A Rare Solitary Fibrous Tumor of the Mesorectum: A Case Report.

Solitary fibrous tumors (SFTs) are rare tumors that predominantly occur in the mesorectum. Few case reports have been published on mesorectal tumors, and this is the seventh case report. A 49-year-old female patient presented with a hypervascularized mesorectal tumor discovered incidentally during a routine medical examination. Using preoperative three-dimensional computed tomography (3D-CT), we identified vessels originating from the superior rectal and lateral sacral arteries, which are important sources of nutrients, and performed the procedure safely and without bleeding. Considering the lack of preoperative diagnosis and rectal blood flow, high anterior resection was performed. The histopathological diagnosis confirmed SFT, and the patient is currently doing well with no recurrence. Although SFT of the mesorectum occurs infrequently, it should be included in the differential diagnosis. In addition, the usefulness of preoperative 3D-CT, including the arterial phase, has been emphasized in such cases. This is the seventh reported case of a rare SFT in the mesorectum. Currently, there is no literature highlighting the usefulness of 3D-CT for SFTs of the mesorectum. However, it is a valuable preparatory tool for preoperative evaluation.

Short-term outcomes of robotic tumor-specific mesorectal resection of rectal cancer: surgical techniques in mesorectal division using rolling division of the mesorectum.

BACKGROUND: This study aims to report our surgical techniques for robot-assisted laparoscopic anterior resection, specifically focusing on mesorectal division using rolling division of the mesorectum, and to elucidate short-term outcomes at a single institution. Tumor-specific mesorectal excision (TSME) is commonly performed for resection of a tumor located in the upper rectum. However, especially in a narrow pelvis, it is difficult to perform appropriate mesorectal division at an adequate distance from the tumor in robot-assisted laparoscopic anterior resection. METHODS: Retrospective case series of patients with rectal cancer who underwent robot-assisted TSME using rolling division of mesorectum. Patient characteristics, perioperative clinical results, surgical and pathological details were recorded. RESULTS: A total of 198 patients underwent robot-assisted TSME for rectal cancer using rolling division of mesorectum between May 2019 and December 2023.The tumor was located in the upper rectum in 45 patients, middle rectum in 115 patients and lower rectum in 38 patients. The types of resections were 40 high anterior resection and 158 low anterior resections. The median operation time was 175 (range 109-310) min, and median mesorectal division time was 24 (range 15-45) min. Median blood loss was 3 (range 0-20) ml; no patients required blood transfusion. The overall complication rate of Clavien-Dindo classification grades I-IV was 7.1%. Anastomotic leakage was observed in two patients (1.0%) with grade III. There was no surgical mortality in this series. CONCLUSION: This robotic technique for anterior resection is a feasible and reliable procedure for achieving sufficient and safe TSME in this cohort.

Decoding Hepatic Portal Venous Gas: A Case Report.

Hepatic portal venous gas (HPVG) is an infrequent and life-threatening condition with high morbidity and mortality rates, which consists of the presence of gas in the portal vein and its branches. Improvements in imaging technologies have led to the diagnosis of HPVG in less severe circumstances, which, in turn, has only determined a small amelioration of the prognosis. We present a rare case of HPVG subsequent to paralytic ileus in a patient who attained long-term survival after the surgical treatment was performed. HPVG is considered to be associated with sepsis, parietal/mucosal damage, inflammation of the intraperitoneal organs, and meteorism, which may be found in a variety of pathologies. The severity of this pathology depends on the pre-existing conditions of the patients but also on how quickly a treatment plan is established and applied. As a correct and timely diagnosis is crucial for the increase of the survival rate in HPVG, greater attention shall be paid to the clinical manifestations and the differential diagnosis.

Magnetic resonance imaging for assessment of rectal cancer nodes after chemoradiotherapy: A single center experience.

