Extent of regional lymphadenectomy and number-based nodal classification for non-ampullary duodenal adenocarcinoma.

BACKGROUND: This study aimed to evaluate the adequate extent of regional lymphadenectomy according to tumor location and the impact of number-based nodal classification on survival in patients with non-ampullary duodenal adenocarcinoma (NADAC). METHODS: A total of 85 patients with NADAC who underwent surgery were enrolled. The frequency of metastasis was calculated for each node group in the respective tumor locations for 63 patients who underwent lymphadenectomy for pT2-pT4 tumor. RESULTS: The frequency of metastasis in the pancreaticoduodenal (nos. 13 and 17) and superior mesenteric artery (no. 14) nodes was high (16.7 %-52.3 %) regardless of tumor location. Metastasis in the perigastric (nos. 3 and 4d) and right celiac artery (no. 9) nodes was not uncommon (14.3 %-22.2 %) for tumors in the first portion. The frequency of metastasis in the pyloric (nos. 5 and 6) and the other peripancreaticoduodenal (nos. 8 and 12) nodes varied depending on tumor location but could not be ignored for staging. When these nodes were classified as regional nodes, the 5-year survival in patients with pN0, pN1 (1-2 positive nodes), and pN2 (≥3 positive nodes) were 82.9 %, 51.7 %, and 19.2 %, respectively (p < 0.001). pN classification independently predicted survival (pN1, p = 0.022; pN2, p < 0.001). CONCLUSIONS: Nos. 5, 6, 8, 12, 13, 14, and 17 nodes in all advanced NADAC and nos. 3, 4d, and 9 nodes in advanced NADAC in the first portion should be considered as regional nodes for accurate staging. The number-based nodal classification allows good patients' prognostic stratification.

Two Cases of Gastric Varices with Left-sided Portal Hypertension Due to Essential Thrombocythemia Treated with Gastric Devascularization or Partial Splenic Embolization.

Left-sided portal hypertension (LSPH) is a condition of extrahepatic portal hypertension that often results in bleeding from isolated gastric varices (GVs). LSPH is sometimes caused by myeloproliferative diseases, such as essential thrombocythemia (ET). We herein report two cases of GVs with LSPH due to ET that were successfully controlled by gastric devascularization (GDS) or partial splenic embolization (PSE). Since each patient with LSPH due to ET has a different pathology, optimal treatment should be performed depending on the patient's condition, such as platelet counts, hemodynamics, or the prognosis. We believe that these cases will serve as a reference for future cases.

Learning curve for the surgical time of laparoscopic cholecystectomy performed by surgical trainees using the three-port method: how many cases are needed for stabilization?

BACKGROUND: The assessment of laparoscopic cholecystectomy (LC) skills using operating times has not been well reported. We examined the total and partial operating times for LC procedures performed by surgical trainees to determine the required number of surgeries until the surgical time stabilizes. METHODS: We reviewed the video records of 514 consecutive LCs using the three-port method, performed by 16 surgical trainees. The total and partial surgical times were calculated and correlated to the surgeons' experience. RESULTS: The median total surgical time for a trainee's first LC was 112 (range 71-226) minutes. It reduced rapidly after the first 20 LCs and plateaued to its minimum after approximately 60 cases. A statistically significant time decrease was observed between the first 10 (median, range 112, 46-252 min) and the next 50-59 cases (64, 34-198 min), but not between the 50-59 and the subsequent 100-109 cases (71, 33-127 min). The total times taken by trainees who had performed > 50 operations were not significantly different from those taken by instructors during the study period. Surgery for 125 patients with acute cholecystitis took a significantly longer time (median 99 vs. 74 min with non-acute cholecystitis); however, the abovementioned time reduction findings showed similar results regardless of the patient's acute inflammation status. The partial operating times around the cervical/cystic duct and gallbladder bed reduced uniformly between the first 10 and the following 50-59 cases. Although time variations in total and cervical/cystic duct operating times were not correlated to the surgical experience, time fluctuation of gallbladder bed procedures reduced after 60 cases. CONCLUSION: The time required to perform an LC was inversely correlated with the experience of surgical trainees and halved after the first 60 cases. The surgical experience required for LC time stabilization is approximately 60 cases.

Treatment for Appendicitis With Appendicolith by the Stone Size and Serum C-Reactive Protein Level.

