Combined laparoscopic and thoracoscopic repair of adult right-sided Bochdalek hernia with massive liver prolapse: A case report

BACKGROUND A Bochdalek hernia(BH)is a congenital diaphragmatic hernia that often develops in the neonatal period.BH typically occurs on the left side of the diaphragm.A right-sided BH in an adult is rare.CASE SUMMARY A 45-year-old man was referred to our hospital because of an abnormal shadow seen on chest radiography during a medical check-up.A chest radiograph showed elevation of the right hemidiaphragm.Computed tomography showed prolapse of multiple intraabdominal organs into the right thoracic cavity,corresponding to a right-sided BH.The herniated contents included the stomach,transverse colon,and left lobe of the liver.The left lobe of the liver was enlarged,particularly the medial segment.Laparoscopic surgery was performed.However,the left lobe of the liver was completely trapped in the thoracic cavity.Therefore,thoracoscopic manipulation had to be performed to return the liver to the abdominal cavity.The hernia was repaired with interrupted nonabsorbable sutures and reinforced with mesh.CONCLUSION Combined laparoscopic and thoracoscopic surgery was successfully performed for right-sided BH with massive liver prolapse and abnormal liver morphology.

Comparison of decompression tubes with metallic stents for the management of right-sided malignant colonic obstruction

BACKGROUND Emergency surgical resection is a standard treatment for right-sided malignant colonic obstruction; however, the procedure is associated with high rates of mortality and morbidity. Although a bridge to surgery can be created to obviate the need for emergency surgery, its effects on long-term outcomes and the most practical management strategies for right-sided malignant colonic obstruction remain unclear.AIM To determine the appropriate management approach for right-sided malignant colonic obstruction.METHODS Forty patients with right-sided malignant colonic obstruction who underwent curative resection from January 2007 to April 2017 were included in the study.We compared the perioperative and long-term outcomes of patients who received bridges to surgery established using decompression tubes and those created using self-expandable metallic stents(SEMS). The primary outcome was the overall survival duration(OS) and the secondary endpoints were the diseasefree survival(DFS) duration and the preoperative and postoperative morbidity rates. Analysis was performed on an intention-to-treat basis.RESULTS There were 21 patients in the decompression tube group and 19 in the SEMS group. There were no significant differences in the perioperative morbidity rates of the two groups. The OS rate was significantly higher in the decompression tube group than in the SEMS group(5-year OS rate; decompression tube 79.5%,SEMS 32%, P = 0.043). Multivariate analysis revealed that the bridge to surgery using a decompression tube was significantly associated with the OS(hazard ratio, 17.41; P = 0.004). The 3-year DFS rate was significantly higher in thedecompression tube group than in the SEMS group(68.9% vs 45.9%; log-rank test,P = 0.032). A propensity score–adjusted analysis also demonstrated that the prognosis was significantly better in the decompression tube group than in the SEMS group.CONCLUSION The bridge to surgery using trans-nasal and trans-anal decompression tubes for right-sided malignant colonic obstruction is safe and may improve long-term outcomes.

En bloc pancreaticoduodenectomy and right hemicolectomy for locally advanced right-sided colon cancer

