures. The mean selective cerebral perfusion time was 52.2±31.9 min (range, 18–220 min). Preoperative, intraoperative, and postoperative factors were analyzed by univariate and multivariate analysis to identify predictors of hospital mortality and neurologic outcome. Results: There were no operative deaths; the hospital mortality rate was 11.5% (11/96). Stepwise logistic regression revealed preoperative renal dysfunction (P=0.021), type A acute dissection (P=0.053), coronary artery bypass grafting (P=0.058), post-operative pulmonary complications (P=0.000) and repeat thoracotomy for bleeding (P=0.027) as independent predictors of hospital mortality. One patient sustained a permanent neurologic deficit (1%). Transient neurologic deficit occurred in eight patients (8.3%). Coronary artery bypass grafting (P=0.013), and postoperative cardiac complications (P=0.049) were statistically associated with an increased risk of any (transient and permanent) neurologic dysfunction on univariate analysis. Stepwise logistic regression indicated coronary artery bypass grafting as independent factor for any neurologic dysfunction. Conclusion: This study confirmed that selective cerebral perfusion is an effective method of cerebral protection allowing complex thoracic aorta operations to be performed with low risk of hospital mortality and adverse neurologic outcome. We didn't find that the duration of selective cerebral perfusion time influence hospital mortality and any neurologic deficit.     

A case of successful surgery in ruptured aneurysm of the aortic arch under profound hypothermic selective cerebral perfusion

We experienced a case of surgery for ruptured aneurysm of the aortic arch. A 51-year-old man who had been admitted complaining of back pain was diagnosed as ruptured aortic arch aneurysm by chest X-ray film and computed tomography. The aortic arch and descending aorta was replaced with a Dacron graft under profound hypothermic selective cerebral perfusion (PHSCP). The post operative course was well without neurological complications. Since 1982 we have utilized PHSCP in four cases of thoracic aortic aneurysms including this case. The average of PHSCP time was 143 minutes. Perfusion rate of carotid arteries was 400-800 ml/min during PHSCP. The average of lowest blood temperature was 15.5 degrees C. It was suggested that PHSCP was a safe and effective method for surgical treatment of thoracic aortic aneurysms.     

一期次全或全主动脉替换术的临床应用

目的 总结全主动脉替换术治疗全程主动脉瘤及慢性Stanford A型主动脉夹层的临床经验。方法 2004年2月至11月对8例全程主动脉瘤或慢性Stanford A型主动脉夹层的患者施行一期次全（2例）或全主动脉替换术（6例）。其中7例男性,1例女性,年龄23～47岁。病因均为马凡综合征。手术均在全身麻醉深低温停循环顺行性脑灌注下进行。采用左后外胸腹联合切口及胸骨正中切口。手术采用四分支人工血管,先行升主动脉替换或Bentall手术,然后行主动脉弓替换,最后完成胸腹主动脉替换。结果 无手术及住院死亡。1例脑梗死。随访2～12个月,无晚期死亡及再手术病例。结论 一期次全或全主动脉替换术可减少分期手术的痛苦,节约医疗费用,并消除分期手术残余动脉瘤破裂的风险,是治疗全程主动脉瘤及慢性Stanford A型主动脉夹层的有效方法。     

Thoracoabdominal aortic aneurysm repair through redo left-sided thoracotomy

BACKGROUND: The outcome of thoracoabdominal aortic aneurysm repair through redo-left thoracotomy after operations for descending thoracic aortic aneurysms was investigated. METHODS: Between May 1982 and March 2003, 100 patients underwent thoracoabdominal aortic aneurysm repair in elective surgery without profound hypothermic circulatory arrest. Thirty of these patients had previously undergone operations for descending thoracic aortic aneurysms. To evaluate the influence of previous descending thoracic aortic aneurysm repairs on the results of thoracoabdominal aortic aneurysm replacements, patients were divided into two groups: (1) patients who had previously undergone descending thoracic aortic aneurysm repair (group I; n = 30), and (2) patients who had not previously undergone descending thoracic aortic aneurysm repair (group II; n = 70). RESULTS: The distal aortic perfusion time and operation time were both longer in group I than in group II, but there was no significant difference between the two groups in total selective visceral and renal perfusion time or aortic clamp time. In-hospital mortality rates were 13% in group I and 19% in group II (p = 0.52). Major postoperative complications included paraplegia (10% of patients in group I and 4.3% of patients in group II; p = 0.36), renal failure requiring hemodialysis (20% of patients in group I and 11% of patients in group II; p = 0.35), respiratory failure (30% of patients in group I and 19% of patients in group II; p = 0.22). CONCLUSIONS: Previously descending thoracic aortic aneurysm and redo-left thoracotomy do not adversely affect the outcome of thoracoabdominal aortic aneurysm repair.     