INTRODUCTION: Appendicolith causes acute appendicitis. However, surgical indications for appendicolith-related acute appendicitis have not been established. We aimed to clarify the clinical features of appendicolith-associated appendicitis and determine an appropriate treatment strategy based on the initial presentation. MATERIALS AND METHODS: We retrospectively reviewed the records of 479 consecutive patients with acute appendicitis and verified the therapeutic strategy as per the appendicolith and clinical status. RESULTS: Appendicoliths were identified in 214 of 479 patients (44.6%) using computed tomography. Surgery was more frequently required in patients with appendicolith than in patients without appendicolith (82.7 versus 64.9%; P < 0.001). The stones were smaller and serum C-reactive protein (CRP) concentration was lower among patients with appendicoliths treated with medication alone than among those surgically treated (both P < 0.001). An appendicolith measuring ≤5 mm in diameter and CRP concentration ≤5.36 mg/dL were predictive of completion of nonsurgical therapy. CRP concentration >10 mg/dL and stone diameter of 10 mm were significantly associated with appendiceal perforation. CONCLUSIONS: Nonsurgical therapy could be considered for patients with appendicoliths measuring ≤5 mm in diameter and in cases where the serum CRP concentration is ≤5 mg/dL. An appendicolith measuring >10 mm in diameter or CRP concentration >10 mg/dL is an indication for surgery.

Laparoscopic surgery for a hydrocele of the canal of Nuck with an ovarian tumor: An extremely rare clinical finding.

This clinical image presents an unusual report of simultaneous laparoscopic resection of a hydrocele of the canal of Nuck and an ovarian tumor. Laparoscopic treatment with a proper approach is a useful technique in some cases.

Laparoscopic transabdominal preperitoneal hernioplasty for bilateral obturator hernias and left inguinal hernia with emaciation caused by anorexia nervosa: A case report.

A 55-year-old woman receiving treatment for anorexia nervosa presented with abdominal pain and right thigh pain. Her body mass index was 12.9 kg/m2 . Computed tomography showed fluid storage in the distal side of the right obturator foramen and revealed a dilated small bowel without a starting point of obstruction. We diagnosed a naturally reduced incarcerated right obturator hernia and performed elective surgery with a laparoscopic approach for hernia repair the next day. Intraperitoneal observation revealed bilateral obturator hernias and a left direct-type inguinal hernia. Transabdominal preperitoneal hernioplasty was performed using two self-gripping polyester meshes for bilateral obturator hernia repair and a lightweight 3D-shaped mesh for left inguinal hernia repair. Women with emaciation caused by anorexia nervosa may be more likely to have complex hernias, including obturator hernia, and laparoscopic approaches may be useful for preoperatively diagnosed nonstrangulated obturator hernias.

Comparison of surgical smoke between open surgery and laparoscopic surgery for colorectal disease in the COVID-19 era.

BACKGROUND: Surgical smoke during operation is a well-known health hazard for medical staff. This study aimed to investigate the dynamics of surgical smoke during open surgery or laparoscopic surgery for colorectal disease. METHODS: This study quantitated particulate matter (PM) counts as part of surgical smoke in 31 consecutive patients who underwent colectomy at the Niigata City General Hospital using a laser particle counter. Particles were graded by size as ≤ 2.5 µm PM (PM2.5) or > 2.5 µm PM (large PM). Operative procedures were categorized as either open surgery (n = 14) or laparoscopic surgery (n = 17). RESULTS: The median patient age was 72 (range 41-89) years and 58.1% were male. The total PM2.5, PM2.5 per hour, and maximum PM2.5 per minute counts during operation were significantly higher in open surgery than in laparoscopic surgery (P = 0.001, P < 0.001, and P = 0.029, respectively). Large PM counts (total, per hour, and maximum per minute) were also higher in the open surgery group than in the laparoscopic surgery group. The maximum PM2.5 concentration recorded was 38.6 µm/m3, which is considered "unhealthy for sensitive groups" according to the U.S. Environment Protection Agency air quality index standards, if it was a 24-h period mean value. CONCLUSION: Exposure to surgical smoke is lower during laparoscopic surgery than during open surgery for colorectal diseases.

Is radiological psoas muscle area measurement a predictor of postoperative complications after rectal resection for rectal cancer? A retrospective study.

