3D Observation of Pelvic Organs with Dynamic MRI Segmentation: A Bridge Toward Patient-Specific Models.

INTRODUCTION AND HYPOTHESIS: Female pelvic organ prolapses are common, but their treatment is challenging. Notably, diagnosis and understanding of these troubles remain incomplete. Tridimensional observations of displacement and deformation of the pelvic organs during a strain could support a better understanding and help to develop comprehensive tools for preoperative planning. METHODS: The present feasibility study evaluates tridimensional dynamic MRI in 12 healthy volunteers. Tridimensional acquisitions were approximated using five intersecting slices, each recorded twice per second. MRI was performed during rest and strain, with intrarectal and intravaginal contrast gel. Subject-specific dynamic 3D models were built for each volunteer through segmentation. RESULTS: For each volunteer, pelvic organs could be segmented in three dimensions with a rate of acquisition of two cycles per second on five slices, allowing for a fluid observation of displacements and deformations during strain. Manual segmentation of a full strain required 2 h and 33 min on average. The upper limit of the rectum and the pelvic floor were the most difficult structures to identify. This technique is limited by its time-consuming manual segmentation, which impedes its implantation for routine clinical use. This method must be tried in patients with pelvic organ prolapse. CONCLUSIONS: This multi-planar acquisition technique applied during a dynamic MRI allows for observation of displacement and deformations of pelvic organs during a strain.

Enhanced recovery after surgery (ERAS) for deep infiltrating endometriosis surgery: Experience of a French center.

OBJECTIVE: The objective of the study was to evaluate the implementation of an ERAS programme for deep pelvic endometriosis (DPE) surgery in terms of length of stay (LOS), postoperative complications (POC) and rehospitalisation rate. METHODS: This was a comparative retrospective monocentric study in the Gynaecologic Department of the La Conception Hospital in Marseille, France. We compared a 'conventional' group, with classic perioperative management corresponding to patients undergoing DPE surgery between April 8, 2014 and January 23, 2018, and an 'ERAS' group after setting up the ERAS protocol from February 6, 2018 to March 6, 2020. RESULTS: A total of 101 patients with DPE surgery were included, with 39 in the conventional group and 53 in the ERAS group. The LOS decreased by 1.91 days (p < 0.001). During the 45 postoperative days, no difference was found in rehospitalised rate (p = 1). The POC rate was 15/39 (38.5 %) in the conventional group and 12/53 (22.6 %) in the ERAS group (p = 0.1). CONCLUSION: The implementation of an ERAS programme for DPE surgery is an effective strategy because it can reduce the LOS without increasing the POC rate.

Is robotic ventral mesh rectopexy for pelvic floor disorders better than laparoscopic approach at the beginning of the experience? A retrospective single-center study.

PURPOSE: To compare perioperative results of laparoscopic and robotic ventral mesh rectopexy for pelvic floor disorders at the beginning of the surgical experience. METHODS: Between 2017 and 2022, the first 30 laparoscopic ventral mesh rectopexies and the first 30 robotic ventral mesh rectopexies at the beginning of the experience of 2 surgeons were retrospectively analyzed. Perioperative (demographic characteristics, surgical indication, conversion rate, operative time), and postoperative (complications, length of stay, unplanned reintervention) data were compared between groups. RESULTS: Demographic characteristics were similar between groups. Conversion rate was lower (0 vs 17%, p = 0.05), but the operative time was significantly longer (182 [146-290] vs 150 [75-240] minutes, p < 0.0001) during robotic procedure when compared with laparoscopic approach. In terms of learning curve, the number of procedures to obtain the same operative time between the 2 approaches was 15. Postoperative results were similar between groups, in terms of pain (visual analogic scale = 2 [0-8] vs 4 [0-9], p = 0.07), morbidity (17 vs 3%, p = 0.2), and unplanned reintervention (1 vs 0%, p = 0.99). Mean length of stay was significantly reduced after robotic approach when compared with laparoscopic approach (3 [2-10] vs 5 [2-11] days, p < 0.01). Functional results were better after robotic than laparoscopic ventral mesh rectopexy, with higher satisfaction rate (93 vs 75%, p = 0.05), and reduced recurrence rate (0 vs 14%, p = 0.048). CONCLUSION: Despite longer operative time at the beginning of the learning curve, robotic ventral mesh rectopexy was associated with similar or better perioperative results than laparoscopic ventral mesh rectopexy.

