Young Chul Kim

Multicenter Analysis of Clinicopathologic Features of Intraductal Papillary Mucinous Tumor of the Pancreas: Is It Possible to Predict the Malignancy Before Surgery?

BackgroundDespite recently increasing numbers of reports on intraductal papillary mucinous tumors (IPMTs), difficulties still remain in terms of diagnosis, treatment, and prognosis. The purpose of this multicenter study was to evaluate the clinicopathologic features of IPMT in Korea and to suggest predictive criteria for malignancy in IPMT.MethodsWe retrospectively reviewed the clinicopathologic data of 208 patients who underwent operations for IPMT between 1993 and 2002 at 28 institutes in Korea.ResultsOf the 208 patients (mean age, 61 years), 147 were men and 61 were women. A total of 124 patients underwent pancreatoduodenectomy, 42 underwent distal pancreatectomy, 17 underwent total pancreatectomy, and 25 underwent limited pancreatic resection. There were 128 benign cases (adenoma, n = 62; borderline, n = 66) and 80 malignant cases (noninvasive, n = 29; invasive, n = 51). A significant difference in 5-year survival was observed between the benign and malignant groups (92.6% vs. 65.3%; P = .006). Of the six factors (age, location, duct dilatation, mural nodule, main duct type, and tumor size) that showed statistical differences by univariate analysis between the benign and malignant groups, three were significant by multivariate analysis—namely, mural nodule (P = .009), tumor size (P = .023), and a dilated duct size (P = .010).ConclusionsA significant proportion of IPMTs are malignant, although the overall prognosis of IPMT is superior to that of ordinary pancreatic cancer. Radical surgery is recommended for IPMT with the predictors of malignancy: mural nodule, tumor size (⩾30 mm), and dilated duct size (⩾12 mm).

Performance analysis on a multi-type inverter air conditioner

An analysis was conducted for a multi-type inverter air conditioner with a linear electronic valve as the expansion device and a variable speed compressor. The system performance was analyzed with variations of operating frequency of the compressor, cooling load imposed on the system and cooling load fraction (i.e. load ratio) between rooms in which is installed an evaporator. The optimum opening of the electric expansion valve (EEV) was calculated when the compressor operating frequency was specified at a given cooling load. As compressor operating frequency increased with cooling load increment, the EEV should have adjusted to get wide openings to get an optimum COP of the system. While total cooling load of the system was constant, the cooling load fraction changed due to the cooling load differences between each room in the multi-type air conditioning system with a number of evaporators and EEVs. The operating frequency of the compressor was increased with increment of the load ratio, and consequently, the power consumption of the compressor increased. The increment of the load ratio, which means increasing the load difference between each room, causes a reduction of the system performance (COP), although the total cooling capacity was constant.

Direct and indirect contribution of human embryonic stem cell-derived hepatocyte-like cells to liver repair in mice.

BACKGROUND & AIMSnMany studies of embryonic stem cells have investigated direct cell replacement of damaged tissues, but little is known about how donor cell-derived signals affect host tissue regeneration. We investigated the direct and indirect roles of human embryonic stem cell-derived cells in liver repair in mice.nnnMETHODSnTo promote the initial differentiation of human embryonic stem cells into mesendoderm, we activated the β-catenin signaling pathway with lithium; cells were then further differentiated into hepatocyte-like cells. The differentiated cells were purified by indocyanine green staining and laser microdissection and characterized by immunostaining, polymerase chain reaction, biochemical function, electron microscopy, and transplantation analyses. To investigate indirect effects of these cells, secreted proteins (secretomes) were analyzed by a label-free quantitative mass spectrometry. Carbon tetrachloride was used to induce acute liver injury in mice; cells or secreted proteins were administered by intrasplenic or intraperitoneal injection, respectively.nnnRESULTSnThe differentiated hepatocyte-like cells had multiple features of normal hepatocytes, engrafted efficiently into mice, and continued to have hepatic features; they promoted proliferation of host hepatocytes and revascularization of injured host liver tissues. Proteomic analysis identified proteins secreted from these cells that might promote host tissue repair. Injection of the secreted proteins into injured livers of mice promoted significant amounts of tissue regeneration without cell grafts.nnnCONCLUSIONSnHepatocyte-like cells derived from human embryonic stem cells contribute to recovery of injured liver tissues in mice, not only by cell replacement but also by delivering trophic factors that support endogenous liver regeneration.