改良全弓置换加支架象鼻术在DeBakeyⅠ型主动脉夹层术中的应用

目的 总结改良主动脉全弓置换加支架象鼻术治疗DeBakey Ⅰ型主动脉夹层的临床经验.方法 2006年1月至2010年10月,101例DeBakey Ⅰ型主动脉夹层患者接受改良全弓置换加支架象鼻术,其中急诊手术73例.全组男性76例,女性25例;年龄21～77岁,平均(49±8)岁.手术包括升主动脉置换术31例、Bentall术29例、Wheat术7例、David术34例.支架象鼻术的同时行左锁骨下动脉开窗以重建血运.在深低温停循环时改行双侧顺行脑灌注下完成脑保护.结果 手术改良后平均心肺转流时间(212±40)min,平均心肌阻断时间(95±16)min,平均停循环时间(42±8)min.手术死亡1例,住院死亡5例,分别死于感染败血症、急性肾功能衰竭、偏瘫并发多器官功能衰竭.双侧脑灌注后脑血管意外和短暂脑神经功能障碍的发生率低于选择性脑灌注.76例患者出院前复查主动脉CT血管造影,人工血管无扭曲,血流通畅,胸降主动脉夹层假腔闭合率为78.9%.71例随访5～49个月,其中50例复查CT血管造影,胸降主动脉夹层假腔闭合率为88.0%,无晚期死亡及再次手术者.结论 改良的全弓置换加支架象鼻术治疗DeBakey Ⅰ型主动脉夹层安全、有效,可减少术后并发症.

Abstract：

Objective To summarize the clinical study of modified total aortic arch replacement and stent elephant trunk technique treatment to patients with DeBakey Ⅰ thoracic aortic dissection. Methods From January 2006 to October 2010, 101 cases of DeBakey Ⅰ aortic dissection were treated by modified total arch replacement and stent elephant trunk technique, in which emergency surgery for 73 cases. There were 76 male and 25 female patients, aged from 21 to 77 years with a mean of(49 ±8)years. Intraoperative ascending aortic replacement in 31 cases, Bentall procedure in 29 cases, Wheat procedure in 7 cases, David procedure in 34 cases. At the same time stent elephant trunk in the left subclavian artery corresponding position was windowed to rebuild the blood supply. Deep hypothermic circulatory arrest cerebral protection was completed by bilateral antegrade cerebral perfusion. Results The mean cardiopulmonary bypass time was(212 ±40)min, mean myocardial occlusion time was(95 ± 16)min, mean circulatory arrest time was (42 ±8)min. Operative mortality was 1 case and hospital mortality was 5 case, which died of septicemia,acute renal failure and hemiplegia complicated with multiple organ failure. Compared with selective cerebral perfusion, the incidence of postoperative cerebral vascular accident and transient neurological dysfunction decreased. Seventy-six cases received aorta CTA before discharged, the closure rate of descending thoracic aortic dissection false lumen was 78. 9%. Seventy-one patients were followed up for 5 to 49 months, 50cases was reviewed by CTA, of which closure rate of descending thoracic aortic dissection false lumen was 88.0%, no late death and re-surgery. Conclusions The modified total aortic arch replacement and stent elephant trunk technique treatment for patients with DeBakey Ⅰ thoracic aortic dissection was safe and effective, with less postoperative complications.     

Early and long-term results of surgery for aneurysms of the thoracic aorta in septuagenarians and octogenarians.

