Direct Intraoperative Measurement Research Articles

Direct intraoperative measurement of isometric contractile properties in living human muscle.

Skeletal muscle's isometric contractile properties are one of the classic structure-function relationships in all of biology allowing for extrapolation of single fibre mechanical properties to whole muscle properties based on the muscle's optimal fibre length and physiological cross-sectional area (PCSA). However, this relationship has only been validated in small animals and then extrapolated to human muscles, which are much larger in terms of length and PCSA. The present study aimed to measure directly the in situ properties and function of the human gracilis muscle to validate this relationship. We leveraged a unique surgical technique in which a human gracilis muscle is transferred from the thigh to the arm, restoring elbow flexion after brachial plexus injury. During this surgery, we directly measured subject specific gracilis muscle force-length relationship in situ and properties ex vivo. Each subject's optimal fibre length was calculated from their muscle's length-tension properties. Each subject's PCSA was calculated from their muscle volume and optimal fibre length. From these experimental data, we established a human muscle fibre-specific tension of 171kPa. We also determined that average gracilis optimal fibre length is 12.9cm. Using this subject-specific fibre length, we observed an excellent fit between experimental and theorical active length-tension curves. However, these fibre lengths were about half of the previously reported optimal fascicle lengths of 23cm. Thus, the long gracilis muscle appears to be composed of relatively short fibres acting in parallel that may not have been appreciated based on traditional anatomical methods. KEY POINTS: Skeletal muscle's isometric contractile properties represent one of the classic structure-function relationships in all of biology and allow scaling single fibre mechanical properties to whole muscle properties based on the muscle's architecture. This physiological relationship has only been validated in small animals but is often extrapolated to human muscles, which are orders of magnitude larger. We leverage a unique surgical technique in which a human gracilis muscle is transplanted from the thigh to the arm to restore elbow flexion after brachial plexus injury, aiming to directly measure muscles properties in situ and test directly the architectural scaling predictions. Using these direct measurements, we establish human muscle fibre-specific tension of ∼170kPa. Furthermore, we show that the gracilis muscle actually functions as a muscle with relatively short fibres acting in parallel vs. long fibres as previously assumed based on traditional anatomical models.

Correlations Between Radial Head Diameters and Humeral Articular Dimensions: Bilateral MRI Morphometric Analysis on 39 Healthy Subjects

Choosing the correct size of head component in radial head arthroplasty is often challenging, particularly in comminuted fractures, deformities, and revision surgery. The main aim of this study was to investigate possible correlations between radial head diameters and the morphometric parameters of the articular distal humerus in order to find mathematical equations that may be used to infer radial head dimensions indirectly. We performed bilateral elbow magnetic resonance imaging on 39 healthy young subjects, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). The following measurements, which included cartilage thickness, were calculated on the axial plane: maximum (Dmax) and minimum (Dmin) radial head diameters, capitellum width, capitellum to lateral trochlear ridge width (CAP-TROCHridge), humeral articular width (HUMwidth), capitellum radius of curvature, and lateral, medial, and total trochlear width. The anteroposterior diameters of the capitellum, trochlear sulci, and lateral and medial trochlear ridges were measured on the sagittal plane. CAP-TROCHridge and HUMwidth were found to be the parameters most strongly correlated with the radial head diameters. Four mathematical equations that allowed Dmax and Dmin to be calculated with an average residual error less than 1 mm, were obtained. The intraclass coefficient was greater than 0.95 for all the measurements. Radial head diameters can be accurately inferred from 2 humeral dimensions by magnetic resonance imaging. The HUMwidth, which is not influenced by cartilage thickness, may be useful for planning with preoperative imaging because it can also be calculated by computed tomography scan, whereas CAP-TROCHridge, which is influenced by cartilage thickness, might be useful for direct intraoperative measurement. Diagnostic III.