AIM To assess the usefulness of en bloc right hemicolectomy with pancreaticoduodenectomy(RHCPD) for locally advanced right-sided colon cancer(LARCC).METHODS We retrospectively reviewed the database of Saitama Medical Center, Jichi Medical University, between January 2009 and December 2016. During this time, 299 patients underwent radical right hemicolectomy for right-sided colon cancer. Among them, 5 underwent RHCPD for LARCC with tumor infiltration to adjacent organs. Preoperative computed tomography(CT) was routinely performed to evaluate local tumor infiltration into adjacent organs. During the operation, we evaluated the resectability and the amount of infiltration into the adjacent organs without dissecting the adherent organs from the cancer. When we confirmed that radical resection was feasible and could lead to R0 resection, we performed RHCPD. The clinical data were carefully reviewed, and the demographic variables, intraoperative data, and postoperative parameters were recorded.RESULTS The median age of the 5 patients who underwent RHCPD for LARCC was 70 years. The tumors were located in the ascending colon(three patients) and transverse colon(two patients). Preoperative CT revealed infiltration of the tumor into the duodenum in all patients, the pancreas in four patients, the superior mesenteric vein(SMV) in two patients, and tumor thrombosis in the SMV in one patient. We performed RHCPD plus SMV resection in three patients. Major postoperative complications occurred in 3 patients(60%) as pancreatic fistula(grade B and grade C, according to International Study Group on Pancreatic Fistula Definition) and delayed gastric empty. None of the patients died during their hospital stay. A histological examination confirmed malignant infiltration into the duodenum and/or pancreas in 4 patients(80%), and no patients showed any malignant infiltration into the SMV. Two patients were histologically confirmed to have tumor thrombosis in the SMV. All of the tumors had clear resection margins(R0). The median follow-up time was 77 mo. During this period, two patients with tumor thrombosis died from liver metastasis. The overall survival rates were 80% at 1 year and 60% at 5 years. All patients with node-negative status(n = 2) survived for more than seven years.CONCLUSION This study showed that the long-term survival is possible for patients with LARCC if RHCPD is performed successfully, particularly in those with node-negative status.

Carcinoma located in a right-sided sigmoid colon:A case report

BACKGROUND A right-sided sigmoid colon is an extremely rare anatomic variation that should be considered as a possibility by surgeons and radiologists before surgery.Here,we report the first clinical case of a carcinoma in a right-sided sigmoid colon revealed by a preoperative computed tomography(CT).CASE SUMMARY A 56-year-old Chinese man was admitted to the hospital with abdominal pain.CT revealed a redundant sigmoid colon with a mass on the right side of the cecum and ascending colon.Laparoscopy confirmed an abnormal course in the descending colon and sigmoid colon.Subsequently,hemicolectomy was performed in an open manner after laparoscopic exploration.Pathological examination revealed an infiltrative mucinous adenocarcinoma with two lymph node metastases.The patient was discharged without any complications after a week.There were no signs of recurrence or metastasis during the 3-month followup period.CONCLUSION We report a rare anomaly of a right-sided sigmoid colon with carcinoma,which should be differentiated from ascending colon cancer and pericecal hernia to prevent errors and other surgical complications.

Endovascular repair of thoracic aortic dissection associated with right-sided aortic arch：report of four cases

Aortic dissection involving a right-sided aortic arch（RAA）is extremely rare with an incidence in adults of 0.04%to 0.1%^（[1]）.Thoracic aortic dissection associated with RAA is even a more uncommon and life-threatening condition.For complicated aortic dissection,conventional open surgical repair is considered a standard therapy^（[2]）.However,

A Comparative Study of the Short-Term Efficacy of Laparoscopic Radical Resection of Right-Sided Colon Cancer with Two Different Surgeon Positions and Trocar Placements

