Advanced 3D Through-Si-Via and Solder Bumping Technology: A Review.

Three-dimensional (3D) packaging using through-Si-via (TSV) is a key technique for achieving high-density integration, high-speed connectivity, and for downsizing of electronic devices. This paper describes recent developments in TSV fabrication and bonding methods in advanced 3D electronic packaging. In particular, the authors have overviewed the recent progress in the fabrication of TSV, various etching and functional layers, and conductive filling of TSVs, as well as bonding materials such as low-temperature nano-modified solders, transient liquid phase (TLP) bonding, Cu pillars, composite hybrids, and bump-free bonding, as well as the role of emerging high entropy alloy (HEA) solders in 3D microelectronic packaging. This paper serves as a guideline enumerating the current developments in 3D packaging that allow Si semiconductors to deliver improved performance and power efficiency.

Ultrasonic-Assisted Dispersion of ZnO Nanoparticles to Sn-Bi Solder: A Study on Microstructure, Spreading, and Mechanical Properties.

Nanocomposite Sn-Bi solders received noticeable attention for flexible electronics due to their improved mechanical properties. The main limitation is the dispersion of nanoparticles in the solder alloy. Accordingly, in this work, varying additions of ZnO nanoparticles were successfully dispersed into Sn57Bi solder via the liquid-state ultrasonic treatment. Nanocomposite solders were prepared using the melting and casting route. The solder alloys were then characterized for microstructure, spreading and mechanical properties. With increasing ZnO addition, the microstructure revealed significant refinement of Bi- and Sn-rich phases. Consequently, the eutectic lamellar spacing also decreases. The spreading improved up to 0.1 wt.% ZnO addition. For higher additions, nanocomposite solders experienced deterioration in spreading characteristics. The tensile strength of the solder increases with an increase in the amount of ZnO nanoparticles. High ductility is achieved for nanocomposite solder containing 0.05 wt.% ZnO. An attempt was made, to explain the effect of increasing ZnO nanoparticle addition on microstructural, spreading, and mechanical properties of Sn57Bi solder.

Predictors of Disease Progression or Performance Status Decline in Patients Undergoing Neoadjuvant Therapy for Localized Pancreatic Head Adenocarcinoma.

INTRODUCTION: Neoadjuvant therapy (NT) is a growing strategy in localized head pancreatic adenocarcinoma (PDC). However, a significant portion of NT patients do not reach resection due to disease progression or performance status decline. We sought to identify predictors of disease progression or performance status decline during NT. METHODS: Retrospective cohort analysis of consecutive patients with localized head-PDC who received NT at a tertiary referral center between 2005 and 2017. Univariate and multivariate (MVA) analysis were performed to identify factors associated with disease progression or performance status decline during NT preventing surgical resection. RESULTS: A total of 479 patients with PDC underwent NT; 71.2% proceeded to surgery, 20.5% had disease progression, and 8.3% experienced performance status decline. Median OS was 28 [95% confidence interval (CI) 23.8-32.3], 12.8 (CI 11.2-14.3), and 6.9 (CI 5.2-9.4) months, respectively (p < 0.05). MVA predictors of disease progression were larger clinical CT tumor size [odds ratio (OR) 1.03, CI 1.0-1.1], unplanned change in NT regimen (OR 2.6, CI 1.0-6.9), hospital admission during NT (OR 2.2, CI 1.2-3.9), and lack of CA19-9 response (OR 4.4, CI 4.0-8.4). MVA predictors of performance status decline were increasing age (OR 1.1, CI 1.0-1.2), presence of pre-NT diabetes (OR 3.8, CI 1.3-11.3), hospital admission during NT (OR 14.0, CI 3.9-49.8), and lack of CA19-9 response (OR 4.7, CI 1.4-15.5). CONCLUSIONS: This analysis identifies several predictors of disease progression and performance status decline during NT for PDC. Knowledge of these factors informs the physician on the risks and limitations of NT and provides insight to guide patient selection and counseling.

Correction to: Serum CA19-9 Response to Neoadjuvant Therapy Predicts Tumor Size Reduction and Survival in Pancreatic Adenocarcinoma.

In the original article, Caroline J. Rieser's last name is spelled wrong. It is correct as reflected here.

Serum CA19-9 Response to Neoadjuvant Therapy Predicts Tumor Size Reduction and Survival in Pancreatic Adenocarcinoma.

