Effect of endoscopic surgical skill qualification system for laparoscopic multivisceral resection: Japanese multicenter analysis.

BACKGROUND: The efficacy of laparoscopic multivisceral resection (Lap-MVR) has been reported by several experienced high-volume centers. The Endoscopic Surgical Skill Qualification System (ESSQS) was established in Japan to improve the skill of laparoscopic surgeons and further develop surgical teams. We examined the safety and feasibility of Lap-MVR in general hospitals, and evaluated the effects of the Japanese ESSQS for this approach. METHODS: We retrospectively reviewed 131 patients who underwent MVR between April 2016 and December 2019. Patients were divided into the laparoscopic surgery group (LAC group, n = 98) and the open surgery group (OPEN group, n = 33). The clinicopathological and surgical features were compared between the groups. RESULTS: Compared with the OPEN group, BMI was significantly higher (21.9 vs 19.3 kg/m2, p = 0.012) and blood loss was lower (55 vs 380 ml, p < 0.001) in the LAC group. Operation time, postoperative complications, and postoperative hospital stay were similar between the groups. ESSQS-qualified surgeons tended to select the laparoscopic approach for MVR (p < 0.001). In the LAC group, ESSQS-qualified surgeons had superior results to those without ESSQS qualifications in terms of blood loss (63 vs 137 ml, p = 0.042) and higher R0 resection rate (0% vs 2.0%, p = 0.040), despite having more cases of locally advanced tumor. In addition, there were no conversions to open surgery among ESSQS-qualified surgeons, and three conversions among surgeons without ESSQS qualifications (0% vs 15.0%, p = 0.007). Multivariate analysis revealed blood loss (odds ratio 1.821; 95% CI 1.324-7.654; p = 0.010) as an independent predictor of postoperative complications. Laparoscopic approach was not a predictive factor. CONCLUSIONS: The present multicenter study confirmed the feasibility and safety of Lap-MVR even in general hospitals, and revealed superior results for ESSQS-qualified surgeons.

Charlson comorbidity index predicts anastomotic leakage in patients with resected right-sided colon cancer.

PURPOSE: Anastomotic leakage after right-sided colon cancer surgery is a serious complication that affects postoperative mortality. The Charlson comorbidity index (CCI) has been reported to be a useful predictor of postoperative complications. METHODS: A total of 593 cases of right-sided colon cancer resections performed from 2016 to 2020 were examined. The patients were divided into two groups according to the presence or absence of anastomotic leakage (AL, n = 28; no-AL, n = 565); clinicopathological and surgical characteristics were compared between the groups. RESULTS: The AL group patients had a higher comorbidity rate (96.4% vs. 66.9%, p < 0.001), higher CCI score (p < 0.001), higher blood loss (42 mL vs. 23 mL, p = 0.046), and longer hospital stay (30 days vs. 12 days, p < 0.001) than the no-AL group patients. The percentages of chronic pulmonary disease (14.3% vs. 3.9%, p = 0.029), cerebrovascular disease (14.3% vs. 1.9%, p = 0.022), connective tissue disease (39.3% vs. 3.2%, p < 0.001), leukemia (3.6% vs. 0%, p = 0.042), and moderate to severe liver disease (7.1% vs. 0%, p = 0.002) were significantly higher in the AL group. In the multivariate analysis, CCI ≥ 2 was identified as an independent predictor of postoperative anastomotic leakage (hazard ratio 4.91, 95% confidence interval 2.23-10.85, p < 0.001). CONCLUSIONS: CCI could predict anastomotic leakage after right-sided colon cancer surgery.

A new method using a vessel-sealing system provides coagulation effects to various types of bleeding with less thermal damage.