BACKGROUND: Accurate nodal restaging is becoming clinically more important in patients with locally advanced rectal cancer (LARC) with the emergence of organ-preserving treatment after a good response to neoadjuvant chemoradiotherapy (nCRT). PURPOSE: To evaluate the accuracy of MRI in identifying negative N status (ypN0 patients) in LARC after nCRT. MATERIAL AND METHODS: 191 patients with LARC underwent MRI before and 6-8 weeks after nCRT and subsequent total mesorectal excision. Short-axis diameter of mesorectal lymph nodes was evaluated on the high resolution T2-weighted images to compare MRI restaging with histopathology.. RESULTS: 146 and 45 patients had a negative N status (ypN0) and positive N status (ypN + ), respectively. On restaging MRI, the 70 % reduction in size of the largest node was associated with an area under the curve (AUC) of 0.818 to predict ypN0 stage, with a sensitivity of 93.3 % and a negative predictive value (NPV) of 95.4 %. No nodes were observed in 38 pts (37 pts ypN0 and 1 patient ypN + ), with sensitivity and NPV of nodes disappearance for ypN0 stage of 93.3 % and 92.5 % respectively. A 2.2 mm cut-off in short-axis diameter was associated with an AUC of 0.83 for the prediction of ypN0 nodal stage, with sensitivity and NPV of 79,5% and 91.1 % respectively. CONCLUSION: A reduction in size of 70 % of the largest limph-node on MRI at rectal cancer restaging has high sensitivity and NPV for prediction of ypN0 stage after nCRT. The high NPV of node disappearance and of a ≤ 2.2 mm short-axis diameter is confirmed.

Femalenear-TME: estandarización de la proctectomía en mujeres con colitis ulcerosa / Female near-TME: Standardization of proctectomy in women with ulcerative colitis

Dos técnicas quirúrgicas de proctectomía en colitis ulcerosa (CU) han sido empleadas tradicionalmente: la escisión total de mesorrecto (TME) y la disección perirrectal (CRD). Recientemente, el presente grupo de trabajo ha propuesto la estandarización de la técnica near-TME, la cual reúne las ventajas de estas dos. Disminuye el riesgo de lesión nerviosa autónoma pélvica, así como el volumen de remanente mesorrectal. Las referencias anatómicas a la hora de realizar la near-TME varían entre el varón y la mujer, sobre todo en la hemicircunferencia anterolateral. El objetivo del presente trabajo es estandarizar la técnica de near-TME en mujeres (femalenear-TME) con base en landmarks anatomoquirúrgicos característicos de la pelvis femenina a partir de ilustraciones y de un caso real intervenido de forma laparoscópica. Esta técnica debe ser llevada a cabo por cirujanos con experiencia en cirugía de la enfermedad inflamatoria intestinal y con amplios conocimientos anatomoquirúrgicos.(AU)

Traditionally, two surgical techniques for proctectomy in ulcerative colitis have been used: total mesorectal excision (TME), and close rectal dissection (CRD). Recently, our research group has proposed the standardization of the near-TME technique, which unites the advantages of both methods. It decreases the risk of pelvic autonomic nerve injury and reduces the volume of mesorectal remnant. When performing the near-TME, the anatomical landmarks differ between men and women, especially in the anterolateral hemicircumference. The objective of this paper is to standardize the near-TME technique in women (female near-TME) using characteristic surgical-anatomic landmarks of the female pelvis based on illustrations and a real case treated laparoscopically. This technique should be carried out by surgeons with experience in inflammatory bowel disease surgery and extensive knowledge of surgical anatomy.(AU)

Female near-TME: standardization of proctectomy in women with ulcerative colitis.

Traditionally, 2 surgical techniques for proctectomy in ulcerative colitis have been used: total mesorectal excision (TME), and close rectal dissection (CRD). Recently, our research group has proposed the standardization of the Near-TME technique, which unites the advantages of both methods. It decreases the risk of pelvic autonomic nerve injury and reduces the volume of mesorectal remnant. When performing the Near-TME, the anatomical landmarks differ between men and women, especially in the anterolateral hemicircumference. The objective of this paper is to standardize the Near-TME technique in women (Female Near-TME) using characteristic surgical-anatomic landmarks of the female pelvis based on illustrations and a real case treated laparoscopically. This technique should be carried out by surgeons with experience in inflammatory bowel disease surgery and extensive knowledge of surgical anatomy.

A primary hydatid cyst in the mesorectum uncommon location - A rare case report.

