Clamp Placement Research Articles

Accuracy of warm ischemia time measurement using a surgical intelligence software in partial nephrectomies: A validation study

AbstractObjectivesThe objectives of this study are to compare the accuracy of warm ischemia times (WITs) derived by a surgical artificial intelligence (AI) software to those documented in surgeon operative reports during partial nephrectomy procedures and to assess the potential of this technology in evaluating postoperative renal function.Patients and methodsA surgical AI software (Theator Inc., Palo Alto, CA) was used to capture and analyse videos of partial nephrectomies performed between October 2023 and April 2024. The platform utilized computer vision algorithms to detect clamp placement and removal, enabling precise WIT measurement. Expert‐reviewed surgical videos served as the ground truth. Platform‐derived WITs were compared to those in surgeon operative reports using paired‐sample t‐tests. Additionally, we analysed the correlation between platform‐derived WITs and postoperative creatinine levels extracted from electronic health records (EHRs) integrated via health level seven (HL7) messaging protocols.ResultsOf 64 eligible cases, 61 were included in the final analysis. Platform‐derived WITs were within 1 min of the ground truth in all procedures, within 30 s in 97%, and within 10 s in over 80%. The mean difference between platform‐derived WITs and ground truth was 8.3 s, significantly lower than the 2.45 min difference for operative reports (p < 0.001). No significant correlation was found between platform‐derived WIT and postoperative creatinine changes, aligning with the view that WIT may not independently determine postoperative renal function. Although not the primary goal of this study, significant correlations were observed between WIT, tumour size and RENAL score.ConclusionThis study demonstrates the high accuracy of a surgical intelligence platform in measuring WIT during partial nephrectomies. The findings support the use of AI‐based surgical time measurement for precise intraoperative documentation and highlight the potential of integrating these data with EHRs to advance research on surgical outcomes.

Comparing the Efficacy of 5% EMLA Cream and 20% Benzocaine Gel on Gingival Tissue Surrounding Non-Carious Cervical Lesions for Reduction of Pain Following Rubber Dam Clamp Placement: A Split-Mouth Randomized Clinical Trial.

Aim The aim of this study was to evaluate the effectiveness of 5% eutectic mixture of local anesthetics (EMLA) cream and 20% benzocaine gel in reduction of pain during rubber dam clamp placement in the treatment of non-carious cervical lesions (NCCLs). Methodology In this split-mouth single-blind randomized clinical trial, 50 adult participants were selected from the outpatient department. The test group was treated using 5% EMLA cream for three minutes, and visual analog scale (VAS) scores were recorded. The comparison group was treated using 20% benzocaine gel and procedure was repeated as that in the test group. After recording the VAS scores, NCCLs in both the groups were restored using composite restoration. Results In the included 50 participants, 70% were males, with an age group of 31-67 years. The mean VAS score at 3 minutes in EMLA group was significantly lower than that in benzocaine group. Conclusion Application of 5% EMLA cream for 3 minutes showed greater pain reduction during rubber dam clamp placement as compared to 20% benzocaine gel in adult patients with NCCLs.

Endopelvic zones and constant fragment mapping in acetabular fractures

ObjectiveThis study aims to characterize the constant fragment (CF) in acetabular fractures and to provide a novel nomenclature of anatomic zones from the vantage point of the endopelvic approach. DesignRetrospective clinical study SettingUrban Level I trauma center, Patients/participants: One hundred and eleven consecutive acetabular fractures eligible for an AIP approach and treated surgically. Intervention: 3D mapping of the CF line of fractures using a novel endopelvic anatomical zoning system. Main outcome measurement: Correlation of Letournel's fracture types to the size of the CF and its location based on precise anatomical nomenclature. ResultsThe average age of patients was 47 years (range, 12 to 88 years), predominantly comprising male patients (78 %, n = 87) and female patients (22 %, n = 24). Fractures were grouped into 3 categories based on the size of the CF and its location from anterior to posterior. Group 1 included AC fractures which demonstrated the largest CF. The CF nearly always spared Zone 4. Group 2 included transverse fractures, T-Type fractures, and T-Type with posterior wall fractures. The CF was of intermediate size, and it often spared Zone 4. Group 3 included anterior column posterior hemitransverse fractures and associated both column fractures. The CF was the smallest of all categories and rarely spared Zone 4. ConclusionOur analysis suggests consistent and repeatable patterns and sizes of constant fragments. These findings can serve as an endopelvic roadmap for the AIP approach based on fracture types, guiding placement of reduction clamps, vectors of reduction and hardware position.