OBJECTIVE: The purpose of this study was to demonstrate early and long-term results of surgery for thoracic aortic aneurysm in patients over 70 years of age compared with those of patients under 70 years and to clarify the clinical problems peculiar to this subset of patients. PATIENTS AND METHODS: Of 1157 patients who underwent surgery for thoracic aortic aneurysm from 1978 to December 1997, 261 who were 70 years or older were selected for analysis. Mean age at the time of surgery was 74.4 +/- 3.5 years. Aneurysms were atherosclerotic in 177 patients and aortic dissection in 84. Acute aortic dissection was found in 25 patients and ruptured aneurysm in 44. The control group consisted of 896 patients under 70 years. Preoperative complications such as AAA, peripheral arterial disease, emphysema, and old cerebral infraction were more common in the older group. Operative procedures consisted of replacement of the ascending aorta or hemiarch in 51 patients, total arch replacement in 75, distal arch replacement in 35, descending aorta replacement in 75, replacement of the thoracoabdominal aorta in 28, and extra-anatomical repair and others in 15. The technique of extracorporeal circulation was selective cerebral perfusion in 69 patients, deep hypothermic circulatory arrest in 90, femoro-femoral bypass in 39, left heart bypass in 12, and temporary aorto-arterial bypass in 30, and others in 21. RESULT: Early mortality was 21% (54 patients), which was greater than that of the control group (113 patients, 13%, P < 0.01). The incidence of postoperative stroke, transient brain dysfunction, and respiratory problems was higher in the study group (P < 0.01 in all). Mean duration in ICU among survivors was 9.3 +/- 20.2 days and that of the control group was 5.9 +/- 2.8 days (P < 0.01). In a recent series (from 1991 to 1997) postoperative mortality improved to 15.6% (30/192 patients) in the study group however this result was still inferior to that of the control group (8.6%, 39/452, P = 0.03) however mortality of emergency surgery during the same periods was still high (31%, 11/35 patients). Logistic regression analysis revealed that significant risk factors for postoperative hospital death were surgery before 1991, age over 70 years, preoperative cardiac problems, aneurysm rupture, postoperative stroke, low output syndrome, bleeding, and acute renal failure. Postoperative follow-up was obtained in 408 patients/year and the longest period was 10.2 years. Late deaths were documented in 31 patients. Five-year and 10-year survival were 61.2 +/- 5.7% and 31.3 +/- 16.4%, respectively. In the control group the 5-year and 10-year survival were 78.0 +/- 2.1% and 62.5 +/- 4.0%, respectively (P = 0.03). However, survival of the early survivors in the study group was similar with that of the age-matched normal population. Aortic reoperation was performed in 13 patients. Freedom from aortic reoperation was 86.7 +/- 4.2% at 5 years and 80.5 +/- 7.1% at 10 years in the study group and 83.4 +/- 1.8% at 5 years and 64.1 +/- 13.3% at 10 years in the control group (P = 0.27). CONCLUSION: Although recent advances have been achieved, early and long-term results of surgery for thoracic aortic aneurysm in patients older than 70 years were less satisfactory compared with those of patients under 70 years of age, especially in patients who required emergency surgery. Preoperative disorder of the vital organ systems was considered to be the main causative factor for high mortality, however, pertinent surgical strategies are necessary to improve the outcome of elderly patients.     

Retrograde replacement of the thoracic aorta under circulatory arrest and retrograde cerebral perfusion

Single-stage replacement of the ascending, transverse and descending thoracic aorta remains a noteworthy surgical intervention associated with significant morbidity. Aside from the surgical aspects, brain preservation during the circulatory arrest period, which is generally needed to perform the procedure, is a constant preoccupation for the surgeon. A 43-year-old man had an extensive thoracic aneurysm 4 years after an initial type A aortic dissection involving the entire thoracic aorta. The Cooley technique of retrograde replacement of the thoracic aorta was performed along with retrograde cerebral perfusion. The combined sternal and thoracic approach suggested for this technique provided excellent exposure and, despite a circulatory arrest time of 88 minutes, the patient’s cognitive abilities were found to be well preserved at follow-up 2 months after the surgery, indicating the efficacy of the cerebral retrograde perfusion. The authors conclude that retrograde replacement of the thoracic aorta combined with cerebral retrograde perfusion are convenient procedures that allow extensive aortic replacement without brain damage.     

