Kyokun Uehara

Topical Application of a Biodegradable Disc With Amiodarone for Atrial Fibrillation

BACKGROUND Amiodarone is a potent anti-atrial fibrillation (AF) agent; however, its systemic administration induces serious side effects such as interstitial pneumonia. To avoid such effects, we developed a local sustained-release system for amiodarone. METHODS A biodegradable, cross-linkable dextran disc was developed as a sustained-release carrier for amiodarone. Under general anesthesia, Japanese white rabbits underwent median sternotomy and the biodegradable disc with or without amiodarone (30 mg) was implanted onto the surface of the right atrium. Three days after implantation, we measured tissue amiodarone concentrations (n = 5), the AF threshold, and the atrial effective refractory period of the left atrium by using the Langendorff apparatus. The incidences of induced AF evoked by rapid pacing were measured and compared. RESULTS The right atrial concentration of amiodarone was far higher than that in the lungs, ventricles, or other organs (p < 0.01). The blood concentration of amiodarone was below detectable levels. The amiodarone biodegradable disc significantly increased the AF threshold (amiodarone group, 6.9 ± 4.6 mA versus control group, 0.5 ± 0.6 mA; p < 0.01) and the effective refractory period (amiodarone group, 53.9 ± 8.9 milliseconds versus control group, 43.9 ± 9.5 milliseconds; p = 0.035) of the left atrium, indicating the electrophysiologic effect of the amiodarone biodegradable disc on the left atrium. Further, the amiodarone group was significantly less likely to experience AF, as compared with the control group (p < 0.01). CONCLUSIONS This approach may be a less invasive and effective therapeutic option for preventing postoperative AF.

Tricuspid valve repair for severe tricuspid regurgitation due to pacemaker leads

Background Tricuspid valve regurgitation due to pacemaker leads is a well-known complication. Although some reports have suggested that pacemaker leads should be surgically explanted, strongly adhered leads cannot always be removed. The aim of this study was to describe our tricuspid valve repair techniques with pacemaker leads left in situ. Methods Our retrospective study investigated 6 consecutive patients who required tricuspid valve surgery for severe regurgitation induced by pacemaker leads. Results From the operative findings, we identified 3 patterns of tricuspid valve and pacemaker lead involvement. In 3 patients, the leads were caught in the chordae, in 2 patients, tricuspid regurgitation was caused by lead impingement on the septal leaflet, and in 3 patients, tricuspid valve leaflets had been perforated by the pacemaker leads. During surgery, all leads were left in situ after being separated from the leaflet or valvular apparatus. In addition, suture annuloplasty was performed for annular dilatation in all cases. In one patient, the lead was reaffixed to the annulus after the posterior leaflet was cut back towards the annulus, and the leaflet was then closed. There was one hospital death due to sepsis. The degree of tricuspid regurgitation was trivial in all surviving patients at discharge. During a mean follow-up of 21 months, one patient died from pneumonia 20 months after tricuspid valve repair. Conclusion In patients undergoing tricuspid valve surgery due to severe tricuspid regurgitation caused by pacemaker leads, the leads can be left in situ after proper repair with annuloplasty.

Comparison of endovascular repair with branched stent graft and open repair for aortic arch aneurysm

OBJECTIVES Although conventional open repair is our preference for patients with aortic arch aneurysms, we have often chosen thoracic endovascular aneurysm repair (TEVAR) with a handmade branched stent graft (bTEVAR) in high-risk patients. The aim of this study was to compare the midterm clinical outcomes of our bTEVAR technique to those of the open repair. METHODS Between January 2007 and December 2014, we treated 129 patients with aortic arch aneurysm by means of either conventional open repair (OPEN, n = 61) or bTEVAR (n = 68) at our institution. RESULTS The mean ages were 70.5 ± 12.7 years in the OPEN group and 72.7 ± 12.5 years in the bTEVAR group (P = 0.32). The aetiologies included true aneurysm in 101 patients (78.3%) and chronic dissection in 26 (20.1%). There were 2 (3.3%) in-hospital deaths in the OPEN group and 3 (4.4%) in the bTEVAR group. The mean follow-up duration was 3.0 ± 2.1 years (2.4 ± 1.9 years in the OPEN group and 3.6 ± 2.3 years in the bTEVAR group). There was no difference in 5-year aneurysm-related mortality between groups (10.7% in OPEN vs 12.8% in bTEVAR, P = 0.50). In terms of late additional procedures, however, none were required in the OPEN group, whereas 10 (15.4%) additional endovascular repairs and 4 (6.2%) open repairs were required in the bTEVAR group. CONCLUSIONS Our bTEVAR could be performed with low early mortality, and it yielded similar midterm aneurysm-related mortality to that of conventional open repair. However, these patients undergoing this technique required more late additional procedures than those undergoing conventional open repair.