Resection of hepatocellular carcinoma in patients with portal hypertension: long-term results based on direct intraoperative measurement of portal venous pressure

Introduction: The existence of differences in long-term prognosis of hepatocellular carcinoma (HCC) patients with or without portal hypertension (PH) undergoing hepatic resection remains controversial. Our aim was to clarify the long-term prognosis of HCC patients with PH undergoing hepatectomy. PH diagnosis was based on intraoperative portal venous pressure (PVP) measurement. Materials and Methods: Between May 2001 and April 2005, 68 patients with HCC underwent liver resection. PVP was directly measured at the beginning of surgery. Patients were divided into a high (>11 mm Hg) (n=33) or a low (≤11 mm Hg) (n=35) PVP group. Clinicopathologic factors and postoperative outcomes were compared between the 2 groups, with tumor staging stratification according to Milan criteria (selection criteria for patients receiving transplantation). Median follow-up time was 101 months. Results: Postoperative mortality was 0. Median PVP was 10.7 mm Hg (range; 2.9–23.5 mm Hg). Compared with patients with low PVP, patients with high PVP had lower platelet counts, lower serum albumin levels, higher ALT concentration, higher international normalized ratio, higher Model for End-Stage Liver Disease (MELD score), and increased blood loss and blood transfusion. Multivariate logistic regression analysis revealed factors related to high PVP: serum albumin level <3.6 g/dL (odd ratio: 5.532, 95% confidence interval: 1.286-23.79, P=0.022), and MELD score >6 (odd ratio: 5.585; 95% confidence interval: 1.638-19.040, P=0.006). Postoperative morbidity was comparable between the 2 groups. Overall survival and disease-free survival rates in the high PVP group were significantly lower than in the low PVP group (P<0.05). Subgroup analysis showed that, for patients within Milan criteria, those in the high PVP group had lower overall survival (P=0.032) and disease-free survival (P=0.016) than in those in the low PVP group. For patients outside the Milan criteria, no differences in survival were observed. Conclusions: In patients with early stage HCC undergoing resection, high PVP is associated with impaired long-term prognosis. For these patients, close follow-up and early salvage liver transplants for recurrent disease may be necessary to improve long-term prognosis after surgery.

Intraoperative Sphenoid Sinus Volume Measurement as an Alternative Technique to Intraoperative Computer Tomography.

Isolated sphenoid sinus disease (ISSD) is where there is a group of pathologies characterized by inflammation in one or both sphenoid sinuses. Although computer tomography (CT)-based 3D reconstruction remains the gold standard among noninvasive approaches to ISSD diagnostics, no standardized techniques for direct intraoperative measurements of the sphenoid sinus volume in ISSD patients have been documented. We suggest a novel technique for the intraoperative measurement of the sphenoid sinus volume. Our technique is based on filling the sinus with 0.01% methylene blue solution after an endoscopic endonasal sphenoidotomy. The proposed technique was applied to 40 ISSD patients during surgery. Obtained intraoperative measurements were compared to noninvasive measurements from 3D reconstructions based on preoperative CT scans. Our results demonstrated that the obtained measurements did not exhibit significant differences exceeding 0.4 cm3, with CT-scan-based measurements in 39 out of 40 cases (p < 10−6, Wilcoxon sign-rank nonparametric test), thus confirming the accuracy of the proposed technique. Disagreements between direct intraoperative and CT-based measurements in a single case have been attributed to the presence of remaining pathological masses in the sinus, which was further confirmed during the secondary check of the operated sinus. Accordingly, we suggest that the agreement between the CT-based and intraoperative volume measurements can be used as an indicator of the successful elimination of all pathological masses from the sinus without having to perform an adequate exposure of the entire sphenoid sinus to reduce intraoperative bleeding. The proposed technique is accurate and does not require the involvement of specialized intraoperative CT scanners and avoids additional radiation exposure for the patient during an additional postoperation CT scan to confirm the success of the surgery.

Influence of implant mucosal thickness on early bone loss: a systematic review with meta-analysis.

