Prediction of the risk of developing hepatocellular carcinoma in health screening examinees: a Korean cohort study.

BACKGROUND: Almost all Koreans are covered by mandatory national health insurance and are required to undergo health screening at least once every 2 years. We aimed to develop a machine learning model to predict the risk of developing hepatocellular carcinoma (HCC) based on the screening results and insurance claim data. METHODS: The National Health Insurance Service-National Health Screening database was used for this study (NHIS-2020-2-146). Our study cohort consisted of 417,346 health screening examinees between 2004 and 2007 without cancer history, which was split into training and test cohorts by the examination date, before or after 2005. Robust predictors were selected using Cox proportional hazard regression with 1000 different bootstrapped datasets. Random forest and extreme gradient boosting algorithms were used to develop a prediction model for the 9-year risk of HCC development after screening. After optimizing a prediction model via cross validation in the training cohort, the model was validated in the test cohort. RESULTS: Of the total examinees, 0.5% (1799/331,694) and 0.4% (390/85,652) in the training cohort and the test cohort were diagnosed with HCC, respectively. Of the selected predictors, older age, male sex, obesity, abnormal liver function tests, the family history of chronic liver disease, and underlying chronic liver disease, chronic hepatitis virus or human immunodeficiency virus infection, and diabetes mellitus were associated with increased risk, whereas higher income, elevated total cholesterol, and underlying dyslipidemia or schizophrenic/delusional disorders were associated with decreased risk of HCC development (p < 0.001). In the test, our model showed good discrimination and calibration. The C-index, AUC, and Brier skill score were 0.857, 0.873, and 0.078, respectively. CONCLUSIONS: Machine learning-based model could be used to predict the risk of HCC development based on the health screening examination results and claim data.

Ventral segment-preserving right hepatectomy in patients with hepatocellular carcinoma.

BACKGROUND: Transection along the anterior fissure was proposed as a mechanism by which to open the third door of the liver. In this study, we investigated surgical outcomes of a ventral segment-preserving right hepatectomy (VSPRH) compared with those of conventional right hepatectomy in patients with hepatocellular carcinoma (HCC). METHODS: Between January 2007 and December 2010, 595 primary HCC patients underwent liver resection at the authors' institution. Among them, the 123 HCC patients who underwent a right hepatectomy were retrospectively analyzed. The patients were classified into two groups according to the type of resection: those who underwent a VSPRH (Group A; 27 cases) and those who underwent a conventional right hepatectomy (Group B; 96 cases). RESULTS: In Group A, expected remnant liver volume after a right hepatectomy was calculated to be 32.1 ± 7.2% of functional total liver volume (FTLV); remnant liver volume increased up to 54.7 ± 7.2% of FTLV after a VSPRH. Clinicopathologic characteristics and intraoperative data did not differ between the two groups. The liver-related complication rate was higher in Group B (P = 0.02). Overall survival and disease-free survival rates were similar (3-year disease-free survival (Group A: 67.8%; Group B: 71.7%; P = 0.65); 3-year overall survival (Group A: 91.7%; Group B: 87.4%; P = 0.26). In regard to long-term synthetic function, the 1-year postoperative serum albumin level was higher in Group A. CONCLUSIONS: A VSPRH yielded fewer liver-related complications and similar long-term oncologic outcomes, compared with conventional right hepatectomy in cirrhotic patients with a small left lobe volume. Therefore, VSPRH can be considered to be an alternative procedure for a right hepatectomy.

The clinical behavior of transplantable recurrent hepatocellular carcinoma after curative resection: implications for salvage liver transplantation.

BACKGROUND: This study aimed to classify transplantable recurrent hepatocellular carcinoma (HCC) after resection into subgroups according to the pattern of progression and to identify risk factors for each subgroup to select optimal candidates for salvage liver transplantation (LT). METHODS: The patients that met the Milan criteria (MC) and were child-pugh class A at initial hepatectomy were included in the study. Of these patients, the patients with transplantable recurrence were identified and further divided into two groups according to the recurrent HCC progression pattern. Group 1 contained patients with controlled tumors within the MC. Group 2 contained patients with progressive tumors that spread beyond the MC. A controlled tumor was defined as the absence of tumor recurrence after locoregional treatment for ≥12 months or control of a recurrent tumor within the MC by active locoregional treatment. RESULTS: After curative resection of HCC, 114 patients with transplantable recurrence were identified: 70 were classified as group 1 and 44 as group 2. Overall survival after recurrence was significantly higher in group 1 compared to group 2 (65.4 vs 35.7 %, respectively; P < 0.003). Multiple logistic regression analysis showed that risk factors in group 1 were age >50 years and an indocyanine green retention at 15 min >10 %. The presence of a satellite nodule (SN) and/or microscopic portal vein invasion (mPVI) was the only independent risk factor identified in group 2. Among the 15 patients that underwent salvage LT, 2 of 3 patients (66.7 %) with SN and/or mPVI at initial hepatectomy developed extrahepatic recurrence. CONCLUSIONS: The patients with SN and/or mPVI at initial hepatectomy may not be candidates for salvage LT, and an extended observation time is required to determine tumor biology.

