Radiological characteristics and diagnostic clues for persistent descending mesocolon in patients with rectal cancer.

PURPOSE: Persistent descending mesocolon (PDM) increases the difficulty and colonic ischemia in the surgery of colorectal cancer, but the preoperative diagnostic criteria have not yet been clearly demonstrated. This study explored the MR imaging features and diagnostic criteria of PDM to improve the preoperative diagnostic rate. METHODS: The clinical data of 54 patients with PDM and 270 patients without PDM who underwent rectal surgery at the Department of Colorectal Surgery, Fujian Medical University Union Hospital, from March 2018 to December 2022 were analyzed, retrospectively. The radiological parameters of PDM from MRI were analyzed. RESULTS: On MRI T2WI axial image, the left edge of the abdominal aorta was defined as the reference line. The shortest vertical distance between the right edge of the descending colon and this line (dN) and the maximum transverse diameter of the peritoneal cavity (dA) at the same level and the maximum vertical distance between the right edge of the descending colon and this line (dW) were measured. There were significant statistical differences in dN, dW, dN/dW, and dN/dA between the PDM group and the non-PDM group. dN, dN/dW, and dN/dA have high diagnostic performance for the PDM. dN < 4.16 cm, dN/dW < 0.52, and dN/dA < 0.15 can all be used as clues to diagnose PDM. CONCLUSIONS: We propose a feasible set of diagnostic criteria for PDM based on abdominal MRI, which can quickly and accurately diagnose PDM, and provide some reference for preoperative planning and surgical decision-making.

Developing a phantom for simulating robotic-assisted complete mesocolic excision using 3D printing and medical imaging.

BACKGROUND: Robotic-assisted complete mesocolic excision is an advanced procedure mainly because of the great variability in anatomy. Phantoms can be used for simulation-based training and assessment of competency when learning new surgical procedures. However, no phantoms for robotic complete mesocolic excision have previously been described. This study aimed to develop an anatomically true-to-life phantom, which can be used for training with a robotic system situated in the clinical setting and can be used for the assessment of surgical competency. METHODS: Established pathology and surgical assessment tools for complete mesocolic excision and specimens were used for the phantom development. Each assessment item was translated into an engineering development task and evaluated for relevance. Anatomical realism was obtained by extracting relevant organs from preoperative patient scans and 3D printing casting moulds for each organ. Each element of the phantom was evaluated by two experienced complete mesocolic excision surgeons without influencing each other's answers and their feedback was used in an iterative process of prototype development and testing. RESULTS: It was possible to integrate 35 out of 48 procedure-specific items from the surgical assessment tool and all elements from the pathological evaluation tool. By adding fluorophores to the mesocolic tissue, we developed an easy way to assess the integrity of the mesocolon using ultraviolet light. The phantom was built using silicone, is easy to store, and can be used in robotic systems designated for patient procedures as it does not contain animal-derived parts. CONCLUSIONS: The newly developed phantom could be used for training and competency assessment for robotic-assisted complete mesocolic excision surgery in a simulated setting.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study.

BACKGROUND: Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO). METHOD: Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants. RESULTS: Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n = 65; median score 8/14] vs. AMIGO [n = 65; median score 6/14; p < 0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging. CONCLUSIONS: 3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

Routine CT evaluation of central vascular ligation in patients undergoing complete mesocolic excision for sigmoid colon cancer.

AIM: Objective and reproducible quality measures of complete mesocolic excision (CME) for colon cancer are not currently available. This study aimed to measure the inferior mesenteric stump length following CME for sigmoid colon cancer and explore surgical, pathological and oncological outcomes in patients with a stump length of <10 mm vs. ≥10 mm. METHOD: This was a single-centre, retrospective cohort study including patients undergoing minimally invasive surgery for sigmoid colon cancer between May 2013 and May 2015. Follow-up CT scans were reviewed, and a vascular stump cut-off of <10 mm for adequate central ligation of the inferior mesenteric artery was applied. Differences in perioperative, histopathological and oncological outcome parameters (overall, disease-free and recurrence-free survival) were explored between <10 mm vs. ≥10 mm groups. RESULTS: A total of 127 patients (43% female) with a median age of 68 years were included. The median follow-up time was 68 months. CT measurements showed good interrater agreement (90% absolute agreement) and reliability among raters (kappa = 0.77, 95% CI 0.53-1.00, p < 0.001). A stump length ≥10 mm was associated with longer operating time (150 vs. 180 min, p = 0.021), intramesocolic resection (p = 0.008), and a shorter distance from the bowel wall to vascular tie (120 vs. 102 mm, p = 0.005). CONCLUSION: An arterial stump length ≥10 mm in sigmoid resection for colon cancer was associated with key clinical quality measures. Measurement of arterial stump length using routine follow-up CT may serve as a quality indicator of vascular ligation in CME surgery.