BACKGROUND: Hemostasis is very important for a safe surgery, particularly in endoscopic surgery. Accordingly, in the last decade, vessel-sealing systems became popular as hemostatic devices. However, their use is limited due to thermal damage to organs, such as intestines and nerves. We developed a new method for safe coagulation using a vessel-sealing system, termed flat coagulation (FC). This study aimed to evaluate the efficacy of this new FC method compared to conventional coagulation methods. METHODS: We evaluated the thermal damage caused by various energy devices, such as the vessel-sealing system (FC method using LigaSure™), ultrasonic scissors (Sonicision™), and monopolar electrosurgery (cut/coagulation/spray/soft coagulation (SC) mode), on porcine organs, including the small intestine and liver. Furthermore, we compared the hemostasis time between the FC method and conventional methods in the superficial bleeding model using porcine mesentery. RESULTS: FC caused less thermal damage than monopolar electrosurgery's SC mode in the porcine liver and small intestine (liver: mean depth of thermal damage, 1.91 ± 0.35 vs 3.37 ± 0.28 mm; p = 0.0015). In the superficial bleeding model, the hemostasis time of FC was significantly shorter than that of electrosurgery's SC mode (mean, 19.54 ± 22.51 s vs 44.99 ± 21.18 s; p = 0.0046). CONCLUSION: This study showed that the FC method caused less thermal damage to porcine small intestine and liver than conventional methods. This FC method could provide easier and faster coagulation of superficial bleeds compared to that achieved by electrosurgery's SC mode. Therefore, this study motivates for the use of this new method to achieve hemostasis with various types of bleeds involving internal organs during endoscopic surgeries.

Factors related to short-term outcomes and delayed systemic treatment following primary tumor resection for asymptomatic stage IV colorectal cancer.

BACKGROUND: The effectiveness of primary tumor resection (PTR) for asymptomatic stage IV colorectal cancer patients to continue prolonged and safe systemic chemotherapy has recently been re-evaluated. However, postoperative complications lead to a prolonged hospital stay and delay systemic treatment, which could result in a poor oncologic outcome. The objective of this study was to identify the risk factors for morbidity and delay of systemic chemotherapy in such patients. METHODS: Between April 2016 and March 2018, 115 consecutive colorectal cancer patients with distant metastasis who had no clinical symptoms and underwent PTR in all participating hospitals were retrospectively reviewed. The patients were divided into two groups according to the presence (CD ≥ 2, n = 23) or absence (CD < 2, n = 92) of postoperative complications. RESULTS: The proportion of combined resection of adjacent organs was significantly higher in the postoperative complication group (p = 0.014). Complications were significantly correlated with longer hospital stay (p < 0.001) and delay of first postoperative treatment (p = 0.005). Univariate and multivariate analyses showed that combined resection (odds ratio 4.593, p = 0.010) was the independent predictor for postoperative complications. Median survival time was 8.5 months. Postoperative complications were not associated with overall survival, but four patients (3.5%) could not receive systemic chemotherapy because of prolonged postoperative complications. CONCLUSIONS: Although PTR for asymptomatic stage IV CRC patients showed an acceptable prognosis, appropriate patient selection is needed to obtain its true benefit.

The C-reactive protein to albumin ratio predicts postoperative complications in oldest-old patients with colorectal cancer.

PURPOSE: The C-reactive protein to albumin ratio (CAR) is a simple and useful score for predicting the outcomes of patients with various cancers. The aim of this study was to evaluate the CAR and short-term outcomes in oldest-old patients with colorectal cancer. METHODS: A total of 126 patients aged 85 years and older with colorectal cancer who underwent resection for primary colon cancer from April 2015 to December 2018 were included. The preoperative cutoff value of the CAR for predicting postoperative complications was 0.19 on receiver operating characteristic curve analysis. Clinical characteristics and inflammation-based scores were compared between patients with a high CAR (CAR ≥ 0.19, n = 44) and a low CAR (CAR < 0.19, n = 82). RESULTS: A high preoperative CAR level (≥ 0.19) was significantly associated with stoma construction (p = 0.004), blood loss (p = 0.003), postoperative complications (p = 0.016), and systemic inflammation marker levels, including a low neutrophil to lymphocyte ratio (p = 0.006), a low platelet to lymphocyte ratio (p = 0.005), a low prognostic nutritional index (p < 0.001), and a high modified Glasgow prognostic score (p < 0.001). On univariate and multivariate analyses, only the CAR was an independent predictor of postoperative complications (HR 2.864, p = 0.029). CONCLUSIONS: A high CAR was significantly associated with postoperative complications for oldest-old patients with colorectal cancer.

Questionnaire survey of virtual reality experiences of digestive surgery at a rural academic institute: A pilot study for pre-surgical education.

