Posterior Plane Research Articles

Cortical thickness of supratemporal plane predicts auditory N1 amplitude

The auditory-evoked potential's N1 component of the scalp electroencephalogram is a well-established measure of electrical brain activity. The N1 reflects basic auditory processing and is modulated by auditory experience, for instance, by musical training. Here, we explore a possible correlation between the auditory N1 amplitude and cortical architecture in the supratemporal plane. We hypothesize that individual differences in N1 amplitude reflect differential acuity, which might also be reflected by differences in auditory cortex anatomy. Auditory potentials evoked by sine wave tones and structural MRI were collected from 27 healthy volunteers. The thickness and surface area of the cortex were calculated using a surface-based morphometry approach. Cortical thickness, rather than surface area, in a cluster on the posterior supratemporal plane, predominantly located on Heschl's sulcus and lateral aspects of Heschl's gyrus, correlated with the N1 amplitude. In particular, lower cortical thickness was associated with larger N1 amplitudes. This is well in agreement with previous functional magnetic resonance studies reporting a thinner cortex to be related to a larger functional response.

Left-Sided Pancreatic Cancer

Adenocarcinoma of the body and tail of the pancreas is an aggressive malignancy, and classically there have been few survivors after surgery. Radical antegrade modular pancreatosplenectomy and distal pancreatectomy with celiac axis resection are new procedures for these tumors. Radical antegrade modular pancreatosplenectomy is designed to establish an operation with oncologic rationales both for the dissection planes used to achieve negative margins and the extent of node dissection. The extent of lymph node dissection is based on the descriptions of N1 lymph node drainage, and dissection planes are based on fascial planes of the retroperitoneum. Radical antegrade modular pancreatosplenectomy is modular, adjusting the posterior plane of dissection based on the position of the tumor on preoperative computed tomograms. It is also performed right to left to increase visibility and control blood supply early. Radical antegrade modular pancreatosplenectomy is not an extended pancreatectomy but brings the rationales of the modern Whipple procedure to left-sided tumors. In long-term results from our center in 47 patients, there was a high negative tangential margin rate of 89% and an actuarial overall 5-year survival rate of 35.5%. The actual 5-year survival in 23 patients was 30.4%. Distal pancreatectomy with celiac axis resection is a procedure for cancers that have involved the celiac axis. It is based on the fact that resection of the celiac axis may be performed without devascularizing the liver, which then receives its blood supply by the pancreaticoduodenal arcade. It is an extended pancreatectomy. Mature long term results are just becoming available. Results with distal pancreatectomy with celiac axis resection are mixed with some series reporting few or no long-term survivors, whereas others report long-term survival at approximately 20%.

Functional Morphometry of Horizontal Rectus Extraocular Muscles during Horizontal Ocular Duction

We explored multiple quantitative measures of horizontal rectus extraocular muscle (EOM) morphology to determine the magnetic resonance imaging (MRI) measure best correlating with duction and thus contractility. Surface coil coronal MRI was obtained in target-controlled central gaze and multiple positions of adduction and abduction in 26 orbits of 15 normal volunteers. Duction angles were determined by position changes of the globe-optic nerve junction. Cross-sectional areas, partial volumes, and location of peak cross-sections of the horizontal rectus EOMs were computed in contiguous image planes 2-mm thick spanning the EOM origins to the globe equator. All measures correlated significantly with duction angle (P < 0.0001). The best measures obtainable in single image planes were the maximum change in the cross-sectional area between equivalent image planes, with coefficients of determination R(2) = 0.92 for medial rectus (MR) and 0.91 for lateral rectus (LR), and percentage change in maximum cross-section with R(2) = 0.79 for MR and 0.78 for LR. The best partial volume measure of contractility was the change in partial volumes in four contiguous posterior planes (R(2) = 0.86 MR and for 0.89 LR), particularly when combined with the corresponding change in partial volume for the antagonist EOM (R(2) = 0.95 for MR and LR). EOM morphologic changes are highly correlated with degrees of duction and thus contractility. Both changes in single-plane maximum cross-sectional areas and posterior partial volumes provide accurate, quantitative measures of EOM contractility.