What is the optimal surgical strategy for Stanford Type A acute aortic dissection in patients with a patent false lumen at the descending aorta

OBJECTIVES Aggressive total arch replacement (TAR) to obtain thrombosis of the distal false lumen (FL) in patients with Stanford Type A acute aortic dissection, particularly with a patent FL at the descending aorta, is discussed. The aim of this study was to examine the efficacy of our strategy. METHODS In the last 20 years, we retrospectively reviewed the records of 518 patients with Type A acute aortic dissection who underwent an emergent surgery. Among them, 290 patients with a preoperative patent FL at the descending aorta were enrolled in this study. Patients were divided in 2 groups: the non-TAR group (n = 124; 68 ± 14 years) and the TAR group (n = 166; 61 ± 13 years). RESULTS In-hospital mortality was 11% (32/290) without significant difference between the 2 groups (the non-TAR group 13% vs the TAR group 10%, P = 0.45). The rates of FL thrombosis of the entire descending aorta were detected at 32% in the non-TAR group and 41% in the TAR group (P = 0.16). Freedom from distal aortic dilatation ≥50 mm was significantly higher in the TAR group (P = 0.03) than in the non-TAR group. Independent predictors of distal aortic dilatation >50 mm were patients in the non-TAR group (P = 0.01; hazard ratio 3.1, 95% confidence interval 1.28-8.05) and unachieved primary entry tear resection (P = 0.002; hazard ratio 6.2, 95% confidence interval 1.38-8.66). CONCLUSIONS Our surgical strategy with an aggressive entry resection with higher rate of TAR was acceptable. In patients with a patent FL at the descending aorta, TAR should be considered to prevent the future growth of the distal aorta.

Efficacy of protocol‐based pharmacotherapy management on anticoagulation with warfarin for patients with cardiovascular surgery

Anticoagulation therapy with warfarin requires periodic monitoring of prothrombin time‐international normalized ratio (PT‐INR) and adequate dose adjustments based on the data to minimize the risk of bleeding and thromboembolic events. In our hospital, we have developed protocol‐based pharmaceutical care, which we called protocol‐based pharmacotherapy management (PBPM), for warfarin therapy. The protocol requires pharmacists to manage timing of blood sampling for measuring PT‐INR and warfarin dosage determination based on an algorithm. This study evaluated the efficacy of PBPM in warfarin therapy by comparing to conventional pharmaceutical care.

Early and late outcomes of open repair for dissecting aneurysms of the descending or thoraco-abdominal aorta

OBJECTIVES Although open repair is the standard surgical option for dissecting descending thoracic aneurysms (DTAs) and thoraco-abdominal aorta aneurysms (TAAAs), it remains a significant challenge with considerable perioperative morbidity and mortality. We retrospectively analysed early and late outcomes of open repair for these aortic aneurysms. METHODS Early and late outcomes were investigated for 223 consecutive patients who underwent open repair for dissecting DTA or TAAA between January 2003 and December 2014 (mean age 55 ± 16 years). The basic strategy for open surgery comprised liberal use of deep hypothermia and aggressive preservation or reattachment of intercostal arteries, i.e. donor arteries for the artery of Adamkiewicz. RESULTS Deep hypothermia was used in 150 (67.3%) patients. The overall in-hospital mortality rate was 3.6% and 1.5% for elective cases. The rates of spinal cord ischaemic injury and stroke were 3.1% and 4.5%, respectively. During follow-up (mean 63 ± 40 months), overall 5-year survival rates was 89.2 ± 2.4% and 91.3 ± 2.8% and 86.3 ± 4.1% for DTA and TAAA, respectively. Five- and 10-year rates of freedom from aortic events, defined as surgery for initial operation-related events or for downstream aortic dilation, were 89.1 ± 3.5% and 68.2 ± 7.8% for DTA and 100% and 96.6 ± 3.4% for TAAA, respectively (P < 0.01). CONCLUSIONS Our approach in treating this aortic pathology showed favourable early and long-term outcomes with acceptable neurological complication rates. More careful follow-up is necessary in patients with DTA repair, because downstream aortic enlargement occurs in some patients.