We developed a prototype VR platform, VECTORS L&M (VLM), aiming to enhance the understanding of digestive surgery for students, interns, and young surgeons by limiting costs. Its efficacy was assessed via questionnaires before implementation in surgical education. The VLM provides nine-minute VR views of surgeries, from both 180- and 360-degree angles. It was created with L.A.B. Co., Ltd. and incorporates surgery videos from biliary malignancy patients. Following VLM development, a survey was conducted among surgeons who had experienced it. Twenty-eight participants (32% of observers) responded to the survey. A majority (81%) reported positive experiences with the VR content and showed interest in VR video production, though some reported sickness. Most respondents were experienced surgeons, and nearly all believed VR was important for medical education with a mean score of 4.14 on a scale of up to 5. VR was preferred over 3D printed models due to its application versatility. Participants expressed the desire for future VR improvements, such as increased mobility, cloud connectivity, cost reduction, and better resolution. The VLM platform, coupled with this innovative teaching approach, offers experiential learning in intraabdominal surgery, effectively enriching the knowledge of students and surgeons ahead of surgical education and training.

Short- and Long-term Outcome After Gastric Cancer Resection in Patients Aged 80 Years and Older.

Background/Aim: We aimed to assess the risk factors for postoperative complications and long-term outcome of patients aged ≥80 years after curative resection for gastric cancer (GC). Patients and Methods: Patients aged ≥80 years who underwent curative gastrectomy for stage I-III GC between 2013 and 2020 were included. Clinical factors were retrospectively analyzed. Results: Of all 109 patients, 29 (26.6%) had 33 postoperative complications (Clavien-Dindo grade ≥2). The rate of postoperative complications was higher in those with greater blood loss (≥170 ml, p<0.001). In multivariate analysis, greater blood loss was confirmed as an independent predictor of postoperative complications (p<0.001). The 30-day, 180-day, 1-year, and 3-year cumulative overall survival rates were 100%, 97.0%, 91.6%, and 74.7%, respectively. Multivariate analysis showed postoperative complications (p=0.014) and low prognostic nutritional index (PNI, p=0.044) were independent prognostic factors for poor overall survival. Conclusion: Performing operations with less bleeding is important to reduce postoperative complications. According to the analysis of long-term survival, patients who experience postoperative complications and patients with a low preoperative PNI require special attention in the follow-up period. Nutritional support should be considered in patients with malnutrition.

Persistent Descending Mesocolon as An Intraoperative Risk Factor in Laparoscopic Surgery for Left-Sided Colon and Rectal Cancer.

INTRODUCTION: Persistent descending mesocolon (PDM) represents a failure of fusion of the descending mesentery, leading to anatomical abnormalities. This study aimed to examine the effects of anatomical features of PDM on laparoscopic surgical outcomes. METHODS: Patient backgrounds, surgical outcomes, anatomical characteristics, and operative findings were retrospectively compared between 186 patients classified into PDM and non-PDM groups who underwent primary resection for left-sided colon and rectal cancer at our hospital from January 2019 to December 2020. RESULTS: PDM was diagnosed in nine patients (4.8%). The operative time (337 ± 165 vs 239 ± 107 min, p = 0.010) was significantly different between PDM and non-PDM groups, but bleeding loss was not different (108 ± 97 ml vs 53 ± 142 ml, p = 0.259). In PDM patients, in addition to abnormal fixation of the sigmoid-descending colon junction, adhesion of the mesentery of the colon and small intestine in 100%, and adhesion between the mesocolon in 33% patients was confirmed intraoperatively. Ileus was more common in the PDM group (two cases, 22%) and in the non-PDM group (10 cases, 5.6%), but there was no significant difference in overall postoperative complications between the two groups (p = 0.215). The duration of postoperative hospital stay (28 ± 20 vs 16 ± 11 days, p = 0.002) was significant between the two groups. The left colonic artery (LCA) could not be preserved in six patients in the PDM group, one of whom had anastomotic leakage and two of whom required additional resections due to intraoperative intestinal blood flow failure. CONCLUSION: PDM prolonged operative times and duration of postoperative stay in laparoscopic surgery for left-sided colon and rectal cancer. Division of the LCA in PDM patients should be considered an intraoperative risk factor for injury to the marginal artery.

Effect of hemodialysis on short-term outcomes after colon cancer surgery.

BACKGROUND: Hemodialysis patients who undergo surgery have a high risk of postoperative complications. The aim of this study was to determine whether colon cancer surgery can be safely performed in hemodialysis patients. METHODS: This multicenter retrospective study included 1372 patients who underwent elective curative resection surgery for colon cancer between April 2016 and March 2020. RESULTS: Of the total patients, 19 (1.4%) underwent hemodialysis, of whom 19 (100%) had poor performance status and 18 had comorbidities (94.7%). Minimally invasive surgery was performed in 78.9% of hemodialysis patients. The postoperative complication rate was significantly higher in hemodialysis than non-hemodialysis patients (36.8% vs. 15.5%, p = 0.009). All postoperative complications in the hemodialysis patients were infectious type. Multivariate analysis revealed a significant association of hemodialysis with complications (odds ratio, 2.9362; 95%CI, 1.1384-7.5730; p = 0.026). CONCLUSION: Despite recent advances in perioperative management and minimally invasive surgery, it is necessary to be aware that short-term complications can still occur, especially infectious complications in hemodialysis patients.

