S H Chu's research while affiliated with Chang Gung University and other places

Backgrounds: Fractional flow reserve of myocardium (FFRmyo) is a functional study of significant coronary artery stenosis, defined as the ratio of the pressure distal to the stenosis (poststenosis) divided by the pressure of aortic root (prestenosis). Instead of cath laboratory, we could measure it in operating room for off-pump coronary artery bypass (OPCAB) surgery and here shared our methods in the pilot study. Methods and results: We used needles, catheters, and pressure tracing but without guidewires or fluoroscopy to measure FFRmyo during OPCAB. In February 2010, we conducted the pilot study and collected 32 anastomosis data from 10 patients. Without revising the anastomosis plans based on coronary angiographies, 24 FFRmyo of the 32 anastomoses (75%) were less than 0.75, which represented significant functional stenosis. The FFRmyo measurements did not lead to any adverse events. Conclusion: The measurement of fractional flow reserve in OPCAB is safe and feasible. It can serve as a functional assessment of coronary artery stenosis in adjuvant to conventional coronary angiography.

We reviewed the national results of heart transplantation in Taiwan. From July 1987 to December 2012, 1354 patients underwent heart transplantation in 18 qualified heart centers in Taiwan. The transplantation volume and survival rate were reviewed. The median age of recipients was 49 years at surgery, with 37% in the International Society for Heart and Lung Transplantation (ISHLT)-1A, 30% in ISHLT-1B, and 32% in ISHLT-2. The allograft 1-, 3-, 5-, and 10-year survival rates were 78%, 68%, 61%, and 47%, respectively. Mostly difficult recipients were bridged by extracorporeal membrane oxygenation (ECMO) instead of ventricular assist device (VAD). The results of heart transplantation in Taiwan are comparable with ISHLT world results. In Taiwan, we use more ECMO than VAD for mechanical circulatory support to bridge critical recipients to heart transplantation.

Background Obesity has been related to poor renal graft function. The aim of this study was to compare the long-term graft outcomes of living-related kidney recipients regarding donor-to-recipient body mass index (BMI) parameters using the old Quetelet BMI formula and the new Trefethen BMI formula. Methods From November 2002 to November 2010, 62 consecutive living-related kidney transplantations were reviewed retrospectively. Four donor-to-recipient BMI parameters were used: (1) BMI difference by the old formula, (2) BMI difference by the new formula, (3) BMI ratio by the old formula, and (4) BMI ratio by the new formula. Long-term outcomes, including graft survival (GS) and rejection-free graft survival (RFGS) either overall or at 5 years post-transplantation, were analysed according to these parameters. Results The baseline demography was similar among tertiles according to the four BMI parameters tested. Although there is no significant difference in the long-term survivals by the old and new BMI formula, we found that the area under receiver operating characteristic (ROC) curve is larger using the new formula, either by BMI difference (0.584 vs 0.559 in 5-year GS and 0.658 vs 0.636 in 5-year RFGS) or by BMI ratio (0.584 vs 0.561 in 5-year GS and 0.644 vs 0.626 in 5-year RFGS). The same trend was observed in overall survival outcomes. Conclusion The new Trefethen BMI formula seems to predict long-term renal graft outcomes better than the old Quetelet BMI formula.

Background: Serum amyloid A (SAA), associated with C-reactive protein (CRP), had unknown roles in off-pump coronary bypass operations and hence we would like to explore. Methods: From 43 consecutive patients with uneventful OPCAB, SAA and CRP serum sample were collected at preoperative baseline, postoperative hour 0, hour 6, hour 12, day 1, day 3, and day 7. Relative serum level ratios (serum levels divided by preoperative baselines) were used for analyses. Results: CRP and SAA both climbed since postoperative hour 6 and peaked at day 3. Except for postoperative hour 6 and day 3, they did not differ significantly. From postoperative hour 6 to day 7, CRP and SAA had significant time-wise correlation. Age and gender had no significant time-wise correlation with the CRP or SAA. Conclusion: For uneventful OPCAB cases, SAA and CRP had similar time trends from immediate postoperative to one week, not affected by age or gender.

For cardioplegia delivery and removing air from the aorta in minimally invasive mitral valve operations, we would like to propose a cost-effective pigtail method. The 8F pigtail punctures the aorta, delivers cardioplegia, and stays in place for removing air from the aorta. We then slide its tip out of the aorta as an accessory drain. With more than 100 successes, we are using it in every case and would like to share it with peer surgeons. (Ann Thorac Surg 2013;95:e77-8) (C) 2013 by The Society of Thoracic Surgeons

Background: Caudate hepatectomy remains a surgical challenge in spite of recent advances in laparoscopic technique. Hepatic tumor in the caudate lobe is usually deeply located in the center of the liver and close to the vena cava and hepatic hilum. Thus, lesion in this region was considered as a contraindication of laparoscopic hepatectomy. Only sporadic reports could be found in the literature. The aim of this study is to review the safety and feasibility of laparoscopic hepatectomy for lesions in the caudate lobe. Methods: Nine consecutive patients with caudate hepatic tumor received laparoscopic caudate hepatectomy in our institute from February 2006 to July 2010. One patient with hepatic adenoma was excluded from the analysis. Demographic data, intraoperative parameters, and postoperative outcomes of the remaining eight patients were assessed. Results: All procedure for these eight patients with caudate hepatic tumors (size 0.9-4.5 cm) were completed with totally laparoscopic technique except one in which additional left hepatectomy was also done. The average operative time was 254 min (range 210-345 min) and estimated blood loss was 202 ml (range 10-1,000 ml), and average length of postoperative hospital stay was 6.9 days (range 4-11 days). There was no perioperative complications and patient mortality in this series. Conclusions: Our experience demonstrated that laparoscopic hepatectomy is a safe and feasible procedure for caudate hepatic tumors in selected patients.