Objective: To investigate the short-term efficacy of laparoscopic radical resection of right-sided colon cancer with two different surgeon positions and trocar placements. Methods: The data of 78 patients who underwent laparoscopic radical resection of right-sided colon cancer between January 2018 and August 2019 were retrospectively analysed. The surgical method was selected by the patients. The patients were divided into two groups according to the surgeons’ positioning habits and trocar placements. The group with the lead surgeon standing between the patient’s legs had 35 patients, and the group with the lead surgeon standing at the left side of the patient had 43 patients. The operation time, intraoperative blood loss, postoperative anal gas evacuation time, postoperative urinary catheter indwelling time, postoperative hospital stay, C-reactive protein (CRP) level on the first day after surgery, and postoperative pathological data and complications were compared between the two groups. Results: All patients underwent the laparoscopic radical resection of right-sided colon cancer, none converting to laparotomy. No significant difference (P > 0.05) in intraoperative blood loss (57.6 ± 21.3 ml vs 60.2 ± 35.3 ml), postoperative anal gas evacuation time (3.5 ± 1.1 d vs 3.8 ± 1.3 d), postoperative urinary catheter indwelling time (2.6 ± 1.3 d vs 2.4 ± 1.2 d), postoperative hospital stay (7.1 ± 1.8 d vs 7.5 ± 2.1 d), or CRP level on the first day after surgery (54.7 ± 9.6 mg/L vs 53.9 ± 8.2 mg/L) was detected between the two groups. The operation time was shorter in the group with the lead surgeon standing between the patient’s legs (185.2 ± 25.6 min vs 196.2 ±19.7 min) (P < 0.05). The two groups did not differ significantly in the tumour length (4.2 ± 1.3 cm vs 3.9 ± 1.5 cm), number of dissected lymph nodes (27.5 ± 11.6 vs 25.1 ± 15.4), pathological type, or postoperative pathological tumour-node-metastasis stage (P > 0.05). No patients died or had anastomotic fistula during their postoperative hospital stay, and the incidence of postoperative complications did not differ between the two groups (22.9% (8/35) vs 23.3% (10/42);P > 0.05). Conclusion: Under the principle of radical resection, the surgeon should adopt the most suitable standing position and trocar placement according to the specific situation. If the surgeon stands between the patient’s legs, this might shorten the operation time and promote a smoother surgery.

A case of acquired right-sided subclavian steal syndrome successfully treated with stenting using brachial approach

Subclavian steal syndrome (SSS) is defined as a group of symptoms that arise from reversed blood flow in the ipsilateral vertebral artery. It is the consequence of proximal occlusion or high-grade stenosis of the subclavian artery. The subclavian obstructive lesions are mostly located in the proximal segment of the subclavian artery and predominantly on the left side. In contrast, there are only a small number of patients that present with right-sided symptoms and even fewer with bilateral symptoms. Endovascular therapy of occlusions and high-grade stenosis of subclavian artery proximal to the origin of the vertebral artery becomes an established therapy in last two decades. We report a case of successful endovascular treatment of right-sided subclavian steal and high-grade (80%) right subclavian artery stenosis due to atherosclerotic occlusive disease with balloon-expandable stent using brachial approach.

Hepatectomy for gallbladder-cancer with unclassified anomaly of right-sided ligamentum teres: A case report and review of the literature

Right-sided ligamentum teres(RSLT) is a congenital anomaly in which the right umbilical ligament becomes dominant and anomalous ramifications of the hepatic vessels and biliary system are present. A male patient in his 70 s was diagnosed with advanced gallbladder cancer directly infiltrating the right hepatic duct(RHD), together with RSLT. Preoperative three-dimensional simulation of the liver based on multiple detector computed tomography images after cholangiography revealed ramifications of all segmental portal veins from the portal trunk and discordance of the arterial and biliary branching patterns of segment 8. Fusion analysis of the biliary architecture and segmental volumetry showed that the RHD drained segments 1 r, 5, 6, and 7. We successfully performed a modified right-sided hepatectomy sparing segment 8(i.e., resection of the RHD drainage territory), with negative surgical margins. This report is the first to describe major hepatectomy for advanced gallbladder cancer with RSLT.

Presentation of Boerhaave's syndrome as an upper-esophageal perforation associated with a right-sided pleural effusion:A case report