BACKGROUND: The optimal cutoffs for carbohydrate antigen 19-9 (CA19-9) response after neoadjuvant therapy (NT) for pancreatic adenocarcinoma (PDAC) are not well characterized. This study aimed to analyze the relationship of serum CA19-9 to other markers of response and to identify thresholds correlating to outcomes. METHODS: A retrospective review of resected PDAC patients from 2010 to 2017 at an academic tertiary referral center was conducted. RESULTS: The analysis enrolled 250 subjects. Normalization and multiple cutoff points for CA19-9 response were assessed. Normalization was not associated with improved survival (35.17 vs. 29.43 months; p = 0.173). Although a response 45% or higher was associated with longer survival (35 vs. 20 months; p = 0.018), a response of 85% or higher was optimal (55.7 vs. 25.97 months; p < 0.0001). A response of 85% or higher remained a strong independent predictor of survival [hazard ratio (HR), 0.47; p = 0.007]. Subjects with a response of 85% or higher had received more NT cycles [3 (range 2-6) vs. 3 (range 2-4) cycles; p = 0.006] and fewer adjuvant cycles [4 (range 3-6) vs. 5 (range 3-6) cycles; p = 0.027]. Reduction in T-size correlated with a drop in CA19-9 and a size reduction of 25% or higher (56.97 vs. 28.17 months; p = 0.016) improved survival. A serum CA19-9 response of 85% or higher was a strong independent predictor of a reduction in T-size of 25% or higher (HR 2.40; p = 0.007). CONCLUSION: A CA19-9 response of 85% or higher is the optimal threshold for predicting survival. It is predictive of T-size reduction. Future NT trials should incorporate CA19-9 response as an end point.

Effect of ZrO2 Nanomaterials on Wettability and Interfacial Characteristics of Al-19Cu-11Si-2Sn Filler Metal for Low Temperature Al to Cu Dissimilar Brazing.

Dissimilar Al 3003 and Cu tubular components were successfully brazed without interface cracking using ZrO2 nanomaterials reinforced with Al-19Cu-11Si-2Sn filler. The filler was initially cast using an induction furnace and processed into ring form for brazing. Al-19Cu-11Si-2Sn filler with coarse CuAl2 and Si phases (43 and 20 µm) were refined to 8 and 4 µm, respectively, after the addition of 0.1 wt. % ZrO2 and shows significant improvement in the mechanical properties. ZrO2 nanomaterials' induced diffusion controlled growth mechanism is found be the responsible for the refinement of CuAl2 intermetallic and Si particles. The wettability of Al-19Cu-11Si-2Sn-0.1ZrO2 increased to 78.17% on Cu side and 93.19% on the Al side compared from 74.8% and 89.9%, respectively. Increase in the yield strength, ultimate tensile strength, and percentage elongation were noted for the brazed joints. Microstructure of induction brazed joint with 40 kW for 6 seconds using Al-19Cu-11Si-2Sn-0.1ZrO2 filler shows thin interfacial CuAl2 intermetallic compound along the copper side and inter-diffusion region along the aluminum side and their respective mechanism is discussed. The tensile strength of the joints increased with increasing the nanomaterials addition and shows a base metal fracture. Analysis of fractured samples shows the effectiveness of ZrO2 reinforced filler in crack propagation through the filler.

Use of Video Review to Investigate Technical Factors That May Be Associated With Delayed Gastric Emptying After Pancreaticoduodenectomy.

Importance: Technical proficiency at robotic pancreaticoduodenectomy (RPD) and video assessment are promising tools for understanding postoperative outcomes. Delayed gastric emptying (DGE) remains a major driver of cost and morbidity after pancreaticoduodenectomy. Objective: To determine if technical variables during RPD are associated with postoperative DGE. Design, Setting, and Participants: A retrospective study was conducted of technical assessment performed in all available videos (n = 192) of consecutive RPDs performed at a single academic institution from October 3, 2008, through September 27, 2016. Exposures: Video review of gastrojejunal anastomosis during RPD. Main Outcomes and Measures: Delayed gastric emptying was classified according to International Study Group of Pancreatic Surgery criteria. Video analysis reviewed technical variables specific in the construction of the gastrojejunal anastomosis. Using multivariate analysis, DGE was correlated with known patient variables and technical variables, individually and combined. Results: Of 410 RPDs performed, video was available for 192 RPDs (80 women and 112 men; mean [SD] age, 65.7 [11.1] years). Delayed gastric emptying occurred in 41 patients (21.4%; grade A, 15; grade B, 14; and grade C, 12). Patient variables contributing to DGE on multivariate analysis were advanced age (odds ratio [OR] 1.11; 95% CI, 1.05-1.16; P < .001), small pancreatic duct size (OR, 0.84; 95% CI, 0.72-0.98; P = .03), and postoperative pseudoaneurysm (OR, 17.29; 95% CI, 2.34-127.78; P = .005). However, technical variables contributing to decreased DGE on multivariate analysis included the flow angle (within 30° of vertical) between the stomach and efferent jejunal limb (OR, 0.25; 95% CI, 0.08-0.79; P = .02), greater length of the gastrojejunal anastomosis (OR, 0.40; 95% CI, 0.20-0.77; P = .006), and a robotic-sewn anastomosis (robotic suture vs stapler: OR, 0.30; 95% CI, 0.09-0.95; P = .04). Conclusions and Relevance: This study examines modifiable technical factors through the use of review of video obtained at the time of operation and suggests ways by which the surgical construction of the gastrojejunal anastomosis during RPD may reduce the incidence of DGE as a framework for prospective quality improvement.

