Shinsuke Nishimura

Mitral valve repair for atrial functional mitral regurgitation in patients with chronic atrial fibrillation

OBJECTIVES Atrial functional mitral regurgitation (MR) has been recently described in patients with chronic atrial fibrillation (AF). However, the results of surgical mitral valve (MV) repair for this type of MR have not been comprehensively reported. Our study aimed to address this deficiency. METHODS We retrospectively studied 10 chronic AF patients who underwent MV repair for atrial functional MR with normal left ventricular dimension and preserved left ventricular systolic function. All patients had chronic heart failure (HF) symptoms and at least one prior admission for HF complicated by severe MR. RESULTS Ring annuloplasty was performed in all patients; the median ring size was 26 mm (range, 26-30 mm). Concomitant tricuspid valve repair was undertaken in all patients. Preoperatively, left atrial (LA) diameter on the parasternal long-axis view, LA volume index and mitral annular diameter were 52 ± 9 mm, 72 ± 26 ml/m(2) and 33 ± 4 mm, respectively. There was no mortality and no re-admission due to HF during follow-up (range, 10-52 months). MR at the most recent examination was mild or improved in degree in all patients. The LA volume index decreased from the preoperative period, measuring 48 ± 17 ml/m(2) at the most recent period (P = 0.03). The New York Heart Association functional class dramatically improved from the preoperative period to the most recent period (from 3.0 ± 0.7 to 1.2 ± 0.4, P < 0.0001). CONCLUSIONS Our results suggest that MV repair leads to reductions in MR, LA size and HF symptoms, and that it may prevent future HF events in patients with atrial functional MR.

Endovascular Repair of Ruptured Aberrant Left Subclavian Artery With Right Aortic Arch

Association of a right-sided aortic arch with an aberrant left subclavian artery is rare. We present a case of successful endovascular repair of a ruptured Kommerell diverticulum associated with a right-sided aortic arch and aberrant left subclavian artery. We treated a 47-year-old woman with a diagnosis of ruptured aberrant left subclavian artery with thoracic endovascular stent-grafts. The descending aorta above Kommerell diverticulum was a reverse-tapered configuration. We managed the rather hostile neck with an extra-large Palmaz stent. A left carotid-to-subclavian bypass with an 8-mm Dacron graft was also performed to restore left arm perfusion and prevent vertebrobasilar insufficiency.

Effect of negative pressure wound therapy followed by tissue flaps for deep sternal wound infection after cardiovascular surgery: propensity score matching analysis

OBJECTIVES Deep sternal wound infection (DSWI) after cardiovascular surgery via median sternotomy remains a severe complication associated with a drastic decrease in the quality of life. We assessed the risk factors for in-hospital death caused by DSWI and the available treatments for DSWI. METHODS Between January 1991 and August 2015, we retrospectively reviewed 73 patients (51 males and 22 females, mean age 67.5 ± 10.3 years) who developed DSWI after cardiovascular surgery via median sternotomy. Pathogenic bacteria mainly comprised methicillin-resistant Staphylococcus aureus (MRSA) (49.3%). Fifteen patients (20.5%) died in hospital with DSWI. Treatment of DSWI consisted of open daily irrigation (up to 2006) or negative pressure wound therapy (NPWT) (2007 onwards), followed by primary closure or reconstruction of tissue flaps. We assessed the risk factors for in-hospital mortality from DSWI by comparing data from the 15 patients who died and the 58 survivors using propensity score matching analysis of the treatments used for DSWI. RESULTS Univariate analysis identified age, use of intra-aortic balloon pumping, prolonged mechanical ventilation, tracheotomy, prolonged intensive care unit stay, postoperative low output syndrome, postoperative myocardial infarction, postoperative renal failure, postoperative use of haemodialysis, postoperative pneumonia, postoperative cerebral disorder, MRSA infection, NPWT and tissue flaps as being associated with in-hospital mortality (P < 0.05). Multivariate analysis identified NPWT (odds ratio, 0.062; 95% confidence interval, 0.004-0.897; P = 0.041) and tissue flaps (odds ratio, 0.022; 95% confidence interval, 0.000-0.960; P = 0.048) as independently associated with reduced in-hospital mortality after DSWI. On comparing 22 patients receiving NPWT with 22 not on NPWT using propensity score matching, patients on NPWT had significantly lower in-hospital mortality than those without NPWT (NPWT vs non-NPWT, 5 vs 36%, P = 0.021). In DSWI infected by MRSA, NPWT significantly reduced the in-hospital mortality caused by DSWI (NPWT vs non-NPWT, 0 vs 52%, P = 0.003). CONCLUSIONS NPWT and tissue flaps may be favourable factors associated with reduced in-hospital mortality attributable to DSWI. NPWT as a bridge therapy to tissue flaps may play a major role in treating DSWI and improve the prognosis for patients with MRSA-infected DSWI.

