Pelvic Anatomy Research Articles

ASO Author Reflections: It Does Not Matter Whether Radical Prostatectomy is Performed in High-Risk Localized Disease or at the Oligometastatic Stage.

Radical prostatectomy (RP) alone has traditionally been considered insufficient for patients with high-risk localized prostate cancer (HRPC) owing to the frequent need for adjuvant salvage radiotherapy or androgen deprivation therapy (ADT) following surgery. Previously, systemic therapy, such as ADT, was the standard treatment for metastatic prostate cancer (PC) patients; RP was not considered viable for these patients. However, since 2015, there has been a recognition that metastatic PC patients can be categorized based on the extent of their metastases, leading to the consideration of RP for some metastatic cases. In recent years, the concept of cytoreductive RP has gained traction; studies suggest that it may improve survival rates in metastatic PC patients through mechanisms, such as tumor debulking and enhancement of the immune response. A meta-analysis of retrospective studies has shown that cytoreductive RP is associated with higher cancer-specific survival rates at 1-year, 3-year, and 5-year intervals compared with systemic therapy alone. In our study, which followed HRPC and oligometastatic PC patients for an average of 46 months, we observed biochemical recurrence in 17.8% of HRPC and 13% of oligometastatic patients, with overall survival rates of 96.4% and 87%, respectively. Although prospective or randomized studies are still lacking, current retrospective studies, including our own, suggest promising outcomes for RP in HRPC and oligometastatic patients. With the increasing prevalence of robotic surgery, improved pelvic anatomy observation, and growing surgical confidence, the realization of prospective randomized study results may not be far off.

Transanal total mesorectal excision: Understanding indications, managing complications, and effective prevention methods

AbstractTransanal total mesorectal excision (TaTME) has emerged as a surgical method for treating rectal malignancies in the middle and lower third of the rectum over the past 15 years. This approach was adopted because of the challenges encountered in secure total mesorectal excision (TME). Patient selection criteria and the rationale for TaTME have evolved, leading to improved oncological outcomes and patient quality of life. The procedure includes inserting a unique platform through the anus, forming a purse‐string closure, and endoscopically sealing the lower rectum. The mesorectum is then removed laparoscopically following a ‘down‐to‐up’ approach, finalised with a transabdominal laparoscopic phase and anastomosis. Pelvic anatomy complexity poses challenges, including potential injuries to the urinary tract, surgical site leakage, sinus damage, sagittal vein harm, nerve injury, carbon dioxide embolism, bowel function disturbance, sphincter mechanism issues, and rectal abscess formation. Proficient anatomy knowledge, precise surgical techniques, and advanced technologies contribute to their prevention. In conclusion, TaTME offers a promising approach to rectal surgery with satisfactory oncological outcomes. However, vigilance is required to eliminate potential complications.

Pelvic Floor Muscle Anatomy and its Contribution to Penile Erection in Olive Baboons.

Despite the number of studies on the contribution of pelvic floor muscles (PFM) to the penile erection process, their significance is still underestimated. The goal of this study was to investigate the role of PFM in the erection process in non-human primates. First, we performed an anatomical study of the penile structures in 12 baboon cadavers. Next, we created chronic electrophysiological models of normal erectile function in 25 olive baboons. We implanted electrodes on the cavernous nerves to control penile blood filling and placed other electrodes on the pudendal nerve to stimulate the ischiocavernosus muscles (ICM) contractions after sufficient blood filling, thus simulating both vascular and muscular phases of penile erection. We controlled the intracavernous pressure (ICP) during nerve stimulations and further performed a mathematical analysis of the collected data. We described the main pro-erectile muscle anatomy and its relationship with penile structures in monkeys. During neurostimulation studies, we showed the key role of ICM in achieving full penile rigidity with suprasystolic ICP up to 120-300 mm Hg. We also developed a math model for calculating the pro-erectile muscle's contraction force with high accuracy. In this study, we demonstrated the crucial role of PFM in the penile erection process using the monkey model, supporting the previous studies' data. We consider these results essential for a better, more complex understanding of the penile erection process and the participating structures in each stage. This is essential for further improving and designing novel erectile dysfunction diagnostics and treatment techniques.