Morbidity of diverting stoma during colorectal surgery for deep infiltrating endometriosis - an observational study.

PURPOSE: To evaluate stoma-related complications after rectal resection and colorectal anastomosis with diverting stoma for deep infiltrating colorectal endometriosis. METHODS: All the consecutive adult women who underwent colorectal resection with low anastomosis and diverting stoma for deep infiltrating endometriosis in one center between 2013 and 2020 were retrospectively included. Stoma-related complications were retrieved during the stoma period and after stoma reversal. RESULTS: 33 patients (mean age = 32 years (±6, range=24-45 years) were included. After the first surgery, overall and surgical morbidities were observed in 42% and 30% of patients, including stoma-related complications in 3 patients (9%): high output (n = 2) and prolapse (n = 1). One patient presented with rectovaginal fistula, requiring several unplanned surgeries. No anastomotic leakage was observed. All the patients underwent stoma reversal, after mean delay of 3 months (±3, range=1-20 months). Overall morbidity after stoma closure occurred in 9 patients (27%), including 1 major morbidity (digestive bleeding). Long-term results were obtained after a mean follow-up of 21 months (±9, range=14-34 months). Four patients presented with hernia at the stoma site (12%). The cumulative rate of stoma-related complications was 45%. CONCLUSION: There is no consensus about the impact of diverting stoma after rectal resection with colorectal anastomosis for deep infiltrating colorectal endometriosis. Stoma-related complications are frequently observed but there are major in only 12% of patients. High risk patients of rectovaginal fistula and/or anastomotic leakage need to be identified to better indicate the diverting stoma, waiting for randomized trials evaluating the real impact of diverting stoma.

Enhanced recovery after posterior deep infiltrating endometriosis surgery: a national study.

OBJECTIVE: To evaluate the impact of the implementation of a national enhanced recovery after surgery (ERAS) program for posterior deep infiltrating endometriosis (DIE) surgery on the length of hospital stay, the rate of postoperative complications, and readmission within 30 days. DESIGN: Comparative exposed/nonexposed observational study. SETTING: Study based on the French national medicoeconomic database of the Program of Medicalization of Information System. PATIENTS: Seven hundred and sixty-four women who underwent DIE surgery were involved and matched (1:3 ratio) into two groups: ERAS group for the year 2019 and non-ERAS group for the year 2015. INTERVENTIONS: Surgical management for posterior DIE. MAIN OUTCOME MEASURES: The length of hospital stay, the rate of postoperative complications during the initial hospital stay, and readmission within 30 days. RESULTS: The ERAS group included 191 women, and the non-ERAS group included 573 women. The mean length of hospital stay was shorter in the ERAS group than in the non-ERAS group (4.28 ± 3.80 days vs. 5.42 ± 4.04 days, respectively). The rate of postoperative abdominal or pelvic pain syndromes was lower in the ERAS group than in the non-ERAS group (5/191 (2.62%) vs. 48/573 (8.38%), respectively; relative risk, 0.31 [0.125-0.7969]). The rate of postoperative complication and the rate of readmission within 30 days were not different between the two groups. CONCLUSIONS: The implementation of ERAS has a significant positive impact on patient outcomes after DIE surgery. The length of hospital stay and abdominal or pelvic pain syndromes were reduced without increasing complications or readmission within 30 days.

Half of Postoperative Deaths After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Could be Preventable: A French Root Cause Analysis on 5562 Patients.

