The Effects of the Warm Ischemic Time, the Preserving Temperature and the Cryopreservation Solution on the Viability of Tracheas / 대한흉부외과학회지

BACKGROUND: Tracheal reconstruction after extended tracheal resection still remains as a major surgical challenge because good clinical outcomes are usually correlated with limited tracheal resection. Recent investigations with a using cryopreserved trachea for the reconstruction of a trachea have been carried out to overcome this problem. In this study, we analyzed viability of tracheas, which is an important determining factor for the success of transplanting a cryopreserved trachea and the development of post-transplantation tracheal stenosis, according to three different experimental factors: 1) the warm-ischemic time, 2) the cryopreservation solution and 3) the preserving temperature, to determine a better cryopreservation protocol and a better composition of the cryopreservation solution. MATERIAL AND METHOD: Rats tracheas were harvested for different warm-ischemic times (0 hr, 12 hrs, 24 hrs). The tracheas were treated with recombinant insulin growth factor-1 (IGF-1) and they were stored at three different temperatures (4 degreesC, -80 degreesC, -196 degreesC) for two weeks. After two weeks, we thawed the stored trachea and isolated the cells of the tracheas with using type II collagenase. We cultured the cells for seven days and then we compared the cellular viability by the MTT reduction assay. RESULT: Though cryopreservation is required to preserve a trachea for a longer time period, the viability of the tracheas stored at -80 degreesC and -196 degreesC was significantly reduced compared to that of the tracheas stored at 4 degreesC. The viability of the tracheas with warm-ischemic times of 12 hrs and 24 hrs was also reduced in comparison to the tracheas with a warm-ischemic time of 0 hrs.Department of Thoracic and Cardiovascular Surgery, St. Mary's Hospital, The Catholic University of Korea College of Medicine Our data showed that the warm ischemic time and the parameters of cryopreservation negatively affect on trachea viability. However, a cryopresrvation solution containing IGF-1 improved the cellular viability better than the existing cryopreservation solution. For the warm ischemic time group of 0 hr, the addition of IGF-1 improved the viability of trachea at all the preserving temperatures. CONCLUSION: These experiments demonstrate that the viability of a cryopreserved trachea can be improved by modifying the components of the cryopreservation solution with the addition of IGF-1 and reducing the warm-ischemic time.

In-Hospital Outcomes of Acute Renal Failure Requiring Continuous Renal Replacement Therapy in Patients with On-pump CABG / 대한흉부외과학회지

BACKGROUND: Although acute renal failure (ARF) after coronary artery bypass graft (CABG) is relatively rare, but devastating complication with high mortality. Our study aims to evaluate the effectiveness of early application of CRRT in patients with ARF which developed after on-pump CABG. MATERIAL AND METHOD: Two hundred and eighty seven patients underwent isolated on-pump CABG between May 2002 and Feb. 2006 at our institution, of whom 15 (5.2%) needed CRRT (11 patients for postoperatively developed ARF and the remaining 4 patients with pre- existing dialysis-dependent chronic renal failure (CRF) for postoperative hemodynamic and metabolic control). Criteria for early application of CRRT were as follows; decreased urine output less than 0.5 cc/h/kg for 2 consecutive hours and elevated serum creatinine level greater than 2.0 mg/dL. RESULT: The incidence of ARF requiring CRRT after on-pump CABG was 3.9% (11/283) and the overall hospital mortality of patient with CRRT was 33.3% (5/15). Of 5 deaths, 4 were patients with postoperatively developed ARF, and 1 was a patient with pre-existing dialysis- dependent CRF patient. The mean time between the operation and the initiation of CRRT was 25.8+/-5.8 hours and the mean duration of CRRT was 62.1+/-41.2 hours. Of the 7 survivors who were not on dialysis-dependent preoperatively, 6 patients fully recovered renal function during hospital stay and 1 patient required permanent renal supportive treatment after discharge from hospital. CONCLUSION: Early application of CRRT could maintain stable postoperative hemodynamic status and make outcomes better than those of previous reports in patients with ARF which developed after on-pump CABG.