BACKGROUND Spontaneous esophageal rupture or Boerhaave’s syndrome is a rare and acute disease with a high incidence of misdiagnosis and mortality.Here,we aimed to explore the clinical characteristics,diagnosis,treatment,and prognosis of spontaneous esophageal rupture,and to analyze the causes of misdiagnosis during the treatment of spontaneous esophageal rupture.CASE SUMMARY The clinical features of the patient with spontaneous esophageal rupture misdiagnosed earlier as pleural effusion were retrospectively analyzed and the reasons for misdiagnosis are discussed based on a current review of the literature.The patient was admitted to a local hospital due to shortness of breath accompanied by vomiting and abdominal distension for five hours.Based on the computed tomography(CT)scan analysis,clinically,right pleural effusion was diagnosed.However,the patient was unwilling to undergo right closed thoracic drainage.The patient also had intermittent fevers against infection,and during the course of treatment,he complained of chest pain,following which,he was transferred to our hospital.Grapefruit-like residue drainage fluid was observed.Re-examination of the chest CT scans suggested the presence of spontaneous perforation in the upper left esophagus.Therefore,the patient underwent an urgent esophageal hiatus repair.Unfortunately,the patient died of infection and respiratory failure due to progressive dyspnea after surgery.CONCLUSION Spontaneous esophageal rupture is a rare disease associated with high fatality.The patients do not present typical clinical symptoms and the disease progresses rapidly.This case report highlights the importance of a dynamic review of chest CT scan,not only for the initial identification of segmental injury but also for prioritizing subsequent treatment strategies.Moreover,we have presented some clues for clinicians to recognize and diagnose spontaneous esophageal rupture at rare sites(upper-esophageal segment)through this case report of spontaneous esophageal rupture that caused the patient’s death.We have also summarized the reasons for the misdiagnosis and lessons learned.

HSP27:a candidate differentially expressed protein between left-and right-sided colon carcinomas

Objective:The aim of the study was to screen differentially expressed proteins between left-and right-sided colon cancers by proteomics techniques and provide molecular genetic basis for oncobiological difference between left-and rightsided colon cancers.Methods:Tissue samples including left-and right-sided colon cancers were collected and preserved in the-80 ℃ refrigeratory.In the first part of our experiment,protein separating was performed by using two-dimensional gel electrophoresis(2-DE) and the images of the gels were acquired by the scanner and then analyzed to find the differentially expression protein-spots in different groups.The peptide mass fingerprintings(PMF) was acquired by matrix assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS) and the proteins were identified by data searching in the Mascot-database.Differentially expression proteins were assayed by RT-PCR,Western blot,and immunohistochemical methods.Results:The 55 differentially expressed protein spots were screened and 23 spots of them were identified.Compared to right-sided colon cancer,15 proteins up-regulated and 8 proteins down-regulated including HSP27 in left-sided colon cancer.HSP27 expressed higher in right-sided than in left-sided colon cancers by RT-PCR,Western blot and immunohistochemical methods.Conclusion:There were differentially expressed proteins between left-and right-sided colon cancers,especially differences in HSP27 expression in mRNA and protein level,which were molecular genetic basis for oncobiological difference between left-and right-sided colon cancers.

One Case about the Diagnosis and Treatment of Right-Sided Infective Endocarditis without Any Inducement

We present a case of Staphylococcus aurous tricuspid valve endocarditis without any risk factors (intravenous drug users, with pacemaker or central venous lines and with congenital heart disease). Transthoracic echocardiography, as first line examination, showed the vegetations on tricuspid valve. In our case, the diagnosis and treatment of right-sided infective endocarditis without any inducement were extremely difficult. Therefore, once a patient comes out with fever, the blood culture remains positive for gram-positive bacterium, and the infectious location still unknown, then the infective endocarditis should be considered. In addition, surgical measure is also an important therapy for right-sided infective endocarditis.

Intracranial hemangiopericytoma with right-sided aortic arch: a case report and summary of experience

Hemangiopericytoma is clinically rare and easily confused with meningioma.Right-sided aortic arch is also a rare disease of congenital cardiovascular variability.The intracranial hemangiopericytoma associated with the right-sided aortic arch has not been reported in the literature.We are here to register a case of right aortic arch concurrent with intracranial hemangiopericytoma;the patient was initially thought to be a simple meningioma,but he was eventually diagnosed as a hemangiopericytoma with right aortic arch and multiple intracranial vascular stenosis and malformation.Whether there was a genetic correlation between the two provides a potential research direction for us.Therefore,the diagnosis and treatment of some rare diseases should be a more comprehensive analysis and evaluation.Adequate examination and accurate diagnosis are crucial,which will directly affect the efficacy of surgery and the prognosis of patients.