Application of Surface Protective Coating to Enhance Environment-Withstanding Property of the MEMS 2D Wind Direction and Wind Speed Sensor.

In this study, a microelectromechanical system (MEMS) two-dimensional (2D) wind direction and wind speed sensor consisting of a square heating source and four thermopiles was manufactured using the heat detection method. The heating source and thermopiles of the manufactured sensor must be exposed to air to detect wind speed and wind direction. Therefore, there are concerns that the sensor could be contaminated by deposition or adhesion of dust, sandy dust, snow, rain, and so forth, in the air, and that the membrane may be damaged by physical shock. Hence, there was a need to protect the heating source, thermopiles, and the membrane from environmental and physical shock. The upper protective coating to protect both the heating source and thermopiles and the lower protective coating to protect the membrane were formed by using high-molecular substances such as SU-8, Teflon and polyimide (PI). The sensor characteristics with the applied protective coatings were evaluated.

Low incidence of KRAS, BRAF, and PIK3CA mutations in adenocarcinomas of the ampulla of Vater and their prognostic value.

Ampullary adenocarcinomas (A-ACs) are rare malignancies with considerable importance because of their high curable resection rate and improved survival rate among periampullary cancers. The RAS-RAF-MAPK pathway is involved in the development of A-ACs and is a potential therapeutic target. However, molecular profiles of A-ACs and their prognostic impact are poorly understood. Peptide nucleic acid-mediated polymerase chain reaction clamping and Mutyper were used to detect KRAS, BRAF, and PIK3CA mutations in 62 paraffinized samples of A-ACs. Of 62 A-ACs, 30.6% had KRAS mutations, but no BRAF mutations and low frequency (1.6%) of PIK3CA mutation were detected. KRAS mutation was correlated with poor tumor differentiation and was a predictor of shorter recurrence-free survival period in overall A-ACs, whereas the prognosis according to the histologic subtypes was not affected by KRAS mutation. Lymph node metastasis was an independent prognostic factor of poor overall survival. Intestinal- and pancreatobiliary-type A-ACs had similar prognosis. Intestinal- and pancreatobiliary-type A-ACs had different prognostic factors; tumor differentiation and lymph node metastasis strongly predicted overall survival and recurrence-free survival in pancreatobiliary-type tumors, respectively, whereas no independent prognostic factors were demonstrated for intestinal-type tumors. Low incidence of KRAS mutations and their strong prognostic value in A-ACs may suggest the potential of survival benefit depending on the epidermal growth factor receptor-targeted therapy. Much lower frequencies of BRAF and PIK3CA mutations may suggest that they do not play a major role in the tumorigenesis of A-ACs. Different therapeutic protocols should be considered for treating pancreatobiliary- and intestinal-type A-ACs.

Outcome of transilluminated powered phlebectomy for varicose vein: review of 299 patients (447 limbs).

