Joon Seong Park

Clinical validation and risk factors for delayed gastric emptying based on the International Study Group of Pancreatic Surgery (ISGPS) Classification

BACKGROUND Delayed gastric emptying (DGE) is one of the most common complications after pancreatoduodenectomy (PD). Because an objective, universally accepted definition of DGE does not yet exist, it is impossible to compare complication rates and outcomes of new operative approaches, operative techniques, and clinical trials. The International Study Group of Pancreatic Surgery (ISGPS) has proposed a universal classification for DGE based on clinical outcomes, but this classification has not been tested rigorously and applied to clinical data. Therefore, the aim of this study was to analyze our experience and to identify predictive factors for DGE by applying the ISGPS classification at a high-volume hospital. METHODS From October 2002 to December 2007, 129 consecutive patients underwent PD at the Department of Surgery, Yonsei University Medical Center. The severity of DGE was determined according to the ISGPS classification, and risk factors were evaluated retrospectively. RESULTS The overall incidence of DGE was 33.3%, with 16 (12.4%) patients having grade A, 14 (10.9%) grade B, and 13 (10.1%) grade C. Clinical outcomes worsened progressively as clinical relevant DGE increased. In multivariate analysis, clinically relevant pancreatic fistula (grade B/C) and patients with benign pathology were identified as independent factors for DGE. CONCLUSION Pancreatic leakage is a serious complication after PD and is also associated with DGE. The ISGPS classification is a clear and useful tool to assess clinical outcomes.

Early Experiences of Robotic-assisted Laparoscopic Liver Resection

Purpose The surgical robotic system is superior to traditional laparoscopy in regards to 3-dimensional images and better instrumentations. Robotic surgery for hepatic resection has not yet been extensively reported. Patients and Methods Between March and May 2007, we performed 3 robot-assisted left lateral sectionectomies of the liver. Case 1 had a hepatocellular carcinoma (HCC), case 2 had colon cancer with liver metastasis, and case 3 had intrahepatic duct stones. Results All patients had successful operation and recovered without complications. Shorter length of hospital stays, earlier start of oral feeding and less amount of ascites were found. However, case 1 had recurrent HCC at 3 months after operation. Conclusion Robotic-assisted liver surgery is still a new field in its developing stage. In patients with small malignant tumors and benign liver diseases, robotic-assisted laparoscopic resection is feasible and safe. Through experience, the use of robotics is expected to increase in the treatment of benign diseases and malignant neoplsms. However, careful patient selection is important and long-term outcomes need to be evaluated.

Clinical Significance of p16 Protein Expression Loss and Aberrant p53 Protein Expression in Pancreatic Cancer.

Pancreatic cancer is a disease with poor prognosis mainly due to low resection rates and late diagnosis. To increase resectability and improve survival rates, a better understanding of pancreatic cancer pathogenesis and more effective screening techniques are required. New methods, such as genetic and molecular alterations, may suggest novel approaches for pancreatic cancer diagnosis and treatment. We immunohistochemically investigated 44 formalin-fixed, paraffin-embedded specimens of pancreatic ductal adenocarcinoma using monoclonal anti-p16 antibodies and monoclonal anti-p53 antibodies. The expressions of p16 and p53 proteins were compared using the Chi-square test with SPSS. Disease-free survival was analyzed using the Kaplan-Meier method, verified by the Log-Rank test. Loss of p16 expression was noted in 20 (45.5%) cases and aberrant p53 protein expression was detected in 14 (31.8%) cases. Loss of p16 expression was associated with a higher incidence of lymph node metastasis (p=0.040) and a more advanced stage (p=0.015), although there was no significant correlation between p16 expression and survival. Aberrant p53 protein expression correlated with histologic grade (p=0.038). Disease-free survival rate was significantly lower in the aberrant p53 protein positive group compared to the negative group (p=0.029). From our results, we suggest that p53 is not a prognostic factor; however, p16 and p53 genes do play important roles in the progression of pancreatic ductal adenocarcinoma.