Left hepatic trisectionectomy for perihilar cholangiocarcinoma with a right-sided round ligament:A case report

BACKGROUND A right-sided round ligament(RSRL)is a rare,congenital anomaly of the intrahepatic portal vein,with a reported frequency of 0.2%-1.2%.For patients with perihilar cholangiocarcinoma associated with an RSRL,an accurate understanding of the vascular and biliary anatomy is indispensable.CASE SUMMARY We report a 70-year-old male with perihilar cholangiocarcinoma associated with an RSRL.After percutaneous transhepatic embolization of the left and anterior portal branches,we conducted a left trisectionectomy of the liver with extrahepatic bile duct resection and hepaticojejunostomy.The postoperative course was uneventful,and R0 resection was achieved.When the liver volume of each section was compared between 7 patients with an RSRL and 20 patients with normal portal vein anatomy,the posterior section in RSRL patients was significantly larger than that in patients with normal portal vein anatomy(median:457 mL vs 306 mL,P=0.031).In patients with perihilar cholangiocarcinoma associated with an RSRL,left trisectionectomy has several surgical advantages:(1)The posterior branch of the portal vein often ramifies independently,and the division of the portal vein is easily conducted;(2)A relatively large amount of remnant liver can be retained;and(3)The anatomy of the posterior branch of the Glissonian pedicle is similar to that in patients with normal anatomy.CONCLUSION In patients with an RSRL and perihilar cholangiocarcinoma that does not involve the posterior section,left trisectionectomy may be a favorable choice.

Unexpected right-sided sigmoid colon in laparoscopy: A case report and review of literature

BACKGROUND The presence of a right-sided sigmoid colon is a rare anatomical variation usually discovered incidentally during surgical interventions.This case report details an unexpected right-sided sigmoid colon identified during a laparoscopic appendectomy and examines the pertinent literature to explore its clinical importance.CASE SUMMARY A 71-year-old woman presented with acute appendicitis.A preoperative computed tomography(CT)scan showed peri-appendiceal inflammation but no significant anatomical abnormalities.During laparoscopic surgery,an unexpected finding was encountered:The sigmoid colon was situated on the right side and exhibited an abnormal relationship with the cecum and ascending colon.Postoperative pathological examination confirmed appendicitis with no additional pathological findings.The right-sided sigmoid colon anomaly was verified through intraoperative assessment and later re-evaluation with CT and colonographic imaging.The patient underwent a laparoscopic appendectomy and experienced a smooth postoperative recovery.CONCLUSION This case highlights the necessity of being attentive to anatomical variations during laparoscopic surgery,particularly when managing appendicitis.A review of the literature indicated that the occurrence of a right-sided sigmoid colon is infrequent and may be associated with anomalies in midgut rotation during embryonic development.Awareness of this variation can help prevent surgical complications and inform future clinical practice.

Early bifurcation of hepatic artery in right-sided living-donor hepatectomy at Asan Medical Center: rarely a critical issue

In living donor liver transplantation(LDLT),early bifurcation of hepatic artery(HA)relative to the cutting line of bile duct(BD)requires additional skeletonization of the hilar plate,especially around BD,compared to opposite condition.Subsequently,it may preclude higher chances of biliary complications such as bile leak and biliary stenosis in the donor.Hence,donor surgeons should be well aware of the anatomical correlations among HA,BD,and portal vein(PV),based on preoperative 3-dimensional(3D)images,and also intraoperatively perform meticulous dissection of HA from the surrounding tissues and minimize the damage of microcirculation to the BD without using energy devices such as electrocautery(1).When extensive dissection around BD&its ischemic damage in the donor is expected to obtain single HA opening of the harvesting graft,we prefer separate two HA openings including right anterior and posterior HAs to single right HA(RHA)opening without skeletonization of donor’s BD.