Incidental Gallbladder Cancer Diagnosed Following Laparoscopic Cholecystectomy

BackgroundLaparoscopic cholecystectomy (LC) is the treatment of choice for benign gallbladder disease. Gallbladder cancers have been found following LC. The aim of the present study was to evaluate the survival outcome and prognosis of incidental gallbladder cancer diagnosed after LC.MethodsFrom January 2002 to December 2007, 3,145 patients underwent LC at the Department of Surgery, Korea University Medical Center. Of these, 33 patients (1.05%) were diagnosed with gallbladder cancer after LC. Clinicopathological characteristics were retrospectively reviewed in this study.ResultsOf the 33 patients studied, 9 were men and 24 were women. Laparoscopic cholecystectomy alone was performed in 26 patients, and additional radical surgery was performed in 7 others. Regarding tumor staging, there were 2 Tis, 6 T1a, 4 T1b, 17 T2, and 4 T3 tumors. Male patients had a significantly higher incidence of moderately and poorly differentiated tumors (Pxa0<xa00.001), T2 and T3 tumors (Pxa0=xa00.02), additional second operations (Pxa0=xa00.046), and recurrence (Pxa0=xa00.016). The cumulative 1-, 3-, and 5-year survival rates were 87.2, 73.1, and 47.0%, respectively. Univariate analysis revealed that significant prognostic factors for poorer survival were male gender (Pxa0=xa00.026), age older than 65xa0years (Pxa0=xa00.013), the presence of inflammation (Pxa0=xa00.009), moderately or poorly differentiated tumor (Pxa0<xa00.001), nonpolypoid gross type (Pxa0=xa00.003), and pT stage (Pxa0<xa00.001). Tumor differentiation was a significantly independent predictor of poor prognosis.ConclusionsMale patients exhibited aggressive tumor characteristics. Laparoscopic cholecystectomy is an adequate treatment for pT1 tumors. For pT2 and pT3 patients, additional radical surgery might be needed to achieve a tumor-free surgical margin, along with lymph node dissection.

Systemic immune response after open versus laparoscopic cholecystectomy in acute cholecystitis : A prospective randomized study

Objective. Laparoscopic surgery is thought to reduce the postoperative immunologic effects of surgical trauma. The aim of this study is to evaluate the influence of surgical trauma on systemic inflammation and the immune response in acute cholecystitis. Material and methods. Thirty‐three patients with acute calculous cholecystitis were assigned to laparoscopic cholecystectomy (LC, n = 18) or open cholecystectomy (OC, n = 15). Blood samples were obtained preoperatively and on postoperative day 1 (24u2005h after surgery) and day 3 (72u2005h after surgery), and blood concentration of C‐reactive protein (CRP), leukocyte subpopulations, as well as levels of tumor necrosis factor‐α (TNF‐α) ex vivo secretion by peripheral blood mononuclear cells (PBMCs) were measured in both groups. Results. Hospitalization was significantly shorter in the LC group than in the OC group (LC group: 3.7±1.2 days versus OC group: 6.3±2.7 days, p = 0.010). There was no postoperative morbidity in the LC group, but two patients in the OC group had postoperative complications. Postoperative TNF‐α ex vivo secretion by PBMCs and PBMC counts in the OC group were significantly lower than those in the LC group (p = 0.002). The CRP level declined by postoperative day 3, but was significantly less in the OC group than in the LC group (p<0.001). Postoperative monocyte counts significantly decreased in the OC group compared with those in the LC group (p = 0.001). Conclusions. A laparoscopic approach appears to cause less surgical trauma and immunosuppression than open surgery in patients with acute cholecystitis.

Management of umbilical hernia complicated with liver cirrhosis: An advocate of early and elective herniorrhaphy

BACKGROUNDnPatients with umbilical hernias complicated by liver cirrhosis have an increased likelihood of complications following herniorrhaphy. The aim of this study was to investigate the clinical outcomes in patients with umbilical hernias complicated by liver cirrhosis.nnnMETHODSnBetween 2001 and 2010, 44 patients were enrolled in this study. The comparison between non-operative and operative group was performed. Patients who underwent emergency versus elective surgery were also compared.nnnRESULTSnOf the 44 patients, there were 33 men and 11 women. Thirty-one patients (70.5%) underwent surgery and 13 patients (29.5%) were treated conservatively. Overall morbidity and mortality rates following herniorrhaphy were 42% and 6.5%. The mean albumin level was significantly lower and total bilirubin, creatinine and mean model of end-stage liver disease score were significantly higher in non-operative group than in operative group. Combined resection was performed more frequently in the emergency group than in elective group. A significantly higher proportion of patients in emergency operation group had postoperative complications (P=0.01), especially ascites (P=0.02). The operative time and postoperative hospital stay were significantly shorter in the elective operation group than in emergency operation group.nnnCONCLUSIONSnEarly, elective repair of umbilical hernias in cirrhotic patients should be advocated considering the hepatic reserve and patients condition. Ascites control is the mainstay of post-operative management.