Surgical resection after down-staging of locally advanced hepatocellular carcinoma by localized concurrent chemoradiotherapy.

BACKGROUND: This study evaluated the down-staging efficacy and impact on resectability of concurrent chemoradiotherapy (CCRT) followed by hepatic arterial infusion chemotherapy (HAIC) in locally advanced hepatocellular carcinoma, and identified prognostic factors of disease-free survival (DFS) and overall survival (OS) after curative resection. METHODS: DFS and OS were investigated using clinicopathologic variables. Functional residual liver volume (FRLV) was assessed before CCRT and again before surgery in patients with major hepatectomy. Tumor marker response was defined as elevated tumor marker levels at diagnosis but levels below cutoff values before surgery (α-fetoprotein < 20 ng/mL, protein induced by vitamin K absence or antagonist-II < 40 mAU/mL). RESULTS: Of 243 patients who received CCRT followed by HAIC between 2005 and 2011, 41 (16.9 %) underwent curative resection. Tumor down-staging was demonstrated in 32 (78 %) of the resected patients. FRLV significantly increased from 47.5 to 69.9 % before surgery in patients who underwent major hepatectomy. In addition, the OS of the curative resection group was significantly higher than the OS of the CCRT followed by HAIC alone group (49.6 vs. 9.8 % at 5-year survival; p < 0.001). By multivariate analysis, the poor prognostic factors for DFS after curative resection were tumor marker non-response and the presence of a satellite nodule; however, tumor marker non-response was the only independent poor prognostic factor of OS. CONCLUSIONS: CCRT followed by HAIC increased resectability by down-staging tumors and increasing FRLV. Curative resection may provide good long-term survival in tumor marker responders who undergo CCRT followed by HAIC.

Impact of spontaneous hepatocellular carcinoma rupture on recurrence pattern and long-term surgical outcomes after partial hepatectomy.

BACKGROUND: The clinical significance of spontaneous hepatocellular carcinoma (HCC) rupture association with recurrence pattern and long-term surgical outcomes remains under debate. We investigated the impact of spontaneous HCC rupture on recurrence pattern and long-term surgical outcomes after partial hepatectomy. METHODS: From 2000 to 2012, 119 patients with diagnosed ruptured HCC were reviewed. To compare outcomes between staged hepatectomy in spontaneously ruptured HCC and hepatectomy in non-ruptured HCC, we performed propensity score-matching to adjust for significant differences in patient characteristics. Overall survival, disease-free survival, and recurrence pattern were compared between the matched groups. RESULTS: Forty-four patients with newly diagnosed ruptured HCC and Child A class were initially treated with transcatheter arterial embolization for hemostasis. Three patients underwent emergency laparotomy, 18 underwent staged hepatectomy, and 23 received transarterial chemoembolization (TACE) alone after transcatheter arterial embolization. Among the 23 patients treated with TACE alone, 10 had resectable tumors. The staged hepatectomy group shows significantly higher overall survival with TACE alone than the resectable tumor group (P < 0.001). After propensity score-matching, overall survival, disease-free survival, and recurrence pattern were not significantly different between the ruptured HCC with staged hepatectomy group and the non-ruptured HCC with hepatectomy group. Peritoneal recurrence rates were similar at 14.3% versus 10.0%, respectively (P = 0.632). CONCLUSIONS: Patients with spontaneously ruptured HCC with staged hepatectomy show comparable long-term survival and recurrence pattern as patients with non-ruptured HCC having similar tumor characteristics and liver functional status. Thus, spontaneous HCC rupture may not increase peritoneal recurrence and decrease long-term survival after partial hepatectomy.

Robotic transabdominal preperitoneal repair for bilateral obturator hernia: a video vignette.