Pan-immune-inflammation value as a prognostic biomarker for colon cancer and its variation by primary tumor location

BACKGROUND A growing body of research indicates significant differences between left-sided colon cancers(LCC)and right-sided colon cancers(RCC).Pan-immune-inflammation value(PIV)is a systemic immune response marker that can predict the prognosis of patients with colon cancer.However,the specific distinction between PIV of LCC and RCC remains unclear.AIM To investigate the prognostic and clinical significance of PIV in LCC and RCC patients.METHODS This multicenter retrospective cohort study included 1510 patients with colon cancer,comprising 801 with LCC and 709 with RCC.We used generalized lifting regression analysis to evaluate the relative impact of PIV on disease-free survival(DFS)in these patients.Kaplan-Meier analysis,as well as univariate and multivariate analyses,were used to examine the risk factors for DFS.The correlation between PIV and the clinical characteristics was statistically analyzed in these patients.RESULTS A total of 1510 patients{872 female patients(58%);median age 63 years[interquartile ranges(IQR):54-71];patients with LCC 801(53%);median follow-up 44.17 months(IQR 29.67-62.32)}were identified.PIV was significantly higher in patients with RCC[median(IQR):214.34(121.78-386.72)vs 175.87(111.92-286.84),P<0.001].After propensity score matching,no difference in PIV was observed between patients with LCC and RCC[median(IQR):182.42(111.88-297.65)vs 189.45(109.44-316.02);P=0.987].PIV thresholds for DFS were 227.84 in LCC and 145.99 in RCC.High PIV(>227.84)was associated with worse DFS in LCC[PIV-high:Adjusted hazard ratio(aHR)=2.39;95%confidence interval:1.70-3.38;P<0.001]but not in RCC(PIV-high:aHR=0.72;95%confidence interval:0.48-1.08;P=0.114).CONCLUSION These findings suggest that PIV may predict recurrence in patients with LCC but not RCC,underscoring the importance of tumor location when using PIV as a colon cancer biomarker.

Right-and left-sided colorectal cancers respond differently to traditional Chinese medicine

AIM To explore the differences in the responses of left-sided colorectal cancer(LSCRC) and right-sided colon cancer(RSCC) to traditional Chinese medicine(TCM).METHODS Patients with postoperative stage I-III colorectal cancer(CRC) were enrolled and divided into the LSCRC with or without TCM and RSCC with or without TCM groups depending on the primary tumor side and TCM administration. Patients in the TCM group were given TCM for at least 6 mo. Our research adopted diseasefree survival(DFS) as the primary endpoint. We applied a Cox proportional hazards regression model for the multivariate factor analysis using Stata 12.0 and SPSS 22.0 software for data analysis.RESULTS Of the 817 patients included in our study, 617 had LSCRC(TCM group, n = 404; Non-TCM group, n = 213), and 200 had RSCC(TCM group, n = 132; NonTCM group, n = 68). The 6-year DFS for patients with LSCRC was 56.95% in the TCM group and 41.50% in the Non-TCM group(P = 0.000). For patients with RSCC, the 6-year DFS was 52.92% in the TCM group and 37.19% in the Non-TCM group(P = 0.003). Differences between LSCRC and RSCC were not statistically significant regardless of TCM ingestion.CONCLUSION Patients with either LSCRC or RSCC and who took TCM experienced longer DFS; furthermore, patients with RSCC benefited more from TCM in DFS.

LEARNING RATES OF KERNEL-BASED ROBUST CLASSIFICATION

This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship between the excess misclassification error and the excess generalization error is provided;from this,along with the convex analysis theory,a kind of learning rate is derived.The results show that the performance of the classifier is effected by the outliers,and the extent of impact can be controlled by choosing the homotopy parameters properly.