OBJECTIVE: To perform a retrospective root-cause analysis of postoperative death after CRS and HIPEC procedures. BACKGROUND: The combination of CRS and HIPEC is an effective therapeutic strategy to treat peritoneal surface malignancies, however it is associated with significant postoperative mortality. METHODS: All patients treated with a combination of CRS and HIPEC between January 2009 and December 2018 in 22 French centers and died in the hospital, were retrospectively analyzed. Perioperative data of the 101 patients were collected by a local senior surgeon with a sole junior surgeon. Three independent experts investigated the typical root cause of death and provided conclusions on whether postoperative death was preventable (PREV group) or not (NON-PREV group). A typical root cause of preventable postoperative death was classified on a cause-and-effect diagram. RESULTS: Of the 5562 CRS+HIPEC procedures performed, 101 in-hospital deaths (1.8%) were identified, of which a total of 18 patients of 70 years old and above and 20 patients with ASA score of 3. Etiology of peritoneal disease was mainly colorectal. A total of 54 patients (53%) were classified in the PREV group and 47 patients (47%) in the NON-PREV group. The results of the study show that in the PREV group, WHO performance status 1-2 was more frequent and the Median Peritoneal Cancer Index was higher compared with those of the NON-PREV group. The cause of death in the PREV group was classified as: (i) preoperatively for debatable indication (59%), (ii) intraoperatively (30%) and (iii) postoperatively in 17 patients (31%). A multifactorial cause of death was found in 11 patients (20%). CONCLUSION: More than half of the postoperative deaths after combined CRS and HIPEC may be preventable, mainly by following guidelines regarding preoperative selection of the patients and adequate intraoperative decisions.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for resectable peritoneal metastases is feasible in elderly patients.

The aim is to evaluate the feasibility and the prognosis of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for resectable peritoneal metastases (RPM) in elderly patients. Patients who underwent CRS with HIPEC for RPM between 2012 and 2018 in one tertiary reference center were retrospectively included and divided according to the age: Group A (< 65 years) and Group B (≥ 65 years). Postoperative outcomes and survivals were compared. Ninety-five patients were included in Groups A (n = 65) and B (n = 30). The incidence of comorbidities was significantly higher in elderly patients (65 vs 90%, p = 0.01), but RPM characteristics were similar between groups. There was no difference between groups in terms of postoperative results: 30-day major morbidity (33 vs 23%, p = 0.4), 30-day mortality (0 vs 3%, p = 0.3), mean length of stay (26.7 ± 19.4 vs 22.4 ± 10.3 days, p = 0.3) and readmission's rate (15 vs 33%, p = 0.06). The only one significant difference was the 90-day mortality which never occurred before 65 years but in 10% of elderly patients (p = 0.03). There was no difference regarding recurrence's rate (56 vs 37%, p = 0.1), neither 1-, 3- and 5-year overall survival rates (86, 64 and 52% vs 85, 74% and not reached, p = 0.8) and disease-free survival rates (61, 28 and 28% vs 56, 45% and not reached, p = 0.6). CRS with HIPEC is feasible in elderly patients. Since the 90-day mortality appeared to be higher in elderly patients, additional criteria are necessary to improve the selection of elderly patients for this major surgery.

Second-look surgery plus hyperthermic intraperitoneal chemotherapy versus surveillance in patients at high risk of developing colorectal peritoneal metastases (PROPHYLOCHIP-PRODIGE 15): a randomised, phase 3 study.