PurposeMarginal bone loss (MBL) is an important clinical issue in implant therapy. One feature that has been cited as a contributing factor to this bone loss is peri-implant mucosal thickness. Therefore, in this report, we conducted a systematic review of the literature comparing bone remodeling around implants placed in areas with thick (≥2-mm) vs. thin (<2-mm) mucosa.MethodsA PICO question was defined. Manual and electronic searches were performed of the MEDLINE/PubMed and Cochrane Oral Health Group databases. The inclusion criteria were prospective studies that documented soft tissue thickness with direct intraoperative measurements and that included at least 1 year of follow-up. When possible, a meta-analysis was performed for both the overall and subgroup analyses.ResultsThirteen papers fulfilled the inclusion criteria. A meta-analysis of 7 randomized clinical trials was conducted. Significantly less bone loss was found around implants with thick mucosa than around those with thin mucosa (difference, −0.53 mm; P<0.0001). Subgroups were analyzed regarding the apico-coronal positioning, the use of platform-matched vs. platform-switched (PS) connections, and the use of cement-retained vs. screw-retained prostheses. In these analyses, thick mucosa was found to be associated with significantly less MBL than thin mucosa (P<0.0001). Among non-matching (PS) connections and screw-retained prostheses, bone levels were not affected by mucosal thickness.ConclusionsSoft tissue thickness was found to be correlated with MBL except in cases of PS connections used on implants with thin tissues and screw-retained prostheses. Mucosal thickness did not affect implant survival or the occurrence of biological or aesthetic complications.Trial RegistrationInternational Prospective Register of Systematic Reviews (PROSPERO): CRD42018084598

Fact or myth? The long shared common wall between the fistula and the urethra in male anorectal malformation with urethral bulbar fistula.

It has long been considered surgical dogma that the length of the shared common wall (CW) between a fistula and the urethra in males with anorectal malformation (ARM) and rectourethral bulbar fistula (RUBF) is considerably longer than in males with ARM and rectourethral prostatic fistula (RUPF). This belief has led surgeons who perform laparoscopic-assisted anorectoplasty (LAARP) for RUPF to avoid LAARP for RUBF for risk of potential injury to the urethra or incomplete removal of the fistula. In this study, we compared CW between RUBF and RUPF using distal colostography (DCG) and direct intraoperative measurements. DCG of rectourethral fistula patients (n = 63; RUBF: n = 44; RUPF: n = 19) were used to measure CW retrospectively. Results were expressed as a ratio of the height of L4; i.e., CW:L4. If less than 0.7, the CW was classified as being "short"; if 0.71-1.4, as being "medium"; and if greater than 1.41, as being "long". CW that could not be measured was classified as indeterminate. 24 of these patients also had CW measured intraoperatively during LAARP as previously described. The results obtained using both techniques were also compared. Surprisingly, CW:L4 in RUBF patients was short in 47.7%, medium in 27.3%, long in 20.5%, and indeterminate in 4.5% on DCG, equivalent to mean lengths of 7mm, 8.5mm, and 10.3mm obtained using direct intraoperative measurement for short, medium, and long CW:L4 categories, respectively. CW:L4 in RUPF was short in 73.6%, medium in 10.5%, and long in 5.2% on DCG, while mean intraoperative measurements were 5mm, 7mm, and 10mm, respectively. Differences in CW measured intraoperatively were not significantly different between RUBF and RUPF (p = NS). From our findings, 47.7% of CWs in RUBF were short using two independent methods, with only 20.5% being long. Thus, LAARP should be considered actively for treating selected RUBF cases and not be excluded on the basis of CW length.

Accuracy and usefulness of aortic annular measurement using real-time three-dimensional transesophageal echocardiography: Comparison with direct surgical sizing

BackgroundThere is a paucity of data that demonstrates a clinical impact of anatomical measurements of the aortic annulus by three-dimensional (3D) transesophageal echocardiography (TEE) on surgical aortic valve replacement (AVR). The aim of this study is to validate the accuracy of 3D TEE measurements compared with the direct intraoperative annular diameter and to investigate an impact of 3D TEE on a prediction of AVR with aortic annular enlargement (AAE). Methods and resultsWe retrospectively enrolled 61 patients who underwent both two-dimension (2D) and 3D TEE and transthoracic echocardiography (TTE) before AVR. The annular diameters were measured noninvasively with 2D TEE (D2D) and TTE (DTTE) in a classical manner and the area- and perimeter-derived annular diameters (Darea, Dperim) were measured from using 3D TEE analysis. Intraoperative annular diameter was measured with the manufacture's sizer (Dintraope). Darea showed the best agreement with Dintraope in the Bland–Altman analysis. Darea, Dperim, D2D, and DTTE correlated well with Dintraope (r=0.821, 0.820, 0.532, and 0.610, respectively; all p<0.001). Three patients underwent AVR with AAE and the specificity of Dperim for prediction of AAE was significantly higher than D2D (p=0.008). Conclusions3D TEE measurement of aortic annular diameter showed better agreement with the direct intraoperative measurement than 2D TEE and TTE measurements. 3D TEE measurement could predict AVR with AAE more accurately than 2D TEE and TTE measurements.

