Wooil Kwon

The Effect of Doppler Ultrasound on Early Vascular Interventions and Clinical Outcomes After Liver Transplantation

AbstractBackgroundnDuring the immediate postoperative period after liver transplantation (LT), postoperative bleeding and vascular complications (stenosis, thrombosis) are the two most common complications that require therapeutic decisions. Doppler ultrasound (DUS) is the established method for screening vascular patency after LT during the immediate postoperative period. The objective of our study was to evaluate the impact of DUS performed on postoperative days (POD) 1 and 2 on early vascular interventions.MethodsnWe studied 200 patients who had undergone living donor or deceased donor liver transplantation between January 2011 and March 2012. Postoperative liver DUS findings of up to POD 14, including patency of hepatic artery, portal vein, and hepatic vein, were retrieved. Patients with normal DUS findings on POD 1 and POD 2 were classified as the normal early DUS group. Patients with abnormal DUS findings at POD1 or POD2 were classified as the abnormal early DUS group. Frequency of vascular interventions was compared between the two groups. Risk factors that predict vascular interventions also were assessed.ResultsnOn POD 1 and 2, 81.5xa0% (163/200) had normal DUS findings and management was not altered by subsequent DUS findings. Two patients in the normal group were found to have hepatic artery dissection and hepatic vein thrombosis on routine CT on POD 7 and received vascular intervention. DUS results in the two patients were normal until POD 6, but DUS performed after the CT on POD 7 were consistent with the CT findings. Of the 37 recipients who showed abnormal DUS findings on POD 1 or 2, the DUS findings were normalized or unchanged thereafter in 33 patients and no vascular interventions were performed. Two patients underwent hepatic artery thrombectomy on POD 2, one patient required a portal vein thrombectomy on POD 1, and one patient died on POD 3 due to bleeding. The overall incidence of vascular complication requiring vascular interventions was 2.5xa0%. Logistic regression identified abnormal DUS findings on POD 1 or 2 as an independent risk factor of vascular complications requiring intervention.ConclusionsIn LT recipients who demonstrate normal DUS findings in the first 2 postoperative days, additional DUS screening may have value only when clinically indicated.

Progression of Pancreatic Branch Duct Intraductal Papillary Mucinous Neoplasm Associates With Cyst Size

BACKGROUNDS & AIMSnMost guidelines for management of patients with intraductal papillary mucinous neoplasms (IPMN) vary in proposed surveillance intervals and durations-these are usually determined based on expert opinions rather than substantial evidence. The progression of and optimal surveillance intervals for branch-duct IPMNs (BD-IPMN) has not been widely studied. We evaluated the progression of BD-IPMN under surveillance at a single center, and determined optimal follow-up intervals and duration.nnnMETHODSnWe performed a retrospective analysis of 1369 patients with BD-IPMN seen at Seoul National University Hospital in Korea from January 2001 through December 2016. We included only patients whose imaging studies showed classical features of BD-IPMN, and collected data from each patient over time periods of at least 3 years. We reviewed radiologic and pathologic findings, and performed linear and binary logistic regressions to estimate cyst growth.nnnRESULTSnThe median annual growth rate of the cyst was 0.8 mm over a median follow-up time of 61 months. During surveillance, 46 patients (3.4%) underwent surgery because of disease progression after a median follow-up time (in this group) of 62 months. Worrisome features were observed in 209 patients (15.3%) during surveillance, including cyst size of 3 cm or more (n = 109, 8.0%), cyst wall thickening (n = 51, 3.7%), main pancreatic duct dilatation (nxa0=xa077, 5.6%), and mural nodule (n = 43, 3.1%). Along with annual rate of cyst growth, incidences of main pancreatic duct dilatation and mural nodules associated with the sizes of cysts at detection (P < .001).nnnCONCLUSIONSnIn a retrospective analysis of patients with BD-IPMN followed for more than 5 years, we found most cysts to be indolent, but some rapidly grew and progressed. Surveillance protocols should therefore be individualized based on initial cyst size and rate of growth.

Optimal extent of surgery for early gallbladder cancer with regard to long‐term survival: a meta‐analysis

The optimal surgical extent for T1 gallbladder cancer (GBC) remains controversial. Simple cholecystectomy is routinely performed for T1 GBC while several guidelines recommend extended cholecystectomy for T1b GBC. However, evidence regarding the optimal surgical extent for T1 GBC is lacking. This study aims to systematically evaluate the optimal surgical extent for early GBC with regard to long‐term survival.