BACKGROUND: Diagnosis and treatment of colorectal peritoneal metastases at an early stage, before the onset of signs, could improve patient survival. We aimed to compare the survival benefit of systematic second-look surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC), with surveillance, in patients at high risk of developing colorectal peritoneal metastases. METHODS: We did an open-label, randomised, phase 3 study in 23 hospitals in France. Eligible patients were aged 18-70 years and had a primary colorectal cancer with synchronous and localised colorectal peritoneal metastases removed during tumour resection, resected ovarian metastases, or a perforated tumour. Patients were randomly assigned (1:1) to surveillance or second-look surgery plus oxaliplatin-HIPEC (oxaliplatin 460 mg/m2, or oxaliplatin 300 mg/m2 plus irinotecan 200 mg/m2, plus intravenous fluorouracil 400 mg/m2), or mitomycin-HIPEC (mitomycin 35 mg/m2) alone in case of neuropathy, after 6 months of adjuvant systemic chemotherapy with no signs of disease recurrence. Randomisation was done via a web-based system, with stratification by treatment centre, nodal status, and risk factors for colorectal peritoneal metastases. Second-look surgery consisted of a complete exploration of the abdominal cavity via xyphopubic incision, and resection of all peritoneal implants if resectable. Surveillance after resection of colorectal cancer was done according to the French Guidelines. The primary outcome was 3-year disease-free survival, defined as the time from randomisation to peritoneal or distant disease recurrence, or death from any cause, whichever occurred first, analysed by intention to treat. Surgical complications were assessed in the second-look surgery group only. This study was registered at ClinicalTrials.gov, NCT01226394. FINDINGS: Between June 11, 2010, and March 31, 2015, 150 patients were recruited and randomly assigned to a treatment group (75 per group). After a median follow-up of 50·8 months (IQR 47·0-54·8), 3-year disease-free survival was 53% (95% CI 41-64) in the surveillance group versus 44% (33-56) in the second-look surgery group (hazard ratio 0·97, 95% CI 0·61-1·56). No treatment-related deaths were reported. 29 (41%) of 71 patients in the second-look surgery group had grade 3-4 complications. The most common grade 3-4 complications were intra-abdominal adverse events (haemorrhage, digestive leakage) in 12 (23%) of 71 patients and haematological adverse events in 13 (18%) of 71 patients. INTERPRETATION: Systematic second-look surgery plus oxaliplatin-HIPEC did not improve disease-free survival compared with standard surveillance. Currently, essential surveillance of patients at high risk of developing colorectal peritoneal metastases appears to be adequate and effective in terms of survival outcomes. FUNDING: French National Cancer Institute.

Cytoreductive Surgery With or Without Hyperthermic Intraperitoneal Chemotherapy for Gastric Cancer With Peritoneal Metastases (CYTO-CHIP study): A Propensity Score Analysis.

PURPOSE: Gastric cancer (GC) with peritoneal metastases (PMs) is a poor prognostic evolution. Cytoreductive surgery (CRS) yields promising results, but the impact of hyperthermic intraperitoneal chemotherapy (HIPEC) remains controversial. Here we aimed to compare outcomes between CRS-HIPEC versus CRS alone (CRSa) among patients with PMs from GC. PATIENTS AND METHODS: From prospective databases, we identified 277 patients with PMs from GC who were treated with complete CRS with curative intent (no residual nodules > 2.5 mm) at 19 French centers from 1989 to 2014. Of these patients, 180 underwent CRS-HIPEC and 97 CRSa. Tumor burden was assessed using the peritoneal cancer index. A Cox proportional hazards regression model with inverse probability of treatment weighting (IPTW) based on propensity score was used to assess the effect of HIPEC and account for confounding factors. RESULTS: After IPTW adjustment, the groups were similar, except that median peritoneal cancer index remained higher in the CRS-HIPEC group (6 v 2; P = .003). CRS-HIPEC improved overall survival (OS) in both crude and IPTW models. Upon IPTW analysis, in CRS-HIPEC and CRSa groups, median OS was 18.8 versus 12.1 months, 3- and 5-year OS rates were 26.21% and 19.87% versus 10.82% and 6.43% (adjusted hazard ratio, 0.60; 95% CI, 0.42 to 0.86; P = .005), and 3- and 5-year recurrence-free survival rates were 20.40% and 17.05% versus 5.87% and 3.76% (P = .001), respectively; the groups did not differ regarding 90-day mortality (7.4% v 10.1%, respectively; P = .820) or major complication rate (53.7% v 55.3%, respectively; P = .496). CONCLUSION: Compared with CRSa, CRS-HIPEC improved OS and recurrence-free survival, without additional morbidity or mortality. When complete CRS is possible, CRS-HIPEC may be considered a valuable therapy for strictly selected patients with limited PMs from GC.

