Toshihito Sakamoto

Recent advancements of total aortic arch replacement

OBJECTIVE Recent advancements in total aortic arch replacement achieved by our approach were presented. METHODS From January 2002 to December 2010, 321 consecutive patients (mean age 69.8 ± 13.3 years) underwent total arch replacement through a median sternotomy at our institute. Aortic dissection was present in 94 (28.3%) patients and shaggy aorta in 36 (11.2%), with emergency/urgent surgery required in 106 (33.0%). Our current approach included the following: (1) meticulous selection of arterial cannulation site and type of arterial cannula; (2) antegrade selective cerebral perfusion; (3) maintenance of minimal tympanic temperature between 20 °C and 23 °C; (4) early rewarming just after distal anastomosis; (5) after 2004, bolus injection of 100 mg of sivelestat sodium hydrate into the pump circuit at the initiation of cardiopulmonary bypass; (6) after 2006, maintaining fluid balance below 1000 mL during cardiopulmonary bypass. RESULTS Overall hospital mortality was 4.4% (14/321) and was 1.9% (4/215) in elective cases. Permanent neurologic deficit occurred in 4.4% (14/321) of patients and in 2.8% (6/215) of elective cases. Prolonged ventilation was necessary in 53 (16.5%), with a significant reduction after 2006 (22.8% vs 12.6%; P = .02). Multivariate analysis demonstrated that risk factors for hospital mortality were octogenarian (odds ratio, 4.32; P = .03), brain malperfusion (odds ratio, 21.2; P = .001) and cardiopulmonary bypass time (odds ratio, 1.01; P = .04). Survival at 3 and 5 years after surgery was 82.4% ± 2.5% and 78.5% ± 3.1%, respectively. CONCLUSIONS Our current approach for total aortic arch replacement was associated with low hospital mortality and morbidities and with favorable long-term outcome.

Aortic regurgitation after valve-sparing aortic root replacement: modes of failure.

BACKGROUND Despite the positive clinical results of valve-sparing aortic root replacement, little is known about the causes of reoperations and the modes of failure. METHODS From October 1999 to June 2010, 101 patients underwent valve-sparing aortic root replacement using the David reimplantation technique. The definition of aortic root repair failure included the following: (1) intraoperative conversion to the Bentall procedure; (2) reoperation performed because of aortic regurgitation; and (3) aortic regurgitation equal to or greater than a moderate degree at the follow-up. Sixteen patients were considered to have repair failure. Three patients required intraoperative conversion to valve replacement, 3 required reoperation within 3 months, and another 8 required reoperation during postoperative follow-up. At initial surgery 5 patients had moderate to severe aortic regurgitation, 6 patients had acute aortic dissections, 3 had Marfan syndrome, 2 had status post Ross operations, 3 had bicuspid aortic valves, and 1 had aortitis. Five patients had undergone cusp repair, including Arantius plication in 3 and plication at the commissure in 2. RESULTS The causes of early failure in 6 patients included cusp perforation (3), cusp prolapse (3), and severe hemolysis (1). The causes of late failure in 10 patients included cusp prolapse (4), commissure dehiscence (3), torn cusp (2), and cusp retraction (1). Patients had valve replacements at a mean of 23 ± 20.9 months after reimplantation and survived. CONCLUSIONS Causes of early failure after valve-sparing root replacement included technical failure, cusp lesions, and steep learning curve. Late failure was caused by aortic root wall degeneration due to gelatin-resorcin-formalin glue, cusp degeneration, or progression of cusp prolapse.

Early and late outcomes of repaired acute DeBakey type I aortic dissection after graft replacement