PURPOSE: Previous studies have reported that sarcopenia increases the risk of postoperative complications following colorectal resection. This retrospective study assessed the postoperative complications of rectal resection associated with sarcopenia. METHODS: We retrospectively analyzed 262 patients who underwent curative low anterior resection for primary rectal cancer from January 2008 to May 2020 at our institution. The patients were divided into a sarcopenia group (normalized total psoas muscle area < 6.36 cm2/m2 in males and < 3.92 cm2/m2 in females; N = 49) and a non-sarcopenia group (N = 213). RESULTS: The overall rate of postoperative complications within 30 days of surgery was higher in the sarcopenia group than in the non-sarcopenia group (46.9 vs. 29.6%; P = 0.028). The rate of postoperative remote infections was higher in the sarcopenia group than in the non-sarcopenia group (12.2 vs. 2.8%; P = 0.012). Sarcopenia was found to be a predictor of remote infection by a multivariate analysis (odds ratio, 4.08; 95% confidence interval, 1.12-14.80; P = 0.033). CONCLUSION: Sarcopenia diagnosed using the psoas muscle index was found to be an independent predictive factor for postoperative remote infection after curative low anterior resection for rectal cancer.

[A Case of Suspected Lynch Syndrome Due to Radical Resection for Descending Colon Cancer and Renal Pelvic Cancer].

A 60-year-old woman was admitted on account of presenting with bloody stools. She had a history of endometrial cancer surgery. Family history revealed 3 colorectal cancer cases among the first or second relatives. Colonoscopy and contrast- enhanced computed tomography revealed descending colon cancer and left renal pelvic cancer. We performed partial resection of the descending/transverse colon with D3 lymph node dissection and total resection of the left kidney and ureter with curative intent. Postoperative pathological diagnosis revealed descending colon cancer(pT4bN0M1c, pStage Ⅳc)and left renal pelvic cancer (T1N0M0, Stage Ⅰ). In this case, Lynch syndrome was suspected based on the family history and medical history. The clinical findings were consistent with Amsterdam Criteria Ⅱ. The microsatellite instability(MSI)test result was MSI-H and the BRAF genetic test result showed a wild type. Immunohistochemical staining of descending colon cancer tissue showed loss of expression of MSH2 and MSH6 proteins. Genetic counseling was provided because Lynch syndrome was strongly suspected. Capecitabine plus oxaliplatin therapy was performed for 6 months for descending colon cancer. Nine months postoperatively, the patient remained recurrence-free for both colon cancer and renal pelvic cancer. We report a case of suspected Lynch syndrome triggered by double cancer of the descending colon and renal pelvis.

Influence of Suture Materials on Incisional Hernia Rate after Laparoscopic Colorectal Cancer Surgery: A Propensity Score Analysis.

OBJECTIVES: Incisional hernia is a common problem after colorectal surgery, and a laparoscopic approach does not reduce the incisional hernia rate. Previous reports have described the risk factors for incisional hernia; however, the impact of suture materials remains unclear. As such, this study compared the incisional hernia rate using different suture materials for abdominal wall closure after laparoscopic colorectal cancer surgery. METHODS: Patients undergoing laparoscopic colorectal cancer surgery between January 2014 and December 2016 were included in this study. We separated patients into the following two groups based on the suture materials used for abdominal wall closure: (1.) fast-absorbable group and (2.) non-absorbable group. The primary outcome was incisional hernia rate that was diagnosed using computed tomography. We compared outcomes between these two groups using propensity score matching. RESULTS: Before matching, 394 patients were included (168 in the fast-absorbable group and 226 in the non-absorbable group). After one-to-one matching, patients were stratified into the fast-absorbable group (n = 158) and the non-absorbable group (n = 158). The incisional hernia rate was higher in the fast-absorbable group than in the non-absorbable group (13.9% vs. 6.3%; P = 0.04). The median time to develop an incisional hernia was significantly shorter in the fast-absorbable group (6.7 months vs. 12.3 months; P < 0.01). The incidence of surgical site infection was not different between the two groups, but the incidence of suture sinus was lower in the fast-absorbable group (0% vs. 5.1%; P < 0.01). CONCLUSIONS: The use of fast-absorbable sutures may increase the risk of incisional hernia after laparoscopic colorectal cancer surgery.

Surgical approach for right-sided colonic diverticular bleeding: A single-center review of 43 consecutive cases.