Mechanical Testing of Sliding on Pivot-Locking Clamp (SOP-LC) Fracture Repair System in Four-Point Bending and Torsion.

The first objective of this study was to compare the mechanical performance of a straight and contoured rod for the sliding on pivot-locking clamp (SOP-LC) system. The second objective was to compare single-cycle bending and torsion of the SOP-LC rod-bone constructs to a bone gap model between two clamp configurations. First experiment, 5 mm diameter rods from the 3.5 mm SOP-LC system, 4 straight and 4 bent rods were mechanically compared in four-point bending. The second experiment, 8 constructs with clamps on a single side of the rod and 8 constructs with clamps on alternating sides were compared in four-point bending and torsion. A torque limiting screwdriver at 2.5N was used for all constructs. There were not significant differences between the noncontoured versus contoured rods. Constructs with clamps on a single side had a significantly higher yield load, yield displacement and bending strength, but the constructs with alternating clamps had a significantly higher initial torsional stiffness. There were no other significant differences. Mild clamp slippage and mild screw bending were noted in all the torsion tested constructs graphically with multiple stiffness slopes and visually on the post-tested constructs. Torque applied to initial screw placement may play a role in reducing clamp slippage. Although bending yield load, bending yield displacement, bending strength and torsional stiffness were improved by different clamp placement, clinically this will depend on fracture type. Further studies are needed for clinical significance.

Coral reef aorta: a rare form of obstruction of the ascending aorta in adolescent with aortopathy- case report

BackgroundSupra aortic obstruction in children is uncommon and is seen in certain unique conditions. While intraluminal obstruction due to heavy calcification is seen in older populations, it is not described in pediatric populations. The coral reef aorta is a rare and distinct calcifying disease causing luminal obstruction of the suprarenal aorta in adults. The definition of this diagnosis relies entirely on the unique aspects and consistency of the lesions, which are rock-hard, irregular, gritty plaques with a white luminal surface resembling a coral reef. However, no such case has been described in children.Case presentationWe present an adolescent boy who presented with a heavily calcified ascending aortic lesion associated with aortopathy and hypertension, 12 years after an aortic coarctation repair. The investigations included echocardiography, magnetic resonance and computer-tomographic imaging. A 3-D model was printed in order to visualize and plan surgical steps in advance for safe placement of clamps and defining the extent of resection. In addition, it provided an idea about tissue quality, thickness, spatial relationship, and orientation in relation to surrounding structures. Successful resection and replacement of the diseased segment of the aorta were achieved on cardiopulmonary bypass support. Post-operative recovery was uneventful, and at 6-month follow-up, the patient is doing well. In this report, various aspects of such lesions have been discussed, including clinical presentations, complications, planning and conduct of a safe cardiopulmonary bypass, and precautions during surgery for a successful outcome.ConclusionComplicated obstructive aortic lesions in children require careful assessment, appropriate advanced imaging, and the use of 3-D printing technology in order to plan and perform safe and effective surgical management. The etiology of severe calcified aorta in children may be related to metabolic factors, previous surgery, use of a homograft, or an inflammatory process. However, it has yet to be proven.

The Center-Center Image Closely Approximates Other Methods for Syndesmosis Reduction Clamp Placement.