Salvage Robotic Assisted Laparoscopic Radical Prostatectomy: A Single Institution, 5-Year Experience

Salvage robotic assisted laparoscopic prostatectomy is a treatment option for certain patients with recurrent prostate cancer after primary therapy. Data regarding patient selection, complication rates and cancer outcomes are scarce. We report the largest, single institution series to date, to our knowledge, of salvage robotic assisted laparoscopic prostatectomy. We reviewed our database of 4,234 patients treated with robotic assisted laparoscopic prostatectomy at Vanderbilt University and identified 34 men who had surgery after the failure of prior definitive ablative therapy. Each patient had biopsy proven recurrent prostate cancer and no evidence of metastases. The primary outcome measure was biochemical failure. Median time from primary therapy to salvage robotic assisted laparoscopic prostatectomy was 48.5 months with a median preoperative prostate specific antigen of 3.86 ng/ml. Most patients had Gleason scores of 7 or greater on preoperative biopsy, although 12 (35%) had Gleason 8 or greater disease. After a median followup of 16 months 18% of patients had biochemical failure. The positive margin rate was 26%, of which 33% had biochemical failure after surgery. On univariable analysis there was a significant association between prostate specific antigen doubling time and biochemical failure (HR 0.77, 95% CI 0.60-0.99, p = 0.049) as well as between Gleason score at original diagnosis and biochemical failure (HR 3.49, 95% CI 1.18-10.3, p = 0.023). There were 2 Clavien II-III complications, namely a pulmonary embolism and a rectal laceration. Postoperatively 39% of patients had excellent continence. Salvage robotic assisted laparoscopic prostatectomy is safe, with many favorable outcomes compared to open salvage radical prostatectomy series. Advantages include superior visualization of the posterior prostatic plane, modest blood loss, low complication rates and short length of stay.

Laparoscopic extraperitoneal colostomy in elective abdominoperineal resection for cancer: a single surgeon experience

Parastomal herniation of end colostomies can be chronically debilitating for patients and a difficult problem to treat. To prevent parastomal hernia (PSH) formation an extraperitoneal colostomy (EPC) approach has been developed in open colorectal surgery and some studies have suggested a potential advantage to this approach. Here we describe our technique of laparoscopic extraperitoneal stoma formation and present our experience to date. We performed a retrospective analysis of consecutive patients undergoing a laparoscopic abdominoperineal resection between March 1999 and March 2011. We performed the EPC technique as follows: under laparoscopic guidance, a smooth tip instrument was used to gently separate the peritoneum from the posterior aponeurotic plane to create an extraperitoneal tunnel running from the skin incision to the left flank of the abdominal cavity to join the previously dissected paracolic gutter. The colon was exteriorized and the position was checked to ensure the absence of torsion or kinking. Twenty-two patients underwent a standard laparoscopic abdominoperineal resection with total mesorectal excision. Colostomy was constructed extraperitoneally (EPC) or transperitoneally (TPC) in 12 and 10 patients respectively. There were five complications requiring operative intervention: two stomal necrosis and one surgical site infection in the TPC group and two small bowel occlusions in the EPC group. Four patients from the TPC group developed PSH at 24, 36, 48 and 72 months respectively while there were no cases of PSH in the EPC group. Extraperitoneal laparoscopic colostomy showed a potential reduction of PSH in our series of patients.

Pectus excavatum repair improves cardiovascular function at maximal exercise by facilitating heart filling