INTRODUCTION AND IMPORTANCE: The tapeworm Echinococcus granulosus sensu lato is the causative agent of cystic echinococcosis (CE), often known as hydatid disease. Over two-thirds of all occurrences of this zoonotic disease process in humans are caused by hepatic infection. Clinicians should have a low threshold to consider CE as a differential diagnosis in patients with positive serology and suggestive radiological findings, especially in endemic regions, because signs and symptoms are typically non-specific, especially in early disease. CASE PRESENTATION: This is a case report of a 26-year-old male who presented with increasing lower abdominal discomfort, mild pain, sense of fullness in the lower abdomen, described as (I'm having a ball in my abdomen), with a history of early satiation and tenesmus, frequency of urine, and history of weight loss and general weakness of 10-months duration. The diagnosis of a hydatid cyst in the mesorectum was made. The cyst was completely excised via open surgery. No local recurrence has been detected up to the present time. CLINICAL DISCUSSION: Given how uncommon a site like this is, this case report helps broaden the differential diagnosis of soft tissue masses in such settings, especially in endemic areas. It also describes in great detail how these locations are affected by the hydatid disease. CONCLUSION: The mesorectal hydatid cyst was challenging to diagnose initially due to its infrequent incidence and uncommon location. In a few rare cases, the diagnosis of a hydatid cyst might be guided by the detection of the cyst membrane and daughter cysts in the germinal membrane.

La escisión total del mesorrecto transanal en el tratamiento del cáncer del recto como nueva técnica en Cuba / Total Excision of the Transanal Mesorectum as a New Technique for Treating Rectal Cancer in Cuba

Introducción: Las indicaciones de la Microcirugía Transanal Endoscópica han evolucionado desde la cirugía de tumoraciones rectales hasta otras enfermedades pélvicas. La asociación de esta y la escisión total del mesorrecto transanal ofrece una serie de ventajas. Objetivo: Determinar las indicaciones, describir la técnica quirúrgica y mostrar los resultados a largo plazo obtenidos en la realización de la escisión total del mesorrecto transanal en el tratamiento del cáncer del recto medio y bajo. Métodos: Se realizó un estudio observacional descriptivo y prospectivo de los pacientes con cáncer del recto medio y bajo sometidos a esta técnica quirúrgica en el período comprendido entre febrero de 2017 y febrero de 2022 en el Centro Nacional de Cirugía de Mínimo Acceso. Resultados: Se operaron 13 pacientes, 9 con cáncer del recto bajo y 4 con cáncer del recto medio y un promedio de edad de 56,2 años (rango 28-76). El promedio de tiempo quirúrgico fue de 183 minutos (rango 120-270) y las pérdidas hemáticas estimadas de 68 mililitros. La incidencia de morbilidad mayor fue de 15,4 por ciento y la media de estadía hospitalaria de 5,4 días. La media del período de seguimiento fue de 35 (rango 9-69) meses con una recidiva local de 7,7 por ciento y una supervivencia global a los 5 años de 100 por ciento. Conclusiones: La escisión total del mesorrecto transanal combinado con cirugía laparoscópica es una técnica factible y segura. La introducción de la variante técnica utilizando el instrumental de la Microcirugía Transanal Endoscópica es más ergonómica y disminuye los costos(AU)

Introduction: The indications for transanal endoscopic microsurgery have evolved from surgery of rectal tumors to other pelvic diseases. The association between this and total excision of the transanal mesorectum offers a series of advantages. Objective: To determine the indications, to describe the surgical technique and to show the long-term outcomes obtained in the performance of total excision of the transanal mesorectum for treating cancer of the middle and lower rectum. Methods: A descriptive and prospective observational study was carried out of patients with cancer of the middle and lower rectum who underwent this surgical technique in the period from February 2017 to February 2022 at Centro Nacional de Cirugía de Mínimo Acceso. Results: Thirteen patients were operated on, 9 with cancer of the lower rectum and 4 with cancer of the middle rectum, as well as an average age of 56.2 years (range 28-76). The average surgical time was 183 minutes (range 120-270) and estimated blood loss was 68 milliliters. The incidence of highest morbidity was 15.4 percent and mean hospital stay was 5.4 days. The median follow-up period was 35 (range 9-69) months, with a local recurrence of 7.7 percent and an overall 5-year survival of 100 percent . Conclusions: Total excision of the transanal mesorectum combined with laparoscopic surgery is a feasible and safe technique. The introduction of the variant technique using the instruments of endoscopic transanal microsurgery is more ergonomic and reduces costs(AU)

Radiomics from Mesorectal Blood Vessels and Lymph Nodes: A Novel Prognostic Predictor for Rectal Cancer with Neoadjuvant Therapy.

