M. Gwak

Comparison of the tolerance of hepatic ischemia/reperfusion injury in living donors: macrosteatosis versus microsteatosis.

A safe use of intermittent hepatic inflow occlusion (IHIO) has been reported for living donor hepatectomy. However, it remains unclear whether the maneuver is safe in steatotic donors. In addition, the respective importance of macrosteatosis (MaS) and microsteatosis (MiS) is an important issue. Thus, we compared MiS and MaS with respect to the tolerance of hepatic ischemia/reperfusion (IR) injury induced by IHIO. One hundred forty‐four donors who underwent a right hepatectomy were grouped according to the presence of MaS and MiS: a non‐MaS group (n = 68) versus an MaS group (n = 76) and a non‐MiS group (n = 51) versus an MiS group (n = 93). The coefficients of the regression lines between the cumulative IHIO time and the peak postoperative transaminase concentrations were used as surrogate parameters indicating the tolerance of hepatic IR injury. The coefficients were significantly greater for the MaS group versus the non‐MaS group (4.12 ± 0.59 versus 2.22 ± 0.46 for alanine aminotransferase, P = 0.01). Conversely, the MiS and non‐MiS groups were comparable. A subgroup analysis of donors who underwent IHIO for >30 minutes showed that MaS significantly increased the transaminase concentrations, whereas MiS had no impact. Also, IHIO for >30 minutes significantly increased the biliary complication rate for MaS donors (12.1% for ≤ 30 minutes versus 32.6% for >30 minutes, P = 0.04), whereas MiS donors were not affected. In conclusion, the tolerance of hepatic IR injury might differ between MaS livers and MiS livers. It would be rational to assign more clinical importance to MaS versus MiS. We further recommend limiting the cumulative IHIO time to 30 minutes or less for MaS donors undergoing right hepatectomy. Liver Transpl 20:775–783, 2014.

Evaluation of "Flat-Line" Thromboelastography After Reperfusion During Liver Transplantation

BACKGROUNDnFlat-line (no clot formation) thromboelastography (TEG) is frequently observed after graft reperfusion during liver transplantation (LT). We aimed to evaluate the incidence and causes of flat-line TEG after graft reperfusion during LT.nnnMETHODSnWith institutional review board approval, data of 208 consecutive recipients who underwent LT from May 2010 to May 2012 were retrospectively reviewed. We performed 3 different types of TEG measurements at 5 minutes after graft reperfusion: native TEG (nTEG), tranexamic acid-added TEG (tTEG), and protamine-added TEG (pTEG). The flat-line TEG was defined as having no trace at all at 60 minutes of TEG. We examined the incidence and causes of flat-line nTEG. We also compared recipients with flat-line nTEG (F group) and clot-forming nTEG (C group).nnnRESULTSnOne hundred eighty-two recipients were included in the final analysis. The incidence of flat-line nTEG was 27% (49/182 cases). Among 49 recipients in the F group, 28 recipients showed clot formation in both tTEG and pTEG, 19 recipients in only tTEG, and 1 recipient in only pTEG; 1 recipient showed no clot formation in any TEGs. Graft from the deceased donor was more frequently observed in the F group than in the C group (P = .039). The F group showed decreased platelet count (P = .001), increased prothrombin time (P = .002), and decreased fibrinogen (P = .009) compared with the C group.nnnCONCLUSIONSnNo clot formation was relatively common after reperfusion during LT, and the main causes were hyperfibrinolysis and heparin effect. Liver graft from deceased donors was associated more frequently with no clot formation after reperfusion during LT.

Higher Risk of Post-Transplant Graft Failurein Male Recipients of Female Donor Grafts is not Due to Anastomosis Mismatch

Objective To evaluate the association between donor gender and mortality after living donor liver transplantation (LDLT) with adjustment for size mismatch issues. Methods This retrospective cohort study analyzed 309 non-HCC male recipients who underwent LDLT between 2003 and 2016 in our center. Survival analysis was performed using the Cox model to compare death risk of recipients who received grafts from female donors (female donor group) and those who received graft from male donors (male donor group). Backward selection was performed for selecting variables during multivariable analysis. Size mismatch issues included the size/number/anastomosis type of the hepatic artery, hepatic vein, portal vein, and bile ducts (Table 1). Results The median follow-up time was 60 months. Death probability at 1/2/5 years after transplantation was 20.2/24.0/27.0% in female donor group and 8.1/10.1/13.5% in male donor group (Fig. 1). Death risk was significantly higher in male donor groupin univariable analysis (HR=2.28 [1.34–3.87], P=0.002) and in multivariable analysis (HR=1.88 [1.04-3.41], P=0.037). The following variables were included in the multivariable model: donor gender, operative year, ascites degree, encephalopathy degree, bile duct size, bile duct anastomosis type, and red blood cell transfusion. As shown in Fig. 1, the two groups showed most differences in death probabilities within 6 months after transplantation with 6-month mortality was 5.5% in female donor group versus 18.3% in male donor group (P<0.001). Conclusion Donor gender appears to be an important graft factor modulating death risk after LDLT irrespective of the size/number/anastomosis type of graft vessels and bile ducts. Possible mechanisms include the disparity in the changes in sex hormone receptors between male donor grafts and female donor grafts after transplantation.