The recent article by Tang et al. [1] supports the idea that Nuss repair improves cardiopulmonary exercise function in teenagers with moderate-to-severe pectus excavatum (PEx). We would like to congratulate the authors for this study and emphasize the relevance of this research, as well as their results, by making some brief remarks. First, the authors circumvented the difficulties in measuring cardiac output during exercise by using a gas-rebreathing technique, which has been previously validated in exercise testing conditions [2]. The authors demonstrated that Nuss-operated teenagers significantly increased their cardiac index at submaximal exercise. Postoperative increase of maximum exercise cardiac index was attributed in this study to enlargement of the thoracic dimension in the anterior–posterior plane facilitating heart filling and/or their better aerobic fitness due to increased physical activity. Second, Tang et al. [1] mentioned some of the study limitations, including the influence of growth and changes in sport habits on maximal exercise capacity. We feel that another important issue may be the misinterpretation of the relationship between cardiac performance and exercise limitation. Indeed, in healthy individuals, exercise tolerance is limited by the cardiovascular response and the degree of physical fitness, whereas no ventilation limitation is typically achieved [3]. In this setting, cardiac output is thus driven by oxygen demand, which increases with peripheral muscular exercise. In the Tang et al. study, teenagers experienced no changes in maximum oxygen uptake after Nuss repair, whereas cardiac output increased, which was mainly the result of increased maximal heart rate. One could interpret these findings as evidence of cardiovascular maladaptation, i.e. tachycardia, due to postoperative deconditioning. In a recent study [4], we confirm that PEx open repair [5] also can beneficially impact maximal exercise capacity in young adults. Although we did not directly measure the cardiac index, our results suggested that improved aerobic capacity was accompanied by increased oxygen pulse, a surrogate of stroke volume. We speculated that better postoperative aerobic capacity was directly related to improved haemodynamic conditions because such improvements were also observed in a series of athletes who experienced long-term, constant and heavy training protocols before and after PEx repair. Mechanisms by which cardiovascular function improves after PEx repair remain elusive. Normalization of thoracic geometry by PEx surgery can restore the adequate development of negative pulmonary pressure that is necessary to enhance venous return, heart filling and cardiac output. Consistently, we recently demonstrated that PEx repair improved the capacity of the inspiratory muscle system to generate intrathoracic negative pressure [6]. We speculated that postoperative increased respiratory pump efficacy to generate negative pulmonary pressure and to enhance venous return facilitates better cardiovascular adaptation at maximal exercise.

Visual pathway‐related horizontal reference plane for three‐dimensional craniofacial analysis

To construct three-dimensional (3D) horizontal reference planes based on visual pathway and to determine their stability and reliability by analyzing the structural patterns of normal and dysmorphology for 3D craniofacial analysis. Thirty-six subjects with maxillofacial dysmorphology and malocclusion, and eight normal controls. MATERIALS AND METHODS POPULATION: On the 3D computed tomographic images of the subjects, the visual pathway-based planes, including the orbital axis plane (OAP), visual axis plane (VAP), and the optical axis plane (OpAP), were constructed and evaluated. The OAP, but not the VAP and OpAP, showed the ideal relationship between the midsagittal and posterior maxillary plane, and properly described the different patterns of maxillofacial dysmorphology with craniofacial plane 1 of Delaire's analysis and the occlusal plane. The proposed visual pathway-related horizontal reference planes, and in particular the OAP, seem to correctly express the visual axis and the position of the head in natural head position and can be used as a horizontal reference plane for the 3D analysis of craniofacial dysmorphology and anthropology.

Early Retrograde Nerve Preservation During Robot-Assisted Radical Prostatectomy: Description of Technique and Potency Outcomes

Introduction: Antegrade nerve sparing (ANS) is commonly performed during robot-assisted radical prostatectomy (RARP). However, this approach provides limited observation of the neurovascular bundle (NVB) course with the potential risk for injury. Objective: Our technique of retrograde, early release of the NVB is described. Mid-term outcomes are presented. Methods: Over 8 months, 200 consecutive patients with a preoperative sexual health index male (SHIM) score >21 underwent athermal, full bilateral retrograde nerve sparing (RNS). Data were compared to a previous cohort of 146 consecutive patients in whom ANS was performed. Surgical Procedure: Key aspects of the technique include initial athermal seminal vesicle dissection followed by thorough development of the posterior plane. An interfascial plane of dissection is developed on the prostate laterally until it meets with the previously developed posterior plane. The course of the NVB becomes clear and the pedicle is now transected. NVB dissection is completed antegrade toward the apex. Measurements: Postoperative potency was assessed objectively and defined as a score ≥4 on questions 2 and 3 of SHIM questionnaire, with or without use of phosphodiesterase‐5 (PDE-5) (–). Results: Groups were comparable regarding age, body–mass index, preoperative prostate specific antigen (PSA) clinical stage, Gleason grade, gland size, and postero-lateral positive surgical margins (PSM). Blood loss was higher and operating room (OR) time longer in the ANS group than in the retrograde group. Potency recovery was better in the RNS group at 6 weeks, 3 months, 6 months, and 12 months than in the ANS group (64%, 85%, 92.3%, 94.4% vs. 50%, 75%, 82.1%, 88.5%, respectively). On the log-rank test, patients undergoing RNS demonstrated a significantly improved probability of potency return compared to ANS. Conclusions: Retrograde early release of the NVB is feasible during RARP. It does not increase the risk for a PSM, but it allows for improved overall potency rates and earlier return of sexual function. No competing financial interests exist. Runtime of video: 7 mins 58 secs