Direct intraoperative measurement of residual pressure gradient after resection of discrete subaortic stenosis

Transesophageal echocardiography (TEE) plays an important role for congenital cardiac surgery, such as measurement of residual shunt, residual regurgitation, residual pressure gradient (PG), and so on. For discrete subaortic stenosis, it could be a simple and effective option to check residual PG by direct intraoperative periaortic retrograde left ventricular catheterization if infantile TEE is not available.

Agreement between intraoperative measurements and optical coherence tomography of the limbus-insertion distance of the extraocular muscles

Objective To assess the agreement between intraoperative measurements of the limbus-insertion distance of the extraocular muscles with those measured by spectral domain optical coherence tomography. Methods An analysis was made of a total of 67 muscles of 21 patients with strabismus. The limbus-insertion distance of the horizontal rectus muscles were measured using pre-operative SD-OCT and intra-operatively in 2 ways: (1) direct, after a conjunctival dissection in patients who underwent surgery, or (2) transconjunctival in patients who were treated with botulinum toxin, or in those who were not going to be operated. The intraclass correlation coefficient and Bland–Altman plots were calculated to determine the concordance between the 2 methods. Results The mean age was 45.9 ± 20.9 years (range 16 to 85), with 52% being women. The percentage of identification by direct intraoperative measurement was 95.6% (22/23), by transconjunctival intraoperative measurement 90.9% (40/44), and by OCT 85% (57/67), with 22 muscles finally being analyzed for the agreement study between direct intraoperative measurement and OCT measurements, and 35 muscles for the agreement between transconjuctival intraoperative measurement and OCT. The intraclass correlation coefficient showed good agreement with OCT and direct intraoperative measurements (0.931; 95% confidence interval (95% CI): 0.839–0.972; P < .001), and with transconjunctival intraoperative measurements (0.889; 95% CI: 0.790–0.942; P < .001). Conclusions The SD-OCT is an effective technique to measure the distance from the insertion of the horizontal rectus muscles to the limbus, with a high agreement with intraoperative measurements being demonstrated.

Concordancia de la distancia desde la inserción hasta el limbo de los músculos rectos entre la medida intraoperatoria y con tomografía de coherencia óptica

ObjectiveTo assess the agreement between intraoperative measurements of the limbus-insertion distance of the extraocular muscles with those measured by spectral domain optical coherence tomography. MethodsAn analysis was made of a total of 67 muscles of 21 patients with strabismus. The limbus-insertion distance of the horizontal rectus muscles were measured using pre-operative SD-OCT and intra-operatively in 2 ways: 1) direct, after a conjunctival dissection in patients who underwent surgery, or 2) transconjunctival in patients who were treated with botulinum toxin, or in those who were not going to be operated. The intraclass correlation coefficient and Bland-Altman plots were calculated to determine the concordance between the 2 methods. ResultsThe mean age was 45.9 ±20.9 years (range 16 to 85), with 52% being women.The percentage of identification by direct intraoperative measurement was 95.6% (22/23), by transconjunctival intraoperative measurement 90.9% (40/44), and by OCT 85% (57/67), with 22 muscles finally being analysed for the agreement study between direct intraoperative measurement and OCT measurements, and 35 muscles for the agreement between transconjuctival intraoperative measurement and OCT. The intraclass correlation coefficient showed good agreement with OCT and direct intraoperative measurements (0.931; 95% confidence interval (95% CI): 0.839–0.972; P<.001), and with transconjunctival intraoperative measurements (0.889; 95% CI: 0.790–0.942; P<.001). ConclusionsThe SD-OCT is an effective technique to measure the distance from the insertion of the horizontal rectus muscles to the limbus, with a high agreement with intraoperative measurements being demonstrated.

Lumbar spinal canal dimensions measured intraoperatively after decompression are not properly rendered on early postoperative MRI.