OBJECTIVE The present study aimed to determine the impact of the extent of graft replacement on early and late outcomes in acute DeBakey type I aortic dissection. METHODS Between October 1999 and July 2014, 197 consecutive patients were surgically treated for acute DeBakey type I aortic dissection. The extent of graft replacement (hemiarch, partial, or total arch replacement) was mainly determined by the location of the primary entry. Early and late results were compared in patients after total arch replacement (n = 88) and combined hemiarch and partial arch replacement: non-total arch replacement (n = 109). RESULTS The in-hospital mortality rates of the total arch replacement and non-total arch replacement groups were 10.2% and 14.7%, respectively (P = .47). Multivariate analysis revealed preoperative cardiopulmonary resuscitation and visceral organ malperfusion as significant risk factors for in-hospital mortality, but not total arch replacement. During a mean follow-up period of 60 ± 48 months, the 5-year survivals in the total arch replacement and non-total arch replacement groups were 88.6% ± 4.2% and 83.8% ± 4.4%, respectively (P = .54). Rates of distal aortic events (defined as freedom from surgery for distal aorta dilation or distal arch diameter expanding to 50 mm) at 5 years were significantly better in the total arch replacement group than in the non-total arch replacement group (94.9% ± 3.5% vs 83.6% ± 4.9%, P = .01). CONCLUSIONS The operative mortality of patients with acute DeBakey type I aortic dissection treated by total arch replacement was acceptable with good long-term survival after both total arch replacement and non-total arch replacement. The frequency of distal aortic events might be reduced in patients after total arch replacement compared with non-total arch replacement.

Strategies for the treatment of aorto-oesophageal fistula

OBJECTIVES Presenting a surgical strategy for aorto-oesophageal fistula (AEF). METHODS From October 1999 to August 2013, 16 patients with AEF were treated at Kobe University Hospital. The mean age was 65.5 ± 10.2 years, and the male/female ratio was 13/3. Eight patients had non-dissecting thoracic aneurysm, 3 had chronic aortic dissection, 5 had oesophageal cancer and 1 had fish bone penetration. Five patients were in shock. Four patients had previous thoracic endovascular aortic repair (TEVAR) in the descending aorta and 1 had hemi-arch replacement. As treatment for AEF, 8 patients underwent TEVAR, 2 had a bridge TEVAR to open surgery, 2 had extra-anatomical bypass (EAB) and 5 had in situ reconstruction of the descending aorta. The oesophagus was resected in 8 patients, and an omental flap was installed in 7 patients. For the 4 most recent cases, simultaneous resection of the aorta and oesophagus, in situ reconstruction of the descending aorta using rifampicin-soaked Dacron graft and omental flap installation were performed. RESULTS Hospital mortality was noted in 4 patients (25.0%; persistent sepsis n = 3 and pneumonia n = 1). However, since 2007, only 1 of 5 patients died (pneumonia). All patients with oesophageal cancer died during follow-up. Two patients underwent oesophageal reconstruction using a pedicled colon graft and one is on the waiting list for oesophageal reconstruction. CONCLUSIONS Bridging TEVAR is a useful adjunct in treating AEF patients with shock. One-stage surgery consisting of resection of the aneurysm and oesophagus, in situ reconstruction of the descending aorta and omental flap installation provided a better outcome in the AEF surgical strategy compared with conservative treatment.

Mid-Term Results of Valve-Sparing Aortic Root Replacement in Patients With Expanded Indications

BACKGROUND The mid-term results of valve-sparing aortic root reimplantation (VSRR) for various indications were investigated. METHODS From 2000 to 2013, 183 consecutive patients undergoing VSRR were enrolled. Expanded indications, defined as a patient on the marginal operative indication, included age 65 years or older (n = 33), age 15 years or younger (n = 4), acute type A aortic dissection (AAAD) (n = 21), aortitis (n = 8), reoperative root replacement (n = 11), cusp prolapse (n = 67), large aortoventricular junction of greater than 28 mm (AVJ) (n = 42), preoperative severe aortic regurgitation (AR) (n = 89), left ventricular ejection fraction 0.40 or less (n = 12), LV dilation (n = 66), New York Heart Association class III or greater (n = 5), need for total arch replacement (n = 29), and concomitant mitral valve repair (n = 12). RESULTS The overall survival at 5 years was 96.6%. Freedom from greater than mild AR and reoperation at 5 years was 85.8% and 92.9%, respectively. Cox proportional hazard model revealed that AAAD, cusp prolapse, AVJ 28 mm or greater, and operation before 2009 were at risk for late AR recurrence (p = 0.015, p = 0.0041, p = 0.032, and p = 0.014, respectively). After 2009, freedom from late AR in the cusp prolapse group improved (p = 0.055, versus control). Both freedom from recurrent AR and reoperation were worse as the number of expanded indications increased (log-rank trend p = 0.00017 and p = 0.00067, respectively). CONCLUSIONS Surgical outcomes of VSRR in these patient cohorts were satisfactory with some room for improvement in patients with cusp prolapse. Although the indications for VSRR are being expanded, a larger number of expanded indications were associated with poor outcomes in terms of longevity of valve function.