The objective of our study is to investigate the predictive value of various combinations of radiomic features from intratumoral and different peritumoral regions of interest (ROIs) for achieving a good pathological response (pGR) following neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC). This retrospective study was conducted using data from LARC patients who underwent nCRT between 2013 and 2021. Patients were divided into training and validation cohorts at a ratio of 4:1. Intratumoral ROIs (ROIITU) were segmented on T2-weighted imaging, while peritumoral ROIs were segmented using two methods: ROIPTU_2mm, ROIPTU_4mm, and ROIPTU_6mm, obtained by dilating the boundary of ROIITU by 2 mm, 4 mm, and 6 mm, respectively; and ROIMR_F and ROIMR_BVLN, obtained by separating the fat and blood vessels + lymph nodes in the mesorectum. After feature extraction and selection, 12 logistic regression models were established using radiomics features derived from different ROIs or ROI combinations, and five-fold cross-validation was performed. The average area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the models. The study included 209 patients, consisting of 118 pGR and 91 non-pGR patients. The model that integrated ROIITU and ROIMR_BVLN features demonstrated the highest predictive ability, with an AUC (95% confidence interval) of 0.936 (0.904-0.972) in the training cohort and 0.859 (0.745-0.974) in the validation cohort. This model outperformed models that utilized ROIITU alone (AUC = 0.779), ROIMR_BVLN alone (AUC = 0.758), and other models. The radscore derived from the optimal model can predict the treatment response and prognosis after nCRT. Our findings validated that the integration of intratumoral and peritumoral radiomic features, especially those associated with mesorectal blood vessels and lymph nodes, serves as a potent predictor of pGR to nCRT in patients with LARC. Pending further corroboration in future research, these insights could provide novel imaging markers for refining therapeutic strategies.

Laparoscopic Observation of Adhesive Rectal Fixation after Gant-Miwa-Thiersch Procedure for Rectal Prolapse: A Case Report.

In our previous report, we have noted an increase of computed tomography (CT) attenuation values in perirectal fat tissue after Gant-Miwa-Thiersch (GMT) procedure for rectal prolapse. Based on these results, we hypothesized that the GMT procedure may have a rectal fixation effect due to inflammatory adhesions extending to the mesorectum. Herein, we report a case of laparoscopic observation of perirectal inflammation after GMT. A 79-year-old woman with a history of seizures, stroke, subarachnoid hemorrhage, and spondylosis underwent the GMT procedure under general anesthesia in the lithotomy position for rectal prolapse measuring 10 cm in length. But rectal prolapse recurred 3 weeks after surgery. Therefore, an additional Thiersch procedure was performed. However, rectal prolapse still recurred, and laparoscopic suture rectopexy was performed 17 weeks after initial surgery. During rectal mobilization, marked edema and rough membranous adhesions were observed in the retrorectal space. The average CT attenuation value obtained 13 weeks after initial surgery was found to be significantly elevated in the mesorectum compared with the subcutaneous fat, especially in the posterior side (P < 0.05). These findings suggest that the extension of inflammation to the rectal mesentery after the GMT procedure may have strengthened adhesions in the retrorectal space.

Predictors for selective flexure mobilization during robotic anterior resection for rectal cancer: a prospective cohort analysis.

INTRODUCTION: Splenic flexure mobilization (SFM) may be indicated during anterior resection to provide a tension-free anastomosis. However, to date, no score allows identifying patients who may benefit from SFM. METHODS: Patients who underwent robotic anterior resection for rectal cancer were identified from a prospective register. Demographic and cancer-related variables were extracted, and predictors of SFM were identified using regression models. Thereafter, 20 patients with SFM and 20 patients without SFM were randomly selected and their pre-operative CTscan were reviewed. The radiological index was defined as 1/(sigmoid length/pelvis depth). The optimal cut-off value for predicting SFM was identified using ROC curve analysis. RESULTS: Five hundred and twenty-four patients were included. SFM was performed in 121 patients (27.8%) and increased operative time by 21.8 min (95% CI: 11.3 to 32.4, p < 0.001). The incidence of postoperative complications did not differ between patient with or without SFM. Realization of an anastomosis was the main predictor for SFM (OR: 42.4, 95% CI: 5.8 to 308.5, p < 0.001). In patients with colorectal anastomosis, both sigmoid length (15 ± 5.1 cm versus 24.2 ± 80.9 cm, p < 0.001) and radiological index (1 ± 0.3 versus 0.6 ± 0.2, p < 0.001) differed between patients who had SFM and patients who did not. ROC curve analysis of the radiological index indicated an optimal cut-off value of 0.8 (sensitivity: 75%, specificity: 90%). CONCLUSION: SFM was performed in 27.8% of patients who underwent robotic anterior resection, and increased operative time by 21.8 min. For optimal surgical planning, patients requiring SFM can be identified based on pre-operative CT using the index 1/(sigmoid length/pelvis depth) with a cut-off value set at 0.8.