The Pattern and Pace of Hyperacute Hemorrhage Expansion

Intracerebral hemorrhage (ICH) expansion is common during the first 24h after onset, but the pattern and pace of hyperacute hemorrhage growth have not been described because serial imaging is typically performed over the course of hours and days, not minutes. The purpose of this study is to elucidate the spatial and temporal characteristics of hyperacute hemorrhage expansion within minutes of ICH onset. An 86-year-old man with probable cerebral amyloid angiopathy developed an ICH while in the MRI scanner. Hyperacute hemorrhage growth was captured at three time points over a 14-min interval of MRI data acquisition and at fourth time point with CT 22h later. MRI and CT datasets were spatially coregistered, and three-dimensional models of ICH expansion were generated. Longitudinal analysis revealed that the spatial pattern of ICH growth was asymmetric at each time point. Maximal expansion occurred along the anterior-posterior plane during the first 4min but along the superior-inferior plane during the next 10min. The temporal pace of ICH expansion was also non-uniform, as growth along the anterior-posterior plane outpaced medial-lateral growth during the first 4min (2.8 vs. 2.5cm), but medial-lateral growth outpaced anterior-posterior growth over the next 10min (1.0 vs. 0.2cm). We provide evidence for asymmetric, non-uniform expansion of a hyperacute hemorrhage. These serial imaging observations suggest that hemorrhage expansion may be caused by local cascades of secondary vessel rupture as opposed to ongoing bleeding from a single ruptured vessel.

Posterior Coronal Plating of Bicondylar Tibial Plateau Fractures Through Posteromedial and Anterolateral Approaches in a Healthy Floating Supine Position

Bicondylar tibial plateau fractures pose a significant challenge for treating surgeons. If the articular surface of the medial plateau has a second split component in the posterior coronal plane, it is difficult to get direct visualization and ensure plate fixation when the patient is in the supine position. Using a technique in which a single preparation and draping of both legs is needed, patients were operated on using a healthy floating supine position maneuver through dual posteromedial and anterolateral incisions and triple plate fixations. By flexing and adducting the contralateral healthy hip over the injured leg, more lateral rotation of the fractured knee can be achieved, providing better access and visualization of the posterior medial plateau using a posteromedial gastrocnemius approach.

Calculation of patient effective dose and scattered dose for dental mobile fluoroscopic equipment: application of the Monte Carlo simulation

The objective of this study was to evaluate the patient effective dose and scattered dose from recently developed dental mobile equipment in Korea. The MCNPX 2.6 (Los Alamos National Laboratory, USA) was used in a Monte Carlo simulation to calculate both the effective and scattered doses. The MCNPX code was constructed identically as in the general use of equipment and the effective dose and scattered dose were calculated using the KTMAN-2 digital phantom. The effective dose was calculated as 906 μSv. The equivalent doses per organ were calculated via the MCNPX code, and were 32 174 and 19 μSv in the salivary gland and oesophagus, respectively. The scattered dose of 22.5-32.6 μSv of the tube side at 25 cm from the centre in anterior and posterior planes was measured as 1.4-3 times higher than the detector side of 10.5-16.0 μSv.