Minimally invasive surgery for colorectal cancer with persistent descending mesocolon: radiological findings and short-term outcomes.

BACKGROUND: Persistent descending mesocolon (PDM) is typically asymptomatic. However, features such as adhesion and variations in vessel anatomy could affect the surgical techniques for colorectal cancer (CRC). This study aimed to investigate the frequency and radiological features of PDM. Short-term outcomes after conventional laparoscopic surgery (CLS) for CRC with PDM were also investigated to assess the feasibility of CLS and identify strategies for minimally invasive surgery (MIS) in CRC with PDM. METHODS: Patients who underwent MIS, including CLS and robot-assisted laparoscopic surgery (RALS), for left-sided CRC between April 2016 and June 2019, were investigated. PDM was defined as the existence of the right border of the descending colon inside the right border of the left kidney based on preoperative computed tomography findings. RESULTS: Radiological findings of 837 patients were examined, and PDM was found in 19 (2.3%) patients. Radiality of the inferior mesenteric artery (IMA) was found in 5 of 19 (26.3%) PDM cases, which was significantly higher than that in non-PDM cases. The median lengths between the IMA and inferior mesenteric vein (IMV) and between the IMV and descending colon in PDM cases were 14.8 mm and 17.2 mm, respectively, which were significantly shorter than those in non-PDM cases. Short-term outcomes were evaluated only in CLS cases since the rate of hybrid surgery among RALS cases differed between non-PDM and PDM cases (0% vs. 44.4%), which would affect the surgical outcomes. The short-term outcomes in 447 CLS cases were similar between PDM and non-PDM cases. The frequency of extracorporeal division of the left colic artery (LCA) and IMV was significantly higher in PDM than in non-PDM cases (70.0% vs. 5.7%). CONCLUSIONS: This radiological definition of PDM was feasible. CLS for left-sided CRC with PDM was feasible, and dividing the LCA and IMV extracorporeally would be vital for safe surgery.

Primary extraskeletal osteosarcoma of sigmoid mesocolon: a case report and a review of the literature.

BACKGROUND: Extraskeletal osteosarcoma (ESOS) is a rare mesenchymal malignancy, which produces osteoid, bone, or chondroid material and is located in the soft tissue without attachment to skeletal bones and periosteum. One of the things that ESOS originated from mesentery is much rarer. CASE PRESENTATION: A 75-year female had a history of pain in the left lower abdomen for more than 4 months. Abdominal computerized tomography (CT) and magnetic resonance imaging revealed a large, irregular, and solid-cystic mass (largest diameter was 11.5 cm). The tumor was radically removed during an open operation. It was composed of abundant osteoid and polyhedral-shaped tumor cells with high atypia and high mitotic activity microscopically. The final pathological diagnosis was osteoblastic osteosarcoma, arising from the sigmoid mesocolon with negative margins. A 9-month follow-up by CT exhibited signs of peritoneal metastasis. CONCLUSIONS: Given the rarity of cases of mesenteric ESOS, diagnosis mainly depended on pathology findings or should be taken into consideration when the mesenteric mass was found. Its most effective treatment had not been determined, with surgical excision being generally accepted. Ensuring negative surgical margins may be an important factor affecting prognosis.

The use of ultrasound in central vascular ligation during laparoscopic right-sided colon cancer surgery: technical notes.