Obturator hernias (OHs) are a rare cause of bowel obstruction that requires immediate surgical intervention to prevent morbidity and mortality. Patients with OHs present with acute intestinal obstruction secondary to incarceration, with a high morbidity and mortality rate due to delayed diagnosis and treatment. Although several surgical approaches have been reported, a standard approach for OH treatment has not yet been established. Here, we report the case of a 74-year-old woman who presented with bilateral OHs. The patient presented at our institution with pain in the left lower quadrant. Computed tomography revealed preperitoneal fat in both obturator foramen. Robotic transabdominal preperitoneal (R-TAPP) bilateral OH repair was performed, and a mesh was placed over both obturator foramen. The patient recovered without postoperative complications and was discharged on postoperative day 2. This suggests that the R-TAPP approach is safe for OH repair without incarceration.

Early outcomes of robotic transabdominal preperitoneal inguinal hernia repair: a retrospective single-institution study in Korea.

Purpose: Robotic hernia repair has increased in popularity since the introduction of da Vinci robots (Intuitive Surgical). However, we lack quantitative analyses of its potential benefits. Herein, we report our initial experience with robotic transabdominal preperitoneal (R-TAPP) inguinal hernia repair. Methods: We retrospectively reviewed the data from patients who underwent R-TAPP inguinal hernia repair with a prosthetic mesh using the da Vinci platform. Data on patient characteristics and surgical outcomes were also collected. Results: Twenty-one patients (including 20 male patients [95.2%]) with a mean age of 54.1 ±16.4 years and body mass index of 23.8 ± 1.9 kg/m2 underwent R-TAPP inguinal hernia repair. Bilateral hernia repair was performed in two patients (9.5%), and six patients (28.5%) with scrotal hernia underwent R-TAPP hernia repair. A sigmoid colon sliding hernia was present in three patients (14.3%). The mean operation and console times were 91.8 ± 20.4 minutes and 154.5 ± 26.2 minutes, and 61.4 ± 16.9 minutes and 128.0 ± 25.5 minutes for unilateral and bilateral inguinal hernia, respectively. Spermatic vessel injury was identified intraoperatively in one patient. Two minor postoperative complications, postoperative ileus, and wound seroma were reported. The mean duration of hospitalization was 3.8 ± 0.9 days. No recurrence or conversion to open surgery was required. Conclusion: Our findings suggest that R-TAPP inguinal hernia repair is safe and feasible. Its cost-effectiveness, optimal procedural steps, and indications for a robotic approach require further investigation.

Prevention and management of intraoperative complication during single incision laparoscopic totally extraperitoneal repair.

Serious complications related to hernia surgeries have rarely been reported. One meta-analysis comparing laparoscopic and open mesh repair reported that 0.4% of potentially serious operative complications were reported. Previous studies have reported that uncommon serious intraoperative complications more frequently occur during laparoscopic inguinal hernia repairs. One study has shown that patients with history of lower abdominal surgery are at an increased risk of visceral injury during laparoscopic hernia repair. Vascular injuries at dissection and mesh fixation or suturing in the preperitoneal space typically involve the epigastric or aberrant obturator vessels crossing the Cooper's ligament. However, complications can occur at every step of the operation, although only few are reported. Therefore, we report our experiences of intraoperative complications during single-incision laparoscopic totally extraperitoneal hernia repair and how to prevent and manage intraoperative complications.

Pregnancy outcomes after living kidney donation from a nationwide population-based cohort study from Korea.

While most living kidney donors experience good outcomes and high rates of satisfaction, kidney donation can increase the risk of gestational hypertension or preeclampsia. However, pregnancy outcomes in non-white donors are limited. We conducted a nationwide cohort study of 112 living kidney donors and 672 matched healthy non-donors using the Korean National Health Insurance Claims Database. Donors and healthy non-donors were matched according to age, year of cohort entry, residency, income, number of pregnancies, and the time to the first pregnancy after cohort entry. We assessed pregnancy outcomes of live kidney donors compared with matched healthy non-donors using the nationwide database. Gestational hypertension or preeclampsia was more common in kidney donors than in non-donors (8.9% vs. 1.8%; adjusted odds ratio, 2.68; 95% confidence interval, 1.11-6.50). However, the incidence of severe gestational hypertension or preeclampsia that required antihypertensive medication was comparable (2.7% vs. 0.9%; P = 0.121). The time from donation to delivery within 5 years and primiparity were risk factors for preeclampsia in donors. Low birth weight, stillbirth, and ectopic pregnancy were not significantly different between the two groups. Maternal death occurred in two non-donor cases, but none occurred in donors compared to non-donors. Our findings indicate that kidney donors are associated with an increased risk of gestational hypertension or preeclampsia than matched healthy non-donors. However, the probabilities of serious maternal and fetal outcomes remained low and are not increased significantly after kidney donation.