Toward painless road-cycling for women: Innovative pressure distribution through lattice-based seat pads

Potential health risks for male athletes in professional road cycling are numerously investigated. For female athletes, necessary information is missing and thus there is a lack of equipment meeting their specific needs. The different pelvic anatomy of women compared to men suggests different saddle designs, different cycling short pads, and even different types of material to avoid pain and health problems. To collect data for a systematic development of pads specifically for women, we performed a study with 29 ambitious female athletes, who road cycle long distances (>90 min) at least once a week. First, we documented each athlete’s recent cycling situation, including the perceived comfort, grievances and the equipment used. Second, molds of the pelvis-saddle interfaces were generated using a previously developed measurement saddle to analyze pressure distributions during both static and dynamic loading. Measures were taken using the idmatch system following a bike fitting, which suggested a bicycle setup incorporating, among other factors, the individual athlete’s anthropometric data. Molds were subsequently digitized with a calibrated 3D scanner. Third, the digital pressure data resulting from the molds was analyzed considering its ability to represent interindividual differences, which validated the developed measurement saddle. Finally, a novel lattice-based pad prototype was designed based on the measured pressure data. Finite element analyses (FEA) were carried out to observe mechanical loads in the lattice structure and enable an optimization of the design. The prototype was additively manufactured using stereolithography (SLA).

Radiographically Apparent Acetabular Sourcil Landmarks Are Created by Comparable Regions of the Pelvis With Extraarticular Bone Variably Confounding Estimates of Joint Coverage.

The severity of hip dysplasia is characterized by radiographic measurements that require user definition of the acetabular sourcil edge, a bony landmark for which the corresponding three-dimensional (3D) anatomy is not well defined in any imaging plane. To use digitally reconstructed radiographs to determine: (1) What 3D anatomy is contributing to the "acetabular sourcil" location used to make lateral center-edge angle (LCEA) and anterior center-edge angle (ACEA) measurements in standing AP and false-profile radiographic views, respectively? (2) How do intraobserver and interobserver agreement in LCEA and ACEA translate into agreement of the 3D anatomy being evaluated? (3) How distinct are regions around the acetabular rim circumference that are evaluated by LCEA and ACEA measurements on radiographs? Between January 2018 and May 2019, 72 patients were indicated for periacetabular osteotomy to treat hip dysplasia or acetabular retroversion at our institution. From these patients, a series of 10 patients were identified of the first 12 patients in 2018 who were treated with periacetabular osteotomy, excluding two with missing or low-quality clinical imaging. A second series of 10 patients was identified of the first 11 patients in 2019 who were treated with periacetabular osteotomy and concurrent hip arthroscopy, excluding one who was missing clinical imaging. Pelvis and femoral bone surface models were generated from CT scans of these two series of 10 patients. There were 15 female and five male patients, with a median patient age of 18 years (IQR 17 to 23 years), a preoperative LCEA of 22° (IQR 18° to 24°), and a preoperative ACEA of 23° (IQR 18° to 27°). Exclusion criteria included missing preoperative CT or standard clinical radiographic imaging or severe joint incongruity. To address our first study question, digitally reconstructed radiographs matching each patient's standing AP and false-profile clinical radiographs were created from the segmented CT volumes. A board-certified orthopaedic surgeon and three trained researchers measured LCEA and ACEA on the digitally reconstructed radiographs, and the selected sourcil points were projected back into coordinates in the 3D anatomic space. To address our second study question, intraobserver and interobserver agreement in radiographic coverage angles were related to variations in 3D coordinates of the selected bony anatomy. Lastly, to address our third study question, 3D locations around the acetabular rim identified as contributing to the lateral and anterior sourcil points were summarized across patients in a clockface coordinate system, and statistical analysis of the "time" separating the 3D acetabular contributions of the sourcil edges was performed. The 3D anatomy contributing to the lateral sourcil was a variable length (27 mm [IQR 15 to 34 mm]) span of the laterosuperior acetabular edges, with contributions by the anterior inferior iliac spine in 35% (7 of 20) of hips. The anterior sourcil reflected a 28-mm (IQR 25 to 31 mm) span of bone from the medial ilium (posterior-medial to the anterior-inferior iliac spine and anterior-lateral to the arcuate line) to the anterior and lateral edges of the acetabulum. Interobserver variability was good for LCEA (intraclass correlation coefficient [ICC] 0.82 to 0.83) and moderate to good for ACEA (ICC 0.73 to 0.79), whereas the agreement in identified 3D sourcil locations varied widely (ICC 0.32 to 0.95). The acetabular edge of the 3D anatomy contributing to the anterior sourcil overlapped the circumferential range of the acetabular rim contributing to the lateral sourcil. Projection of two-dimensional radiographic landmarks contributing to the diagnosis of structural hip deformity into 3D allowed for the identification of the overlapping bony anatomy contributing to radiographically visible anterior and lateral sourcil edges. This work leveraging digitally reconstructed radiographs and 3D pelvis anatomy has found that bone outside the joint contributes to the radiographic appearance of the sourcil and may variably confound estimates of joint coverage. Furthermore, the substantial overlap between the acetabular bone contributing to measurement of the LCEA and ACEA would indicate that these angles measure similar acetabular deformity, and that additional measures are needed to assess anterior coverage independent of lateral coverage.