BACKGROUND: Complete mesocolic excision (CME) with central vascular ligation (CVL) requires the surgeon to sharply dissect the mesocolon and approach the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) for ligation of the supplying vessels relating to right-sided colon cancer at their origin. Even with preoperative images, it can still be challenging to identify these structures during laparoscopic surgery because of various intraoperative conditions. The aim of this study was to assess the efficacy of intraoperative ultrasound (IOUS) for identification of blood vessels during right-sided colon cancer surgery. METHODS: We performed IOUS on 19 patients diagnosed with right-sided colon cancer at our institution, in January-October 2020. Preoperatively, a three-dimensional computed tomography (3D-CT) angiogram was obtained for the majority of patients to visualize the SMA, SMV, and their respective branches. The running position of the ileocolic artery (ICA) and right colic artery (RCA) related to the SMV and the presence of the middle colic artery were identified and compared using preoperative 3D-CT, IOUS, and intraoperative findings. RESULTS: Nineteen patients [seven men and 12 women with a mean age of 73.9 ± 8.4 years (range 58-82 years)] were studied, including some with a body mass index of > 30 kg/m2, locally advanced cancer, and severe adhesion. There were IOUSs that detected the SMA, SMV, and their tributaries in all patients. The positional relationships between the SMV and the ICA and RCA revealed by IOUS were consistent with the preoperative and intraoperative findings. CONCLUSION: IOUS is a safe, feasible, and reproducible technique that can assist in detecting the branching of the SMA and SMV during CME with CVL in laparoscopic right-sided colon cancer surgery, regardless of individual conditions.

Superior Mesenteric Vein-First Approach for Robotic Salvage Surgery with Indocyanine Green Fluorescence Angiography.

INTRODUCTION: Inadequate lymphadenectomy is still a major concern in colon cancer surgery. The superior mesenteric vein (SMV)-first approach is a novel, standardized, reproducible method for robotic complete mesocolic excision surgery. OBJECTIVE: Our aim was to present the application of the SMV-first approach principles to facilitate robotic salvage surgery for recurrent disease within the mesocolon. METHODS: A 78-year-old female presented with a malignant lymph node deposit within residual right mesocolonic tissue, approximately 3 months following a laparoscopic right hemicolectomy for colon cancer. Dissection was initiated with a transverse curvilinear incision along the inferior aspect of the remaining ileocolic pedicle to identify the SMV. Dissection continued along the ventral aspect of the SMV in a cephalad direction to identify and expose the middle colic vessels at their origin. The use of idocyanine green (ICG) confirmed the vascular anatomy, demonstrating the right branch of the middle colic artery traversing the malignant deposit in the residual mesocolon. Following ligation at the origin of the right branch of the middle colic and ileocolic vessels, the retro-mesocolic plane dissection was completed to excise the malignant deposit and the residual mesocolon. RESULTS: The patient was discharged home the following day. The pathological specimen confirmed metastatic poorly differentiated adenocarcinoma in one of nine lymph nodes, and the vascular pedicle resection margin was negative for tumor. CONCLUSION: Following the SMV-first approach principles provides a safe plane for dissection, and, in conjunction with ICG, facilitates the delineation of the vascular anatomy, to enable robotic salvage surgery to be performed.1-3.

Navigating the mesentery: Part III. Unusual anatomy of ileocolic vessels.

AIM: The ileocolic vessels are important landmarks in advanced surgery of the midgut. The aim of the present study is to present variations of ileocolic vessels relevant to complete mesocolic excision with D3 lymphadenectomy of the right colon, within their detailed and precise morphometric framework and deriving from a large and consistent series of operated patients. METHODS: An ongoing prospective trial 'Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multidetector Computed Tomography Angiography' was reviewed. The imaging datasets underwent manual segmentation and 3D reconstruction, and the results were validated at surgery. A total of 356 patients were included in the study. RESULTS: A cross-section of the series revealed five cases (1.4%) with variation of ileocolic vessels relevant to complete mesocolic excision or D3 extended mesenterectomy. There were two cases with absence of a true classical ileocolic artery, two cases with absence of a true classical ileocolic vein, and one case of precocious bifurcation of the ileocolic artery, left to the superior mesenteric vein. The entire D3 area in all the cases was thoroughly documented and analysed from the morphometric point of view (calibres, lengths of vessels, crossing patterns). CONCLUSION: The preoperative visualization of a patient's individual 3D anatomy is a powerful tool in identifying the variations whose negligence could have dire consequences in complete mesocolic excision of the right colon.

Ex vivo specimen MRI and pathology confirm a rectosigmoid mesenteric waist at the junction of the mesorectum and mesocolon.