Supine bottom-up extralevator abdominoperineal excision for anorectal adenocarcinoma is not inferior to standard approach and may be thus safely performed.

BACKGROUND: Extralevator abdominoperineal excision (APE) for rectal carcinoma has been described in order to improve pathological and oncological results compared to standard APE. To obtain the same oncological advantages as extralevator APE, we have previously described a new procedure starting by a perineal approach: the supine bottom-up APE. Our objective is to compare oncological and surgical outcomes between the supine bottom-up APE and the standard APE. METHODS: All patients with low rectal adenocarcinoma requiring APE were retrospectively included and divided into 2 groups: supine bottom-up APE (Group A) and standard APE (Group B). RESULTS: From 2008 to 2016, 61 patients were divided into Groups A (n = 30) and B (n = 31). Postoperative outcomes and median length of stay were similar between groups. Patients from Group A had a significantly longer distal margin (30 [8-120] vs. 20 [1.5-60] mm, p = 0.04) and higher number of harvested lymph nodes (14.5 [0-33] vs. 11 [5-25], p = 0.03) than those from Group B. Circumferential resection margin involvement was similar between groups (28 vs. 22%, p = 0.6), whereas tumors from Group A were significantly larger and more frequently classified as T4 than those from Group B. Operative time was significantly shorter in Group A (437.5 [285-655] minutes) than in Group B (537.5 [361-721] minutes, p = 0.0009). At the end of follow-up, local recurrence occurred in 7 and 16% of patients from Groups A and B (p = 0.68). Three-year overall and disease-free survival rates were similar between groups (87 vs. 90%, p = 0.62 and 61 vs. 63%, p = 0.88, respectively). CONCLUSION: Our findings suggest that supine bottom-up APE doesn't impair surgical outcomes, pathological results, overall and disease-free survivals in comparison with standard APE. This new procedure may be thus safely performed and decrease the operative time. Further randomized multicentric studies are required to confirm these results.

Prognosis of Mesorectal Tumor Deposits in Patients with Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision.

BACKGROUND: Tumor deposits (TDs) are associated with adverse prognostic factors and decreased survival in colon cancer. However, there is no information of their survival impact in rectal cancer with neoadjuvant chemoradiotherapy (n-CRT). METHODS: Retrospective study in 223 patients with rectal cancer with n-CRT. A survival analysis of factors associated with decreased overall survival (OS) including TDs was performed. RESULTS: From 223 patients, 131 (58.7%) were men, mean age 59.8 (± 13.06) years, and 42 (18.8%) of them revealed TDs. Survival analysis of TDs showed no association with mortality. Factors associated with decreased 5-year OS were the histologic grade (p = 0.42), perineural invasion (p = 0.001), and mesorectal quality (p = 0.067). Perineural invasion (HR = 2.335, 95% CI = 1.198-4.552) remained as independent factor in the multivariate analysis. CONCLUSIONS: TDs were not associated with mortality in rectal cancer patients treated with n-CRT. Factors associated with decreased survival were inadequate mesorectal quality and perineural invasion.

Efficacy of transperineal minimally invasive surgery with laparoscopic abdominoperineal excision for lower rectal cancer.

PURPOSE: In abdominoperineal excision (APE), the advantages of the "down-to-up" approach are expected to be more obvious when performed as a two-team approach, including transperineal minimally invasive surgery (TpMIS). We investigated the efficacy of TpMIS with laparoscopic APE for lower rectal cancer. METHODS: Patients who underwent laparoscopic APE with (n = 20) or without (n = 30) TpMIS between December 2013 and April 2020 were retrospectively reviewed. Patient and tumor characteristics, intraoperative outcome, short-term outcome, and pathological findings were compared. Additional subgroup analyses were performed in technically challenging cases, including male patients, obese patients, and patients with tumors located at the anterior wall. RESULTS: There was no marked difference in the patient or tumor characteristics or short-term outcomes, including morbidity and mortality between the two groups. Pathological results were comparable, and the circumferential resection margin (CRM) positive rate was 10% in both groups. TpMIS achieved a significant reduction in operative time (p = 0.02). In a subgroup analysis, the amount of blood loss was also smaller in males (p = 0.02) and patients with a high BMI (> 25) (p = 0.005) than in others. CONCLUSION: Simultaneously performing TpMIS and laparoscopic APE is feasible owing to the favorable complication and CRM-positive rates. In terms of operative time and blood loss, TpMIS is expected to be advantageous in both easy and challenging cases.