Surgical Outcomes and Prognostic Factors for Ampulla of Vater Cancer

Background and Aims: The prognosis for patients with ampulla of Vater cancer is better than other periampullary cancers. The aim of the present study is to determine the clinicopathologic factors predictive of survival and recurrence in patients with ampulla of Vater cancer. Material and Methods: From 1991 to 2008, we identified and reviewed 78 patients with ampulla of Vater cancer retrospectively. Clinicopathologic factors possibly influencing survival and recurrence were statistically analyzed. Results: Pancreaticoduodenectomy was performed in 68 patients and 2 patients underwent transduodenal ampullectomy. Hospital mortality was 2.6%. The 5-year survival rates following resection were 59.9%. Univariate analysis for overall survival revealed that total bilirubin greater than 5mg/dl, ulcerative tumors, differentiation, and pancreatic invasion were significant prognostic factors. Recurrence occurred in 31 patients. Univariate analysis for disease-free survival revealed that total bilirubin greater than 5mg/dl, preoperative biliary drainage, tumor differentiation, and stage were statistically significant. Multivariate analysis revealed that tumor differentiation was an independent prognostic factor for recurrence. The presence of lymph node metastasis did not affect overall survival significantly in this study. However, two or more metastatic lymph nodes significantly affect disease-free survival. Conclusions: Pancreaticoduodenectomy is a safe surgical procedure with acceptable long-term survival for ampulla of Vater cancer. Pancreaticoduodenectomy with lymph node dissection might control lymph node spread and enhance survival outcome.

Surgical Outcomes and Prognostic Factors for T2 Gallbladder Cancer Following Surgical Resection

BackgroundDepth of tumor invasion is an important prognostic factor for gallbladder cancer. The aim of this study was to investigate the clinicopathological prognostic factors of T2 gallbladder cancer.MethodsWe retrospectively reviewed the clinicopathological data and survival for 83 patients with T2 gallbladder cancers who underwent surgical resection between January 1995 and December 2007.ResultsThe overall survival rates were 48.9% at 3xa0years and 29.3% at 5xa0years. Univariate analysis revealed that R0 resection (Pu2009<u20090.001), extended surgery (Pu2009=u20090.028), lymph node dissection (Pu2009=u20090.024), non-infiltrative tumors (Pu2009=u20090.001), well differentiation (Pu2009=u20090.001), absence of lymphatic (Pu2009=u20090.025), perineural (Pu2009=u20090.001), and vascular (Pu2009=u20090.025) invasion, absence of lymph node metastasis (Pu2009=u20090.001), negative resection margin (Pu2009=u20090.016), and stage (Pu2009=u20090.002) were significantly better predictors for survival. A significant difference in survival between Rx and R1 was not found. R0 resection, lymph node dissection, well differentiation, and absence of perineural and vascular invasion were significantly independent prognostic factors for overall survival. Recurrence occurred in 48 patients (57.8%). Age older than 65xa0years, R0 resection, non-infiltrative tumors, and good differentiation were significant independent predictors of disease-free survival by multivariate analysis.ConclusionsFor T2 tumors, radical surgery including lymph node dissection should be performed to achieve R0 resection. Tumors with infiltrative types and suspicious lymph node metastasis in the intraoperative findings were candidates for aggressive surgical management to improve patient survival.

Hepatic Splenosis Diagnosed as Hepatocellular Carcinoma: Report of a Case

Abstract We report one case of splenosis. A 43-year-old male patient was referred to our hospital because of a hepatic mass. The hepatic lesion was incidentally found during an annual ultrasonographic follow-up since the patient was a known chronic hepatitis B carrier for the previous 10 years. Surgical records revealed a history of splenectomy in conjunction with a blunt abdominal trauma, which the patient had sustained 20 years prior to this admission. On abdominal computed tomography scanning, a 3.5-cm sized focal bulging mass was noted in segment 6 of the liver. An inferior phrenic artery angiogram showed a hepatic tumor and the patient was treated by chemoembolization for hepatocellular carcinoma. A partial resection of the liver with a portion of the diaphragm was done after the transcatheter arterial chemoembolization procedure. A pathologic examination revealed splenosis within the hepatic parenchyme.

Expression and Clinical Significance of Cell Cycle Regulatory Proteins in Gallbladder and Extrahepatic Bile Duct Cancer

Disruption of cell cycle controls is a pathognomonic feature of all malignant cells. Therefore, we immunohistochemically investigated the relationship between cell cycle regulatory proteins and clinicopathologic features in order to identify the biomarkers related to the outcome of patients with biliary tract cancer (BTC). A cohort of paraffin-embedded specimens were selected from 36 patients, including 18 gallbladder and 18 extrahepatic bile duct cancers, who underwent curative or palliative surgical resection at Korea University Medical Center from June 1998 to December 2004. Tissue microarrays were used to investigate the immunohistochemical staining for p21, p27, p53, cyclin D1, bcl2, and Ki-67. Univariate and multivariate survival analyses were performed to determine the prognostic significance of each protein expression. Absence of p21 expression independently predicted poor outcome in all cases. Well-differentiated tumor was found to be an independent good prognostic factor in gallbladder cancer. Absence of p21 expression and moderately to poorly differentiated tumor were found to be an independent poor prognostic factor in patients with negative for neural invasion. Absence of p21 and bcl2 were found to be an independent poor prognostic factor in patients with no lymph node metastasis. Absence of p21 expression was a significant independent poor prognostic factor in BTC, partly in patients with biologically less aggressive phenotypes. This finding suggests that determination of p21 expression in surgically resected specimens may provide prognostic information in addition to conventional pathologic findings for patients with BTC, especially those who have biologically less aggressive phenotypes.