Mitral valve repair with loop technique via median sternotomy in 180 patients

OBJECTIVES Artificial chordal reconstruction technique uses several expanded polytetrafluoroethylene loops to achieve mitral valve repair. METHODS We studied retrospectively 180 patients who underwent mitral valve repair using the loop technique via median sternotomy: 86 for posterior leaflet prolapse, 48 for anterior leaflet prolapse and 26 for bileaflet prolapse. RESULTS Of the 180 patients, 138 required 1 loop set; 40 patients required 2 and 2 patients with Barlows disease required 3. Loop sets contained two to nine loops ranging in length from 14 to 26 mm. Additional techniques required to ensure complete repair using the loop technique included commissural edge-to-edge suture in 78 patients, loop-in-loop technique for extension of the artificial loop in 18 and use of needle-side sutures in 18. Systolic anterior leaflet motion was observed in only 2 patients (1.1%). One patient with immune deficiency died of sepsis. Predischarge echocardiograms showed no or trace mitral regurgitation (MR) in 160 patients (89%), mild MR in 17 patients (9.4)% and mild-to-moderate MR in 3 patients (1.7%). Only 1 patient required redo operation due to recurrent MR freedom from MR greater than moderate was seen in 98.0 ± 1.4% of patients at 1 year, 91.5 ± 2.8% of patients at 3 years, and 91.5 ± 2.8% at 5 years postoperatively. No significant difference was seen in the rate of recurrence of MR among the sites of prolapsing leaflets. CONCLUSIONS The loop technique via median sternotomy to treat posterior, anterior and, especially, bileaflet prolapse provided satisfactory mid-term outcomes.

Evaluation of Aortic Valve Replacement via the Right Parasternal Approach without Rib Removal

BACKGROUND Although right parasternal approach (RPA) decreases the incidence of mediastinal infection, this approach is associated with lung hernia and flail chest. Our RPA employs thoracotomy with bending rib cartilages and wound closure performed by repositioning the ribs with underlying sheet reinforcement. METHODS We evaluated 16 patients who underwent aortic valve replacement via the RPA from January 2010 to August 2013. We compared outcomes of 15 male patients had the RPA with 30 male patients had full median sternotomy. RESULTS One patient with a history of radical breast cancer treatment underwent RPA with concomitant right coronary artery bypass grafting. No hospital deaths occurred. Four patients developed hospital-associated morbidity (re-exploration for bleeding, prolonged ventilation, cardiac tamponade, and perioperative myocardial infarction). There were no conversions to full median sternotomy, mediastinal infections, and lung hernias. Preoperative computed tomography showed that the distance from the right sternal border to the aortic root was significantly associated with operation times. With RPA, there was no significant difference in outcomes, despite significantly longer operation times compared with full median sternotomy. CONCLUSION Our RPA provides satisfactory outcomes without lung hernia, especially in patients unsuitable for sternotomy. Preoperative computed tomography is useful for identifying appropriate candidates for the RPA.