INTRODUCTION: While Asian populations develop colonic diverticular disease predominantly in the right colon, Western populations mainly present with left-sided disease. The present study aimed to clarify the outcomes of surgical treatment for right-sided colonic diverticular bleeding. METHODS: Medical records of 43 patients who underwent surgery for right-sided colonic diverticular bleeding between 2010 and 2019 were reviewed. Those whose general condition became unstable underwent open surgery at our institution. Patients were then divided into two groups, the open surgery group (n = 17) and laparoscopic surgery group (n = 26), after which operative outcomes between both groups were compared. RESULTS: This study included 36 men and seven women with a median age of 76 (range: 37-91) years. Laparoscopic surgery had a significantly longer operative time (183.5 minutes vs 110 minutes; P < .001) and significantly lower intraoperative blood transfusion rate (19.2% vs 82.4%; P < .001) than open surgery. The laparoscopic surgery group had earlier resumption of postoperative meals than open surgery group (postoperative day 3 vs postoperative day 4; P = .010). No significant difference in postoperative complications was observed between both groups. With regard to long-term outcomes, none of the cases exhibited rebleeding from the right-sided colon. CONCLUSION: The present study revealed that laparoscopic surgery promoted lower intraoperative blood transfusion rates and earlier resumption of postoperative meals compared to open surgery for right-sided colonic diverticular bleeding. Hence, laparoscopic surgery can be feasible for right-sided colonic diverticular bleeding provided that the patient's general condition is stable.

Oncological outcomes of surgery for recurrent biliary tract cancer: who are the best candidates?

BACKGROUND: This study aimed to investigate the impact of surgery on outcomes in patients with recurrent biliary tract cancer (BTC) and elucidate factors affecting survival after surgery for this disease. METHODS: A single-center study was undertaken in 178 patients with recurrent BTC, of whom 24 underwent surgery for recurrence, 85 received chemotherapy, and 69 received best supportive care. Then, we carried out a multicenter study in 52 patients undergoing surgery for recurrent BTC (gallbladder cancer, 39%; distal cholangiocarcinoma, 27%; perihilar cholangiocarcinoma, 21%; intrahepatic cholangiocarcinoma, 13%). RESULTS: In the single-center study, 3-year survival after recurrence was 53% in patients who underwent surgery, 4% in those who received chemotherapy, and 0% in those who received best supportive care (p < 0.001). Surgery was an independently prognostic factor (p < 0.001). In the multicenter series, the respective 3-year and 5-year survival after surgery for recurrence was 50% and 29% in the 52 patients. Initial site of recurrence was the only independent prognostic factor (p = 0.019). Five-year survival after surgery for recurrence in patients with single distant, multifocal distant, and locoregional recurrence was 51%, 0%, and 0%, respectively (p = 0.002). Sites of single distant recurrence included the liver (n = 13, 54%), distant lymph nodes (all from gallbladder cancer, n = 7, 29%), lung (n = 2, 9%), peritoneum (n = 1, 4%), and abdominal wall (n = 1, 4%). CONCLUSION: Surgery may be an effective option for patients with less aggressive tumor biology characterized by single distant recurrence in recurrent BTC.

Clinicopathological Characteristics and Surgical Outcomes of Primary Cystic Duct Carcinoma: A Multi-institutional Study.

BACKGROUND: The role of surgery in the management of primary cystic duct carcinoma (CDC) remains unclear especially in advanced disease. This study aimed to evaluate long-term outcomes in patients undergoing surgery for primary CDC. METHODS: From a multi-institutional database, we identified 41 patients who underwent surgery for primary CDC, defined as a part of gallbladder carcinoma with the tumor centre located in the cystic duct. RESULTS: Of the 41 patients, 31 (75.6%) underwent preoperative biliary drainage for jaundice. Twenty-eight (68.3%) patients underwent extensive resection including major hepatectomy (n = 21), pancreaticoduodenectomy (n = 4), or both procedures (n = 3). Thirty-four (82.9%) patients had ≥ pT3 tumor, while 31 (75.6%) patients had involvement of contiguous organs/structures. Nodal and distant metastasis was found in 26 (63.4%) and 7 (17.1%) patients, respectively. Most patients (90.2%) had perineural invasion. Median overall survival was 23.7 months in all 41 patients. Factors independently associated with both overall and disease-specific survival were pN (P = 0.003 and P = 0.007, respectively) and pM (P = 0.003 and P = 0.013, respectively) classification. Median survival was 75.3, 17.7, and 5.2 months for patients with pN0M0 (n = 14), pN1/2pM0 or pN0pM1 (n = 21), and pN1/2pM1 (n = 6) disease, respectively (P < 0.001). CONCLUSIONS: Primary CDC is characterized by locally advanced disease with aggressive histopathological characteristics at surgery, leading to extensive resection during treatment. Surgery provides potential benefits for patients with pN0pM0 disease, whereas pN1/2 and/or pM1 status appear to have strong adverse effects on survival.