The optimal placement for a syndesmosis reduction clamp remains an open question. This study compared the center-center axis, which localizes clamp placement using only an internally rotated lateral ankle X-ray, with other common approaches, whose accuracy can only be confirmed using computed tomography (CT). Bone models of anatomically aligned (n = 6) and malreduced (n = 48) limbs were generated from CT scans of cadaveric specimens. Four axes for guiding clamp placement (center-center, centroid, B2, and trans-syndesmotic) were then analyzed, using digitally reconstructed radiographs derived from the bone models. Each axis' location was defined using angle-height pairs that describe axis orientation along the full anatomical region where syndesmosis fixation occurs. In anatomically aligned limbs, the center-center axis was located on average (±95% CI [confidence interval]), 0.64° (±0.50°) internal rotation, 1.03° (±0.73°) internal rotation, and 2.09° (±7.29°) external rotation from the centroid, B2, and trans-syndesmotic axes, respectively. Fibular displacement altered the magnitude of limb rotation needed to identify the center-center axis. The center-center technique is a valid method that closely approximates previously described methods for syndesmosis clamp placement without using CT, and the magnitude of C-arm rotation needed to transition from a talar dome lateral to a center-center view may be a potential method for assessing syndesmosis reduction. Level III: Retrospective comparative study.

Virtual Planning and Patient-Specific Graft Design for Aortic Repairs.

Patients presenting with coarctation of the aorta (CoA) may also suffer from co-existing transverse arch hypoplasia (TAH). Depending on the risks associated with the surgery and the severity of TAH, clinicians may decide to repair only CoA, and monitor the TAH to see if it improves as the patient grows. While acutely successful, eventually hemodynamics may become suboptimal if TAH is left untreated. The objective of this work aims to develop a patient-specific surgical planning framework for predicting and assessing postoperative outcomes of simple CoA repair and comprehensive repair of CoA and TAH. The surgical planning framework consisted of virtual clamp placement, stenosis resection, and design and optimization of patient-specific aortic grafts that involved geometrical modeling of the graft and computational fluid dynamics (CFD) simulation for evaluating various surgical plans. Time-dependent CFD simulations were performed using Windkessel boundary conditions at the outlets that were obtained from patient-specific non-invasive pressure and flow data to predict hemodynamics before and after the virtual repairs. We applied the proposed framework to investigate optimal repairs for six patients (n = 6) diagnosed with both CoA and TAH. Design optimization was performed by creating a combination of a tubular graft and a waterslide patch to reconstruct the aortic arch. The surfaces of the designed graft were parameterized to optimize the shape. Peak systolic pressure drop (PSPD) and time-averaged wall shear stress (TAWSS) were used as performance metrics to evaluate surgical outcomes of various graft designs and implantation. The average PSPD improvements were 28% and 44% after the isolated CoA repair and comprehensive repair, respectively. Maximum values of TAWSS were decreased by 60% after CoA repair and further improved by 22% after the comprehensive repair. The oscillatory shear index was calculated and the values were confirmed to be in the normal range after the repairs. The results showed that the comprehensive repair outperforms the simple CoA repair and may be more advantageous in the long term in some patients. We demonstrated that the surgical planning and patient-specific flow simulations could potentially affect the selection and outcomes of aorta repairs.

Reducing pain and discomfort associated with rubber dam clamp placement in children and adolescents: a systematic review and meta-analysis of effectiveness