BackgroundIn cases of lumbar spinal stenosis (LSS) treated with surgical decompression, a postoperative magnetic resonance imaging (MRI) is sometimes required. In the experience of the investigators of this study, the obtained decompression observed on early postoperative MRI tends to be disappointing compared to the decompression achieved intraoperatively. This raises the question of whether the early postoperative MRI, performed after lumbar decompression, is a fair representation of the ‘real’ decompression. This study investigated the correlation between intraoperative and postoperative measurements of the lumbar spinal canal.MethodTwenty patients with LSS underwent surgical decompression on a single level. The orthopaedic surgeon performed direct intraoperative measurements of width, length and height of the spinal canal. Preoperative supine MR images and postoperative prone and supine MR images were acquired. Two radiologists (R.B. and M.G.) measured width, length and height of the spinal canal on the preoperative and postoperative MRIs. Intraoperative measurements were compared to measurements on postoperative MRI in prone position (thus reproducing the intraoperative situation) to avoid positioning bias. Preoperative and postoperative measurements on MR images were also compared. In addition to this, postoperative measurements on supine and prone MR images were also compared.ResultsInterobserver reliability for MRI measurements by both radiologists was generally excellent (intraclass correlation coefficients ≥0.71). The postoperative spinal canal dimensions improved on both prone and supine MRI compared to the preoperative imaging (P < 0.05). Intraoperatively measured dimensions demonstrated a significantly greater height (difference 2.8 ± 3.3 [R.B.] and 1.9 ± 3.7 [M.G.]) and greater width (difference 2.1 ± 3.2 [R.B.] and 2.5 ± 2.7 [M.G.]) compared to postoperative MRI in the prone position (P < 0.05). Postoperative dural sac height was greater on the supine MRI compared to the prone MRI (P < 0.05).ConclusionsSurgical decompression of the spinal canal effectively decreases the compression of the dural sac. However, early postoperative MRI after lumbar decompression does not adequately represent the decompression achieved intraoperatively.

Outpatient Ultrasound Urethrogram for Assessment of Anterior Urethral Stricture: Early Experience

To describe the technique of ultrasound urethrogram (USUG) for the diagnosis of anterior urethral stricture performed in an ambulatory setting without any adjunctive imaging. Between September 2013 and September 2015, 35 consecutive adult men (>18 years old) presenting for anterior urethral reconstruction underwent outpatient USUG prior to definitive management. No alternative imaging test was performed. Lengths of the strictures as determined by outpatient USUG and via direct intraoperative measurements were compared by a paired t test. Strictures were in the bulbar urethra in 24 men and in the penile urethra in 11 men. The differences between the outpatient USUG length measurements (mean = 1.86 cm) and the intraoperative stricture length measurements (mean = 2.02 cm) were not significantly different (P = .10). Additionally, the correlation coefficient between these length measurements was 0.84 (P < .001). Preoperative USUG performed in the ambulatory setting for the diagnosis and characterization of anterior urethral strictures is safe and feasible. This outpatient imaging modality offers an alternative to retrograde urethrogram.

MP15-11 OUTPATIENT ULTRASOUND URETHROGRAM FOR ASSESSMENT OF ANTERIOR URETHRAL STRICTURE RENDERS RADIATION EXPOSURE UNNECESSARY