Postoperative Nutritional Effects of Early Enteral Feeding Compared with Total Parental Nutrition in Pancreaticoduodectomy Patients: A Prosepective, Randomized Study

The benefits of early enteral feeding (EEN) have been demonstrated in gastrointestinal surgery. But, the impact of EEN has not been elucidated yet. We assessed the postoperative nutritional status of patients who had undergone pancreaticoduodenectomy (PD) according to the postoperative nutritional method and compared the clinical outcomes of two methods. A prospective randomized trial was undertaken following PD. Patients were randomly divided into two groups; the EEN group received the postoperative enteral feed and the control group received the postoperative total parenteral nutrition (TPN) management. Thirty-eight patients were included in our analyses. The first day of bowel movement and time to take a normal soft diet was significantly shorter in EEN group than in TPN group. Prealbumin and transferrin were significantly reduced on post-operative day (POD) 7 and were slowly recovered until POD 90 in the TPN group than in the EEN group. EEN group rapidly recovered weight after POD 21 whereas it was gradually decreased in TPN group until POD 90. EEN after PD is associated with preservation of weight compared with TPN and impact on recovery of digestive function after PD.

The Effect of Visceral Fat Mass on Pancreatic Fistula after Pancreaticoduodenectomy

ABSTRACT Background: Obesity is associated with perioperative complications and has been considered a risk factor for surgical outcomes of patients undergoing abdominal surgery. The aim of this study is to evaluate the impact of the amount of visceral fat on postoperative morbidity of patients who underwent pancreaticoduodenectomy (PD). Methods: We reviewed 181 patients who underwent surgery for periampullary lesions at the Department of Surgery, Gangnam Severance Hospital, Yonsei University Health System between January 2003 and June 2010. The visceral fat area (VFA) and subcutaneous fat area were calculated by computed tomography software. Results: The mean body mass index (BMI) was 23.4 kg/m2 (±3.1 kg/m2), and the mean VFA was 94.4 cm2 (±49.5 cm2). The mean intraoperative blood loss, and the incidence of clinically relevant pancreatic fistula (grade B/C) and clinically relevant delayed gastric emptying (grade B/C) were significantly higher in the high-VFA group (≥100 cm2). In univariate analysis, the incidence of clinically relevant pancreatic fistula (grade B/C) was significantly higher in the high-BMI group (≥25 kg/m2), the high-VFA group(≥100 cm2), the large intraoperative blood loss and transfusion group, and in patients with pathology of nonpancreatic origin (ampulla, bile duct, or duodenum). In multivariate analysis, the high-VFA group (≥100 cm2) and patients with pathology of nonpancreatic origin were identified as independent factors for clinically relevant pancreatic fistula. Conclusion: VFA is a better indicator for the development of pancreatic fistula after PD than BMI. High VFA (≥100 cm2) is a risk factor for developing a pancreatic fistula after PD.

The Actual Five-year Survival Rate of Hepatocellular Carcinoma Patients after Curative Resection

The five-year survival rate of patients after curative resection of hepatocellular carcinoma (HCC) has been reported to be 30 to 50%, however the actual survival rate may be different. We analyzed the actual 5-year survival rate and prognostic factors after curative resection of HCC. Retrospective analysis was performed on 63 HCC patients who underwent curative resection from 1998 to 1999. A total of 63 cases were reviewed, consisting of 53 men and 10 women, with a median age of 49 years. These cases included all four pathologic T stages (pT stage) and had the following representation: stage 1 (1 case), stage 2 (17 cases), stage 3 (38 cases), and stage 4 (7 cases). In our study, the actual 5-year survival rate was 57.0% and the median survival time was 60 months. In addition, the patients in our study had an actual 5-year disease-free survival rate of 50.2% and a median disease-free survival time of 46 months. Thirty-one patients had recurrences, with a majority occurring within one year (65%). These patients with early recurrences had a poor actual 5-year survival rate of 5%. A univariate analysis showed that the prognostic factors influencing survival rate were the presence of satellite nodules, increased pT stage, HCC recurrence, and the time to recurrence (within one year). Interestingly, microvascular invasion made a difference in survival rate but was not statistically significant (p = 0.08). Furthermore, factors influencing the disease free survival rate include the presence of satellite nodules, microvascular invasion, and pT stage. Multivariate analysis identified pT stage as the only statistically related factor in determining the disease-free survival rate. The most important prognostic factor of HCC is recurrence. Moreover, the major risk factor for recurrence is an advanced pT stage. Therefore, performing prospective studies of postoperative adjuvant therapy is necessary to prevent recurrences after hepatic resection. Furthermore, active preventative treatment and early diagnosis of recurrences should be of the highest priority in the care of high-risk patient groups that have an advanced pT stage.