Intravascular ultrasound for transcatheter paravalvular leak closure.

Transcatheter closure of paravalvular leaks requires precise assessment of the location, size, and shape of the defect. Transesophageal echocardiography plays an important role in this process. We encountered a case of a paravalvular leak at the aortic position after aortic and mitral valve replacement. It was impossible to detect the precise location of the paravalvular leak with transesophageal echocardiography because of an acoustic shadow from the mitral mechanical valve. Intraoperative use of intravascular ultrasound was useful for determining the morphology of the defect and evaluating the procedure during the operation.

Transapical Endovascular Repair of Thoracic Aortic Pathology

BACKGROUND Alternative access for thoracic endovascular aortic repair (TEVAR) has been explored for patients with unsuitable femoral and iliac access, but few cases of transapical access have been described. We report our experience with transapical access for various aortic pathologies. METHODS We reviewed 6 cases undergoing transapical access for endovascular repair of thoracic aortic pathology between December 2013 and August 2015. Five patients had an aortic arch aneurysm and 1 patient presented with Stanford type A subacute aortic dissection. Transapical access was indicated to avoid approach through the severely atherosclerotic thoracic descending aorta in 4 patients and severely kinked aorta in 1 patient and to treat an ascending aortic dissection lesion in 1 patient. RESULTS Transapical endografting was completed in all patients. Significant aortic valve regurgitation occurred in 3 patients when a large bore sheath was placed across the aortic valve. There was 1 death attributed to global cerebral ischemia due to carotid dissection after carotid bypass and chimney stent-graft insertion. There were no access-related complications. Computed tomography revealed complete exclusion of the aortic aneurysm in 4 patients, and shrinkage of the false lumen in 1 patient with aortic dissection. CONCLUSIONS Transapical access for TEVAR would be a potential alternative when the anatomy is unfit for routine retrograde approach. This method might have potential benefit of reducing the risk of embolism in patients with severe atherosclerotic thoracic descending aorta. However, certain safety concerns must be addressed, including maintenance of hemodynamics, wire exteriorization for navigation of the device tip, and rapid pacing during deployment.

Successful surgical treatment for total circumferential aortic and mitral annulus calcification: application of half-and-half technique

Patients with total circumferential mitral annular calcification (MAC) extending into the intervalvular fibrous body and aortic annulus have a high risk of cardiac surgery, which remains a technical challenge for surgeons. Our technique for MAC is characterized as simple supra-mitral annular prosthesis insertion after minimum debridement of calcification (“half-and-half technique”). To date, our technique has been applied in only simple MAC cases and has good results. Herein, we report successful two cases of total circumferential MAC, extending into the intervalvular fibrous body and aortic annulus that were treated by a simple double valve replacement with application of our “half-and-half technique”.

Echocardiographic parameters predicting acute hemodynamically significant mitral regurgitation during transfemoral transcatheter aortic valve replacement

Alteration in mitral valve morphology resulting from retrograde stiff wire entanglement sometimes causes hemodynamically significant acute mitral regurgitation (MR) during transfemoral transcatheter aortic valve replacement (TAVR). Little is known about the echocardiographic parameters related to hemodynamically significant acute MR.

Delayed Intestinal Ischemia after Surgery for Type A Acute Aortic Dissection.

We report a rare case of delayed intestinal ischemia after total arch replacement for type A acute aortic dissection. At the onset of acute aortic dissection, computed tomography (CT) angiography revealed celiac trunk occlusion and progressive dissection into the superior mesenteric artery without stenosis. However, following total arch replacement, visceral malperfusion was not detected by exploratory laparotomy. On postoperative day 12, the patient developed paralytic ileus without an elevated lactate level. CT angiography revealed new superior mesenteric artery stenosis by a thrombosed false lumen with persistent celiac trunk occlusion. Endovascular treatment including stent implantation resolved intestinal ischemia.