Short- and long-term survival after curative resection for colorectal cancer in nonagenarian patients.

BACKGROUND/OBJECTIVE: With increased life expectancy, the incidence of colorectal cancer in oldest-old patients has been rising. Advanced age is a risk factor for adverse outcomes after surgery. This study aimed to evaluate the short- and long-term outcomes of curative resection for colorectal cancer in nonagenarians. METHODS: Patients who had undergone curative resection for colorectal cancer (CRC) at Stage I to III from January 2010 to December 2019 were included. Cases of emergent surgery were excluded. The clinical characteristics were documented retrospectively, and factors affecting the long-term outcome were analyzed using multivariate analysis. RESULTS: Fifty patients met the selection criteria. Most of them were women (58.0%), and the median age was 92 years. Among these patients, 29 (58.0%) had a poor performance status (ASA-PS≥3). Laparoscopic surgery was performed in 42.0% of the patients, and 50% of the patients had postoperative complications classified as Clavien-Dindo grade 2 or severer, including 3 patients (6.0%) with grade 3 disease. No postoperative mortality occurred. The 30-day, 180-day, 1-year, 3-year and 5-year survival rates were 100%, 80.4%, 71.0%, 46.3%, and 33.8%, respectively. Multivariate analysis showed that a preoperative poor performance status (ASA-PS≥3) (HR: 3.067; 95% CI: 1.220-7.709; p = 0.017) was an independent prognostic factor for OS. CONCLUSION: Curative elective resections for CRC in nonagenarians were performed safely without postoperative mortality. The preoperative performance status was significantly associated with OS after curative elective resection of colorectal cancer in nonagenarians. Our results suggest that excellent long-term outcomes can be achieved in a selected group with a good performance status.

Usefulness of 18F-fluorodeoxyglucose positron emission tomography for assessment of tumorviability after resection of granulocyte-colony-stimulating-factor -Producing cholangiocarcinoma-a case report.

INTRODUCTION AND IMPORTANCE: Granulocyte colony-stimulating factor (G-CSF)-producing intrahepatic cholangiocarcinoma is rare. Surgical cases with postoperative clinical course have rarely been reported. CASE PRESENTATION: A 63-year-old woman complained upper abdominal pain. Computed tomography (CT) showed intrahepatic mass measuring 9 × 9 × 9 cm in the left lateral segment. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) showed high uptake by the tumor, with diffuse uptake in the bone marrow. An extended left lobectomy was performed to achieve complete resection. Histopathological examination showed poorly differentiated adenocarcinoma with no lymph node metastasis. Immunohistochemical analysis revealed that tumor cells produced G-CSF. After chemotherapy with S-1 regimen at 10 months after the operation, CT and FDG-PET detected lymph node metastasis in the peri-duodenal area and left kidney metastasis, with no FDG uptake in the bone marrow. Serum G-CSF was normal. Combination chemotherapy with gemcitabine plus cisplatin was administered, and, 12 months after liver resection, metastases were enlarged and FDG uptake in the bone marrow was detected again. Serum G-CSF was elevated at 71.6 pg/mL. The patient was enrolled in a clinical trial of chemotherapy with another regimen and was alive at 19 months after liver resection. CLINICAL DISCUSSION: Because of rapid progression, rapid diagnosis and resection are important. FDG uptake in the bone marrow is characteristic in G-CSF producing tumor. In this case, FDG uptake in the bone marrow reappeared after the enlargement of recurrent lesions, followed by tumor enlargement. CONCLUSION: FDG-PET was useful for differential diagnosis and to assess tumor viability and determine the surgical indication.

Postoperative Complications Predict Long-term Outcome After Curative Resection for Perforated Colorectal Cancer.