Temporary successful results of ventral rectopexy for enterocele surgical correction, about 138 patients.

PURPOSE: This work aimed to analyse short- and long-term results of enterocele surgical treatment by ventral rectopexy. METHODS: All females who underwent ventral rectopexy for enterocele in our department were included. All patients underwent standardized preoperative evaluation. Data was retrospectively collected, after examination of patients or by telephone survey. Postoperative evaluation was performed by an independent observer. RESULTS: One hundred thirty-eight females (median age = 63 years [21-86 years]) were included. They were postmenopausal and multiparous in 94 and 70% of cases, respectively. Pelvic pressure, vaginal prolapse, or the both were observed in 28, 16 or 56% of the patients, respectively. The most frequent associated symptoms were dyschezia (63%) and faecal incontinence (30%). On preoperative workup, enterocele was isolated in two cases. Rectocele, internal rectal prolapse and cervicocystoptosis were the most frequently associated pelvic floor disorders. Ventral rectopexy was performed through laparoscopy in 128 patients (93%). In the short term, all pelvic symptoms were significantly improved, except urinary incontinence. At the end of follow-up (56 months [7-125]), specific symptoms and dyschezia were still significantly improved. Secondary failure was reported in 31% of patients. By multivariate analysis, two predictive factors for long-term failure were found: diagnosis of rectocele on preoperative MRI (odd ratio = 15; 95% CI 1.4-163; p = 0.03) and conversion into open surgery (odd ratio = 8; 95% CI 1.4-43; p = 0.02). CONCLUSION: This study suggests that ventral rectopexy is an effective treatment of enterocele, but secondary failure can be observed. Patients should be informed of the potential risk of long-term degradation.

Female patient-specific finite element modeling of pelvic organ prolapse (POP).

Pelvic organ prolapse (POP) occurs only in women and becomes more common as women age. However, the surgical practices remain poorly evaluated. The realization of a simulator of the dynamic behavior of the pelvic organs is then identified as a need. It allows the surgeon to estimate the functional impact of his actions before his implementation. In this work, the simulation will be based on a patient-specific approach in which each geometrical model will be carried out starting from magnetic resonance image (MRI) acquisition of pelvic organs of one patient. To determine the strain and stress in the soft biological tissues, hyperelastic constitutive laws are used in the context of finite element analysis. The Yeoh model has been implemented into an in-house finite element code FER to model these organ tissues taking into account large deformations with multiple contacts. The 2D and 3D models are considered in this preliminary study and the results show that our method can help to improve the understanding of different forms of POP.

Pelvic radiation disease management by hyperbaric oxygen therapy: prospective study of 44 patients.

Pelvic radiation disease (PRD) occurs in 2-11% of patients undergoing pelvic radiation for urologic and gynecologic malignancies. Hyperbaric oxygen therapy (HBOT) has previously been described as a noninvasive therapeutic option for the treatment of PRD. the purpose of study was to analyze prospectively the results of HBOT in 44 consecutive patients with PRD who were resistant to conventional oral or topical treatments. Material and Methods. The median age of the cohort was 65.7 years (39-85). Twenty-seven percent of patients required blood transfusion (n = 12). The median of delay between radiotherapy and HBOT was 26 months (3-175). We evaluated the results of HBOT, using SOMA-LENT Scale. Results. SOMA-LENT score was decreased in 59% of patient. The median of SOMA-LENT score before HBOT was significantly higher, being equal to 14 (0-36), than after HBOT with the SOMA-LENT score of 12 (0-38) (P = 0.003). Tenesmus (P = 0.02), bleeding (P = 0.0001), and ulceration (P = 0.001) significantly decreased after HBOT. Regarding patients with colostomy, 33% (n = 4) benefited from colostomies closure. HBOT was generally well tolerated. Only one patient stopped precociously due to transient myopia. Conclusion. This study is in favor of the interest of HBOT in pelvic radiation disease treatment (PRD).