Investigation of pelvic floor influence on prostate displacement in image-guided radiotherapy.

The uncertainty of target location during prostate cancer radiotherapy plays an important role in accurate dose delivery and radiation toxicity in adjacent organs. This study analyzed displacement correlations between the prostate and pelvic floor. We retrospectively analyzed registration results from 467 daily cone-beam computed tomography (CT) in 12 patients with prostate cancer who received radiation therapy. We analyzed prostate displacement and the pelvic floor relative to the pelvic bone's anatomy in the translational and rotational directions and identified statistical correlations. The systematic (Σ) and random (σ) displacements of the prostate in the three translational directions, anterior-posterior (AP), superior-inferior (SI), and right-left (RL), were 1.49 ± 1.45, 2.10 ± 1.40, and 0.24 ± 0.53 mm, respectively, and in the rotational directions of the pitch, roll, and yaw were 2.10 ± 2.02°, 0.42 ± 0.74°, and 0.42 ± 0.64°, respectively. The pelvic floor displacements were 2.37 ± 1.96, 2.71 ± 2.28, and 0.47 ± 0.84 mm in the AP, SI, and RL directions, respectively, and 0.93 ± 1.49°, 0.98 ± 1.28 °, and 0.87 ± 0.94° in the pitch, roll, and yaw directions, respectively. Additionally, there were statistically significant correlations between the displacement of the prostate and pelvic floor in the AP and SI directions, with correlation coefficients (r) of 0.74 (p < 0.001) and 0.69 (p < 0.001), respectively. The movement of the pelvic floor may be an important factor that causes prostate displacement, affecting the accuracy of radiotherapy. Therefore, it is necessary to take appropriate measures to ensure that the pelvic floor muscle tension is as consistent as possible in the treatment' CT scan and daily treatment.

Pelvic Floor Ultrasound Findings and Symptoms of Pelvic Floor Dysfunction During Pregnancy.

Pregnancy and childbirth predispose to pelvic floor dysfunction (PFD), coinciding with functional and anatomical changes in the pelvic floor. To some extent, these can be assessed by transperineal ultrasound (TPUS), yet the correlation between ultrasound findings and symptoms has not been well elucidated. We hypothesised that pregnant women with PFD would show different findings at TPUS. This is a planned secondary analysis of a prospective cohort study. Pregnant women were asked to fill out standardised questionnaires on PFD and undergo TPUS at 12-14weeks and 28-32weeks of gestation. We compared bladder neck descent, urethral rotation, retrovesical angle, pelvic organ descent, genital hiatus dimensions and the presence of anal sphincter defects between women with and those without PFD using t test and Fisher's exact test. Linear mixed-effects models were used to assess the correlation between TPUS findings and PFD severity. As this is a secondary subgroup analysis of participants who underwent TPUS, no sample size was determined upfront. At Valsalva, women with urinary incontinence had more pronounced bladder neck descent (p = 0.02) and urethral rotation (p < 0.01), as well as wider retrovesical angles (p = 0.04) and larger genital hiatus areas (p < 0.01). After controlling for age, BMI and parity, the retrovesical angle was the only persistent predictor of urinary incontinence. No correlation was observed between any TPUS marker and symptoms of either prolapse or anorectal dysfunction. In pregnant women, symptoms of urinary incontinence, but not of prolapse and anorectal dysfunction, are associated with differences in pelvic floor anatomy at TPUS.