AIM: Continuity of the mesentery has recently been established and may provide an anatomical basis for optimal colorectal resectional surgery. Preliminary data from operative specimen measurements suggest there is a tapering in the mesentery of the distal sigmoid. A mesenteric waist in this area may be a risk factor for local recurrence of colorectal cancer. This study aimed to investigate the anatomical characteristics of the mesentery at the colorectal junction. METHOD: In this cross-sectional study, 20 patients were recruited. After planned colorectal resection, the surgical specimens were scanned in a MRI system and subsequently dissected and photographed as per national pathology guidelines. Mesenteric surface area and linear measurements were compared between MRI and pathology to establish the presence and location of a mesenteric waist. RESULTS: Specimen analysis confirmed that a narrowing in the mesenteric surface area was consistently apparent at the rectosigmoid junction. Above the anterior peritoneal reflection, the surface area and posterior distance of the mesentery of the upper rectum initially decreased before increasing as the mesentery of the sigmoid colon. These anatomical properties created the appearance of a mesenteric 'waist' at the rectosigmoid junction. Using the anterior reflection as a reference landmark, the rectosigmoid waist occurred at a mean height of 23.6 and 21.7 mm on MRI and pathology, respectively. CONCLUSION: A rectosigmoid waist occurs at the junction of the mesorectum and mesocolon, and is a mesenteric landmark for the rectum that is present on both radiology and pathology.

Mesorectal fat area as a useful predictor of the difficulty of robotic-assisted laparoscopic total mesorectal excision for rectal cancer.

BACKGROUND: Various predictors of the difficulty of total mesorectal excision for rectal cancer have been described. Although a bulky mesorectum was considered to pose technical difficulties in total mesorectal excision, no studies have evaluated the influence of mesorectum morphology on the difficulty of total mesorectal excision. Mesorectal fat area at the level of the tip of the ischial spines on magnetic resonance imaging was described as a parameter characterizing mesorectum morphology. This study aimed to evaluate the influence of clinical and anatomical factors, including mesorectal fat area, on the difficulty of total mesorectal excision for rectal cancer. METHODS: This study enrolled 98 patients who underwent robotic-assisted laparoscopic low anterior resection with total mesorectal excision for primary rectal cancer, performed by a single expert surgeon, between 2010 and 2015. Magnetic resonance imaging-based pelvimetry data were collected. Linear regression was performed to determine clinical and anatomical factors significantly associated with operative time of the pelvic phase, which was defined as the time interval from the start of rectal mobilization to the division of the rectum. RESULTS: The median operative time of the pelvic phase was 68 min (range 33-178 min). On univariate analysis, the following variables were significantly associated with longer operative time of the pelvic phase: male sex, larger tumor size, larger visceral fat area, larger mesorectal fat area, shorter pelvic outlet length, longer sacral length, shorter interspinous distance, larger pelvic inlet angle, and smaller angle between the lines connecting the coccyx to S3 and to the inferior middle aspect of the pubic symphysis. On multiple linear regression analysis, only larger mesorectal fat area remained significantly associated with longer operative time of the pelvic phase (p = 0.009). CONCLUSIONS: Mesorectal fat area may serve as a useful predictor of the difficulty of total mesorectal excision for rectal cancer.

Sonographic findings in two cases of lymphangioma of the mesocolon in adults.

Lymphangioma of the mesocolon is very rare. We report two cases of surgically resected and histologically proven mesocolic lymphangioma in adults. In both cases, ultrasound revealed a large cystic mass with multiple thin septa in the lower abdomen. A peculiar finding was the large craniocaudal sliding movement of the mass synchronized with the patient's respiration, which was a clue to the diagnosis of mesenteric lymphangioma. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:78-81, 2018.

[A Case of Epithelioid Sarcoma of the Sigmoid Mesocolon].

A 73-year-old man visited our hospital with the chief complaints of anorexia and weight loss. Computed tomography showed a 5 cm tumor(diameter)in the sigmoid mesocolon. We performed laparoscopic Hartmann operation; however, because of sacral invasion of tumor, curative surgery was difficult. Therefore, the tumor was excised together with the sigmoid colon. Histopathological examination of the tumor confirmed the diagnosis of epithelioid sarcoma. Postoperatively, the patient received heavy-particle radiotherapy at another facility as treatment for the residual tumor. The size of the residual tumor decreased 6 months after the surgery. Up until 1 year after surgery, the patient's condition has remained stable without any disease progression. Epithelioid sarcoma is a rare soft-tissue tumor and often leads to a poor prognosis. We present a case of epithelioid sarcoma occurring in the sigmoid mesocolon.