Long-term outcomes after close rectal dissection and total mesorectal excision in ileal pouch-anal anastomosis for ulcerative colitis.

BACKGROUND: During ileal pouch-anal anastomosis (IPAA) surgery for ulcerative colitis (UC), rectal dissection can be performed via close rectal dissection (CRD) or in a total mesorectal excision plane (TME). Although CRD should protect autonomic nerve function, this technique may be more challenging than TME. The aim of this study was to compare long-term outcomes of patients undergoing CRD and TME. METHODS: This single-centre retrospective cohort study included consecutive patients who underwent IPAA surgery for UC between January 2002 and October 2017. Primary outcomes were chronic pouch failure (PF) among patients who underwent CRD and TME and the association between CRD and developing chronic PF. Chronic PF was defined as a pouch-related complication occurring ≥ 3 months after primary IPAA surgery requiring redo pouch surgery, pouch excision or permanent defunctioning ileostomy. Secondary outcomes were risk factors and causes for chronic PF. Pouch function and quality of life were assessed via the Pouch dysfunction score and Cleveland global quality of life score. RESULTS: Out of 289 patients (155 males, median age 37 years [interquartile range 26.5-45.5 years]), 128 underwent CRD. There was a shorter median postoperative follow-up for CRD patients than for TME patients (3.7 vs 10.9 years, p < 0.01). Chronic PF occurred in 6 (4.7%) CRD patients and 20 (12.4%) TME patients. The failure-free pouch survival rate 3 years after IPAA surgery was comparable among CRD and TME patients (96.1% vs. 93.5%, p = 0.5). CRD was a no predictor for developing chronic PF on univariate analyses (HR 0.7 CI-95 0.3-2.0, p = 0.54). A lower proportion of CRD patients developed chronic PF due to a septic cause (1% vs 6%, p = 0.03). CONCLUSIONS: Although differences in chronic PF among CRD and TME patients were not observed, a trend toward TME patients developing chronic pelvic sepsis was detected. Surgeons may consider performing CRD during IPAA surgery for UC.

Quantitative assessment of the microstructure of the mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighed magnetic resonance imaging.

BACKGROUND: The mesorectum surrounding the rectum provides an ideal substrate for tumour spread. However, preoperative risk assessment is still an issue. This study aimed to investigate the microstructural features of mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI). METHODS: Patients with pathologically proven rectal adenocarcinoma underwent routine high-resolution rectal magnetic resonance imaging (MRI) and IVIM DWI sequences were acquired. The MRI-detected circumferential resection margin (mrCRM) and extramural vascular invasion (mrEMVI) were evaluated. IVIM parameters of the mesorectum adjacent to (MAT) and distant from (MDT) the tumour were measured and compared between and within the prognostic factor groups. RESULTS: The positive mrCRM (pMAT < 0.001; pMDT = 0.013) and mrEMVI (pMAT = 0.001; pMDT < 0.001) groups demonstrated higher D values in the MAT and MDT than the corresponding negative groups. Conversely, the positive mrCRM (p = 0.001) and mrEMVI (p < 0.001) groups both demonstrated lower f values in the MAT. Similarly, in the self-comparison between the MAT and MDT in the above subgroups, D showed a significant difference in all subgroups (p < 0.001 for all), and f showed a significant difference in the positive mrCRM (p = 0.001) and mrEMVI (p = 0.002) groups. Moreover, the MAT displayed a higher D* in the positive mrCRM (p = 0.014), negative mrCRM (p = 0.009) and negative mrEMVI groups (p < 0.001). CONCLUSION: The microstructure of the mesorectum in patients with rectal cancer with poor prognostic status shows changes based on IVIM parameters. IVIM parameters might be promising imaging biomarkers for risk assessment of tumour spread in mesorectum preoperatively.

The distribution of the inferior hypogastric plexus in female pelvis.