Deep pelvis and low visceral fat mass as risk factors for neurogenic bladder after rectal cancer surgery

BackgroundPostoperative neurogenic bladder (PONB) frequently occurs as a complication after rectal cancer surgery. This study aimed to analyze risk factors for developing PONB after rectal cancer surgery, particularly the association between pelvic anatomy and visceral fat mass.MethodsWe included 138 patients who underwent rectal resection for lower rectal cancer in our department between 2017 and 2021. PONB was defined as the need for urethral catheter reinsertion or oral medication administration for urinary retention after catheter removal with severe NB that required treatment for ≥ 60 days. We obtained visceral fat area (VFA) at the umbilical level based on a CT scan and measured five pelvic dimensions.ResultsOf the 138 patients, 19 developed PONB, with 16 being severe cases. PONB more frequently occurs in patients with a height of < 158 cm, age ≥ 70 years, surgery lasting ≥ 8 h, intraoperative bleeding volume ≥ 150 mL, lateral lymph node dissection, and narrower pelvis. It was more prevalent in cases with low VFA. Conversely, gender, body mass index (BMI), and medical history showed no significant correlations. Multivariate analysis revealed older age, prolonged surgery, and low VFA as independent risk factors for PONB. Independent risk factors for severe PONB included low VFA, older age, prolonged surgery, and deep pelvis.ConclusionLower VFA, older age, and prolonged surgery are independent risk factors for developing PONB. Additionally, a deep pelvis is an independent risk factor for severe PONB. Delicate surgical techniques should consider the risk of nerve injury in cases with low VFA and deep pelvis.

Advantages of robotic surgery for rectal cancer compared to laparoscopic surgery: pelvic anatomy and its impact on urinary dysfunction.

The anatomical dimensions and the shape of the pelvis influence surgical difficulty for rectal cancer. Compared to conventional laparoscopic surgery, robot-assisted surgery is expected to improve surgical outcomes due to the multi-joint movement of its surgical instruments. The aim of this study was to investigate the impact of pelvic anatomical indicators on short-term outcomes of patients with rectal cancer. A retrospective analysis was conducted using data from 129 patients with rectal cancer who underwent conventional laparoscopic low anterior resection (L-LAR) or robot-assisted low anterior resection (R-LAR) with total mesorectal excision or tumor-specific mesorectal excision between January 2014 and December 2022. The transverse diameter of the lesser pelvis and the sacral promontory angle were used as indicators of pelvic anatomy. The sacral promontory angle was not associated with age and sex while the pelvic width was smaller in male than in female. The pelvic width did not affect postoperative complications in both L-LAR and R-LAR. In contrast, postoperative urinary dysfunction occurred more frequently in patients with a small sacral promontory angle (p = 0.005) in L-LAR although there was no impact on short-term outcomes in R-LAR. Multivariate analysis demonstrated that a small sacral promontory angle was an independent predictive factor for urinary dysfunction (p = 0.032). Sharp angulation of the sacral promontory was a risk factor for UD after L-LAR. Robot-assisted surgery could overcome anatomical difficulties and reduce the incidence of UD.

On the Shoulders of Giants Through the Lens of the Laparoscope Dr. Harry Reich: Empathy, Optics and Courage.