Predictive Factors of Vasopressor Weaning After Reperfusion in Liver Transplantation.: Abstract# D2627

D2627 Predictive Factors of Vasopressor Weaning After Reperfusion in Liver Transplantation. G. Kim,1 J. Jun,1 H. Park,1 Y. Na,1 J. Ko,1 M. Gwak,1 S. Lee.2 1Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 2Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of. A. Hyperdynamic circulation with decreased systemic vascular resistance (SVR) is common in recipients of liver transplantation (LT) and usually aggravated after reperfusion.Vasopressor was used to maintain adequate mean blood pressure (MBP) and tapered as MBP was increased. We investigated the factors associated with delayed weaning of vasopressor after reperfusion in LT. B. With approval of IRB, 361 LT recipients from October 2010 to July 2013 were retrospectively reviewed. We used vasopressor when MBP < 70mmHg and SVR < 600 dyne · s · cm -5. High dose vasopressor therapy was defi ned as a requirement of ≥ 0.2 mcg/kg/min of norepinephrine equivalent (calculated by summing norepinephrine equivalent infusion rates of all vasopressors). Recipients who weaned the vasopressor down to 0.03mcg/kg/min within 24 hours after reperfusion were early weaning group (E group), and others were late weaning group (L group). Various clinical factors were compared between two groups. C.Ninety-six recipients required high vasopressor therapy after reperfusion, and early tapering of vasopressor occurred in 51% (49/96). Two groups were not different in age, comorbidity (hypertension, diabetes, and ascites), preoperative medications (angiotensin receptor blocker, calcium channel blocker, beta blocker, and diuretics), preoperative hematocrit, sodium, and graft characteristics (type, age, gender ratio, cold ischemic time, warm ischemic time, macrosteatosis, microsteatosis, and graft-recipient weight ratio). However, female gender ratio (p=0.038), MELD score (p=0.025), preoperative lactate (p=0.027), intraoperative RBC transfusion (p < 0.001) were higher, while preoperative albumin (p=0.028) was lower in L group than E group. D. Female gender, poor preoperative recipient condition (high MELD score, high lactate, and low albumin), and intraoperative RBC transfusion increased the prevalence of late weaning of vasopressor after reperfusion of graft in LT. Abstract# D2628 Management of Recipients With Hyponatremia During and After Liver Transplantation; Ten Year Experience of Single Center. G. Kim,1 B. Heo,1 E. Oh,1 H. Park,1 J. Ko,1 M. Gwak,1 S. Youn,2 S. Lee.3 1Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 2Intensive Care Unit, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 3Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of. A.Hyponatemia is frequently found in recipients of liver transplantation (LT) and a known risk factor for specifi c neurologic complication, central pontine myelinolysis (CPM). Although usually recommended rate of sodium increase is ≤ 10mEq/L/d, there was no proven method of safe correction. Since there were few reports about the management of hyponatremia in LT, we report our results of ten year period. B.With IRB approval, consecutive 1000 LT recipients from December 2004 to July 2013 were retrospectively reviewed. We tried to maintain preoperative sodium level during LT with half saline, and after LT with omission of sodium in main fl uid and drug mix fl uid until recipients started oral intake. C.Fifty-three adult LT recipients had preoperative hyponatremia (≤ 125 mEq/L). D2628 Management of Recipients With Hyponatremia During and After Liver Transplantation; Ten Year Experience of Single Center. G. Kim,1 B. Heo,1 E. Oh,1 H. Park,1 J. Ko,1 M. Gwak,1 S. Youn,2 S. Lee.3 1Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 2Intensive Care Unit, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 3Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of. A.Hyponatemia is frequently found in recipients of liver transplantation (LT) and a known risk factor for specifi c neurologic complication, central pontine myelinolysis (CPM). Although usually recommended rate of sodium increase is ≤ 10mEq/L/d, there was no proven method of safe correction. Since there were few reports about the management of hyponatremia in LT, we report our results of ten year period. B.With IRB approval, consecutive 1000 LT recipients from December 2004 to July 2013 were retrospectively reviewed. We tried to maintain preoperative sodium level during LT with half saline, and after LT with omission of sodium in main fl uid and drug mix fl uid until recipients started oral intake. C.Fifty-three adult LT recipients had preoperative hyponatremia (≤ 125 mEq/L). Characteristics of recipients with hyponatremia were age 50.6 ± 9.8 years, gender ratio (male 81.1%), body weight 63.7 ± 11.9 kg, MELD