Early and Late Results of Graft Replacement for Dissecting Aneurysm of Thoracoabdominal Aorta in Patients With Marfan Syndrome

BACKGROUND When treating dissecting aneurysm of the thoracoabdominal aorta surgically in patients with Marfan syndrome, we have usually performed graft replacement- including the entire thoracoabdominal aorta and reconstruction of all visceral branches, even if dilatation is mild in some segments-to avoid further aortic operations in the follow-up period. METHODS From October 1999 through July 2011, 20 consecutive patients with Marfan syndrome underwent repair of dissecting aneurysm of the thoracoabdominal aorta (median age, 45 years; range, 19-65 years). All patients underwent surgical intervention with cerebrospinal fluid (CSF) drainage and distal aortic and selective organ perfusion. Deep hypothermia was used in 13 patients for spinal cord protection. RESULTS No in-hospital mortality was observed. One patient had temporary spinal cord ischemia but was fully recovered by discharge. Other complications included exploration for bleeding (n=1), prolonged ventilation (n=1), and graft infection (n=1). At a mean follow-up of 54 months (range, 9-129 months), 1 patient had died of interstitial pneumonia at 38 months postoperatively. Survival at 8% years was 91.2±9.0%. Two patients required additional aortic procedures (total arch replacement and aortic valve-sparing surgery). Actuarial rate of freedom from aortic operations at 8 years was 83.9%±10.5%, but no patient needed required repeated thoracotomy for an aortic procedure. Neither false nor patch aneurysms were observed using computed tomography (CT) during follow-up surveillance. CONCLUSIONS Graft replacement for dissecting aneurysm of the thoracoabdominal aorta in Marfan syndrome offers good early and long-term results. We believe total aortic replacement including the entire thoracoabdominal aorta and reconstruction of all visceral arteries should be recommended for selected patients with Marfan syndrome.

Open reconstruction of thoracoabdominal aortic aneurysms

Technical details of our strategy for reconstructing the thoracoabdominal aorta are presented. Between October 1999 and June 2012, 152 patients underwent surgery for thoracoabdominal aortic aneurysms (Crawford classification type I =21, type II =43, type III =73, type IV =15). Mean age was 64.6±13.9 years. Sixty-three (41.4%) patients had aortic dissection, including acute type B dissection in 2 (1.2%) and ruptured aneurysms in 17 (11.2%). Eight (5.3%) patients had mycotic aneurysms, and 3 (2.0%) had aortitis. Emergent or urgent surgery was performed in 25 (16.4%) patients. Preoperative computed tomography (CT) scan or magnetic resonance (MR) angiography detected the Adamkiewicz artery in 103 (67.8%) patients. Cerebrospinal fluid drainage (CSFD) was performed in 115 (75.7%) patients and intraoperative motor evoked potentials were recorded in 97 (63.8%). One hundred and seven (70.4%) patients had reconstruction of the intercostal arteries from T7 to L2, 35 of which were reconstructed with the aortic patch technique and 72 with branched grafts. The mean number of reconstructed intercostal arteries was 3.1±2.5 pairs. Mild hypothermic partial cardiopulmonary bypass at 32-34 °C was used in 105 (69.1%) patients, left heart bypass was used in 4 (2.6%), and deep hypothermic cardiopulmonary bypass below 20 °C was used in 42 (27.6%). Thirty-day mortality was 9 (5.9%), and hospital mortality was 20 (13.2%). Independent risk factors for hospital mortality were emergency surgery (OR 13.4, P=0.003) and aortic cross clamping over 2 hours (OR 5.7, P=0.04). Postoperative spinal cord ischemia occurred in 16 (10.5%, 8 patients with paraplegia and 8 with paraparesis). Risk factors for developing spinal cord ischemic complications were prior surgery involving either the descending thoracic or the abdominal aorta (OR 3.75, P=0.05), diabetes mellitus (OR 5.49, P=0.03), and post-bypass hypotension <80 mmHg (OR 1.06, P=0.03). Postoperative survival at 5 years was 83.6±4.5%; 5-year survival was 47.5±8.6% in patients with spinal cord ischemia and 88.9±10.4% in those without spinal cord ischemia.