Reproducibility and Step-By-Step Learning Curve of Retroperitoneal Video-Assisted Mini-Laparotomy Surgery for Living Donor Nephrectomy: A Single-Center Experience.

OBJECTIVES: Living donor transplant techniques must ensure donor safety and minimize complications. To achieve this goal, in 2003, we developed a new surgical procedure named video-assisted mini-laparotomy surgery for living donor nephrectomy. Video-assisted mini-laparotomy surgery standardizes the retroperitoneal mini-laparotomy technique as an alternative to open surgery. We have previously reported on video-assisted mini-laparotomy surgery techniques for use in kidney surgery. However, there are no reports of video-assisted mini-laparotomy surgery performed at other institutions. Therefore, we introduced video-assisted mini-laparotomy surgery at another institution, and here, we report on our experience. MATERIALS AND METHODS: We evaluated a consecutive series of 38 donors who underwent video-assisted mini-laparotomy living donor nephrectomy at National Health Insurance Service Ilsan Hospital from August 2016 to November 2019. All 38 patients were enrolled. Perioperative data and outcomes were retrospectively analyzed. We recorded perioperative and postoperative data, including operative time, estimated blood loss, and duration of hospital stay. RESULTS: The mean operative time was 144.35 ± 22.79 minutes, and the mean warm ischemia time was 184.35 ± 4.97 seconds. Mean estimated blood loss was 72.85 ± 60.81 mL. At 12 months after video-assisted mini-laparotomy surgery, the mean posttransplant serum creatinine level was 1.05 ± 0.18 mg/dL, and estimated glomerular filtration rate (according to the Modification of Diet in Renal Disease study equation) was 71.9 ± 10.34 mL/min/1.73 m2. There was no intraoperative or postoperative complication. CONCLUSIONS: Previous studies reported that video- assisted mini-laparotomy surgery has a steep learning curve and is difficult to reproduce. However, video- assisted mini-laparotomy surgery is a feasible and safe technique at our institution. Video-assisted mini- laparotomy surgery is a solo surgery that can be safely performed by any surgeon with prior kidney surgery experience.

Antitumor Effect of Low-Dose of Rapamycin in a Transgenic Mouse Model of Liver Cancer.

PURPOSE: We investigate whether low-dose rapamycin is effective in preventing hepatocellular carcinoma (HCC) growth and treating HCC after tumor development in transgenic mice. MATERIALS AND METHODS: We established transgenic mice with HCC induced by activated HrasG12V and p53 suppression. Transgenic mice were randomly assigned to five experimental groups: negative control, positive control, tacrolimus only, rapamycin only, and tacrolimus plus rapamycin. The mice were further divided into two groups according to time to commencement of immunosuppressant treatment: de novo treatment and post-tumor development. RESULTS: In the de novo treatment group, marked suppression of tumor growth was observed in the rapamycin only group. In the post-tumor development group, the rapamycin only group displayed no significant suppression of tumor growth, compared to the positive control group. In T lymphocyte subset analysis, the numbers of CD4+ effector T cells and CD4+ regulatory T cells were significantly lower in the positive control, tacrolimus only, and tacrolimus plus rapamycin groups than the negative control group. Immunohistochemical analysis revealed significantly higher expression of phosphorylated-mTOR, 4E-BP1, and S6K1 in the positive control group than in the rapamycin only group. CONCLUSION: Low-dose rapamycin might be effective to prevent HCC growth, but may be ineffective as a treatment option after HCC development.

Outcomes of kidney transplantation over a 16-year period in Korea: An analysis of the National Health Information Database.