BACKGROUND/AIM: Perforation and postoperative complications have a negative effect on long-term outcomes in patients with colorectal cancer (CRC). The aim of this study was to evaluate the clinical factors with special reference to postoperative complications predicting the long-term outcome in those for whom curative resection for perforated CRC was performed. PATIENTS AND METHODS: Patients who underwent curative resection for perforated CRC at stage II or III from April 2003 to March 2020 were included. Clinical factors were retrospectively analyzed. RESULTS: Forty-four patients met the selection criteria. The 30-day mortality rate was 4.5% and the complication rate was 47.7%. Excluding 30-day mortality, five-year recurrence-free survival (RFS) and overall survival (OS) were 62.3% and 73.6%, respectively. Multivariate analysis showed that postoperative complications (p=0.005) and pT4 pathological factor (p=0.009) were independent prognostic factors for RFS. Only postoperative complications (p=0.023) were an independent prognostic factor for OS. CONCLUSION: Postoperative complications were significantly associated with RFS and OS, and pT4 was associated with RFS. The prevention and management of postoperative adverse events may be important for perforated CRC.

Safe laparoscopic resection of a giant schwannoma in the retroperitoneum using a fluorescent ureteral stent: a case report.

Schwannomas that occur in the retroperitoneal cavity are rare. We herein report a patient who underwent safe laparoscopic resection by using a preoperative 3D computed tomography (CT) image and a fluorescent ureteral stent during the surgery. A 47-year-old man presented with left lower abdominal pain. CT showed a 10-cm continuous retroperitoneal tumor originating at the third lumbar nerve in the lower left abdomen. Schwannoma was suspected. We underwent laparoscopic resection of the tumor guided by 3D images obtained preoperatively. A fluorescent ureteral stent was implanted during the surgery to improve visibility and protect the left ureter. The resection was completed without injury of other organs and vessels. The patient was discharged on postoperative Day 5. By performing a preoperative simulation using 3D CT images, we could anticipate the anatomical findings and easily identify them intraoperatively. In addition, the fluorescent ureteral stent provided visual support, thereby contributing to safe surgery.

Long-Term Prognosis after Surgery for Locally Recurrent Rectal Cancer: A Retrospective Study.

OBJECTIVE: Resection is usually recommended for locally recurrent rectal cancer (LRRC) for which R0 resection is possible, but its suitability varies by individual patient risk. Here, we report outcomes of resected LRRC in our hospital. METHODS: We retrospectively evaluated short- and long-term results of 33 patients who underwent resections for LRRC from January 2003 to December 2019. RESULTS: At the initial surgeries for these 33 patients, their disease stages at that time were Stage I: n=2, Stage II: n=12, Stage III: n=11, Stage IV: n=6, and unknown: n=2. Patients with Stage IV disease at their initial surgeries underwent radical one-step or two-step procedures. Metastasis to other organs was observed in 5 patients at the their initial LRRC diagnoses. At the LRRC surgeries, 7 patients received palliative surgeries; 26 received intent-to-treat resections, of which 17 were R0 resections. All-grade postoperative complications were observed in 11 patients, including 1 surgery-related death. Five-year overall survival rates were all cases: 38.4%; R0 group: 52.3%, R1 or R2 group: 19.4%, and palliative surgery group: 0%. The R0 group thus had significantly better prognosis than other patients (P = 0.0012). Eleven patients in the R0 group (64.7%) suffered re-recurrences but some patients achieved long-term survival through chemotherapy, radiation therapy, and surgery for metastasis to other organs, even after re-recurrence. CONCLUSION: Long-term prognosis after surgery for LRRC was significantly better for patients with R0 margins. Multimodal treatments may greatly improve survival for patients who suffer re-recurrences after local recurrence resections.

A learning curve in using organ retractor for single-incision laparoscopic right colectomy.

Single-incision laparoscopic surgery (SILS) has the potential to improve perioperative outcomes, including less postoperative pain, shorter operation time, less blood loss, and shorter hospital stay. However, SILS is technically difficult and needs a longer learning curve. Between April 2016 and September 2019, a total of 198 patients with clinical stage I/II right colon cancer underwent curative resection. In the case of the SILS approach, an organ retractor was usually used to overcome SILS-specific restrictions. The patients were divided into two groups by surgical approach: the SILS with organ retractor group (SILS-O, n = 33) and the conventional laparoscopic surgery group (LAC, n = 165). Clinical T status was significantly higher in the LAC group (p = 0.016). Operation time was shorter and blood loss was lower in the SILS-O group compared to the LAC group (117 vs. 197 min, p = 0.027; 10 vs. 25 mL, p = 0.024, respectively). In the SILS-O group, surgical outcomes including operation time, blood loss, number of retrieved lymph nodes, and postoperative complications were not significantly different between those performed by experts and by non-experts. Longer operation time (p = 0.041) was significantly associated with complications on univariate and multivariate analyses (odds ratio 2.514, 95%CI 1.047-6.035, p = 0.039). SILS-O was safe and feasible for right colon cancer. There is a potential to shorten the learning curve of SILS using an organ retractor.

