Masamichi Matsumori

Aggressive Surgical Treatment of Acute Pulmonary Embolism With Circulatory Collapse

BACKGROUND Acute high-risk pulmonary embolism is a life-threatening condition with high early mortality rates resulting from acute right ventricular failure and cardiogenic shock. We retrospectively analyzed the outcomes of surgical embolectomy among patients with circulatory collapse. METHODS Between July 2000 and September 2011, 24 consecutive patients (17 women and 7 men; mean age, 59.9±17.2 years) underwent emergency surgical embolectomy to treat acute pulmonary embolism with circulatory collapse. Nineteen (79.2%) patients were in cardiogenic shock, and 16 (66.7%) patients received preoperative percutaneous cardiopulmonary support. Eleven (45.8%) patients were in cardiac arrest. The preoperative pulmonary artery obstruction index was 76.9%±16.4% (median, 88.9%; range, 44.4%-88.9%). The indications for surgical intervention were cardiogenic shock (n=16 [66.7%]), failed medical therapy or catheter embolectomy (n=4 [16.7%]), or contraindication for thrombolysis (n=4 [16.7%]). Follow-up was 100% complete with a mean of 6.8±3.9 years (median, 5.6 years). RESULTS The in-hospital mortality rate was 12.5% (n=3). One patient underwent a repeated embolectomy on postoperative day 6. The postoperative course was complicated by cerebral infarction and by mediastinitis in 1 patient each. The 5-year cumulative survival rate was 87.5%±6.8%. Mean right ventricular pressure significantly decreased from 66.9 to 28.5 mm Hg among the survivors. CONCLUSIONS Surgical pulmonary embolectomy is an excellent approach to treating acute pulmonary embolism with circulatory collapse. Providing immediate percutaneous cardiopulmonary support to patients with cardiogenic shock could help to resuscitate and stabilize cardiopulmonary function and allow for a good outcome of pulmonary embolectomy.

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.

Controlled Earlier Reperfusion for Brain Ischemia Caused by Acute Type A Aortic Dissection

Brain malperfusion caused by acute type A aortic dissection is a life threatening situation that should be relieved as early as possible with minimal reperfusion injury prior to aortic repair. The patient was 72-year-old woman with acute type A aortic dissection. She was referred to us 2.5 hours after onset of chest pain, and she was unconscious with a complete left paralysis. The true lumen of internal carotid artery was severely stenosed. A simple bypass circuit was installed from the femoral artery to the true lumen of the right common carotid artery, which consisted with a roller pump and cold bath for blood cooling. Regional oxygen saturation of the right frontal brain was immediately raised after initiation of the bypass, and she underwent emergency ascending hemi-arch replacement. The postoperative course was complicated with a right brain stroke; however, brain computed tomography and magnetic resonance imaging disclosed minimum brain edema. She was discharged on foot on the 35th postoperative day, and she was walking with a stick after 7 months.

Extended replacement of aortic arch aneurysms through left posterolateral thoracotomy

OBJECTIVE To present our experience of total aortic arch replacement through a left posterolateral thoracotomy. METHODS Sixteen patients (13 males; mean age 62.1+/-11.3 years) with extended thoracic aortic aneurysms, including those in the thoracoabdominal aorta, underwent replacement through a left posterolateral thoracotomy. The pathology of the diseased aorta was non-dissecting aneurysm due to aortitis in 1 patient and aortic dissection in 15 patients (acute type A: 1, chronic type A: 12, chronic type B: 2). In a prior operation, the patient with aortitis had undergone the Bentall procedure with endovascular stenting of the brachiocephalic artery, and among the other 15 patients, one previously had endovascular stenting for the aortic arch and 12 had hemi-arch replacement for acute type A dissection. Extension of arch replacement was the aortic arch and descending aorta in eight patients, the ascending arch and descending aorta in five patients and the descending arch, and thoracoabdominal aorta in three patients. Additional retroperitoneal dissection was required for the repair of a thoracoabdominal aortic aneurysm. RESULTS One patient died of traumatic cerebral hemorrhage on day 145 (hospital mortality 6.3%). Average duration of ventilation support was 19.4+/-17.0h and length of ICU stay was 3.6+/-1.6 days. Actuarial survival at 2 years after the operations was 67.7%. However, no aortic-related mortality was observed during follow-up. CONCLUSIONS Early results of extended aortic arch replacement through a left posterolateral thoracotomy were satisfactory in selected patients.

Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular–Aortic Discontinuity

BACKGROUND Destructive aortic valve endocarditis causes the development of left ventricular-aortic discontinuity. Our experience of aortic root replacement in patients with the left ventricular-aortic discontinuity is presented. METHODS Between 1999 and 2006, 8 patients (7 men, 1 woman) with left ventricular-aortic discontinuity underwent aortic root replacement in our institute. Their mean age was 56 years. Six patients were in New York Heart Association functional class III or higher. Four patients were diagnosed to have native valve endocarditis, and 4 had prosthetic valve endocarditis (previous aortic valve replacements in 2 patients, aortic root replacements in 2). Radical débridement of the aortic root abscess was performed in all patients, followed by reconstruction of the aortic annulus using autologous or xenogenic pericardium in 2 patients. Fibrin glue saturated with antibiotics was applied into the cavity in 5 patients. Aortic root replacement was achieved with pulmonary autograft (Ross procedure) in 4 patients and stentless aortic root xenograft in 3. One patient who had advanced liver cirrhosis underwent aortic valve replacement with a stentless xenograft by subcoronary fashion. RESULTS No patients died during hospitalization or follow-up. Freedom from major adverse cardiac events was noted in 67% of the patients at 5 years. CONCLUSIONS An excellent outcome can be achieved by radical exclusion of abscess in the cavity, followed by root replacement with viable pulmonary autograft or flexible stentless aortic root xenograft in patients with left ventricular-aortic discontinuity.

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.

Augmentation of systemic blood pressure during spinal cord ischemia to prevent postoperative paraplegia after aortic surgery in a rabbit model

OBJECTIVE Paraplegia from spinal cord ischemia remains an unresolved complication in thoracoabdominal aortic surgery, with high morbidity and mortality. This study investigated postoperative effects of systemic blood pressure augmentation during ischemia. METHODS Spinal cord ischemia was induced in rabbits by infrarenal aortic occlusion for 15 minutes with infused phenylephrine (high blood pressure group, n = 8) or nitroprusside (low blood pressure group, n = 8) or without vasoactive agent (control, n = 8). Spinal cord blood flow, transcranial motor evoked potentials, neurologic outcome, and motor neuron cell damage (apoptosis, necrosis, superoxide generation, myeloperoxidase activity) were evaluated. RESULTS Mean arterial pressures during ischemia were controlled at 121.9 +/- 2.8, 50.8 +/- 4.3, and 82.3 +/- 10.7 mm Hg in high blood pressure, low blood pressure, and control groups, respectively. In high blood pressure group, high spinal cord blood flow (P < .01), fast recovery of transcranial motor evoked potentials (P < .01), and high neurologic score (P < .05) were observed after ischemia relative to low blood pressure and control groups. At 48 hours after ischemia, there were significantly more viable neurons, fewer terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling-positive neurons, and less alpha-fodrin expression in high blood pressure group than low blood pressure and control groups. Superoxide generation and myeloperoxidase activity at 3 hours after ischemia were suppressed in high blood pressure group relative to low blood pressure group. CONCLUSIONS Augmentation of systemic blood pressure during spinal cord ischemia can reduce ischemic insult and postoperative neurologic adverse events.

Sivelestat attenuates postoperative pulmonary dysfunction after total arch replacement under deep hypothermia

BACKGROUND Total arch replacement necessitating deep hypothermia with circulatory arrest has a greater effect on pulmonary function than other cardiac surgery using cardiopulmonary bypass (CPB). Since April 2004, 100mg of sivelestat sodium hydrate was administrated by bolus injection into pulp circuit at the initiation of CPB in every case performed total arch replacement. We investigated the hypothesis that prophylactic use of the drug attenuates post-pump pulmonary dysfunction. METHODS A retrospective analysis of 120 consecutive patients who underwent total arch replacement from August 2001 to December 2006 was conducted. Patients were divided into two groups according to the date of surgery, April 2004, when we started sivelestat administration. Group A (n=60), operated after April 2004, was administrated sivelestat at the initiation of CPB. Group B (n=60), before April 2004, was not administrated. Time courses of hemodynamic variables were evaluated until 24h after surgery and those of respiratory variables and inflammatory markers until 48 h after surgery. RESULTS There were no significant differences in patient age, sex, prevalence of chronic obstructive lung disease, preoperative lung function, time of operation and CPB, minimum temperature, and aprotinin usage. Hospital mortality occurred in two patients in the group B (3.3%) and no patient in group A (0%). Postoperative hemodynamic variables were not different between the two groups. Respiratory index, oxygenation index were significantly better in patients pretreated with sivelestat (respiratory index; p<0.001, oxygenation index; p<0.001, respectively). CRP was significantly lower in patients pretreated with sivelestat (p=0.022). Except for patients who required tracheostomy or re-exploration for bleeding, patients pretreated with sivelestat were extubated significantly shorter (group A: 12.6+/-10.8h, group B: 25.5+/-12.9h, p=0.033). No patient with postoperative respiratory failure requiring tracheostomy was noted in sivelestat group. CONCLUSION Prophylactic administration of sivelestat at the initiation of CPB results in better postoperative pulmonary function, leading to earlier extubation time. Our study suggests that sivelestat was effective in facilitating postoperative respiratory management in total arch replacement.