Surgical treatment for a ruptured thoracic aortic aneurysm

OBJECTIVE: The treatment for a ruptured thoracic aortic aneurysm remains controversial. This study was undertaken to assess the outcome from surgery. METHODS: Between 1993 and 1998, we have performed 19 operations for a ruptured thoracic aortic aneurysm. Patients with an impending rupture or a chronic false aneurysm were excluded. There were 11 men and 8 women, with a mean age of 70.5 +/- 6.7 years. The aneurysm was caused by dissection in 8 patients. Of these, 7 were acute (Stanford type A, 6; type B, 1), and the other one was chronic (type B). Aortic rupture occurred into the pericardial cavity (n = 7), into the left lung (n = 6), the mediastinum (n = 3), the pleural cavity (n = 2), or into the esophagus (n = 1). Severely unstable hemodynamics were noted in 12 patients with a rupture into the pericardium, mediastinum, or pleural cavity (Group A). Inotropic support was required in each of these patients. Metabolic acidosis developed all but 1 patient. The 7 patients with a rupture into the lung or esophagus coughed or vomited blood (Group B). The operative approach was anterior (n = 17) or lateral (n = 2). Grafts were placed in the ascending aorta (n = 4), ascending and transverse arch aorta (n = 7), transverse arch aorta (n = 3), or in the descending thoracic aorta (n = 5). Selective cerebral perfusion was used in 13 patients. RESULTS: There were 5 hospital deaths (26.3%). The postoperative complications included central nervous system dysfunction (n = 3), low cardiac output syndrome or cardiac arrhythmias (n = 3), respiratory failure (n = 4), acute renal failure (n = 1), and local or systemic infections (n = 4). The perioperative event-free rate was 36.8% overall, 25% in Group A, and 57.1% in Group B. CONCLUSIONS: Patients with unstable hemodynamics require prompt operative intervention. Rupture into the esophagus is associated with a high mortality rate. Rupture in a thoracic aortic aneurysm can be successfully treated with emergency surgery.     

Surgical case of aortic root and thoracic aortic aneurysm after the Wheat procedure.

A 52 year-old man underwent aortic valve replacement and ascending aortic replacement (Wheat procedure) for acute dissection (Stanford type A) and aortic regurgitation (grade 3/4). At that time, the aortic root was slightly dilated at about 45 mm and the descending aorta was within a normal range at about 35 mm. Forty months after the initial operation, a follow-up chest enhanced computed tomography showed an aortic root aneurysm about 60 mm in diameter, a thoracic aortic aneurysm about 70 mm in diameter and chronic aortic dissection. First we performed the Bentall procedure, innominate artery and left common carotid artery replacement by 12 mm, and 10 mm Hemashield grafts during selective cerebral perfusion. After 10 weeks, we carried out aortic arch, descending aorta and left subclavian artery replacement. The postoperative course was uneventful and postoperative examination demonstrated a good surgical result. Histological findings of the aortic aneurysm wall showed cystic medial necrosis, but Marfan's syndrome was excluded clinically. We could diagnose aortic root aneurysm by regular follow-up chest enhanced computed tomography (CT) and echocardiography. Therefore, cases with slight dilation of the aortic root in the Wheat procedure should undergo regular follow-up evaluation by chest enhanced CT and echocardiography.     

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.     

Descending thoracic aortic aneurysms: surgical treatment with the Gott shunt.

Over the past 16 years, 267 consecutive patients underwent surgery for a descending thoracic aortic aneurysm. To provide optimal protection of surrounding organs during aortic occlusion, a 9-mm Gott shunt was used for distal perfusion in all cases. The shunt was placed preferentially between the ascending aorta and the descending aorta; however, alternative sites of proximal and distal cannulation were chosen according to the location and the extent of the aneurysmal disease and the presence of a concomitant aneurysm along the aortic conduit. In one-third of the patients, a flowmeter on the shunt recorded shunt flows, which varied from 1100 mL/min to 4900 mL/min (mean 2526 mL/min). Because the highest shunt flows were obtained with proximal systolic pressures lower than 140 mm Hg, nitroglycerin and nitroprussate were used routinely to improve distal perfusion by arterial vasodilation and release of proximal organs from a circulatory overload. The mean aortic cross-clamp time was 33 minutes for the entire series but was reduced to 25 minutes for the last 140 patients. The hospital death rate was 14.6% overall (12.2% if ruptured aneurysms were excluded). Of the 267 patients, 260 survived the operation and underwent clinical neurologic assessment. No paraplegia or other spinal-cord ischemic deficit occurred.     

