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.

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.

Rectal Artery Embolization for Hemorrhoidal Disease: Anatomy, Evaluation, and Treatment Techniques.

Chronic hemorrhoidal disease is a common anorectal condition that leads to hemorrhoidal hyperplasia, which affects millions of people worldwide and is a significant medical and socioeconomic issue. Rectal bleeding is one of the main chronic symptoms. Recurrent rectal bleeding can alter an individual's quality of life and, more rarely, cause anemia. Pain is less common, occurring only in the event of complications such as congestive exacerbation, external hemorrhoidal thrombosis, or fissures. The most standard treatment involves dietary and hygiene measures, use of phlebotonic drugs, and nonsurgical treatment such as infrared photocoagulation or elastic band ligation. Excisional treatments such as hemorrhoidectomy and hemorrhoidopexy are the reference standards for treatment of hemorrhoidal disease. Embolization of the rectal arteries (ie, emborrhoid) has recently emerged as an effective treatment option, with few reported adverse effects, minimal blood loss, and a same-day hospital procedure. Hemorrhoid embolization is performed by using femoral or radial access. The inferior mesenteric artery and then the superior rectal arteries are catheterized with a microcatheter. Embolization can be performed by using different agents. Studies have shown improvement in symptoms and high technical success rates after treatment. The basic principles of hemorrhoid embolization that must be understood to achieve effective treatment, including those related to patient evaluation, the arterial anatomy, basic embolization, and published results, are reviewed. An invited commentary by Thompson and Kelley is available online. ©RSNA, 2022.

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.

Structure and Reactivity of Alloxan Monohydrate in the Liquid Phase.

Alloxan is an important toxic glucose analogue used to induce diabetes in lab test animals. Once regarded as a "problem structure," the condensed-phase structure of anhydrous alloxan has largely been settled, but literature inconsistencies remain for the structure of the typically employed reagent alloxan monohydrate. Due to the criticality of structure-function relationships, we have used 1H/13C{1H} NMR, IR spectroscopy, as well as quantum mechanical (QM) calculations to probe the liquid-phase structure and reactivity of alloxan monohydrate. In protic solvents (D2O and acetic acid-d4), hydration at the C5 carbonyl of alloxan monohydrate occurs quantitatively to form the C5 gem-diol (5,5'-dihydroxybarbituric acid). In the aprotic solvent dimethyl sulfoxide (DMSO)-d6, there exists a mixture of the C5 gem-diol and planar tetraketo form of alloxan monohydrate. QM calculations explain the solvent-dependent hydration reactivity, where a solvent-assisted H-atom transfer mechanism lowers the activation energy of water addition at the C5 carbonyl by ∼16 or 27 kcal/mol in water or acetic acid, respectively, compared to the unassisted hydration reaction. Prompt recrystallization of alloxan monohydrate from boiling water does not alter the structure of the reagent. These findings probe the exact structure of alloxan monohydrate to guide future research efforts in biological sciences and in organic synthesis.

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.

Investigating the Photochemistry of C7 and C8 Functionalized N(5)-Ethyl-flavinium Cation: A Computational Study.

Flavins are a diverse set of compounds with a wide variety of biological and nonbiological applications. Applications of flavins receiving attention recently consist of electro- and photocatalytic oxidation of substrates for organic synthesis, bioengineered nanotechnology, and water splitting catalysts, among others. While there is vast knowledge regarding the structure-property relationships of flavins and their electrochemistry, there is much less work elucidating the structure property relationships as they pertain to flavinium photochemistry. Herein, we report the effect of molecular tailoring on the molecular properties of N(5)-ethyl-flavinium cation (Et-Fl+), a derivative of the biocatalytic coenzyme riboflavin, by incorporating electron withdrawing and donating groups at the C7 and C8 position of the isoalloxazine ring. The presence of electron withdrawing groups at the C8 position caused a red shift in the absorption spectrum, while the electron donating groups caused a blue shift. Functionalization at the C7 position had the opposite effect on the absorption spectrum. The effects of single substitution were relatively negated with simultaneous functionalization at both the C8 and C7 positions. Difference density plots indicate no change in the nature of the S1 excited state, which was confirmed by optimization of the excited state geometries. The results presented in this study indicate that functionalization of the isoalloxazine unit affects the photophysical properties of N(5)-ethyl-flavinium cations.

Modulation of rumen pH by sodium bicarbonate and a blend of different sources of magnesium oxide in lactating dairy cows submitted to a concentrate challenge.