Comparison of surgical outcomes of intracorporeal hepaticojejunostomy in the excision of choledochal cysts using laparoscopic versus robot techniques

Purpose Increasing surgical expertise in minimally invasive surgery has allowed laparoscopic surgery to be performed in many abdominal surgeries. Laparoscopic choledochal cyst excision and Roux-en-Y hepaticojejunostomy are challenging and sophisticated surgeries because of the difficult anastomosis. Recent advances in robotic surgery have enabled more delicate and precise movements, and Endowrist instruments allow for securing sutures during anastomosis. This study aimed to compare surgical outcomes of laparoscopic and robotic hepaticojejunostomy in choledochal cyst excision. Methods Sixty-seven patients who underwent laparoscopic or robotic-hybrid choledochal cyst excision from 2004 to 2016 were retrospectively analyzed and compared. In robotic surgery, dissection was performed laparoscopically, and hepaticojejunostomy was performed using a robotic platform. Results The mean operative time was significantly longer in robotic surgery than in laparoscopic surgery (247.94 ± 54.14 minutes vs. 181.31 ± 43.06 minutes, P < 0.05). The mean estimated blood loss (108.71 ± 15.53 mL vs. 172.78 ± 117.46 mL, respectively, P = 0.097) and postoperative hospital stay (7.33 ± 2.96 days vs. 6.22 ± 1.06 days, P = 0.128) were comparable between procedures. Compared to the laparoscopic approaches, robotic surgery had significantly less short-term complications (22.4% vs. 0%, P = 0.029). There were more biliary leakage (n = 7, 14.3%) observed during the first 30 days after surgery in laparoscopy while none were observed in the robotic method. Conclusion Robotic surgery allow for more precise and secure sutures during anastomosis thereby reducing biliary complications. With expanding knowledge and expertise, robotic surgery may offer more advantages over laparoscopy in the era of minimally invasive surgery.

Comparison of long-term clinical outcomes of external and internal pancreatic stents in pancreaticoduodenectomy: randomized controlled study

BACKGROUNDnTo determine the most appropriate pancreatic drainage method, by investigating differences in 12-month clinical outcomes in patients implanted with external and internal pancreatic stents as an extension to a previous study on short-term outcome.nnnMETHODSnThis prospective randomized controlled trial enrolled 213 patients who underwent pancreaticoduodenectomy with duct to mucosa pancreaticojejunostomy between August 2010 and January 2014 (NCT01023594). Of the 185 patients followed-up for 12 months, 97 underwent external and 88 underwent internal stenting. Their long-term clinical outcomes were compared.nnnRESULTSnOverall late complication rates were similar in the external and internal stent groups (Pxa0=xa00.621). The percentage of patients with >50% atrophy of the remnant pancreatic volume after 12 months was similar in both groups (Pxa0=xa00.580). Factors associated with pancreatic exocrine or endocrine function, including stool elastase level (Pxa0=xa00.571) and rate of new-onset diabetes (Pxa0=xa00.179), were also comparable. There were no significant between-group differences in quality of life, as evaluated by the EORTC QLQ-C30 and QLQ PAN26 questionnaires.nnnCONCLUSIONnExternal and internal stents showed comparable long-term, as well as short-term clinical outcomes, including late complication rates, preservation of pancreatic duct diameters, pancreatic volume changes with functional derangements, and quality of life after surgery.

Erratum to: Prognostic Relevance of the Timing of Initiating and the Completion of Adjuvant Therapy in Patients with Resected Pancreatic Ductal Adenocarcinoma

Background nAlthough the role of adjuvant therapy in patients with pancreatic ductal adenocarcinoma (PDAC) is well established, its optimal timing and duration are still controversial.

Organ-Preserving Pancreatectomy

The organ-preserving pancreatectomy offers surgical method which can minimize the functional loss and decrease in quality of life. However, this is performed at the cost of compromised radicality. Therefore, organ-preserving pancreatectomy is suitable for low-grade malignant neoplasms of pancreas and not for malignant diseases except for pancreatic metastases. As these low-grade malignant neoplasms have the potential to be malignant, knowing how to treat these diseases optimally is as important as knowing how to treat pancreatic cancer.

Comparative studies for developing protein based cancer prediction model to maximise the ROC-AUC with various variable selection methods

The era of protein data analysis is coming with more accurate quantification experiments such as the multiple reaction monitoring MRM. Protein is easier to obtain than the other genetic variants or gene expression data, which makes it more suitable for early diagnosis of cancer. Each patient has unique patterns of protein data, which makes it imperative for the researcher to select the effective markers to construct a consistent model to predict the patients. This research focuses on finding the most effective variable selection method to be applied in the early diagnosis of the pancreatic cancer. In the process, we compare classical selection methods stepwise selection based on AIC, BIC, machine learning based selection method support vector machine recursive feature selection; SVM-REF, and stepwise selection method using the area under the receiver operating characteristic curve Step-AUC. Based on the simulation and real data analysis, we suggest a Step-AUC method to maximise the prediction performance of the early diagnosis by protein data.

Management of bronchopleural fistula using a modified single lumen tube

Bronchopleural fistula (BPF) is defined as a pathologic connection between the tracheobronchial tree and the pleural space with persistent air leak for more than 24 hours. It is associated with poor prognosis after pneumonectomy [1], which mainly contributes to the occurrence among elective lung resections despite the outstanding advances in surgical techniques. Mechanical ventilation is always problematic for balancing the actual ventilation and the leakage in patients who present a BPF after pulmonary resections. High airway pressure to achieve sufficient minute ventilation may aggravate air leakage and interfere the healing process [2]. We describe a case in which a modified single-lumen endobronchial tube was used in a patient who developed BPF after right lower lung lobectomy in order to improve ventilation and allow adequate suctioning.