Letter to the Editor: Increased Anteversion of Press-Fit Femoral Stems Compared with Anatomic Femur

To the Editor We read the article “Increased Anteversion of Press-fit Femoral Stems Compared With Anatomic Femur” by Emerson with interest [4]. Emerson studied the antetorsion of femoral stems compared with the anatomic antetorsion, based on preoperative MRI studies. However, he does not state specifically how the measures were done. Figure 1 suggests the reference plane is defined as a transverse plane of the pelvis, which is acceptable for measuring anteversion of the acetabulum, but not for antetorsion of the femur. Femoral antetorsion is defined as the angle between the posterior bicondylar plane of the femur and the axis of the femoral neck and therefore needs images at the level of the femoral condyles and the femoral neck to be adequately measured [3]. This technique also was used in a recently published study which compares CT with MRI antetorsion values [2]. Furthermore, the method of measurement used during operations is subject to multiple errors, even if the position of the lesser trochanter is used classically as a reference for femoral torsion during intramedullary nailing [9]. In addition, it seems difficult to correlate MRI values and intraoperative values as the measures are not based on the same reference points. In the Discussion, Emerson stated that “ Because this study is looking at the differences between the preoperative and postoperative angles, the actual angles are not important. Of importance is how the two compare and whether ‘natural anteversion’ has been restored”. However, this statement seems questionable, as it is recognized that antetorsion of the prosthetic femoral neck should be between 10° to 30° to avoid impingement and instability [2, 4, 6]. Hisatome and Doi stated “The best amount of femoral anteversion for the total hip stem has not been determined, although it is generally agreed to be between 10° to 20° [4] and 10° to 30° [2]” [6]. Furthermore, antetorsion is variable among individuals and therefore, only restoring individual antetorsion with the femoral stem may lead to instability of the hip if the patient initially has excessive antetorsion or retrotorsion [1, 2, 5, 8, 12]. Therefore, we think that an analysis of restoration of preoperative antetorsion is of marginal interest and one rather should aim at restoration of physiologic relationships between femoral neck orientation and acetabular orientation [6]. Emerson described what he called “head antetorsion”, which in fact represents the neck antetorsion, and an “anatomic antetorsion”, which was called “helitorsion” in previous studies [5, 8]. The normal values of antetorsion and helitorsion vary widely among individuals depending on the underlying disorder, and it was shown that the value of femoral torsion, or helitorsion, influences orientation of the stem in terms of antetorsion [1, 5, 8]. This explains why Emerson finds differences between the preoperative and the postoperative antetorsion values. To adequately analyze antetorsion and helitorsion of each patient, use of a preoperative CT scan is mandatory [8, 10]. For this reason, we suggest the use of three-dimensional (3-D) planning of total hip prostheses based on a dedicated CT scan protocol to be able to analyze the particular anatomy of each patient and to adequately reconstruct the hip on an individual basis is an interesting alternative to standard planning, which ignores the femoral torsion problem as it is based on two-dimensional rather than 3-D analysis [11]. If a routine CT scan for every patient may seem impractical, its cost and radiation have been evaluated [7]. For us, the important additional information gained with the CT scan largely outweighs the potential negative effects of this examination.

Evaluation of canting correction of the maxillary transverse occlusal plane and change of the lip canting in Class III two-jaw orthognathic surgery

To compare the effect of canting correction in anterior maxillary transverse occlusal planes (AMTOP) and posterior maxillary transverse occlusal planes (PMTOP) on the change of lip canting (LC) in two-jaw surgery (TJS) cases. The samples consisted of eight young adult patients (three males and five females, mean age = 24.1 ± 4.5 years) who had skeletal Class III malocclusion (CIII), facial asymmetry (FA), and LC and who underwent TJS. Two-dimensional lateral and posteroanterior cephalograms and three-dimensional facial scanning taken 1 week before (T1) and 6 months after TJS (T2) were combined using the Morpheus 3D program. Six linear and angular variables were measured and statistically analyzed. When comparing the values of the linear and angular variables at the T1 and T2 stages there was significant canting correction of AMTOP (1.7 mm vs -0.3 mm; 3.0° vs 0.1°), PMTOP (3.5 mm vs 0.1 mm, 3.3° vs -0.1°), and LC (3.0 mm vs 0.7 mm, 4.7° vs 2.1°) (all P < .05). Although the angular change ratios (ΔLC/ΔAMTOP and ΔLC/ΔPMTOP) did not exhibit a significant difference (0.99 vs 0.83), the linear change ratio of ΔLC/ΔAMTOP was significantly higher than that of ΔLC/ΔPMTOP (1.67 vs 0.74, P < .05). The angular change of ΔLC showed a significant correlation with ΔAMTOP (r(2) = 0.64; P < .05). However, the linear change of ΔLC was significantly correlated with both the angular and linear changes of ΔAMTOP (r(2) = 0.62 and 0.66; both P < .05). Therefore, the amount of LC change was more related to the canting correction of AMTOP than to that of PMTOP. In TJS cases with CIII, FA, and LC, the amount of canting correction of the AMTOP should be considered to predict the actual LC change.