Radiological and pathological evaluation of the level of arterial division after colon cancer surgery.

AIM: In aiming to cure patients with colorectal cancer surgery, the surgeon must carefully dissect the mesocolon and mesorectum and divide the vascular pedicle near to its origin so as to include all local lymph nodes. This has been termed complete mesocolic excision. The distance from the distal vascular tie to the bowel wall in the fixed specimen is an indication as to the quality of surgery but this does not assess the length of the residual vascular pedicle and, by implication, residual lymph nodes. The aim of this study was to establish if our surgeons were carrying out complete mesocolic excision by assessing the length of the proximal arterial pedicle and relating this to arterial length in the fixed specimen. METHOD: This was a single centre prospective study of patients undergoing elective surgery for locally advanced colorectal cancer. An abdominal and pelvic CT scan was performed 2 days postoperatively and a radiologist blinded to the operative procedure measured the length of the residual arterial stump. Similarly, the length of the vessel in the fixed resected specimen and lymph node yield were also recorded. RESULTS: Fifty-two patients were recruited. The mean length of the residual arterial stump was 38 mm (95% CI: 33-43), which was significantly longer than the < 10 mm recommended in guidelines (P < 0.0001). The mean length was 31 mm (95% CI: 25-37) and 49 mm (95% CI: 40-57) for left and right sided resections respectively. There was no correlation between the residual arterial stump and the pathology. CONCLUSIONS: The residual arterial length was greater than suggested by guidelines and may indicate that our surgery is less radical than we planned. Caution should be taken when using pathological measurements of vascular ligation as it may not reflect the height of the pedicle division.

An appraisal of the computed axial tomographic appearance of the human mesentery based on mesenteric contiguity from the duodenojejunal flexure to the mesorectal level.

OBJECTIVE: The human mesentery is now regarded as contiguous from the duodenojejunal (DJ) to anorectal level. This interpretation prompts re-appraisal of computed tomography (CT) images of the mesentery. METHODS: A digital model and reference atlas of the mesentery were generated using the full-colour data set of the Visible Human Project (VHP). Seventy one normal abdominal CT images were examined to identify mesenteric regions. CT appearances were correlated with cadaveric and histological appearances at corresponding levels. RESULTS: Ascending, descending and sigmoid mesocolons were identifiable in 75%, 86% and 88% of the CTs, respectively. Flexural contiguity was evident in 66%, 68%, 71% and 80% for the ileocaecal, hepatic, splenic and rectosigmoid flexures, respectively. A posterior mesocolic boundary corresponding to the anterior renal fascia was evident in 40% and 54% of cases on the right and left, respectively. The anterior pararenal space (in front of the boundary) corresponded to the mesocolon. CONCLUSIONS: Using the VHP, a mesenteric digital model and reference atlas were developed. This enabled re-appraisal of CT images of the mesentery, in which contiguous flexural and non-flexural mesenteric regions were repeatedly identifiable. The anterior pararenal space corresponded to the mesocolon. KEY POINTS: The Visible Human Project (VHP) allows direct identification of mesenteric structures. Correlating CT and VHP allows identification of flexural and non-flexural mesenteric components. Radiologic appearance of intraperitoneal structures is assessed, starting from a mesenteric platform.

Real-Time Indocyanine Green Fluorescence Imaging-Guided Complete Mesocolic Excision in Laparoscopic Flexural Colon Cancer Surgery.

INTRODUCTION: Laparoscopic surgery for colon cancer located in the hepatic flexure or splenic flexure is not standardized, because lymphatic drainage at this site may vary and the precise site of lymphatic dissection is uncertain. TECHNIQUE: Indocyanine green was injected into the submucosal layer around the tumor at 2 points with a 23-gauge localized injection before lymph node dissection and the lymph flow was observed using a near-infrared camera system 30 minutes after injection. In addition, a complete mesocolic excision with central vascular ligation guided the region where the lymph flow was fluorescently observed. RESULTS: A total of 20 consecutive patients (hepatic flexure, 10 patients; splenic flexure, 10 patients) were enrolled in this study. All of the procedures were safely performed without any complications. The lymph flow was visualized in 19 patients (95%) intraoperatively. Modification of the operative methods was required for 5 patients (modification in the separation line of the mesocolon and vessel selection for central vascular ligation) because the area of lymph flow observed during surgery differed from that of the preoperative diagnosis. CONCLUSION: Intraoperative real-time visualization of the lymph flow using indocyanine green fluorescence imaging during laparoscopic colon cancer surgery, especially flexural colon cancer surgery, is feasible and a helpful technique for identifying appropriate central vessels to be dissected and for determining an appropriate separation line of the mesentery.