Elements that comprise the inferior hypogastric plexus are difficult to expose, intricate, and highly variable and can easily be damaged during local surgical procedures. We aimed to highlight, through dissection, the origin, formation, and distribution of the hypogastric nervous structures and follow them in the female pelvis. We performed detailed dissections on 7 female formalin-fixed cadavers, focusing on structures surrounding the pelvic organs. For each hemipelvis, we removed the peritoneum from the pelvic floor, and after we identified the hypogastric nerves, we continued our dissection towards the inferior hypogastric plexuses, following the branches of the latter. Laterorectally, the hypogastric nerves form the inferior hypogastric plexus, a variable structure - nervous lamina, neuronal network (more frequently), or sometimes a combination of them. We identified three components of the inferior hypogastric plexus. The anterior bundle travels towards the base of the urinary bladder, the middle part innervates the uterus and the vagina, and the posterior segment provides the innervation of the rectum. The plexus can be identified after removing the pelvic peritoneum and the subperitoneal adipose tissue. Intraoperatively, the structures can be preserved by using an immediately-subperitoneal dissection plane. The variable branches are relatively well-organized around the pelvic vessels, supplying the urinary bladder, the genital organs, and the rectum. The ureter is surrounded by some branches, especially in its last segment, and it also receives innervation directly from the hypogastric nerve. Close to the viscera, the nerves enter neurovascular plexuses, making the intraoperative separation of the nerves and the vessels virtually impossible.

Effect of the Gant-Miwa-Thiersch Procedure for Rectal Prolapse on the Mesorectum.

Rectal prolapse (RP) most commonly occurs among elderly women and is caused by vulnerable suspensory tissue in the pelvis. In Japan, the Gant-Miwa-Thiersch procedure (GMT) is recommended for elderly people with poor general health. We retrospectively analyzed clinical data from 12 patients who underwent GMT at our hospital from September 2005 to July 2021 and investigated the effect of GMT on the mesorectum using abdominal-pelvic computed tomography (CT) performed for other diseases. The median age of the cohort was 82 years, and 92% of the subjects were women. The median RP length was 5 cm, and the median follow-up period was 60 months. Recurrence was observed in 1 of 12 patients (8.0%). CT conducted before and more than 6 months after GMT revealed no abnormal findings in the mesorectum, whereas CT within 5 months after GMT revealed hyperdense fat in the mesorectum in all three patients (100%; P < 0.05). The RP recurrence rate after the GMT was low. The mechanism of the effect of GMT may involve not only a direct mucosal plicating effect but also adhesional rectosacral fixation due to the presence of inflammation extending to the mesorectum.

[A new insights of mesorectum].

Total mesorectal excision (TME) represents the gold standard for radical resection in rectal cancer. The development in radiology and laparoscopic surgical equipment and the advancement in technology have led to a deepened understanding of the mesorectum and its surrounding structures. Both the accuracy of preoperative staging and the preciseness of the planes of TME surgical dissection have been enhanced. The postoperative local recurrence rate is reduced and the long-term survival of rectal cancer patients is improved. The preservation of the pelvic autonomic nervous system maintains the patient's urinary and sexual functions to the greatest extent possible, which in turn improves the patient's postoperative quality of life. A thorough understanding of the anatomy of the mesorectum and its surrounding structures is a prerequisite for successful TME. Herein, we review the basic concepts and the anatomy of the mesorectum in the current literature. Some important clinical issues are also discussed systematically in terms of imaging, surgery, and pathology.

A mesorectal incidentaloma: Rare localization of Castleman disease (Case report).

Incidentalomas are defined as tumors or pseudo-tumoral masses accidentally discovered during clinical and imaging investigations. We present a 51-year-old female patient who presented at the gynecology service for genital bleeding caused by uterine fibromatosis. Computerized pelvic tomography showed an engorged uterus completely deformed by numerous intramural and submucosal nodular structures suggestive of multiple fibroids. Behind the uterus, a well-defined, iodophilic, 49/51 mm diameter, tissue-shaped, nodular mass was identified, with pushing borders into the adjacent fat and showing a mass effect on the rectum against which it retained a demarcation zone. A conclusion of the histopathological examination was made. Histopathological aspects and immunohistochemical tests supported the diagnosis of Castleman disease (CD) variant vascular hyaline variant. The mesorectum is a particularly and extremely rare localization for CD, and preoperative diagnosis is difficult to achieve. The correct surgical attitude in the case of an incidental finding in this localization is the extensive resection that satisfies the presumption of a neoplastic formation.