Automated beam placement for breast radiotherapy using a support vector machine based algorithm

To develop an automated beam placement technique for whole breast radiotherapy using tangential beams. We seek to find optimal parameters for tangential beams to cover the whole ipsilateral breast (WB) and minimize the dose to the organs at risk (OARs). A support vector machine (SVM) based method is proposed to determine the optimal posterior plane of the tangential beams. Relative significances of including/avoiding the volumes of interests are incorporated into the cost function of the SVM. After finding the optimal 3-D plane that separates the whole breast (WB) and the included clinical target volumes (CTVs) from the OARs, the gantry angle, collimator angle, and posterior jaw size of the tangential beams are derived from the separating plane equation. Dosimetric measures of the treatment plans determined by the automated method are compared with those obtained by applying manual beam placement by the physicians. The method can be further extended to use multileaf collimator (MLC) blocking by optimizing posterior MLC positions. The plans for 36 patients (23 prone- and 13 supine-treated) with left breast cancer were analyzed. Our algorithm reduced the volume of the heart that receives >500 cGy dose (V5) from 2.7 to 1.7 cm(3) (p = 0.058) on average and the volume of the ipsilateral lung that receives >1000 cGy dose (V10) from 55.2 to 40.7 cm(3) (p = 0.0013). The dose coverage as measured by volume receiving >95% of the prescription dose (V95%) of the WB without a 5 mm superficial layer decreases by only 0.74% (p = 0.0002) and the V95% for the tumor bed with 1.5 cm margin remains unchanged. This study has demonstrated the feasibility of using a SVM-based algorithm to determine optimal beam placement without a physician's intervention. The proposed method reduced the dose to OARs, especially for supine treated patients, without any relevant degradation of dose homogeneity and coverage in general.

1168 CAN VAGINAL-SPARING CYSTECTOMY BE SAFELY ATTEMPTED IN ALL WOMEN UNDERGOING RADICAL CYSTECTOMY? A SINGLE INSTITUTION STUDY OF PERIOPERATIVE AND ONCOLOGIC OUTCOMES