Perforation of anastomotic peptic ulcer following pancreaticoduodenectomy: a report of three cases.

BACKGROUND: Perforation of a marginal peptic ulcer after pancreaticoduodenectomy (PD) can lead to severe conditions, although its clinical features have not been well reported. In this article, we present three cases of marginal peptic ulcer perforation after PD that we experienced in our institute and attempt to clarify its appropriate treatment and prevention. CASE PRESENTATION: Marginal ulcer perforation confirmed with computed tomography and/or surgical exploration occurred in 3 (1.8%) of 163 consecutive patients who underwent PD (including 160 patients who underwent a total or subtotal stomach-preserving procedure) at our institution. The three patients (one man and two women) had a median age of 77 (65-79) years. Two of these patients had a medical history of duodenal peptic ulcer. All three patients had biliary neoplasms. Two of the patients underwent subtotal stomach-preserving PD with antro-jejunal anastomosis, and the other patient underwent pylorus-preserving PD with duodenal jejunostomy. The perforation occurred with a sudden and severe onset of abdominal pain 34, 94, and 1204 days, respectively, after the PDs. At the time of the perforation, all of the patients had been withdrawn from postoperative prophylactic antipeptic ulcer agents, with the cessation periods ranging from 12 to 1008 days. In addition, all the patients were in fasting conditions for 1 to 13 days just before the perforation. Surgical treatment with direct suturing of the perforated ulcer was performed for two patients, while conservative therapy was performed for one patient. Their primary treatment courses were satisfactory. Chronic antisecretory agent therapy was prescribed for 562, 271, and 2370 days, respectively, from marginal ulcer perforation, and no ulcer recurrence was noted in any of the patients. CONCLUSIONS: Lack of antisecretory therapy and fasting were considered an essential cause of marginal peptic ulcer perforation after PD. In addition, unlike the native duodenum, the jejunal limb used for reconstruction to a preserved stomach may be at increased risk of ulceration. Chronic permanent administration of antisecretory agents and fasting avoidance are desirable for patients who have undergone stomach-preserving PD to prevent marginal ulcer perforation.

Internal hernia beneath the obturator nerve after robot-assisted lateral lymph node dissection for rectal cancer: A case report and literature review.

A 63-year-old man who underwent robot-assisted laparoscopic low anterior resection and right lateral lymph node dissection (LLND) for rectal cancer presented with right thigh pain, nausea, vomiting, and abdominal pain on postoperative day 17. CT revealed dilated small bowel in the pelvis, and a small bowel loop was detected outside the internal iliac artery branch. Emergent laparoscopic surgery revealed the migration of the small bowel into the space beneath the right obturator nerve. The herniated bowel was reduced, and the obturator nerve was sharply dissected from the herniated bowel and preserved. The hernial orifice was left unrepaired. Postoperative recovery was uneventful, and the right thigh pain disappeared. It is important to consider the possibility of internal herniation beneath the obturator nerve after minimally invasive lateral lymph node dissection for rectal cancer.

A rare case of peritoneal deposits with carbon pigmentation after preoperative endoscopic tattooing for sigmoid colon cancer.