Harry Reich, MD, FACOG, FRCOG, FACS is known worldwide as a pioneer in the field of laparoscopic surgery. He performed the first laparoscopic hysterectomy, the first pelvic lymphadenectomy for cancer, and the first excision of cul-de-sac endometriosis that included rectal resection. This article explores his life and contributions. The author knew Dr. Reich from medical conferences over many years and visited Dr. Reich in Pennsylvania to observe him in the operating room. For this article, the author spoke with Dr. Reich on nearly a nightly basis over a 13-month period in 2022 and 2023. Dr. Reich's descriptions were cross-referenced with his publications and those of his peers. The author also interviewed physicians who worked closely with Dr. Reich and reviewed the trial transcript of the February 1980 Nesbitt Memorial Hospital special ad hoc investigatory committee. The result is a comprehensive review spanning from Dr. Reich's early life to his ultimate recognition as one of the most significant innovators of advanced laparoscopic surgery. The author concluded that Dr. Reich's accomplishments are rooted in his command of pelvic anatomy, his lifelong interest in surgery and his willingness to challenge existing surgical dogma. By attending medical school in Ireland, Dr. Reich benefitted from the deep study of anatomy offered there. He also had a unique background of being a Harvard-trained gynecologic surgeon practicing in Wilkes-Barre, a small Pennsylvania community that trusted him because both his parents practiced medicine there before him. Dr. Reich favored conservative surgery rather than hysterectomy for endometriosis and patiently excised deep disease, offering relief to countless women, at times without compensation. He exhibited astonishing bravery and perseverance in the face of scathing criticism. Dr. Harry Reich's empathy for his patients and willingness to challenge the status quo were pivotal in improving the lives of many thousands of women and revolutionizing gynecologic surgery.

Understanding the anatomy of pelvic fascia: implications for regional anesthesia.

The fascia, a continuous structure around the whole body across various anatomical locations, remains underexplored in regional anesthesia. The pelvic fascia is a particularly controversial and complicated anatomical structure. It holds significant relevance not only for surgeons but also in the realms of regional anesthesia and pain management. Many regional nerve blocking techniques in the pelvis are closely related to fascial anatomy, such as fascia iliaca compartment block, circum-psoas block, inferior hypogastric plexus block, and ganglion impar block. The continuity of fascia and interfascial spaces profoundly influences both the efficacy of blockades and the incidence of complications. A thorough understanding of pelvic fascia anatomy is crucial for understanding the potential pathways and barriers for spread of local anesthetics, enhancing analgesia, and minimizing side effects. Currently, a systematic discussion of pelvic fascia from the perspective of regional anesthesia and pain therapy is notably absent. This narrative review aims to consolidate knowledge on the anatomy of pelvic fascia pertinent to regional anesthesia and pain management, detailing relevant pelvic nerves, and associated peripheral nerve blocking techniques.

Pelvis Anatomy and Morphometric Analysis in New Zealand Rabbits

This study aims to obtain three-dimensional models of the cavum pelvis in New Zealand rabbits of both genders using CT images, to measure the pelvis diameters and angles through the created digital models, and to compare female and male New Zealand Rabbits in terms of sexual dimorphism. A total of 20 New Zealand rabbits, 10 females and 10 males, were used in this study. Computed tomography (CT) images of the animals were taken, the images were reconstructed with the MIMICS 20.1 program, and a three-dimensional model of the pelvic cavity was obtained from the two-dimensional images. Morphometric data were obtained by making diameter and angle measurements on the resulting 3D model. Then, the rabbits were dissected and the os coxae was exposed and the anatomical formations were named. When pelvimetry measurements in female and male rabbits were compared, it was seen that all values except pelvic tilt were higher in females. The data reveal that there is no significant difference in the volume and surface area of the right and left os coxae between male and female rabbits (P &amp;gt; .05). In this study comparing the morphometric differences of the pelvis in female and male New Zealand rabbits, volume and surface area data were shared for the first time. The collected data could be used for sex discrimination in rabbits, assist physicians in diagnosing patients, serve as a reference for clinical practices, and form the basis for new research.

"Ultralow-dose" CT Without Sedation in Pediatric Patients With Neuromuscular Scoliosis.