Alternative redo sternotomy in a patient with tracheostoma and patent grafts.

We describe a redo mitral valve replacement operation in a 71-year-old man with a tracheostoma and patent bypass grafts to the coronary arteries. Preoperative investigations revealed that the patent right internal thoracic artery graft ran directly under the sternum just anterior to the ascending aorta, and a saphenous vein graft was adhering to a surgical wire. To prevent injury to the patent grafts and cardiac structures, and to avoid communication with the tracheostoma, the redo procedure was performed via an anterior minithoracotomy combined with a low T-shaped partial sternotomy. The reoperation was successfully completed without any complications.

Fracture Embolization of an Edwards-Duromedics Valve with Asymmetrical Closure

We report a case of sudden leaflet fracture of an Edwards-Duromedics mitral valve 17-years after its implantation. The patient had a history of an asymmetrical motion of the valve, five months earlier. A computed tomography scan showed two fragments that had embolized to the right brachiocephalic artery and left common iliac artery. An emergency mitral replacement surgery was successfully performed. Asymmetrical closure of the valve leaflet may have contributed to valve fracture.

Balloon protection of the left subclavian artery in debranching thoracic endovascular aortic repair

Objectives: Since 2012, we have routinely applied balloon protection of the proximal left subclavian artery to prevent embolic events through the left vertebral artery during debranching thoracic endovascular aortic repair. This study aimed to study the effectiveness of balloon protection of the proximal left subclavian artery. Methods: We reviewed the medical records of 157 patients who underwent debranching thoracic endovascular aortic repair between 2007 and 2017. Of these, 71 patients for whom balloon protection of the proximal left subclavian artery was used were assigned to the balloon protection of the proximal left subclavian artery group (58 men; age: 78 ± 6.7 years), and 86 patients were assigned to the control group (66 men; age: 78 ± 8.9 years). A total of 51 patients from each group were matched by their propensity scores to adjust for differences in the patients’ characteristics. Results: Perioperative stroke was significantly lower in the balloon protection of the proximal left subclavian artery group than in the control group (0%: 0/71 vs 7.9%: 7/86, P = .014). Freedom from all causes of mortality at 2 and 4 years was significantly higher in the balloon protection of the proximal left subclavian artery group compared with the control group (93%/76% vs 77%/59%, P = .015). Freedom from aortic death at 2 and 4 years was similar in both groups (97%/97% vs 91%/86%, P = .094). Propensity score matching yielded similar results of better freedom from all causes of mortality in the balloon protection of the proximal left subclavian artery group (93%/93% vs 81%/63%, P = .017) and equivalent aortic death in both groups (95%/95% vs 92%/88%, P = .30). Conclusions: Debranching thoracic endovascular aortic repair using balloon protection of the proximal left subclavian artery demonstrated more appropriate early and late outcomes. Evaluation using propensity score matching enhanced the efficacy of balloon protection of the proximal left subclavian artery.

Type IIIB endoleak caused by fabric erosion after thoracic endovascular aneurysm repair

A 78-year-old man who had undergone coronary artery bypass grafting and thoracic endovascular aortic repair (TEVAR) for a descending aortic aneurysm 7 years ago (A) developed chest pain. At the initial TEVAR, two stent grafts (Talent; Medtronic, Santa Rosa, Calif) were used; the distal stent graft (34 115 mm) was deployed first, and the proximal stent graft (36 114 mm) was deployed inside the distal stent graft. Contrast-enhanced computed tomography (CT) revealed rupture of the descending aneurysm with weak enhancement of the thrombus outside the stent graft (B). The rupture was diagnosed to be due to type II endoleak, and emergent replacement of the descending aorta was indicated. The aneurysm was exposed through the fourth intercostal space, and femorofemoral partial cardiopulmonary bypass was established with systemic heparinization. Inside the aneurysm, blood flowing out through the hole of the upper stent graft was detected (C). Both stent grafts were partially removed, and 28-mm Gelweave (Vascutek Terumo, Inchinnan, Glasgow, United Kingdom) was anastomosed to the residual stent grafts and native aorta. His postoperative course was vuneventful except for refixation of the rib, and he was discharged home 3 weeks later. Postoperative CT revealed patency of the graft (A). Detailed review of the past CT scan revealed that the bare stent of the distal stent graft had dug into the fabric of the proximal stent graft on the minor curvature (C). At this portion, the erosion was not found 2 years and 5 years after TEVAR but was detected at 7 years with rupture (D). Consent for the publication of images was obtained from the patient in a written form.