BACKGROUND: This study investigated the outcomes of kidney transplantation (KT) over a 16-year period in Korea and identified risk factors for graft failure using a nationwide population-based cohort. METHODS: We investigated the Korean National Health Insurance Service-National Health Information Database. Health insurance claims for patients who underwent KT between 2002 and 2017 were analyzed. RESULTS: The data from 18,331 patients who underwent their first KT were reviewed. The percentage of antithymocyte globulin (ATG) induction continuously increased from 2.0% in 2002 to 23.5% in 2017. Rituximab began to be used in 2008 and had increased to 141 patients (9.6%) in 2013. Acute rejection occurred in 17.3% of all patients in 2002 but decreased to 6.3% in 2017. The rejection-free survival rates were 78.8% at 6 months after KT, 76.1% after 1 year, 67.5% after 5 years, 61.7% after 10 years, and 56.7% after 15 years. The graft survival rates remained over 80% until 12 years after KT, and then rapidly decreased to 50.5% at 16 years after KT. In Cox's multivariate analysis, risk factors for graft failure included being male, more recent KT, KT from deceased donor, use of ATG, basiliximab, or rituximab, tacrolimus use as an initial calcineurin inhibitor, acute rejection history, and cytomegalovirus infection. CONCLUSIONS: ATG and rituximab use has gradually increased in Korea and more recent KT is associated with an increased risk of graft failure. Therefore, meticulous preoperative evaluation and postoperative management are necessary in the case of recent KT with high risk of graft failure.

The impact of prophylactic ureteral stenting during kidney transplantation on postoperative surgical outcomes.

Background: The aim of this study was to evaluate the safety and feasibility of prophylactic ureteric stenting during kidney transplantation (KT). Methods: The authors retrospectively reviewed patients who underwent KT between June 2016 and June 2019. The prophylactic ureteral stenting group (double-J [DJ]) and no-stent group (no-DJ) were compared with respect to the clinical data and surgical outcomes. Results: A total of 42 patients underwent KT; 17 patients were classified into the DJ group and 25 patients into the no-DJ group. Antithymocyte globulin induction and donor-specific antibody positivity were significantly higher in the DJ group. There were no significant differences between the groups in terms of symptomatic urinary tract infection (UTI). The time to postoperative UTI was significantly shorter in the DJ group than in the no-DJ group (33.5±7.8 vs. 105.3±71.6 days, P=0.013). The development of postoperative BK viremia was significantly higher in the no-DJ group (0.0% vs. 16.0%, P=0.035). Urologic complications were significantly higher in the no-DJ group (0.0% vs. 16.0%, P=0.035). In the no-DJ group, urologic complications occurred in four patients ureteroneocystostomy stenosis in three patients and ureteroneocystostomy leakage in one patient. Percutaneous ureteral interventions were performed for all patients using percutaneous nephrostomy and reno-uretero-vesical stenting. However, there were no postoperative urologic complications in the DJ group. Conclusions: Prophylactic ureteric stenting during KT may be safe and feasible without significantly increasing the incidence of UTI and BK viremia. Additionally, prophylactic ureteric stenting may reduce urologic complications after KT.

Perioperative blood usage and therapeutic plasma exchange in kidney transplantation during a 16-year period in South Korea.

BACKGROUND: The frequency of kidney transplantation (KT) is increasing. Blood transfusion plays an important role in the success of KT. Therapeutic plasma exchange (TPE) is also used for desensitisation in ABO-incompatible KT and treatment of antibody-mediated rejection. MATERIALS AND METHODS: We analysed red blood cell (RBC), platelet, and fresh frozen plasma (FFP) usage and the number of TPE procedures performed during the hospitalisation of KT patients from 2002 to 2017 using the Korean National Health Insurance Service-National Health Information Database. RESULTS: A total of 18,331 KT patients were included in this study. The number of transfused RBCs continued to increase from 4,806 units in 2002-2005 to 12,390 units in 2014-2017. However, the average number of RBCs transfused per patient decreased from 2.17 to 1.79 units. Estimated platelet usage increased from 4,259 units in 2002-2005 to 11,519 units in 2014-2017, and the proportion of filtered platelets increased from 72.6% to 83.4% during the same period. There was a huge increase in the total number of FFP units used, from 2,255 units in 2002-2005 to 51,531 units in 2014-2017. The number of TPE procedures performed also increased from 296 to 6,479 during the same period. Patients with acute rejection accounted for 8.8% of all KT patients, and more RBC and FFP were used for these patients and a greater number of TPE procedures were performed compared to those who did not experience rejection. DISCUSSION: Blood usage and TPE have increased steadily with the increasing numbers of KTs. Therefore, continuous efforts are needed to ensure appropriate perioperative blood preparation and usage for KT patients.

Outcomes of open versus single-incision laparoscopic totally extraperitoneal inguinal hernia repair using propensity score matching: A single institution experience.