You have accessJournal of UrologyUrinary Diversion: Bladder Reconstruction, Augmentation, Substitution, Diversion1 Apr 20121168 CAN VAGINAL-SPARING CYSTECTOMY BE SAFELY ATTEMPTED IN ALL WOMEN UNDERGOING RADICAL CYSTECTOMY? A SINGLE INSTITUTION STUDY OF PERIOPERATIVE AND ONCOLOGIC OUTCOMES Michael Large, Sandip Prasad, Amit Patel, Gautam Jayram, Cory Ganshert, and Gary Steinberg Michael LargeMichael Large Chicago, IL More articles by this author , Sandip PrasadSandip Prasad Chicago, IL More articles by this author , Amit PatelAmit Patel Chicago, IL More articles by this author , Gautam JayramGautam Jayram Chicago, IL More articles by this author , Cory GanshertCory Ganshert Chicago, IL More articles by this author , and Gary SteinbergGary Steinberg Chicago, IL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1392AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Little is known regarding the perioperative and oncologic outcomes following vaginal-sparing radical cystectomy (VS-RC). METHODS Between 1/2005 and 12/2009, radical cystectomy was performed for bladder urothelial cell carcinoma in 113 consecutive women. At the University of Chicago, VS-RC is attempted in all women and only aborted if surgeon GDS is unable to propagate a natural surgical plane between the posterior bladder and anterior vagina. RESULTS Of the 113 women who underwent open radical cystectomy by GDS, 94 had VS-RC. Mean age for VS-RC patients was 69.1 years, vs. 73.4 years for non-vaginal-sparing cystectomy (NVS-RC) patients. Mean hospital stay, estimated blood loss, preoperative clinical stage, mean lymph nodes removed, incidence of Clavien grade ≥3 complications, and local recurrence rates did not differ between the two groups. Patients undergoing NVS-RC were more likely to have pathologic stage ≥T3 (78.9% vs. 44.7%, p=0.01), and node-positive disease (58% vs. 26.6%, p=0.03). Frequency of positive posterior surgical margins did not differ between the two groups. Among pathologic stage ≥T3 patients, 42 underwent VS-RC vs. 15 who underwent NVS-RC, and Kaplan-Meier local recurrence-free survival did not differ (p=0.61). CONCLUSIONS Vaginal-sparing radical cystectomy has similar perioperative outcomes versus non-vaginal-sparing cystectomy. The presence of a natural posterior plane may be used to determine viability of vaginal sparing, and the rate of positive posterior surgical margins and local recurrence-free survival do not appear to differ between vaginal- and non-vaginal-sparing patients. Larger studies, multiple surgeons, and both robotic and open approaches are needed to confirm these preliminary findings. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e473-e474 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Michael Large Chicago, IL More articles by this author Sandip Prasad Chicago, IL More articles by this author Amit Patel Chicago, IL More articles by this author Gautam Jayram Chicago, IL More articles by this author Cory Ganshert Chicago, IL More articles by this author Gary Steinberg Chicago, IL More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from cone-beam computed tomography images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation group (n = 82); posterior rotation group (n = 81)], and differences between groups evaluated. Correlation coefficients showed that sagittal inclination of the temporal bone was significantly (P < 0.01) related to midline flexion, transversal width and anterior-posterior length of the basicranium, to the anterior-posterior positioning of the mandible and maxilla, and posterior midfacial height. Frontal inclination of the temporal bone was significantly related (P < 0.01) to basicranium anterior-posterior and transversal dimensions, and to posterior midfacial height. In comparison with the posterior rotation group, the anterior rotation group presented a less flexed and anterior-posteriorly longer cranial base, a narrower skull, porion and the articular eminence located more superiorly and posteriorly, a shorter posterior midfacial height, the palatal plane rotated clockwise, a more retrognathic maxilla and mandible, and the upper posterior occlusal plane more inclined and posteriorly located. The results suggest that differences in craniofacial morphology are highly integrated with differences in the positional relationship of the temporal bones. The sagittal inclination of the temporal bone seems to have a greater impact on the 3D morphology of the craniofacial complex than frontal inclination.

Anterior and posterior compartment 3D endovaginal ultrasound anatomy based on direct histologic comparison

We used direct histologic comparison to validate the use of 3D endovaginal ultrasound (EVUS) as a novel and emerging technology for evaluating the structures found in the anterior and posterior pelvic floor compartments. A young nulliparous female pelvis specimen was dissected and histologic slides were prepared by making 8-Micron-thick sagittal cuts. The slides were stained with Mallory trichrome and arranged to form large sections encompassing each anterior and posterior sagittal plane. Healthy nulliparous women underwent 3D EVUS to obtain 3D cubes of the anterior and posterior compartments. Two investigators independently evaluated the anterior and posterior midsagittal structures. The investigators mutually viewed the images and calculated urethral and anal sphincter measurements. Thirty-one nulliparous women underwent 3D EVUS; 77% of the participants were Caucasian, with mean age 31.8 [standard deviation (SD) 5.8] and mean body mass index (BMI) of 28.5 (SD 7.9). The following mean (SD) measurements were obtained: urethral length 36 mm (± 5); striated urogenital sphincter area 0.6 cm(2) (± 0.16); longitudinal and circular smooth muscle area 1.1 cm(2) (± 0.4); urethral complex width 14 mm (± 2); urethral complex area 1.3 cm(2) (± 0.4); internal anal sphincter length 26 mm (± 4); internal anal sphincter thickness 3.2 mm (± 0.8); and rectovaginal septum length 31 mm (± 5). The agreement for visualization of structures was as follows: vesical trigone 96% (κ = 0.65), trigonal ring 94% (κ = 0.8), trigonal plate 84% (κ = 0.6); longitudinal and circular smooth muscle 100%; compressor urethra 97% (κ = 0.85); striated urogenital sphincter 97% (κ = 0.85); rectovaginal septum 100%; internal anal sphincter 100%; external anal sphincter subdivisions 100%. Three-dimensional EVUS can be used to visualize structures of the anterior and posterior compartments in nullipara.