PURPOSE: We report a case in which pigmented peritoneal deposits were found during laparoscopic surgery following preoperative endoscopic tattooing for sigmoid colon cancer. METHODS: The patient's clinical, endoscopic, and histological data from the Niigata City General Hospital were reviewed, as well as the literature on laparoscopic surgery involving the preoperative endoscopic tattoo, with a focus on the relevance of peritoneal deposits and tattooing ink. RESULTS: A 71-year-old man presented to our hospital complaining of vomiting and abdominal distention. Abdominal computed tomography revealed obstructive sigmoid colon cancer. An emergency endoscopic colon stenting procedure and injection of 0.2 ml India ink to the submucosal layer of the tumor's anal side were performed. Laparoscopic-assisted sigmoid colectomy was done 14 days after stenting. At surgery, seven small peritoneal deposits were seen in the rectovesical pouch and at the site adjacent to the tumor. All peritoneal deposits were stained by the ink. Gross leakage of the ink into extraintestinal sites was seen. The seven peritoneal deposits were resected under laparoscope. Histological findings revealed that the seven peritoneal deposits were composed of adenocarcinoma and carbon pigments. Immunohistochemical staining for cluster of differentiation 163 showed that the carbon pigments in the peritoneal deposits were within macrophages. CONCLUSIONS: The possibility of the tattooing procedure causing peritoneal dissemination cannot be completely denied, but it can be hypothesized that the carbon pigmentation was transferred to peritoneal deposits by macrophages. In the future, we hope that this phenomenon becomes a keystone for diagnoses and treatments for peritoneal dissemination.

Initial Features of Hepatic Metastases From Pancreatic Cancer: Histological and Radiolographical Appraisal of Hepatic Micrometastases Detected by Real-Time Fluorescent Imaging.

OBJECTIVE: The pathophysiology of primary-stage hepatic metastases from gastrointestinal cancers may provide clues to their formation. We investigated initial features of hepatic metastases from pancreatic cancer by examining the histologies of radiographically occult hepatic micrometastases. METHODS: We examined 133 consecutive pancreatic cancer patients with no evident hepatic metastases on preoperative imaging. An indocyanine green near-infrared camera system was used to detect hepatic metastases during surgery; preoperatively acquired images of patients were then retrospectively reviewed. RESULTS: Hepatic micrometastases were histologically confirmed in 20 patients (15%). Immunohistochemically, the metastatic cells were with higher positivity of carcinoembryonic antigen (100%), p53 overexpression (40%), and Ki-67 labeling index (38%, median). All the micrometastases were portal thromboemboli in the intrahepatic portal triad that invaded extravenous structures, causing desmoplasis, local biliary obstruction, and indocyanine green-contained bile stasis A review of preoperative dynamic computed tomography or magnetic resonance images revealed focal circular alterations presenting as arterioportal shunts in 50% of the patient with micrometastases and 11% of those without (P < 0.01). CONCLUSIONS: Hepatic metastasis from pancreatic cancer involves portal vein thrombosis that alters local circulation and bile stasis at the portal triad; this is detectable by presurgical radiological examination or intraoperative fluorescent imaging.

Add-on Antiplatelet Effects of Eicosapentaenoic Acid With Tailored Dose Setting in Patients on Dual Antiplatelet Therapy.

The aim of this study was to investigate the antiplatelet effects of eicosapentaenoic acid (EPA) at a sufficient dose following coronary stent implantation. Thirty-one patients on dual antiplatelet therapy with aspirin and clopidogrel were treated with highly purified EPA-E (Epadel®) for 12 weeks. Based on our previous study, patients with a high baseline EPA/arachidonic acid (AA) ratio (≥ 0.37; n = 11) were given a standard dose (1800 mg daily) of EPA-E, whereas those with a low EPA/AA ratio (< 0.37; n = 20) were given a high dose (2700 mg daily) to reach the target value of > 0.92. Platelet function was then evaluated with agonist-induced aggregation using light transmittance aggregometry and VerifyNow®. After EPA-E treatment, the EPA/AA ratio significantly increased from 0.28 to 1.31 (P < 0.001). Collagen (1, 2, and 4 µg/mL)-induced maximal platelet aggregation (MPA) was significantly suppressed after EPA-E administration (from 28.0 to 24.0, P = 0.033; from 44.0 to 40.0, P = 0.016; from 60.0 to 56.0, P = 0.010; respectively). However, there were no changes in MPA induced by adenosine diphosphate and AA and in P2Y12 reaction units (PRU) and aspirin reaction units. After EPA-E treatment, PRU was significantly suppressed in 8 patients showing high on-treatment platelet reactivity (HTPR) (baseline 305; 266-321 versus on-treatment 256; 233-261, P = 0.012), but not in those without HTPR (201; 156-220 versus 183; 159-233, P = 0.212). In conclusion, EPA treatment at a sufficient dose suppressed platelet aggregation and showed possible add-on effects in patients with clopidogrel hyporesponsiveness.