Current Status of Laparoscopic Liver Resection in Korea

Since laparoscopic liver resection was first introduced in 2001, Korean surgeons have chosen a laparoscopic procedure as one of the treatment options for benign or malignant liver disease. We distributed and analyzed a nationwide questionnaire to members of the Korean Laparoscopic Liver Surgery Study Group (KLLSG) in order to evaluate the current status of laparoscopic liver resection in Korea. Questionnaires were sent to 24 centers of KLLSG. The questionnaire consisted of operative procedure, histological diagnosis of liver lesions, indications for resection, causes of conversion to open surgery, and postoperative outcomes. A laparoscopic liver resection was performed in 416 patients from 2001 to 2008. Of 416 patients, 59.6% had malignant tumors, and 40.4% had benign diseases. A total laparoscopic approach was performed in 88.7%. Anatomical laparoscopic liver resection was more commonly performed than non-anatomical resection (59.9% vs 40.1%). The anatomical laparoscopic liver resection procedures consisted of a left lateral sectionectomy (29.3%), left hemihepatectomy (19.2%), right hemihepatectomy (6%), right posterior sectionectomy (4.3%), central bisectionectomy (0.5%), and caudate lobectomy (0.5%). Laparoscopy-related serious complications occurred in 12 (2.8%) patients. The present study findings provide data in terms of indication, type and method of liver resection, and current status of laparoscopic liver resection in Korea.

Outcome of Adjuvant Therapy for Gallbladder Cancer

Objectives: The aim of this study was to evaluate the outcome of adjuvant therapy on the overall survival (OS) and disease-free survival (DFS) after curative resection (RO) of patients with TNM stage II gallbladder (GB) cancer. Methods: A total of 160 patients who had received curative resection (RO) between January 2000 and December 2009 were retrospectively reviewed. Among 61 stage II GB cancer patients, 43 received adjuvant therapy, while 18 others received surgery alone. The median follow-up period was 27.3 months (range 2.2–98.9 months). Results: OS was not significantly different among the adjuvant therapies (p = 0.180), but DFS was (p = 0.033). The 3-year OS and DFS from surgery alone, adjuvant chemotherapy, adjuvant radiotherapy, and adjuvant concurrent chemo-radiotherapy were 64, 78, 36 and 36%, and 56, 69, 14 and 47%, respectively. Overall, the chemotherapy group had a better prognosis, although there were no significant differences. Conclusions: The data from this study do not provide evidence that adjuvant therapy is an effective treatment option for curative resected GB cancer. A large randomized controlled study is necessary to confirm the efficacy of adjuvant therapy. Newer adjuvant studies should be focused on gemcitabine-based chemotherapy or chemo-radiotherapy with molecular-based target agents.

Use of TachoSil® patches to prevent pancreatic leaks after distal pancreatectomy: a prospective, multicenter, randomized controlled study

We performed a prospective, multicenter, randomized controlled study to investigate the clinical outcomes, including postoperative pancreatic fistulas (POPF), after using the TachoSil® patch in distal pancreatectomy (NCT01550406).

Does Liver Resection Provide Long-Term Survival Benefits for Breast Cancer Patients with Liver Metastasis? A Single Hospital Experience

Purpose Liver resection with colorectal liver metastasis widely accepted and has been considered safe and effective therapeutic option. However, the role of liver resection in breast cancer with liver metastasis is still controversial. Therefore, we reviewed the outcome of liver resection in breast cancer patients with liver metastases in a single hospital experiences. Materials and Methods Between January 1991 and December 2006, 2176 patients underwent breast cancer surgery in Gangnam Severance Hospital. Among these patients, 110 cases of liver metastases were observed during follow-up and 13 of these patients received liver resection with potential feasibility to achieve an R0 resection. Results The median time interval between initial breast cancer and detection of liver metastasis was 62.5 months (range, 13-121 months). The 1-year and 3-year overall survival rates of the 13 patients with liver resection were 83.1% and 49.2%, respectively. The 1-year and 3-year overall survival rates of patients without extrahepatic metastasis were 83.3% and 66.7% and those of patients with extrahepatic metastasis were 80.0% and 0.0%, respectively (p=0.001). Conclusion Liver resection for metastatic breast cancer results in improved patient survival, particularly in patients with solitary liver metastasis and good general condition.