Study of the three‐dimensional orientation of the labrum: its relations with the osseous acetabular rim

Understanding the three-dimensional orientation of the coxo-femoral joint remains a challenge as an accurate three-dimensional orientation ensure an efficient bipedal gait and posture. The quantification of the orientation of the acetabulum can be performed using the three-dimensional axis perpendicular to the plane that passes along the edge of the acetabular rim. However, the acetabular rim is not regular as an important indentation in the anterior rim was observed. An innovative cadaver study of the labrum was developed to shed light on the proper quantification of the three-dimensional orientation of the acetabulum. Dissections on 17 non-embalmed corpses were performed. Our results suggest that the acetabular rim is better represented by an anterior plane and a posterior plane rather than a single plane along the entire rim as it is currently assumed. The development of the socket from the Y-shaped cartilage was suggested to explain the different orientations in these anterior and posterior planes. The labrum forms a plane that takes an orientation in between the anterior and posterior parts of the acetabular rim, filling up inequalities of the bony rim. The vectors V(L) , V(A2) and V(P) , representing the three-dimensional orientation of the labrum, the anterior rim and the posterior rim, are situated in a unique plane that appears biomechanically dependent. The three-dimensional orientation of the acetabulum is a fundamental parameter to understand the hip joint mechanism. Important applications for hip surgery and rehabilitation, as well as for physical anthropology, were discussed.

Antagonist muscle moment is increased in ACL deficient subjects during maximal dynamic knee extension

IntroductionCoactivation of the hamstring muscles during dynamic knee extension may compensate for increased knee joint laxity in anterior cruciate ligament (ACL) deficient subjects. This study examined if antagonist muscle coactivation during maximal dynamic knee extension was elevated in subjects with anterior cruciate ligament (ACL) deficiency compared to age-matched healthy controls. MethodsElectromyography (EMG) and net knee joint moments were recorded during maximal concentric quadriceps and eccentric hamstring contractions, performed in an isokinetic dynamometer (ROM: 90–10°, angular speed: 30°/s). Hamstring antagonist EMG recorded during concentric quadriceps contraction was converted into antagonist moment based on the EMG–moment relationship observed during eccentric agonist contractions. ResultsThe magnitude of antagonist hamstring EMG was 65.5% higher in ACL deficient subjects compared to healthy controls (p<0.05). Likewise, antagonist hamstring moment expressed in percentage of the measured net extension moment was elevated in ACL deficient subjects (56±8 to 30±6%) compared to controls (36±5 to 19±2%) at 20–50° of knee flexion (0°=full extension) (p<0.05). DiscussionThe results showed a marked increase in hamstring coactivation towards more extended joint positions. Notably, this progressive rise in coactivation was greater in ACL deficient subjects, which may reflect a compensatory strategy to provide stability to the knee joint in the anterior–posterior plane during isolated knee extension. The present study encourages further investigations of hamstring coactivation in ACL deficient subjects.

Three-dimensional anal endosonography in depicting anal-canal anatomy

This report describes the advantages of 3D anal endosonography in depicting the normal anatomy of the anal canal in relation to sex and age. A retrospective study was performed of 85 patients, 33 men and 52 women, previously examined with 3D anal ultrasound (US) for clinically suspected anorectal disease but found to be negative. The examinations were performed with a Bruel and Kjaer US system with a 2050 transducer, scanning from the anorectal junction to the subcutaneous portion of the external anal sphincter (EAS). The 3D reconstructions provided an estimation of sphincter length in the anterior and posterior planes, and axial 2D images enabled calculation of the thickness of the internal anal sphincter (IAS) and EAS in the anterior, posterior and lateral transverse planes. Distribution of the sphincter complex is asymmetric in both sexes: the EAS and IAS are significantly shorter in females, especially in the anterior longitudinal plane (p=0.005 and p<0.001, respectively). EAS and IAS thickness increases with age, especially the lateral IAS (R(2)=0.37, p<0.001) and the posterior EAS (R(2)=0.29, p=0.01). A good knowledge of anal-canal anatomy is essential to detect sphincter abnormalities when assessing pelvic floor dysfunction.