Characteristics and natural history of patients with colorectal cancer complicated by infectious endocarditis. Case control study of 25 patients.

UNLABELLED: Association between streptococcal endocarditis and gastrointestinal disease has been well-documented in the literature. However oncological impact of this complicated presentation has not yet been reported. We have conducted to our knowledgethe first case-control study on this subject. PATIENTS AND METHODS: Two groups of five patients with colorectal cancer and either active endocarditis (CRC E+), or without endocarditis (CRC, n=20) were matched 1:4 for age, sex, and location of colorectal tumor. RESULTS: All 25 patients were male, with a median age of 63 (range: 53-85) years. Twenty (80%) had colon cancer and 5 (20%) rectal cancer. There was no post-operative mortality in this population. The overall morbidity was 28% (n=7). The overall 3-year survival and recurrence rates were similar in both groups 80% and 95%; 0% and 30% for group CRC E+ and CRC (p=0.4603). CONCLUSION: This is the first case-control study demonstrating that during the first two years of follow-up, occurrence of endocarditis did not alter the prognosis of patients with CRC.

Splenic sarcoidosis mimicking neoplastic disease.

Sarcoidosis is a multisystem granulomatous disease of unknown cause that commonly involves the spleen. Sarcoid can produce either homogeneous splenomegaly or multiple splenic nodules. Although other organ system involvement usually occurs, this is not invariable. Herein, we report on the clinical, histological, and radiological features-including sonography and MRI-of an isolated splenic sarcoidosis that mimicked neoplastic disease in a 37-year-old female. Knowledge of this atypical sonographic presentation may prevent unnecessary splenectomy.

Anatomical study of the infrapatellar branch of the saphenous nerve using ultrasonography.

INTRODUCTION: The purpose of this study was to determine whether ultrasonography allows precise assessment of the course and relations of the infrapatellar branch of the saphenous nerve. METHODS: This work, initially undertaken in 5 cadavers, was followed by high-resolution ultrasonographic study in 10 healthy volunteers. The location and relations of the infrapatellar branch of the saphenous nerve to the adjacent anatomical structures were analyzed. The course of the nerve was classified according to its relation to the sartorius muscle as posterior or penetrating. RESULTS: The infrapatellar branch of the saphenous nerve could be identified consistently along the majority of its course by ultrasonography. Useful landmarks for the detection of the nerve could be defined. Some anatomical variations were noted. CONCLUSIONS: The infrapatellar branch of the saphenous nerve can be depicted by ultrasonography. Precise mapping of its anatomical course may have significant clinical applications.

The femoral calcar: a computed tomography anatomical study.

The femoral calcar is a dense internal septum reaching from the femoral neck to the distal part of the lesser trochanter. Our study aimed at providing an exhaustive radio-anatomical description of this structure. One hundred pelvic computed tomography examinations were retrospectively selected to bilaterally evaluate the shape, dimensions, and density of the femoral calcar. Then, its relation to the femoral cavity was assessed by recording the dimensions of the medullary canal at the level of the greatest length of the spur. The femoral calcar exhibited a variable shape classified as ridge-type 17% (34/200), spur-type 66.5% (133/200), and septum-type 16.5% (33/200). Its mean dimensions were: height = 33.03 mm (20-46), length = 9.94 mm (5-16), and thickness = 2.71 mm (1-4). These dimensions were positively correlated to the height and weight of the individuals (P < 0.001) and were higher in males (P < 0.001). Its mean density was 788.5 Hounsfield units (530-1,200). The longest oblique and anteroposterior diameters of the femoral cavity were respectively 38.74 mm (28-51) and 22.04 mm (17-27). The femoral cavity dimensions were positively correlated to the height and weight of the individuals (P < 0.001), to the femoral calcar dimensions (P < 0.001) and were higher in males (P < 0.001). The femoral calcar was constantly identified as a vertical plate of compact bone exhibiting a consistent anatomical pattern, which suggests a significant mechanical function within the upper femur. Our results may lead to a greater understanding of the hip fracture patterns and to alternative designs for hip arthroplasties.