Three surgical planes identified in laparoscopic complete mesocolic excision for right-sided colon cancer.

BACKGROUND: Complete mesocolic excision provides a correct anatomical plane for colon cancer surgery. However, manifestation of the surgical plane during laparoscopic complete mesocolic excision versus in computed tomography images remains to be examined. METHODS: Patients who underwent laparoscopic complete mesocolic excision for right-sided colon cancer underwent an abdominal computed tomography scan. The spatial relationship of the intraoperative surgical planes were examined, and then computed tomography reconstruction methods were applied. The resulting images were analyzed. RESULTS: In 44 right-sided colon cancer patients, the surgical plane for laparoscopic complete mesocolic excision was found to be composed of three surgical planes that were identified by computed tomography imaging with cross-sectional multiplanar reconstruction, maximum intensity projection, and volume reconstruction. For the operations performed, the mean bleeding volume was 73±32.3 ml and the mean number of harvested lymph nodes was 22±9.7. The follow-up period ranged from 6-40 months (mean 21.2), and only two patients had distant metastases. CONCLUSIONS: The laparoscopic complete mesocolic excision surgical plane for right-sided colon cancer is composed of three surgical planes. When these surgical planes were identified, laparoscopic complete mesocolic excision was a safe and effective procedure for the resection of colon cancer.

Torsion of a giant mesocolic lipoma in a child with Bannayan-Riley-Ruvalcaba syndrome.

A 6-year-old boy with Bannayan-Riley-Ruvalcaba syndrome (BRRS) presented to the emergency department with periumbilical abdominal pain for 12 h. A contrast-enhanced abdominal and pelvis CT examination revealed significant interval change in the size and appearance of a previously seen hypoattenuating right mesocolic fatty mass suggestive for lipoma, first observed 5 months prior. This lesion demonstrated new enhancing internal septations, a thickened capsule, interval development of adjacent mesenteric fat stranding and engorgement of the mesenteric vessels. Given the short follow-up interval and acute clinical presentation, imaging findings were suggestive for torsion. We present this case for the unusual imaging findings as well as to highlight the differential diagnosis for abdominal fat containing lesions by imaging in patients with BRRS and other hamartomatous syndromes.

Predicting the pathological features of the mesorectum before the laparoscopic approach to rectal cancer.

Pelvic anatomy and tumour features play a role in the difficulty of the laparoscopic approach to total mesorectal excision in rectal cancer. The aim of the study was to analyse whether these characteristics also influence the quality of the surgical specimen. We performed a prospective study in consecutive patients with rectal cancer located less than 12 cm from the anal verge who underwent laparoscopic surgery between January 2010 and July 2013. Exclusion criteria were T1 and T4 tumours, abdominoperineal resections, obstructive and perforated tumours, or any major contraindication for laparoscopic surgery. Dependent variables were the circumferential resection margin (CMR) and the quality of the mesorectum. Sixty-four patients underwent laparoscopic sphincter-preserving total mesorectal excision. Resection was complete in 79.1% of specimens and CMR was positive in 9.7%. Univariate analysis showed tumour depth (T status) (P = 0.04) and promontorium-subsacrum angle (P = 0.02) independently predicted CRM (circumferential resection margin) positivity. Tumour depth (P < 0.05) and promontorium-subsacrum axis (P < 0.05) independently predicted mesorectum quality. Multivariate analysis identified the promontorium-subsacrum angle (P = 0.012) as the only independent predictor of CRM. Bony pelvis dimensions influenced the quality of the specimen obtained by laparoscopy. These measurements may be useful to predict which patients will benefit most from laparoscopic surgery and also to select patients in accordance with the learning curve of trainee surgeons.