BackgroundThe application of rubber dams is a widely accepted method of tooth isolation in dental practice. Placement of the rubber dam clamp might be associated with levels of pain and discomfort, especially in younger patients. The purpose of the present systematic review is to evaluate the efficacy of the methods for reducing pain and discomfort associated with rubber dam clamp placement in children and adolescents.Materials and methodsEnglish-language literature from inception until September 6th, 2022 was searched in MEDLINE (via PubMed), SCOPUS, Web of Science, Cochrane, EMBASE, and ProQuest Dissertations & Theses Database Global for articles. Randomized controlled trials (RCTs) comparing methods of reducing the pain and/or discomfort associated with rubber dam clamp placement in children and adolescents were retrieved. Risk of bias assessment was performed using a Cochrane risk of bias-2 (RoB-2) risk assessment tool and the certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence profile.Studies were summarized and pooled estimates of pain intensity scores and incidence of pain were calculated. The meta-analysis was conducted in the following groups according to type of interventions (LA, audiovisual (AV) distraction, behavior management (BM), electronic dental anesthesia (EDA), mandibular infiltration, inferior alveolar nerve block (IANB), TA), outcome (intensity or incidence of pain), and assessment tool (face – legs – activity – cry – consolability (FLACC), color scale, sounds – motor – ocular changes, and faces pain scale (FPS)):(a) pain intensity using (LA + AV) vs (LA + BM), (b) pain intensity using EDA vs LA (c) presence or absence of pain using EDA vs LA (d) presence or absence of pain using mandibular infiltration vs IANB (e) Comparing pain intensity using TA vs placebo (f) Presence or absence of pain using TA vs placebo.Meta-analysis was conducted using StataMP software, version 17.0 (StataCorp, College Station, Texas). Restricted maximum-likelihood random effect model (REML), Mean difference (MD) with 95% confidence interval, and log odds ratio (OR) with 95% CI were calculated were calculated.ResultsInitially, 1452 articles were retrieved. Sixteen RCTs were finally included for reviewing and summarizing. Nine articles with a total of 867 patients were included for quantitative meta-analysis. The differences in pain intensity scores were not significant in any comparison groups (group a: [MD = -0.04 (95% CI = − 0.56, 0.47), P = 0.87, I2 = 0.00%], group b: [MD = 0.25 (95% CI = -0.08, 0.58), P = 0.14, I2 = 0.00%], group c [MD = -0.48 (95% CI = -1.41, 0.45), P = 0.31, I 2 = 0.00%], group d: [MD = -0.67 (95% CI = -3.17, 1.83), P = 0.60, I 2 = 0.00%], group e: [MD = -0.46 (95% CI = -l.08, 0.15), P = 0.14, I 2 = 90.67%], and group f: [MD = 0.61 (95% CI = -0.01, 1.23), P = 0.06, I 2 = 41.20%]. Eight studies were judged as having some concern for risk of bias and the remaining studies were considered as low risk for bias. The certainty of evidence was considered medium for all comparison groups.DiscussionIn the present meta-analysis, a considerable difference was obtained between the included studies regarding intervention methods and pain assessment tools and the analysis was performed in groups with small numbers of the studies. Owing to the mentioned variabilities and the small number of studies, the results of the analysis should be interpreted with caution. The indistinguishability of the manifestations of pain/discomfort from fear/anxiety, particularly in children, should also be considered while using the results of the present study.Within the limitations of the current study, no significant differences were found between the proposed methods for reducing pain and discomfort associated with rubber dam clamp placement in children and adolescents. A larger number of more homogenous studies regarding intervention methods and pain assessment tools need to be conducted in order to draw stronger conclusions.Trial registrationThis study was registered in PROSPERO (ID number: CRD42021274835) and research deputy of Mashhad University of Medical Sciences with ID number 4000838 (https://research.mums.ac.ir/).