PURPOSE: Varicose vein incompetence in the legs is very prevalent in the Korean population. New technologies and improvements in established methods have changed the treatment of varicose veins. Transilluminated powered phlebectomy is an alternative surgical technique that combines endoscopic powered vein resection and ablation of superficial varicosities with tumescent anesthesia and irrigated illumination. The present study sought to determine the clinical efficacy and safety of transilluminated powered phlebectomy from clinical data. METHOD: Four hundred and forty-seven limbs in 299 patients (157 male, 142 female; mean age 50.6 years) with varicose veins were treated with transilluminated powered phlebectomy over a 7-year period. The patients were followed for 1 year postoperatively. The analyzed data included sex, age, body mass index, operative time (from skin incision to the application of elastic bandages on the legs for compression purposes), and postoperative complications. RESULTS: The mean operative time was 87.2 min for both limbs and 57.3 min for single limbs. The median number of incisions was five. Postoperative complications included an episode of cellulitis in 10 patients (2.2%), wound abscess in two patients (0.4%), hematoma in 15 patients (3.4%), residual veins in five patients (1.1%), cutaneous nerve damage in 10 patients (2.2%), and seroma in 13 patients (2.9%). No skin perforation and deep venous thrombosis were observed at the 1-year follow-up. CONCLUSION: Transilluminated powered phlebectomy is an effective and safe method for the excision of varicosities.

Electroplating characteristics of eutectic Sn-Cu ions for micro-solder bump on a Si chip.

The fabrication of fine bumps on a Si chip is an important issue due to the trend of smaller sized and multi-functioning electronics. In this study, a Sn-Cu near eutectic solder bump was fabricated by electroplating. A Si wafer was used as a substrate, while layers of the Under Bump Metallization (UBM) of Al/Cu/Ni/Au (400/300/400/20 nm in each) were coated onto the Si wafer by electron beam evaporation. The bumps on the UBM were plated by a direct current, and the bump size was 20 x 20 x 10 microm with a 50 microm pitch. Characteristics of the electroplated bumps were examined by XRD, EDS and EPMA. A polarization curve was established to find a potential range of electrodeposition of Sn-Cu. By plating with a reduction current density of 1 A/dm2 for 23 min, a near eutectic Sn-Cu bump was obtained. The bump height increased in current density, namely from 2.25 microm at 0.5 A/dm2 to 6.58 microm at 2 A/dm2 from 10 min of plating. In the electroplated state, a beta-Sn and Sn-Cu intermetallic compound (IMC) coexisted in the bumps. Cu3Sn and Ni3Sn4 IMCs were discovered by XRD analysis along the interface between the bump and the UBM.

Relationship between the risk of bile duct injury during laparoscopic cholecystectomy and the types of preoperative magnetic resonance cholangiopancreatiocography (MRCP).

BACKGROUNDS/AIMS: Bile duct injury is one of the potential severe complications that can occur during laparoscopic cholecystectomy, which can be cause by anatomic variations in the confluence of the bile duct. Recently magnetic resonance cholangiopancreatiocography (MRCP) has become a helpful tool to detect bile duct variation on a preoperative basis and to prevent bile duct injury during laparoscopic cholecystectomy, as well other hepatic surgeries. This study aimed to clarify the types of bile duct on MRCP and to search for a method of avoiding injury during laparoscopic cholecystectomy. METHODS: Between January 2009 and December 2010, 277 patients underwent laparoscopic cholecystectomy with preoperative MRCP in our institution. On a retrospective basis, the bile ducts were categorized into 5 types according to the Couinaud classification system. RESULTS: The proportion of types was revealed type A (70.4%), type B (8.7%), type C (19.5%), type D (0.7%), type E (0%), and type F (0.7%), respectively. Bile duct injury occurred in 4 cases (1.4%) during laparoscopic cholecystectomy. In particular, the possibility of aberrant extrahepatic confluence (Type C and F) represented the highest risk of duct injury (OR=11.89 [CI: 1.21-116.53]). CONCLUSIONS: Preoperative evaluation of the bile duct anatomy is important to avoid injury of duct during laparoscopic cholecystectomy. Specific types of bile duct variation should be considered as a high risk group for bile duct injury.

Percutaneous transhepatic gallbladder drainage changes emergency laparoscopic cholecystectomy to an elective operation in patients with acute cholecystitis.

Many surgeons have found it difficult to decide whether to apply percutaneous transhepatic gallbladder drainage (PTGBD) in patients with acute cholecystitis that is not responsive to initial medical management (IMMx), because the indications of PTGBD are ambiguous. The aim of this study was to evaluate the appropriate treatment for acute cholecystitis that is not responsive to IMMx. Specifically, we focused on differences in surgical outcomes between elective and emergency laparoscopic surgeries. Between March 2006 and February 2009, 738 patients with acute cholecystitis who had undergone laparoscopic cholecystectomy (LC) at our institution were retrospectively studied. We divided them into 3 groups. Group I included 494 patients who underwent elective LC without pre-operative PTGBD, group II included 97 patients who intended to undergo elective LC after preoperative PTGBD, and group III included 147 patients who underwent emergency LC without preoperative PTGBD. We compared age, sex, symptom duration, body temperature, leukocyte counts, and American Society of Anesthesiologists (ASA) class on admission as clinical characteristics. We compared the time interval from symptom development and admission to surgery, operative time, the conversion rate to open surgery, postoperative complications, the total length of stay, and the postoperative length of stay as perioperative surgical outcomes. For patients with ASA 2 and 3, the conversion rate to open surgery in group II was significantly less than that in group III (P<.05, P<.01, respectively). We recommend PTGBD as the first choice for acute cholecystitis in patients who show no improvement after IMMx, to allow the patient to undergo an elective LC rather than emergency surgery for patients with ASA 2 and 3.