score 27.7 ± 10.9, graft type (living 38 vs deceased 15 patients) and indication of LT (HBV 33, HCV 10, Alcoholic 6, Others 4 patients). Although large amounts of isotonic saline-based solutions and blood products (10,326 ± 3,872 ml) were administered intraoperatively, sodium change during LT was 6.1 ± 3.3 mEq/L, and intraoperative sodium increase > 10mEq/L was observed in 3 recipients. Oral intake was started at postoperative day (POD) 6.1 ± 2.5, and sodium change until oral intake was 9.7 ± 6.3 mEq/L. Three recipients with sodium increase > 10mEq/L within 24 h period including LT operation time did not develop neurological manifestations suggesting CPM. In contrast, magnetic resonance imaging (MRI) fi ndings suggestive of CPM were detected in 3 other recipients. But, daily sodium increase was less than 10mEq/L and the reason for MRI examination was nonspecifi c (headache, tremor, and rigidity). D.In spite of our effort, we couldn’t completely maintain preoperative sodium level. Vigilant monitoring of sodium level is strongly recommended to decrease the risk of CPM in LT recipients with hyponatremia. Abstract# D2629 Graft Function and Incidence of Biliary Stenosis After Use of UW or IGL1 Preservation Solutions for Liver Transplantation. A. Lima,1 T. Casali,2 M. Duarte,1 P. Machado,3 R. Porto,3 M. Carvalho Jr.3 1Liver Transplantation Department, Instituto Alfa de Gatroenterologia, Hospital das Clinicas da UFMG, Belo Horizonte, Minas Gerais, Brazil; 2Post Graduation Course, Faculty of Medicine, UFMG, Belo Horizonte, Minas Gerais, Brazil; 3Faculty of Medicine, UFMG, Belo Horizonte, Minas Gerais, Brazil. PURPOSE: To comparatively evaluate the outcome of liver grafts and recipient patients after perfusion of IGL1 or UW preservation solutions to liver transplantation. METHODS: Randomized prospective study evaluated 43 hepatic transplants by means of the following data: clinical and laboratory profi le of donors, postoperative hepatic enzymes levels and post-transplant complications. RESULTS: UW was used in 21 cases whereas 22 were perfused with IGL1 preservation solution. Norepinephrine dose, length of ICU stay, cause of brain death and Donor Risk Index were similar for IGL1 and UW groups. Recipients presented with similar gender distribution, age and MELD scores. Recipient’s AST, ALT, LDH, and total bilirubin levels had similar values from the fi rst to seventh postoperative day (p > 0.05). Allograft dysfunction, primary non-function of the graft, and death rates were similar between groups. Biliary stenosis were four times more prevalent in UW perfused group (19%) as compared to IGL1 (4.5%), p > 0.05. This complication was signifi cantly higher in the UW perfused graft when a subgroup of donors younger than 60 years of age was considered (p = 0.048). CONCLUSION: Perfusion of liver grafts with IGL1 solution resulted in similar outcome when compared to UW perfused graft. A trend to lower biliary complications was observed and a signifi cantly lower rate of biliary damage was confi rmed in transplants of grafts younger than 60 years old. Abstract# D2630 The Effect of a Radiologic Diagnosis of Portal Vein Thrombosis On Outcome: Is an Aggressive Search Warranted? A. Hauch,1 C. Winkler,1 E. Katz,1 M. Killackey,1 A. Paramesh,1 L. Balart,2 N. Shores,2 M. Moehlen,2 W. Miller,2 D. Slakey,1 J. Buell,1 B. Saggi.1 1Surgery (Transplantation), Tulane University School of Medicine, New Orleans, LA; 2Medicine (Hepatology), Tulane University School of Medicine, New Orleans, LA. Background: Liver transplantation (LT) with portal vein thrombosis (PVT) has many pitfalls. The risk factors for PVT are not well-defi ned, and its diagnosis may be elusive. The effects of an occult PVT on outcome are not clear. We review the effects of a lack of a pre-LT diagnosis of PVT on outcome at a single center. Methods: A retrospective analysis of 216 adult patients undergoing LT from 2007 to 2013 was undertaken. Ultrasound (US), CT, MRI, and retrograde portal venography (RPV) were used. Survival, length of stay (LOS), and transfusion (PRBC) were analyzed (ANOVA). Preoperative characteristics were evaluated to identify risk factors for PVT. A multivariate analysis of survival was done with a Cox proportional hazards model. Results: 30/2016 (13.8%) patients had PVT at LT. 205 patients had at least one study within one year of LT. 7/30 PVT patients (23.3%) had at least one positive imaging study. The results of diagnostic studies are below: D2630 The Effect of a Radiologic Diagnosis of Portal Vein Thrombosis On Outcome: Is an Aggressive Search Warranted? A. Hauch,1 C. Winkler,1 E. Katz,1 M. Killackey,1 A. Paramesh,1 L. Balart,2 N. Shores,2 M. Moehlen,2 W. Miller,2 D. Slakey,1 J. Buell,1 B. Saggi.1 1Surgery (Transplantation), Tulane University School of Medicine, New Orleans, L