PURPOSE: The aim of the current study was to compare the outcomes between open and single-incision laparoscopic totally extraperitoneal (SILTEP) inguinal hernia repair. METHODS: To compare the outcomes between the open and SILTEP groups, we performed propensity score matching to adjust for significant differences in patient characteristics. The outcomes were compared between the matched groups. RESULTS: Record review identified 477 patients who had undergone inguinal hernia repair from November 2016 to November 2018. Seventy-one patients were excluded from the propensity score matching because of age <18, femoral hernia, conventional 3-port laparoscopic repair, incarcerated hernia, and combined operation. SILTEP in 142 and open repair in 264 patients were identified. After propensity score matching, these individuals were grouped into 82 pairs. Spinal anesthesia was administered more often in the open group than in the SILTEP group. Operation time was significantly longer in the SILTEP group than in the open group (49.6 ± 17.4 vs. 64.8 ± 28.4 min, p < 0.001). However, urinary retention rates of the open group were significantly higher than that of the SILTEP group (11.0% vs. 0%, p = 0.003). The SILTEP group showed significantly lower pain scores at postoperative 6, 12, and 24 hours, and significantly lower rates of intravenous analgesic requirements through postoperative day 1 (30.5% vs. 13.4%, p = 0.008) compared with the open group. CONCLUSION: The outcomes of SILTEP repair were comparable to those of open repair. SILTEP repair may have advantages over open repair for reducing immediate postoperative pain (≤24 hours).

De Novo Cancer Incidence after Kidney Transplantation in South Korea from 2002 to 2017.

Advances in patient care and immunosuppressive drugs have improved graft survival, resulting in an increase in kidney transplantation (KT); however, persistent immunosuppression is thought to cause late occurrence of cancer. This population-based study consisted of a total of 14,842 patients whose data from the years 2002 to 2017 were collected from the National Health Information Database in South Korea. Malignancies occurred in 7.6% of the total KT patients. Prostate and thyroid cancers were the most common in males and females, respectively. From the age-adjusted incidence analysis, Kaposi's sarcoma showed the highest standardized incidence ratio in both male and female patients. According to the linear regression model, cancer incidence in KT recipients under immunosuppressive conditions increased by approximately 0.1% each month. Patients' age over 39 and the use of prednisolone as an initial steroid regimen were associated with increased risk of cancer development after KT. Our regression and proportional hazards models will help clinicians to predict the approximate cancer incidence risk when monitoring KT recipients. Based on the largest available national database, screening or monitoring methods for cancer detection and prevention can be established for KT patients by considering the factors involved in cancer development.

Crystallization of amorphous Fe90Zr10 under ball milling.

The present study deals with structural transformations induced by high-energy ball-milling of an amorphous Fe90Zr10 alloy prepared by melt-spinning. The amorphous melt-spun ribbons were found to undergo crystallization into BCC alpha-Fe(Zr) nanocrystallites under high-energy ball milling. The decomposition degree of the amorphous phase increased with increasing milling time and intensity. Our results suggest that the observed crystallization is a deformation-induced process rather than a thermally induced one.

Irrigation Versus Suction Alone During Laparoscopic Appendectomy for Uncomplicated Acute Appendicitis.

PURPOSE: To compare the surgical outcomes of peritoneal irrigation versus suction alone during laparoscopic appendectomy and to identify the risk factors of surgical site infection in patients with uncomplicated acute appendicitis. METHODS: Data from patients with uncomplicated acute appendicitis between January 2014 and March 2016 were reviewed. We compared the irrigation and suction alone groups with regard to the following parameters: postoperative complication incidence rate, length of hospital stay, operation time, time to flatus, time to diet commencement, and duration of postoperative antibiotic. RESULTS: A total of 578 patients underwent laparoscopic appendectomy for uncomplicated acute appendicitis. Twenty-five patients were excluded from the analysis because of need for drain insertion, loss to follow-up, simultaneous surgery for another indication, presence of an appendix tumor, or pregnancy. A total of 207 patients (37.4%) had undergone irrigation, and 346 patients (62.6%) received suction alone during laparoscopic appendectomy. The preoperative fever rate was significantly higher in the irrigation group than in the suction alone group. Operative time was also significantly longer in the irrigation group than in the suction alone group (53.8 ± 18.5 minutes vs. 57.8 ± 21.4 minutes, P = 0.027). The postoperative complication rate was higher in the irrigation group than in the suction alone group (4.5% vs. 12.6%, P = 0.001). Multiple logistic regression analysis showed that irrigation and preoperative fever were risk factors for surgical site infection after laparoscopic appendectomy for uncomplicated acute appendicitis. CONCLUSION: There is no advantage to irrigating the peritoneal cavity over suction alone during laparoscopic appendectomy for uncomplicated acute appendicitis. Irrigation may actually prolong the operative time and therefore be detrimental.