You have accessJournal of UrologyTrauma/Reconstruction: Urethral Reconstruction (including Stricture) I1 Apr 2015MP15-11 OUTPATIENT ULTRASOUND URETHROGRAM FOR ASSESSMENT OF ANTERIOR URETHRAL STRICTURE RENDERS RADIATION EXPOSURE UNNECESSARY Darren J. Bryk, Yuka Yamaguchi, Shpetim Telegrafi, Mariana Kozirovsky, and Lee C. Zhao Darren J. BrykDarren J. Bryk More articles by this author , Yuka YamaguchiYuka Yamaguchi More articles by this author , Shpetim TelegrafiShpetim Telegrafi More articles by this author , Mariana KozirovskyMariana Kozirovsky More articles by this author , and Lee C. ZhaoLee C. Zhao More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.894AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Knowledge of urethral stricture anatomy is essential for appropriate surgical management. While retrograde urethrogram is considered the gold standard for evaluation, ultrasound urethrogram has been shown to be more accurate in determining anterior urethral stricture length and extent of spongiofibrosis. To date, ultrasound urethrograms have been primarily performed intra-operatively. We report the results of an outpatient ultrasound urethrogram technique, which eliminates the need for radiation exposure. METHODS Twelve consecutive adult men presenting for anterior urethral reconstruction from 10/2013-10/2014 underwent outpatient ultrasound urethrogram. Patients were excluded from this study if any urethral imaging has been performed using radiation (retrograde urethrogram or voiding cystourethrogram). The Siemens Acuson S2000 Ultrasound System is used at our institution. Outpatient retrograde ultrasound urethrogram is performed with the patient in the frog-leg position. Lidocaine gel is injected through the meatus to distend the urethra and act as contrast. Linear High-frequency multi-hertz 18L6 and curved multi-hertz 6C2 probes are used to study the penile and bulbar urethra, respectively. Lengths of strictures as determined by outpatient ultrasound urethrogram and direct intra-operative measurements were analyzed by a paired t-test. RESULTS Table 1 shows the differences between ultrasound urethrogram and intra-operative stricture lengths. The difference between ultrasound urethrogram stricture length measurement (mean=1.7833, standard deviation=0.8892) and intra-operative stricture length measurement (mean=1.7500, standard deviation=1.011) was not significant with t(11)=0.358, p=0.727. Further, the correlation coefficient between the two length measurements is 0.950 (p<0.001). CONCLUSIONS Our technique of outpatient ultrasound urethrogram for the diagnosis and characterization of anterior urethral strictures is simple, accurate, and eliminates the need for radiation exposure for evaluation of anterior urethral strictures. Table 1. Difference between ultrasound urethrogram and intra-operative measured stricture length ultrasound urethrogram length minus intra-operative length (cm) n (total=12) % of sample 0 8 66.6 > 0 to 0.5 2 16.7 < 0 to -0.5 2 16.7 > 0.5 or < -0.5 0 0 © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e163 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Darren J. Bryk More articles by this author Yuka Yamaguchi More articles by this author Shpetim Telegrafi More articles by this author Mariana Kozirovsky More articles by this author Lee C. Zhao More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP15-12 URETHRAL STRICTURE (US) AND ARTIFICIAL URINARY SPHINCTER (AUS) REINSERTION RATES AFTER URETHRAL REPAIR AT THE TIME OF AUS EXPLANTATION FOR EROSION

INTRODUCTION AND OBJECTIVES: Knowledge of urethral stricture anatomy is essential for appropriate surgical management. While retrograde urethrogram is considered the gold standard for evaluation, ultrasound urethrogram has been shown to be more accurate in determining anterior urethral stricture length and extent of spongiofibrosis. To date, ultrasound urethrograms have been primarily performed intra-operatively. We report the results of an outpatient ultrasound urethrogram technique, which eliminates the need for radiation exposure. METHODS: Twelve consecutive adult men presenting for anterior urethral reconstruction from 10/2013-10/2014 underwent outpatient ultrasound urethrogram. Patients were excluded from this study if any urethral imaging has been performed using radiation (retrograde urethrogram or voiding cystourethrogram). The Siemens Acuson S2000 Ultrasound System is used at our institution. Outpatient retrograde ultrasound urethrogram is performed with the patient in the frog-leg position. Lidocaine gel is injected through the meatus to distend the urethra and act as contrast. Linear High-frequency multi-hertz 18L6 and curved multi-hertz 6C2 probes are used to study the penile and bulbar urethra, respectively. Lengths of strictures as determined by outpatient ultrasound urethrogram and direct intra-operative measurements were analyzed by a paired t-test. RESULTS: Table 1 shows the differences between ultrasound urethrogram and intra-operative stricture lengths. The difference between ultrasound urethrogram stricture length measurement (mean1⁄41.7833, standard deviation1⁄40.8892) and intra-operative stricture length measurement (mean1⁄41.7500, standard deviation1⁄41.011) was not significant with t(11)1⁄40.358, p1⁄40.727. Further, the correlation coefficient between the two length measurements is 0.950 (p<0.001). CONCLUSIONS: Our technique of outpatient ultrasound urethrogram for the diagnosis and characterization of anterior urethral strictures is simple, accurate, and eliminates the need for radiation exposure for evaluation of anterior urethral strictures.