Impact of obesity on short-term outcomes of laparoscopic colorectal surgery for Japanese patients with colorectal cancer: A multicenter study.

INTRODUCTION: The impact of obesity on short-term outcomes after laparoscopic colorectal surgery (LAC) in Asian patients is unclear. The purpose of the present multicenter study was to evaluate the safety and feasibility of LAC in obese Japanese patients. METHODS: We retrospectively reviewed 1705 patients who underwent LAC between April 2016 and February 2019. Patients were classified according to body mass index (BMI): non-obese (BMI < 25 kg/m2 , n = 1335), obese I (BMI 25-29.9 kg/m2 , n = 313), and obese II (BMI ≥30 kg/m2 , n = 57). Clinical characteristics and surgical outcomes were compared among the three groups. RESULTS: The proportion of patients with comorbidities (non-obese, 58.1%; obese I, 69.6%; obese II, 75.4%; P < .001) and median operation time (non-obese, 224 minutes; obese I, 235 minutes; obese II, 258 minutes; P = .004) increased significantly as BMI increased. The conversion rate was similar among the groups (P = .715). Infectious complications were significantly high in obese II patients (non-obese, 10.4%; obese I, 8.3%; obese II, 28.1%; P < .001). Multivariate analysis revealed that in obese II patients, BMI was an independent predictive factor of infectious postoperative complications (odds ratio 2.648; 95% confidence interval, 1.421-4.934; P = .002). CONCLUSION: LAC has an increased risk of postoperative infectious complications in obese II patients, despite improvements in surgical technique. Management of obese II colorectal cancer patients requires meticulous perioperative management.

Acute perforating appendicitis caused by metastatic squamous cell carcinoma from the lung: A case report.

INTRODUCTION: Lung cancer is one of the most common cancers. On the other hand, lung cancer metastasis to the appendix is extremely rare, and in many cases it has been diagnosed with the onset of acute perforating appendicitis. PRESENTATION OF CASE: An 85-year-old man with fever and abdominal pain visited our hospital. He had a history of squamous cell carcinoma of the left upper and lower lobes, metastasis to the ipsilateral lung and femur. CT showed that a finding of acute perforating appendicitis, emergency cecal resection was performed. Examination of the resected specimen showed that the appendix was thickened overall, with a white nodular structure at the root and a perforation in the middle. The final diagnosis was acute perforating appendicitis caused by metastatic squamous cell carcinoma from the lung. The patient had no particular problems during the postoperative course. DISCUSSION: A PubMed search was performed, this appears to be the first reported case of appendiceal metastasis of squamous cell carcinoma of the lung. Since squamous cell carcinoma of the lung has a stronger tendency for local extension than other histological types, perforating appendicitis due to distant metastasis to the abdominal organs and metastasis to the appendix was reported as a very valuable case. CONCLUSION: Because the progression of concomitant or secondary appendicitis is rapid, we recommend frequent imaging modalities, prophylactic appendectomy be considered for patients who also have lung cancer and imaging findings show suspected metastasis to the appendix.

Diagnosis of Lymph Node Metastasis in Colorectal Cancer by a Semi-dry Dot-blot Method.

BACKGROUND/AIM: This study aimed to examine whether the semi-dry dot-blot (SDB) method can correctly identify metastasis to lymph nodes in colorectal cancer. MATERIALS AND METHODS: A total of 200 dissected lymph nodes from 83 patients with colorectal cancer who underwent surgery between November 2013 and May 2016 were examined. Each lymph node was first examined by SDB using anti-pancytokeratin antibody (AE1/AE3). Pathological Stage I/II patients with a negative reaction were further analyzed by SDB using anti-cytokeratin 20 antibody (CK-20) to detect micrometastasis or isolated tumor cells. RESULTS: The sensitivity, specificity, and accuracy of SDB using AE1/AE3 were 91.3%, 100%, and 98.0%, respectively. Five of 99 lymph nodes of pathological Stage I/II patients had a negative reaction to AE1/AE3, but were positive to CK-20, while 3 showed isolated tumor cells. CONCLUSION: The SDB is a useful diagnostic tool to detect lymph node metastases in colorectal cancer.