Children with neuromuscular scoliosis undergoing scoliosis surgery face substantial rates of complications. To mitigate surgical risks such as blood loss in pediatric patients with neuromuscular scoliosis, this study focuses on enabling instrumentation planning for their abnormal vertebral and pelvic anatomy and osteopenia. This study assessed the feasibility of an "ultralow-dose" CT (ULD CT) protocol without sedation in pediatric patients with neuromuscular scoliosis who often have comorbid movement disorders. Our prospective quality improvement study aims: (1) to determine if ULD CT without sedation is feasible in this patient group; (2) to quantify the radiation dose from ULD CT and compare it with preoperative spine radiographs (XR); and (3) to assess if ULD CT allows accurate anatomical assessment and intraoperative navigation given the prevalence of movement disorders. Children with neuromuscular scoliosis underwent spine XR and ULD CT scans. Chart reviews assessed disease etiology and comorbidities. Radiation dose was quantified through Monte-Carlo simulations giving dose indices and effective dose, with statistical analysis done using a paired student's t-test (α=0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation. Fourteen patients (5 males, 9 females, average age 14±3y) participated. One patient needed sedation due to autism spectrum disorder and global developmental delay. The radiation dose for spine XR was 0.5±0.2mSv, and ULD CT was 0.6±0.1mSv. There was no statistically significant difference in radiation doses between methods. All ULD CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2 Alar-Iliac screw orientation, and intraoperative navigation. ULD CT without sedation is feasible for children with neuromuscular scoliosis. Radiation doses were comparable to standard radiographs. ULD CT provided accurate anatomical assessments and supported intraoperative navigation, proving beneficial despite movement disorders in these patients. Level 2-Development of diagnostic criteria on basis of consecutive patients (with universally applied reference widely accepted standard).

Analysis of the gamma index using an indigenously developed anthropomorphic heterogeneous female pelvis (AHFP) phantom.

It is essential in modern radiotherapy treatment practices to evaluate the quality assurance (QA) of the treatment plan prior to the exclusion of patient from treatment. The typical suitable tools used for patient pretreatment QA are phantoms representing the human anatomy. An anthropomorphic heterogeneous female pelvic (AHFP) phantom has been developed to represent the real female pelvic structure. The objective of the current study is to assess the findings of relative dosimetry carried out utilizing an electronic portal imaging device (EPID) on the AHFP phantom fabricated. The planning target volume (PTV) was created on CT slices of an AHFP phantom to confirm the tool's ability to represent female pelvic anatomy and serve as a QA tool. In order to assess the dose received by healthy organs during radiotherapy, organs at risk such as the bladder and rectum were additionally drawn alongside the PTV. Rapid Arc and Intensity modulated radiation therapy (IMRT) were both used to create the treatment plan on treatment planning system, and the Anisotropic Analytical Algorithm Version 11.0.31 was used to calculate the dose. The results obtained for the average gamma value in RapidArc plans are 0.26, 0.27, and 0.28 (g ≤1) and IMRT plans are 0.39, 0.40, and 0.46 (g ≤1) for target 1, target 2, and target 3, respectively. According to the findings of the current study, the AHFP phantom was used to explore the potential of relative dosimetry using EPID as a QA tool, which was found to be suitable.

Clinical application of eight-zone laparoscopic dissection strategy for rectal cancer: Experience and discussion.

The incidence of rectal cancer is increasing worldwide, and surgery remains the primary treatment modality. With the advent of total mesorectal excision (TME) technique, the probability of tumor recurrence post-surgery has significantly decreased. Surgeons' focus has gradually shifted towards minimizing the impact of surgery on urinary and sexual functions. Among these concerns, the optimal dissection of the rectal lateral ligaments and preservation of the pelvic floor neurovascular bundle have become critical. To explore the optimal surgical technique for TME and establish a standardized surgical protocol to minimize the impact on urinary and sexual functions, we propose the eight-zone dissection strategy for pelvic floor anatomy. To compare the differences in surgical specimen integrity and postoperative quality of life satisfaction between the traditional pelvic floor dissection strategy and the innovative eight-zone dissection strategy. We analyzed the perioperative data of patients who underwent laparoscopic radical resection of rectal cancer at Qilu Hospital of Shandong University between January 1, 2021 and December 1, 2023. This study included a total of 218 patients undergoing laparoscopic radical surgery for rectal cancer, among whom 109 patients underwent traditional pelvic floor dissection strategy, and 109 patients received the eight-zone dissection strategy. There were no significant differences in general characteristics between the two groups. Patients in the eight-zone dissection group had higher postoperative specimen integrity (88.1% vs 78.0%, P = 0.047). At the 3-month follow-up, patients in the eight-zone surgery group had better scores in urinary issues (6.8 ± 3.3 vs 5.3 ± 2.5, P = 0.045) and male sexual desire (2.2 ± 0.6 vs 2.5 ± 0.5, P = 0.047) compared to the traditional surgery strategy group. This study demonstrates that the eight-zone dissection strategy for laparoscopic lateral ligament dissection of rectal cancer is safe and effective. Compared with the traditional pelvic floor dissection strategy, this approach can reduce the risk of nerve injury and minimize the impact on urinary and sexual functions. Therefore, we recommend the clinical application of this strategy to better serve patients with rectal cancer.