With the objective of evaluating the potential effects of sodium bicarbonate or a magnesium-based product on rumen pH and milk performance of dairy cattle exposed to a dietary challenge, 30 lactating Holstein cows (648 ± 67 kg of body weight; 44.4 ± 9.9 kg/d of milk yield; 155 ± 75 d in milk) were blocked by parity (9 primiparous and 21 multiparous) and randomly distributed to 3 treatment groups. One group received a total mixed ration (TMR) that acted as a control (CTR), a second group (SB) received the same TMR but with an additional supplementation of 0.8% of sodium bicarbonate, and a third group (MG) received the same TMR as CTR but an additional supplementation of 0.4% of a magnesium-based product (pHix-Up, Timab, Dinard, France). After 1 wk of exposure to this TMR, all 3 rations were supplemented with 1 kg/d of barley, which was then increased 1 kg/wk until reaching 3 kg/d of barley during wk 4 of the study. Every kilogram of barley replaced 1 kg of forage in the diet. Individual feed intake and behavior were monitored using electronic feed bins. Seven cows per treatment were equipped with an intraruminal bolus that recorded pH every 15 min. As the severity of the barley challenge increased, dry matter intake decreased, but this decrease was more pronounced in SB cows than in MG cows, with an intermediate response for CTR cows. The MG cows produced more milk when challenged with 2 or 3 kg/d of additional barley than when challenged with 1 kg/d, whereas CTR cows produced less milk with the 3 kg/d challenge compared with 1 or 2 kg/d, and the SB cows maintained milk production. Milk fat content decreased with barley challenges, with CTR cows experiencing a more severe decrease than SB cows, which maintained stable butterfat values throughout the study, and MG cows showed a decline in milk fat content only with the 3 kg/d of additional barley. Meal size was also reduced as the severity of barley challenge increased, and this reduction was more modest in MG cows than in SB cows. The number of daily meals consumed by SB and MG cows was more constant than that recorded in CTR cows. Cows on the CTR and SB treatments showed a marked decrease in rumen pH with the 3 kg/d of additional barley, whereas MG cows maintained stable rumen pH during the barley challenges and had greater average rumen pH (5.93 ± 0.04) than CTR cows (5.83 ± 0.04) with the 3 kg/d of additional barley; SB cows showed intermediate values (5.85 ± 0.04). Last, MG cows spent less time (32.3 ± 6.1%) with rumen pH ≤5.8 when exposed to the 3 kg/d of barley challenge than CTR and SB cows (50.7 ± 5.02%). In conclusion, supplementation with MG prevents the decline in dry matter intake and milk production induced by a rumen challenge, whereas supplementation with SB prevents the decay in milk production but does not prevent the decrease in feed intake. These changes were probably due to the ability of the MG treatment to prevent a reduction in rumen pH when challenging cows with 3 kg/d of additional barley in the ration.

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.

Laparoscopic resection of retrorectal tumors: a feasibility study in 12 consecutive patients.

BACKGROUND: Surgical approaches for retrorectal tumors (RRT) are either abdominal, dorsal trans-sacrococcygeal, or perineal. Very few cases have been reported so far concerning a laparoscopic approach. The aim of this study was to assess the results of laparoscopy for the treatment of RRT. METHODS: All patients who underwent laparoscopy for RRT between 2003 and 2012 were reviewed. Data included patient and tumor characteristics, surgical morbidity, and mortality. RESULTS: A total of 12 consecutive women with a median age of 55 years underwent laparoscopy for RRT. Median operative time was 145 min (range 70-215). Two conversions in laparotomy occurred, and one patient needed a temporary diverting ileostomy for rectal injury. Postoperatively, two patients presented urinary tract infections. Median length of stay was 8 days (range 4-16). Pathological examinations showed complete resections (R0) for ten benign tumors and one malignant tumor (Ewing sarcoma). One lesion was incompletely resected, a colloid sarcoma (R1 status), and was re-operated on by laparotomy after neoadjuvant chemoradiation. No local recurrence was observed after a median follow-up of 34 months (range 12-79) for benign lesions, and 28 and 71 months for the two patients who underwent resection of Ewing and colloid sarcoma, respectively. CONCLUSIONS: Laparoscopic resection for RRT seems feasible and safe. It allows complete excision of tumors located in the retrorectal space with low morbidity. Thus, this approach can be a valid alternative to standard Kraske or open abdominal approaches for the treatment of RRT.

Influence of larger graft weight to recipient weight on the post-liver transplantation course.

Size matching between recipient and donor livers is an important factor in organ allocation in the context of liver transplantation (LT). The aim of this study was to determine whether a large graft for recipient size influenced the post-transplant course. One hundred and sixty-two successive LT recipients were included and retrospectively divided into two groups: 25 (15%) had a graft-to-recipient weight ratio (GWRW) ≥ 2.5% and 137 (85%) had a GWRW <2.5%. Postoperative complications and outcomes were recorded. In the GWRW >2.5% group, more end-to-end caval replacement (72% vs. 38%, p = 0.003) and veno-venous bypass (48% vs. 23%, p = 0.01) were used. Peak AST/ALT values were higher in the GWRW >2.5% group (AST: 596 [70-5876] vs. 453 [29-5132] IU/l, p = 0.03; ALT: 773 [101-5025] vs. 383 [36-4921] IU/l, p = 0.02). Among postoperative complications, the rate of respiratory failure was higher in the GWRW >2.5% group (32% vs. 14%, p = 0.04). The rates of other complications did not differ between the two groups. Both groups had similar graft and patient survival rates at one yr. Using large grafts for recipient size did not impair liver function and did not modify graft and patient outcomes at one yr. However, a GWRW >2.5% appeared to be a determining factor for respiratory morbidity following LT.