Synchronous double primary malignant tumor of the gallbladder and liver: a case report.

We report a case of synchronous double primary tumor of gallbladder and liver. A 63-year-old male was admitted to the hospital complaining of abdominal discomfort. Enhanced computed tomography of the abdomen showed acute cholecystitis with tiny gallbladder stones and a 2.2 cm size enhanced nodule in the left lobe of the liver. Under the impression of acute cholecystitis with gall bladder stones and hepatocellular carcinoma of the left Liver, the patient underwent a laparotomy. At laparotomy, a mass was palpated on the surface of the neck portion of the gall bladder. Intraoperative frozen diagnosis revealed adenocarcinoma of the gall bladder. The patient was diagnosed as having gall bladder cancer and hepatocellular carcinoma, so extended cholecystectomy with dissection of regional lymph nodes and left hemihepatectomy were performed. Histological examination revealed moderated differentiated adenocarcinoma of gallbladder and hepatocellular carcinoma of liver. To our knowledge, the simultaneous occurrence of primary malignant tumor of the gallbladder and liver has never been published before. The patient is doing well with no evidence of recurrence 17 months after surgery.

Cavo-caval intervention stent insertion after deceased-donor liver transplantation using side-to-side piggyback technique: report of a case.

Liver transplantation with preservation of the recipient vena cava (piggyback technique) has been performed as an alternative to the conventional method. Outflow disturbance or obstruction of the vena cava in the early period after liver transplantation is associated with high morbidity and mortality. We used side-to-side cavo-caval anastomosis (modified piggyback technique) in a deceased-donor liver transplantation (DDLT) for venous outflow reconstruction. On postoperative day 9, the patient developed abdominal discomfort, and abnormal liver function showing serum total bilirubin of 6.2 mg/dl and serum AST/ALT of 297/597 IU/L. Doppler ultrasound showed mono-phasic wave forms of the hepatic vein. Computed tomography showed focal narrowing of 9.5 mm×12 mm in diameter at the cavo-caval anastomosis site. Liver biopsy was showed that there was no evidence of acute allograft rejection. Direct venogram showed stenosis of the cavo-caval anastomosis with a pressure gradient of 12 mmHg. An interventional stent was inserted in the stenotic site of the inferior vena cava, and the pressure gradient decreased to 2 mmHg. He was discharged from hospital on postoperative day 23 without any other complications. Herein we report a case of deceased-donor liver transplantation using the modified piggyback technique, who received an inferior vena cava stent due to stricture of the reconstructed orifice of the vena cava.

Totally laparoscopic left hemihepatectomy using ventral hilum exposure (VHE) for intrahepatic bile duct stone.

The unique technique of ventral hilum exposure (VHE) was reported that it had excellent surgical outcomes in patients with intrahepatic bile duct stone. The basis of this surgical technique is that all the openings of the 2nd-order bile duct branches are exposed fully. In this article, we describe laparoscopic hemihepatectomy from using the VHE method in a patient with intrahepatic bile duct stone. Our patient was a 70-year-old female who had been diagnosed with an intrahepatic duct stone 30 years prior. Multiple intrahepatic bile duct stones in the left lateral section of the liver were revealed by abdominal computed tomography and magnetic resonance cholangiopancreatography. The patient resumed her oral intake on postoperative day 6. The patient had hyperbilirubinemia (10.3 mg/100 mL) on postoperative day 10. However, her serum bilirubin level decreased to 2.7 mg/100 mL on postoperative day 28. She was discharged without any serious complications on postoperative day 31. Totally laparoscopic left hemihepatectomy, using the VHE method, can be one option of surgical procedure in the near future, although a larger series of cases should be necessary to prove the feasibility of laparoscopic VHE.

Imaging findings of primary well-differentiated liposarcoma of the liver: a case report.