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AIMS AND OBJECTIVES: 1. To compare the mitral annulus area measured through indirect 2-dimensional Echocardiography and direct intraoperative measurement with implanted prosthesis area. 2. To determine the existence of area reduction factor (if any) after mitral valve implantation. CONTEXT (BACKGROUND): A frequent mismatch was observed between the anticipated mitral prosthesis dimensions through 2-D Echocardiography and actual best fit size of mitral valve prosthesis. The mitral valve prosthesis was observed of shorter length especially in anterior- posterior dimension on comparing the projected short axis dimensions of annulus by 2-D trans-thoracic Echocardiography. This fact encouraged researchers to investigate the existence of 'area-reduction' on geometrical and statistical parameters. METHODOLOGY: This hospital based longitudinal study was conducted in a tertiary set up for the duration of one year. Sixty-seven Rheumatic Heart Disease (RHD) patients with severe mitral valve disease were included with exclusion of simultaneous significant aortic valve disease. The 2-dimensional trans-thoracic echocardiography was performed on all these patients preoperatively and direct measurement was made intra-operatively to determine mitral valve annular dimensions. Geometrical principles in regards with area of ellipse and circle were used in order to detect the constant related with area reduction. Mean with standard deviation and t-distribution values were calculated for each variable. RESULTS: Prosthetic valve area was not found to be identical with annulus valve area. Calculated value of both coefficients (KE and KD) respectively were 1.961 and 1.644. Further the mean difference in area of annulus fibrosis ((Area echo- Area direct) by ECHO and intraoperatively was calculated as 192.8400(135.017-250.663) which was statistically significant {t=6.5961(df=134); p<0.0001}. CONCLUSION: This study proved the existence of reduction of area during mitral valve prosthesis implant mathematically; which may further affect the fluid dynamics and hemodynamic changes in

English

CONTEXT: Precise estimation of Mitral valve annulus dimensions preoperatively through Echocardiography is of paramount importance in replacement/repair surgeries. However a frequent disagreement was experienced between anticipated size of prosthetic valve based on echocardiography and actual valve size. This fact encouraged the authors to validate the measurements through echocardiography with gold-standard direct intra operative measurement. AIM: To compare the mitral valve anterior-posterior (short axis) and commissure -commissural (long axis) annulus dimensions estimated through 2D Trans-thoracic Echocardiography with Gold Standard direct Intra-operative Measurement. SETTING AND DESIGN: Hospital based prospective longitudinal study. MATERIALS AND METHODS: 67 participants suffering from Rheumatic Heart Disease (RHD) patients with severe mitral valve disease were underwent 2-dimensional trans- thoracic echocardiography preoperatively to determine mitral valve short and long axis. Direct measurements for the same were made intra-operatively at the diastolic arrested heart through left atriotomy. STATISTICAL ANALYSIS: Univariate analysis (t-test) for difference of mean, confidence interval with standard error estimation. RESULTS AND CONCLUSION: Mitral valve annulus axis measurements with or without consideration of Body Surface Area (BSA) were significantly overestimated by 2-D echocardiography judged against direct measurement. A mathematical model or correction index is proposed further to estimate the prosthesis size from these overvalued

Experimental substantiation of acetabular component impaction with uncoverage in arthroplasty of patients with severe hip dysplasia

Purpose. Estimation of critical value of acetabular component uncoverage enabling its implantation without an additional support. Methods. A comparative analysis of an original method for intraoperative measurement of uncoverage space of acetabular component based on the measurement of the depth of uncovered sector with X-ray control by the same technique was carried out. Mathematical computer modeling based on the finite element techniqueand the mechanical experiment were performed. Critical values of uncoverage enabling safe primary fixation of acetabular component were estimated in designed models. Results. High rate of coincidence of direct intraoperative and postoperative measurements by radiograms was obtained, testifying to the possibility of application of this technique of uncoverage estimation at the stage of preoperative X-ray planning in patients with different degree of dysplasia. Using the finite element technique and the mechanical experiment on pelvis models, a possibility of mounting anacetabular component with moderate uncoverage within 25% without screws and with significant uncoverage to 35% with additional two screws fixation was demonstrated.