Comparative muscle anatomy of the anuran pelvis and hindlimb in relation to locomotor mode.

Frogs have a highly conserved body plan, yet they employ a diverse array of locomotor modes, making them ideal organisms for investigating the relationships between morphology and locomotor function, in particular whether anatomical complexity is a prerequisite for functional complexity. We use diffusible iodine contrast-enhanced microCT (diceCT) imaging to digitally dissect the gross muscle anatomy of the pelvis and hindlimbs for 30 species of frogs representing five primary locomotor modes, including the first known detailed dissection for some of the world's smallest frogs, forming the largest digital comparative analysis of musculoskeletal structure in any vertebrate clade to date. By linking musculoskeletal dissections and phylogenetic comparative methods, we then quantify and compare relationships between anatomy and function across over 160 million years of anuran evolution. In summary, we have found that bone lengths and pelvic crest sizes are generally not reliable predictors of muscle sizes, which highlights important implications for future palaeontological studies. Our investigation also presents previously unreported differences in muscle anatomy between frogs specialising in different locomotor modes, including several of the smallest frog hindlimb muscles, which are extremely difficult to extract and measure using traditional approaches. Furthermore, we find evidence of many-to-one and one-to-many mapping of form to function across the phylogeny. Additionally, we perform the first quantitative analysis of how the degree of muscle separation can differ between frogs. We find evidence that phylogenetic history is the key contributing factor to muscle separation in the pelvis and thigh, while the separation of shank muscles is influenced more strongly by locomotor mode. Finally, our anatomical 3D reconstructions are published alongside this manuscript to contribute towards future research and serve as educational materials.

Three-dimensional trans-rectal and trans-abdominal ultrasound image fusion for the guidance of gynecologic brachytherapy procedures: a proof of concept study

High dose-rate brachytherapy is a treatment technique for gynecologic cancers where intracavitary applicators are placed within the patient’s pelvic cavity. To ensure accurate radiation delivery, localization of the applicator at the time of insertion is vital. This study proposes a novel method for acquiring, registering, and fusing three-dimensional (3D) trans-abdominal and 3D trans-rectal ultrasound (US) images for visualization of the pelvic anatomy and applicators during gynecologic brachytherapy. The workflow was validated using custom multi-modal pelvic phantoms and demonstrated during two patient procedures. Experiments were performed for three types of intracavitary applicators: ring-and-tandem, ring-and-tandem with interstitial needles, and tandem-and-ovoids. Fused 3D US images were registered to magnetic resonance (MR) and computed tomography (CT) images for validation. The target registration error (TRE) and fiducial localization error (FLE) were calculated to quantify the accuracy of our fusion technique. For both phantom and patient images, TRE and FLE across all modality registrations (3D US versus MR or CT) resulted in mean ± standard deviation of 4.01 ± 1.01 mm and 0.43 ± 0.24 mm, respectively. This work indicates proof of concept for conducting further clinical studies leveraging 3D US imaging as an accurate, accessible alternative to advanced modalities for localizing brachytherapy applicators.

Dissection layer selection based on an understanding of pelvic fascial anatomy in transanal total mesorectal excision.