Primary liposarcoma of the liver is extremely rare. We report here on a case of primary well-differentiated liposarcoma in the left hepatic lobe of a 63-year-old woman. Abdominal ultrasonography showed a well-defined, echogenic, round mass. Abdominal computed tomography (CT) and magnetic resonance (MR) images showed an almost fatty, lobulated mass with a few, random distributed vascular structures and a small area of nodular enhancement. The resected tumor appeared as a well-defined, round, tan-yellow mass. Histological analysis showed a well-differentiated liposarcoma.

Tailoring transection of segment V vein for optimal sharing of middle hepatic vein in right-lobe living donor liver transplantation.

BACKGROUND/AIMS: Separate reconstruction of multiple V5s (segment V hepatic vein) often resulted in incomplete resolution of hepatic venous congestion (HVC) in the right lobe (RL) grafts. This study intended to obtain single large V5 orifice suitable for middle hepatic vein (MHV) reconstruction. METHODOLOGY: We tried tailoring V5 transection in 3 of 39 RL donors, in whom MHV anatomy would reveal multiple sizable V5 orifices along the classical transection plane. During transection of its ventral half, the liver cut surface was intentionally deviated leftward to obtain single large V5 orifice with small sacrifice of the medial segment. RESULTS: Single V5 and single segment VIII vein were reconstructed with interposition vessel graft. Its final shape resembled the combination of RL graft with MHV trunk at the ventral half and RL graft with MHV reconstruction at the dorsal half. There was no noticeable perfusion defect on follow-up computed tomography of all donor and recipient livers. CONCLUSIONS: We think that this combination of tailoring V5 transection and interposition graft is fully suggestive of the feasibility of modified extended RL graft in donor livers with variant peripheral MHV branching.

Feasibility assessment for tailoring preservation of segment VIII hepatic vein during left liver graft procurement.

BACKGROUND/AIMS: Procurement of left lobe (LL) graft occasionally induces large-sized hepatic venous congestion (HVC) at the remnant right liver. Isolated preservation of segment VIII vein (V8) could reduce this HVC, but it has been applied to only a small number of living donor operations to date. METHODOLOGY: We investigated the indication of tailoring V8 preservation through the anatomical analyses and computer simulation in a large-volume donor pool. After setting up its surgical technique in 3 donor cases, we analyzed the liver anatomy of 147 LL graft donors. RESULTS: We regarded the first anatomical condition as direct convergence of a large V8 branch on middle hepatic vein root, by which 27 livers were selected. The second was absence of complex hepatic vein branching at the graft cutting line, and 4 livers were excluded. The third was relatively large-sized HVC more than 35% of right lobe volume, and 11 livers were additionally excluded. Finally, 12 (8.2%) of 147 were left after 3-step selection processes. V8 preservation was estimated to reduce the total amount of HVC by 40%. CONCLUSIONS: We think that tailoring V8 preservation seems to be indicated for 8.2% of LL graft donor livers according to the 3 anatomical conditions.

Lessons learned from 1,000 living donor liver transplantations in a single center: how to make living donations safe.

Serious complications have occurred in a considerable proportion of living donors of liver transplants, but data from a single high-volume center has rarely been available. We analyzed the medical records of donors and recipients of the first 1,000 living donor liver transplants, performed at Asan Medical Center from December 1994 to June 2005, with a focus on donor safety. There were 107 pediatric and 893 adult transplants. The most common diagnoses were biliary atresia in pediatric recipients (63%) and hepatitis B-associated liver cirrhosis (80%) in adult recipients. Right lobe donors were strictly selected based on liver resection rate and steatosis. From 1,162 living donors, 588 right lobes, 6 extended right lobes, 7 right posterior segments, 464 left lobes, and 107 left lateral segments were obtained. Of these, 837 grafts were implanted singly, whereas 325, along with 1 cadaveric split graft, were implanted as dual grafts into 163 recipients. The 5-yr survival rates were 84.8% in pediatric recipients and 83.2% in adult recipients. There was no donor mortality, but 3.2% of donors experienced major complications. Until the end of 2001, the major donor complication rate was 6.7%, with most occurring in right liver donors. Since 2002, liver resection exceeding 65% of whole liver volume were avoided except for young donors with no hepatic steatosis, and the donor complication rate has been reduced to 1.3%. In conclusion, a majority of major living donor complications appear to be avoidable through the strict selection of living donor and graft type, intensive postoperative surveillance, and timely feedback of surgical techniques. Selection of right lobe graft should be very prudently considered if the donor right liver appears to be larger than 65% of the whole liver volume.