A +20% Adjustment in the Computed Tomography Measured Ureteral Length Is an Accurate Predictor of True Ureteral Length Before Ureteral Stent Placement

The correct length of a ureteral stent is important in minimizing postplacement discomfort and stent migration. We describe and validate a method to accurately measure the ureteral length. The ureteral length in 48 patients undergoing ureteral stent placement for urolithiasis was measured by computed tomography (CT) (total thickness of axial slices between the ureteropelvic junction and ureterovesical junction) and adjusted up by 20%. The adjusted CT measurement of ureteral length was compared with direct intraoperative measurement using scatter plot and Pearson correlation coefficient. Correlation coefficients were also calculated between intraoperative ureteral length and various body habitus measurements such as the height, weight, and waist circumference. Median patient age was 62 years. The median stone diameter was 7.5 mm (1-20). The ratio of left- to right-sided stones was 2:1. The stone location was in the proximal ureter in 45.8%, distal ureter in 37.5%, kidney in 10.4%, and midureter in 6.3%. Symptoms included adnominal/flank pain (93.8%) followed by nausea/vomiting (39.6%) and gross hematuria (16.7%). Median creatinine was 1.4 (0.8-3.6 mg/dl) and median WBC was 8.6 (2.8-17.6). The median ureteral length was 25.8 cm (19.2-29.4) on the CT scan and 25.5 cm (19.0-29.0) on the intraoperative measurement (p=0.57). The Pearson correlation coefficient between the two measurements was 0.979. In contrast, the height, weight, and waist circumference correlated poorly with intraoperative ureteral length measurements (r=0.34, 0.19, and 0.40, respectively). CT-measured ureteral length adjusted up by 20% is a reliable method to accurately measure the true ureteral length. This method is superior to traditional indirect methods that rely on body habitus measurements.

Comparison of the Amount of Iliopsoas Tendon Lengthening That Occurs after ArthroscopicLabral-Level and Lesser Trochanteric Tenotomies

Objectives:The success of arthroscopic iliopsoas tenotomies (AIT’s) performed at the level of the lesser trochanter for treatment of a painful snapping tendon is well documented. Currently, iliopsoas labral-level tenotomies have been advocated for treatment of this problem. However, a recent study reported a high incidence (∼50%) of recurrent snapping after iliopsoas tendon (IT) releases at this level (1). The purpose of this study was to determine if there is a difference in the amount of tendon separation/lengthening following AIT’s at the labral and lesser trochanteric levels. To date, the amount of tendon separation that occurs after releases at these two sites has not been reported. Methods:From the senior author’s data base of 900 hip arthroscopies, 80 patients who had arthroscopic iliopsoas tenotomies performed:1) at the level of the labrum (40 patients); or 2) at the lesse rtrochanter (40 patients) were identified. The amount of tendon separation/lengthening in these 80 patients was determined either from direct intra-operative measurements (40 patients) or from measurements made off of the intra-operative photographs. Image magnification on the intra-operative photographs was controlled for by basing the measurements of tendon separation on the known dimensions of the radiofrequency probe or 5 mm cannula that was present in each iliopsoas release picture (Figure 1). Two sample t tests were used for data analysis with p = <0.05 defined as significant. Results:Average age of the 40 patients with labral-level (LL) tenotomies was 36 years (range 16-58 years), and there were 9 males and 31 females and 19 left and 21 right hips in this group. Average age of the 40 patients with lesser trochanteric (LT) tenotomies was 32 years (range 17-55 years), and there were 8 males and 32 females, and 11 left and 29 right hips in this group. In the LL tenotomy group, the average tendon separation was 8.3 ± 2.04 mm. In the LT tenotomy group, the average tendon separation was 13.3 ± 3.01 mm. The 0.5 cm difference in the amount of tendon separation between the two groups was statistically significant at the p<0.001 level. Conclusion:An arthroscopic, lesser trochanteric iliopsoas tenotomy produces significantly greater (0.5 cm) tendon separation than tenotomies performed at the level of the labrum. The difference in the amount of tendon separation that occurs at these two sites may explain the high rates of recurrent snapping (∼50%) that have been reported with arthroscopic and open labral-level releases.

Relationship between MRI-based mechanical activation delays and direct intraoperative measurements of electrical delay in patients undergoing cardiac resynchronization

Background Magnetic Resonance Imaging (MRI) can be used to create maps of left ventricular (LV) mechanical activation delay by analyzing time-dependent radial motion of the myocardium. Local electrograms (EGM) can be obtained during the CRT procedure to measure local electrical activation delay in the LV myocardium. Preoperative MRI assessment of regional dyssynchrony would be useful to guide CRT lead placement. However, the relationship between electrical and mechanical dyssynchrony has not been studied in humans. We hypothesized that intraoperative electrical delay times will correlate with MR-based mechanical delay times.