Rationale for possible targeting of histone deacetylase signaling in cancer diseases with a special reference to pancreatic cancer.

There is ongoing interest to identify signaling pathways and genes that play a key role in carcinogenesis and the development of resistance to antitumoral drugs. Given that histone deacetylases (HDACs) interact with various partners through complex molecular mechanims leading to the control of gene expression, they have captured the attention of a large number of researchers. As a family of transcriptional corepressors, they have emerged as important regulators of cell differentiation, cell cycle progression, and apoptosis. Several HDAC inhibitors (HDACis) have been shown to efficiently protect against the growth of tumor cells in vitro as well as in vivo. The pancreatic cancer which represents one of the most aggressive cancer still suffers from inefficient therapy. Recent data, although using in vitro tumor cell cultures and in vivo chimeric mouse model, have shown that some of the HDACi do express antipancreatic tumor activity. This provides hope that some of the HDACi could be potential efficient anti-pancreatic cancer drugs. The purpose of this review is to analyze some of the current data of HDACi as possible targets of drug development and to provide some insight into the current problems with pancreatic cancer and points of interest for further study of HDACi as potential molecules for pancreatic cancer adjuvant therapy.

A new lateral approach to the parasacral sciatic nerve block: an anatomical study.

BACKGROUND: Sciatic nerve block is a commonly used technique for providing anesthesia and analgesia to the lower extremity. At the parasacral level, the nerve block is classically performed via a posterior approach in lateral decubitus position causing patient's discomfort. Therefore, we aimed to conduct an anatomical study describing a new lateral approach to the parasacral sciatic nerve in supine position. METHODS: The skin entry point was located on the vertical line through the greater trochanter (GT) at the midpoint between the anterior superior iliac spine (ASIS) level and the GT. The angle to the skin was 10° dorsally oriented. According to these palpable anatomical landmarks, the parasacral lateral approach was simulated bilaterally in four cadavers in supine position. Anatomical dissection allowed assessment of the needle tip position with regard to the sciatic nerve. Then, to refine the anatomical description of this new lateral approach, 40 pelvic computer tomography (CT) examinations were retrospectively selected and post-processed to bilaterally simulate the needle route to the sciatic nerve. The skin-nerve distance, the optimal angle to the skin, and the sciatic nerve anteroposterior diameter at parasacral and ischial tuberosity levels, respectively were recorded by two independent readers. RESULTS: Cadaver dissection showed that the needle tip was placed in the vicinity of the sciatic nerve in 8/8 cases. Then, CT-simulated lateral approach demonstrated a mean skin-nerve distance of 128 mm (81-173), and a 12° dorsally oriented (5-22) optimal angle to the skin. The sciatic nerve anteroposterior diameter was 10 mm (7-15) at the parasacral level, and 7 mm (5-10) more caudally at the ischial tuberosity level. No significant intra- or inter-observer variability was observed. CONCLUSION: This study describes a new lateral approach to the parasacral sciatic nerve block in supine position. These anatomical results should be confirmed by further clinical studies.

Automatic estimation of pelvic organ anatomical references.

Pelvic floor diseases cover pathologies of which physiopathology is not well understood. 2D sagittal MRI sequences used in the clinical assessment allow to visualize the dynamic behavior of the main organs involved (bladder, uterus-vagina and rectum). Clinicians use anatomical landmarks and measurements related to the pelvic organs in their pathology assessment. Usually, those tasks are performed manually which results in being both tedious and subject to operator dependency. A methodology is proposed to attempt a quantitative and objective characterization of the organ behaviors under abdominal strain condition. This approach automatically assesses the organ movements, through the estimation of characteristic angles (anorectal angle, uterovaginal angle, bladder inclination), and the tracking of anatomically significant points (anorectal angle vertex, uterovaginal angle vertex, bladder neck). From a multi-subject analysis, pathological organs have been distinguished from healthy ones, which shows the relevance of the computed features. In addition, a stability analysis has shown the soundness of the approach.