Early patency rate and fate of reattached intercostal arteries after repair of thoracoabdominal aortic aneurysms

OBJECTIVES The present study analyzes the early patency of intercostal artery reconstruction, using graft interposition and aortic patch anastomosis, and determines the fate of reattached intercostal arteries after repair of thoracoabdominal aortic aneurysms. METHODS We selected 115 patients (mean age, 63 ± 15 years; range, 19-83 years; male, n = 83) treated by thoracoabdominal aortic aneurysm repair with 1 or more reconstructed intercostal arteries at the Kobe University Graduate School of Medicine between October 1999 and December 2012. The intercostal arteries were reconstructed using graft interposition (n = 66), aortic patch anastomosis (n = 42), or both (n = 7). RESULTS The hospital mortality rate was 7.8% (n = 9). Eleven patients (9.6%) developed spinal cord ischemic injury (permanent, n = 6, transient, n = 5). The average number of reconstructed intercostal arteries per patient was 3.0 ± 1.5 (1-7), and 345 intercostal arteries were reattached. The overall patency rate was 74.2% (256/345) and that of aortic patch anastomosis was significantly better than that of graft interposition (90.8% [109/120] vs 65.3% [147/225], P < .01), but significantly worse for patients with than without spinal cord ischemic injury (51.9% [14/27] vs 76.1% [242/318], P = .01). There was no patch aneurysm in graft interposition during a mean of 49 ± 38 (range, 2-147) postoperative months, but aortic patch anastomosis including 4 intercostal arteries became dilated in 2 patients. CONCLUSIONS Aortic patch anastomosis might offer better patency rates and prevent spinal cord ischemic injury compared with graft interposition. Although aneurysmal changes in intercostal artery reconstructions are rare, large blocks of aortic wall reconstruction should be closely monitored.

Influences of Chronic Obstructive Pulmonary Disease on Outcomes of Total Arch Replacement

BACKGROUND Although an association between chronic obstructive pulmonary disease (COPD) and adverse surgical outcomes has been proposed, the impact of COPD severity on postoperative outcomes remains unclear. Our objective was to analyze the prognostic implication of COPD severity on outcomes after total aortic arch replacement. METHODS Between October 1999 and December 2012, 269 patients undergoing total arch replacement through median sternotomy, who were elective cases with preoperative spirometry records, were retrospectively reviewed. Patients were divided into four groups: control group, with ratio of forced expiratory volume of air in 1 second (FEV1) to forced vital capacity (FVC) of 70% or greater; mild airflow obstruction, with FEV1/FVC ratio less than 70% and FEV1 80% or greater of predicted; moderate airflow obstruction, FEV1/FVC ratio less than 70% and FEV1 50% to 79% of predicted; severe airflow obstruction, FEV1/FVC ratio less than 70% and FEV1 less than 50% of predicted. Symptoms of functional dyspnea and disability were also assessed. Multivariate logistic and Cox regression methods were used to determine if there was an independent association between COPD and short-term and long-term outcomes, respectively. RESULTS The in-hospital mortality rate was 2.2% (6 of 269). A consistent trend of increasing frequency of postoperative respiratory complications with advanced airflow obstruction was noted. In multivariate analysis, in-hospital mortality (p = 0.022), incidence of respiratory complications (p = 0.021) and overall mortality (p = 0.025) was significantly associated with the symptoms of COPD, respectively. CONCLUSIONS The severity of COPD as defined by spirometry and symptoms of functional dyspnea may be an important prognostic marker of patients undergoing total arch replacement.

Surgical techniques of total arch replacement using selective antegrade cerebral perfusion

This detailed illustrated article describes our preferred surgical technique of total arch replacement using selective antegrade cerebral perfusion (SACP). Our current approach includes: (I) meticulous selection of arterial cannulation site and type of arterial cannula; (II) SACP for neuro-protection; (III) whole body hypothermia with minimal tympanic temperatures between 20 and 23 °C and minimal rectal temperatures below 30 °C; (IV) early re-warming after distal anastomosis with SACP flow adjustment while monitoring brain oxygenation by near infrared spectroscopy (NIRS); and (V) after 2006, maintaining strict fluid balance below 1 L by the extracorporeal ultrafiltration method (ECUM) during cardiopulmonary bypass (CPB), with the expectation of more rapid pulmonary functional recovery.