Right- and left-sided colorectal cancersrespond differently to cetuximab

Introduction Right-sided colon cancer （RSCC） and left-sided colorectal cancer （LSCRC） differ with respect to theirbiology and genomic patterns. This study aimed to examine whether the primary tumor location is associated withthe response to cetuximab in patients with metastatic colorectal cancer （mCRC）.Methods： Patients with mCRC treated with cetuximab and standard chemotherapy as first- or second-line treatmentswere compared with randomly chosen patients who were treated with chemotherapy alone between 2005 and 2013.The main outcome measures were the overall response rate （ORR）, progression-free survival （PFS）, and overall survival （OS）.The differences in the outcome were analyzed by using the chi-squared test, Student＇s t test, and Kaplan-Meier method.Results： The treatment results of 206 patients with mCRC treated with cetuximab and standard chemotherapy asfirst- or second-line treatments were compared with those of 210 patients who were treated with chemotherapyalone. As a first-line treatment, cetuximab with chemotherapy was associated with a significantly higher ORR（49.4 % vs. 28.6 %, P = 0.005） as well as longer PFS （9.1 vs. 6.2 months, P = 0.002） and OS （28.9 vs. 20.1 months,P = 0.036） than chemotherapy alone in patients with LSCRC. However, cetuximab neither improved the ORR（36.4 % vs. 26.2 %, P = 0.349） nor prolonged PFS （5.6 vs. 5.7 months, P = 0.904） or OS （25.1 vs. 19.8 months, P = 0.553） inpatients with RSCC. As a second-line treatment, cetuximab exhibited a tendency to improve the ORR （23.5 % vs. 10.2 %,P = 0.087） and prolong PFS （4.9 vs. 3.5 months, P = 0.064）, and it significantly prolonged OS （17.1 vs. 12.4 months,P = 0.047） compared with chemotherapy alone in the patients with LSCRC. In contrast, as a second-line treatment,cetuximab neither improved the ORR （7.1 % vs. 11.4 %, P = 0.698） nor prolonged PFS （3.3 vs. 4.2 months, P = 0.761） orOS （13.4 vs. 13.0 months, P=0.652） in patients with RSCC.Conclusions： The addition of cetuximab to chemotherapy in both first- and second-line treatments of mCRC may onlybenefit patients with primary LSCRC.

Predicting portal venous anomalies by left-sided gallbladder or rightsided ligamentum teres hepatis: A large scale, propensity scorematched study

BACKGROUND Right-sided ligamentum teres(RSLT)is often associated with portal venous anomalies(PVA)and is regarded as a concerning feature for hepatobiliary intervention.Most studies consider RSLT to be one of the causes of left-sided gallbladder(LGB),leading to the hypothesis that LGB must always be present with RSLT.However,some cases have shown that right-sided gallbladder(RGB)can also be present in livers with RSLT.AIM To highlight the rare variation that RSLT may not come with LGB and to determine whether ligamentum teres(LT)or gallbladder location is reliable to predict PVA.METHODS This study retrospectively assessed 8552 contrast-enhanced abdominal computed tomography examinations from 2018 to 2021[4483 men,4069 women;mean age,59.5±16.2(SD)years].We defined the surrogate outcome as major PVAs.The cases were divided into 4 subgroups according to gallbladder and LT locations.On one hand,we analyzed PVA prevalence by LT locations using gallbladder location as a controlled variable(n=36).On the other hand,we controlled LT location and computed PVA prevalence by gallbladder locations(n=34).Finally,we investigated LT location as an independent factor of PVA by using propensity score matching(PSM)and inverse probability of treatment weighting(IPTW).RESULTS We found 9 cases of RSLT present with RGB.Among the LGB cases,RSLT is associated with significantly higher PVA prevalence than typical LT[80.0%vs 18.2%,P=0.001;OR=18,95%confidence interval(CI):2.92-110.96].When RSLT is present,we found no statistically significant difference in PVA prevalence for RGB and LGB cases(88.9%vs 80.0%,P>0.99).Both PSM and IPTW yielded balanced cohorts in demographics and gallbladder locations.The RSLT group had a significantly higher PVA prevalence after adjusted by PSM(77.3%vs 4.5%,P<0.001;OR=16.27,95%CI:2.25-117.53)and IPTW(82.5%vs 4.7%,P<0.001).CONCLUSION RSLT doesn't consistently coexist with LGB.RSLT can predict PVA independently while the gallbladder location does not serve as a sufficient predictor.