This study aimed to review the historical transition of rectal cancer surgery and recent evidence regarding transanal total mesorectal excision (TaTME). Additionally, it outlined the anatomical landmarks and technical considerations essential for successful TaTME. Anatomical studies and surgical techniques were analyzed to identify key landmarks and procedural steps crucial for TaTME. TaTME offers improved visibility and maneuverability even in the deep and narrow pelvis and is expected to contribute to tumor radical cure rates. By securing the circumferential resection margin and distal margin while preserving pelvic autonomic nerve function, TaTME holds promise for maintaining postoperative urinary and sexual functions. Key anatomical landmarks include the endopelvic fascia posteriorly, the S4-pelvic splanchnic nerve laterally, and the prostate or posterior vaginal wall anteriorly. Selecting the appropriate dissection layer based on tumor depth and ensuring precise incision of the tendinous arch of the pelvic fascia contributes to successful TaTME outcomes. TaTME represents a significant advancement in rectal cancer surgery, offering improved outcomes through meticulous attention to anatomical detail and precise dissection techniques. Understanding the historical context of rectal cancer surgery alongside recent evidence on TaTME is essential for optimizing patient outcomes and expanding the safe implementation of this innovative approach.

Virtual Reality Head-Mounted Display (HMD) and Preoperative Patient-Specific Simulation: Impact on Decision-Making in Pediatric Urology: Preliminary Data.

To assess how virtual reality (VR) patient-specific simulations can support decision-making processes and improve care in pediatric urology, ultimately improving patient outcomes. Children diagnosed with urological conditions necessitating complex procedures were retrospectively reviewed and enrolled in the study. Patient-specific VR simulations were developed with medical imaging specialists and VR technology experts. Routine CT images were utilized to create a VR environment using advanced software platforms. The accuracy and fidelity of the VR simulations was validated through a multi-step process. This involved comparing the virtual anatomical models to the original medical imaging data and conducting feedback sessions with pediatric urology experts to assess VR simulations' realism and clinical relevance. A total of six pediatric patients were reviewed. The median age of the participants was 5.5 years (IQR: 3.5-8.5 years), with an equal distribution of males and females across both groups. A minimally invasive laparoscopic approach was performed for adrenal lesions (n = 3), Wilms' tumor (n = 1), bilateral nephroblastomatosis (n = 1), and abdominal trauma in complex vascular and renal malformation (ptotic and hypoplastic kidney) (n = 1). Key benefits included enhanced visualization of the segmental arteries and the deep vascularization of the kidney and adrenal glands in all cases. The high depth perception and precision in the orientation of the arteries and veins to the parenchyma changed the intraoperative decision-making process in five patients. Preoperative VR patient-specific simulation did not offer accuracy in studying the pelvic and calyceal anatomy. VR patient-specific simulations represent an empowering tool in pediatric urology. By leveraging the immersive capabilities of VR technology, preoperative planning and intraoperative navigation can greatly impact surgical decision-making. As we continue to advance in medical simulation, VR holds promise in educational programs to include even surgical treatment of more complex urogenital malformations.

Urinary Incontinence in Female Athletes: A Systematic Review on Prevalence and Physical Therapy Approaches.

Urinary incontinence (UI) is an involuntary leakage of urine and is classified as stress, mixed, or urge. It is more common in females due to anatomical and physiological body differences. Moreover, the literature remarks an evident presence of UI with high-intensity physical activities. Therefore, the present integrative systematic review focused on the studies aimed at investigating the prevalence of UI in nulliparous sportswomen, studies illustrating sport-specific prevalence of UI, and studies demonstrating the impact of physical therapy intervention on UI. A literature search was carried out systematically on electronic databases consisting of Cochrane and Google Scholar databases from 2018 to December 2023. The keywords utilized to perform the literature search and include relevant articles consisted of "urinary incontinence," AND "nulliparous," AND "sportswomen," OR "female athletes," AND "physical therapy". A total of nine studies were included in the present systematic review. The quality assessment of the studies was performed by using a measurement tool to assess systematic reviews (AMSTAR 2) scale, and the Mixed Methods Appraisal Tool was used for cross-sectional and randomized controlled trial studies. The data extracted included first author and year of publication, study design, sample or number of individuals involved in the study, age range of the participants, type of UI, type of sports involved, purpose of the study, methodological part, outcome measures derived, conclusion, and quality assessment of the studies. The review concludedthat nulliparous athletes, especially those participating in high-impactactivities, have a significant prevalence of UI. In addition,the physical therapy intervention consisting of pelvic floor muscle training (PFMT)along with education about pertinent pelvic anatomy was mostly performed on female athletes for the prevention and management of UI.