Extrathoracic cannulation of the left common carotid artery in thoracic aorta operations through a left thoracotomy: preliminary experience in 26 patients

BACKGROUND: In aortic operations performed through a left thoracotomy, which require total bypass and deep hypothermic circulatory arrest, femoral artery cannulation is commonly used for arterial perfusion. This route limits the time of safe circulatory arrest and is associated with the risks of retrograde embolization or, in the case of aortic dissection, malperfusion of the vital organs. To overcome these problems, we have used cannulation of the extrathoracic left common carotid artery to ensure a central a route of arterial perfusion in these operations. The preliminary results are presented. METHODS: Between December 1999 and April 2001, we used left common carotid artery cannulation in 26 operations on the thoracic aorta performed through a posterolateral thoracotomy with an open technique during deep hypothermic circulatory arrest. Institutional review board approval and informed consent were obtained. The indications included perforating atherosclerotic ulcer (n = 5), chronic aortic aneurysm (n = 9), acute type B aortic dissection (n = 3), and chronic dissection of the thoracic aorta (n = 9). Transcranial Doppler ultrasonographic monitoring of both the right and left middle cerebral arteries was used to assess the adequacy of cerebral bihemispheric perfusion and to determine the differences in blood flow velocities throughout the procedure. RESULTS: Left common carotid artery cannulation was successful in all patients. All patients awoke from the operation, and none had cerebrovascular accidents. None died in the hospital, and complications related to carotid artery cannulation were not observed. None of the patients experienced postoperative paraplegia. In all patients transcranial Doppler monitoring indicated the absence of cerebral embolic phenomena throughout the entire procedure. Significant differences in middle cerebral artery flow velocities were observed at different phases of the procedures and between the right and left middle cerebral arteries during carotid cannulation and during selective cerebral perfusion. Nevertheless, the maximal drop of right middle cerebral artery blood velocity during selective perfusion through the left common carotid artery was within 50% of the left middle cerebral artery velocity, indicating adequate bihemispheric perfusion. CONCLUSIONS: In patients undergoing aortic operations through a left thoracotomy, extrathoracic left common carotid artery cannulation was a safe and effective means of providing proximal arterial inflow during cardiopulmonary bypass, which can be used to selectively perfuse the brain, as well as to prevent embolic phenomena in the arch vessels.     

Long-term results of total aortic arch replacement using selective cerebral perfusion

From June 1994 to July 2001, 92 consecutive patients underwent total aortic arch replacement using hypothermic selective cerebral perfusion. Forty-four patients had nondissecting fusiform or saccular aneurysms (non-ruptured 34, ruptured 10), and 48 patients had dissection (acute 37, chronic 11). Hospital mortality rate was 6.8% in the nondissecting group and 6.3% in the dissecting group. No major operative cerebral complications were observed. There were 9 late deaths in the nondissecting group and 5 late deaths in the dissecting group. The actuarial survival rate was 61.6% after 100 months in the nondissecting group and 82.5% after 86 months in the dissecting group (p = 0.5128). In the postoperative aortic accidents, there were 2 cases of the descending aortic rupture and 2 cases of cholesterol crystal embolization in the nondissecting group and 3 cases of thoracoabdominal grafting, 2 cases of re-operation in the ascending aorta and 1 case of descending aortic rupture in the dissection group. The actuarial freedom from aortic accidents was 88% after 100 months in the nondissecting group and 80% after 86 months in the dissecting group (p = 0.6908). Our surgical outcome of total aortic arch replacement using hypothermic selective cerebral perfusion are satisfactory.     

升主动脉和弓部动脉瘤的外科治疗

目的：总结升主动脉和弓部动脉瘤手术治疗经验，以期进一步提高手术疗效。方法：自2000年7月至2002年5月应用深低温停循环（DHCA）和上腔静脉逆行脑灌注（RCP）技术手术治疗升主动脉和弓部动脉瘤20例，其中急症手术5例。施行全弓置换术2例，全弓置换和象鼻手术3例，半弓置换术15例。同期行Bentall手术8例，升主动脉置换术或同时行主动脉瓣置换术12例，冠状动脉旁路移植术1例。结果：术后早期死亡1例，短时间浅昏迷1例，呼吸功能不全2例，肾功能不全2例，无晚期死亡。结论：DHCA和RCP技术是手术治疗升主动脉和弓部瘤的安全、有效方法，急性A型夹层动脉瘤的手术方式取决于内膜破裂口的位置；正确掌握DHCA和RCP技术，手术方式和手术技术、围术期处理是提高手术疗效的关键因素。