Analysis of Early Death after Elective Open Abdominal Aortic Aneurysm Repair

Mortality after open abdominal aortic aneurysm repair is a quality measure and early death may represent a technical complication or poor patient selection. Our objective was to analyze patients who died in the hospital within postoperative day (POD) 0-2 after elective abdominal aortic aneurysm repair. The Vascular Quality Initiative was queried from 2003-2019 for elective open abdominal aortic aneurysm repairs. Operations were categorized as in-hospital death on POD 0-2 (POD 0-2 Death), in-hospital death beyond POD 2 (POD ≥3 Death), and those alive at discharge. Univariable and multivariable analyses were performed. There were 7,592 elective open abdominal aortic aneurysm repairs with 61 (0.8%) POD 0-2 Death, 156 (2.1%) POD ≥3 Death, and 7,375 (97.1%) alive at discharge. Overall, median age was 70years and 73.6% were male. Iliac aneurysm repair and surgical approach (anterior/retroperitoneal) were similar among groups. POD 0-2 Death, compared to POD ≥3 Death and those alive at discharge, had the longest renal/visceral ischemia time, more commonly had proximal clamp placement above both renal arteries, an aortic distal anastomosis, longest operative time, and largest estimated blood loss (all P<0.05). Postoperative vasopressor usage, myocardial infarction, stroke, and return to the operating room were most frequent in POD 0-2 Death and extubation in the operating room was least frequent (all P<0.001). Postoperative bowel ischemia and renal failure occurred most commonly among POD ≥3 Death (allP<0.001).On multivariable analysis, POD 0-2 Death was associated with congestive heart failure, prior peripheral vascular intervention, female sex, preoperative aspirin use, lower center volume quartile, renal/visceral ischemia time, estimated blood loss, and older age (all P<0.05). POD 0-2 Death was associated with comorbidities, center volume, renal/visceral ischemia time, and estimated blood loss. Referral to high-volume aortic centers could improve outcomes.

Tips and tricks for robotic hepatectomy: Inflow control and exposure

Background: Minimally invasive approaches to hepatobiliary surgery are increasing, including robotic hepatic surgery (RHS). However, there are challenges unique to RHS, including adequate inflow control and atraumatic liver retraction. Methods described for inflow control in RHS include use of an intra- or extracorporeal thoracostomy tube, placement of long vascular clamps through the abdominal wall, and “Huang’s Loop” – a urinary catheter looped onto itself around the porta hepatis. For liver retraction, the fourth robotic arm is used to grasp the liver surface, gallbladder, or falciform ligament and apply traction. Suture elastic bands onto the liver edge provide external retraction. Patient/bed positioning can further assist. Still, exposure of tumors in the right posterior liver remains challenging and using the robotic arm can be traumatic. In this video, we present practical approaches that we developed for inflow control and liver retraction: a modified “Huang’s Loop” and retraction sling respectively.

Evaluation of pain response in children to the SoftClamp™ as an alternative to the metal rubber dam clamp: A randomized clinical trial.

The use of a rubber dam is more important than ever in today's COVID-19 era to limit cross infections. In children, the placement of the metal clamp to retain the rubber dam is perceived to be painful and often requiring a local anesthetic injection. This dissuades many clinicians from placing the rubber dam. Hence, this study evaluated the pain response of children to a SoftClamp™ compared to the conventional metal clamp. This was a randomized controlled, equal allocation ratio, split-mouth clinical trial. Forty-two children aged between 8 and 12 years, having two permanent mandibular molars in need of sealants, were divided into Groups A and B (metal clamp and SoftClamp™, respectively). The pain response was recorded using both an objective and a subjective scale i.e., the Faces Legs Activity Cry Consolability (FLACC) scale and the Wong Baker Faces Pain Rating Scale (WBFPRS). The level of significance was set at 5% (P < 0.05). The pain response recorded from the WBFPRS and the FLACC scale for the metal and the SoftClamp™ were analyzed using the Wilcoxon signed rank test. The difference in pain response between genders and between two age groups (below and above 10 years of age) was analyzed using the Mann-Whitney U-test. The children reported mild discomfort to clamp placement in both the scales. The P values for the FLACC and WBFPRS scores comparing the pain response to the metal and SoftClamp™ were 0.311 and 0.149, respectively. There was no significant difference in the pain response of children to both the clamps. Good rubber dam application practices in children through the use of behavior guidance and a proper topical anesthesia technique may play a far more important role regardless of the clamp used. But the SoftClamp™, with its more child friendly appearance could be a viable alternative to the metal clamp in children.

Nuss Procedure for pectus excavatum repair in a patient with osteogenesis imperfecta

A 17-year-old male with Osteogenesis Imperfecta (OI) type 1 and history of prior spinal instrumentation for kyphosis presented with severe symptomatic pectus excavatum (PEx). His Haller index was 6.7 with a Pectus Correction Index of 51%. He underwent uncomplicated Nuss procedure with insertion of 3 bars and complete repair of the PEx. A single sternal fracture was sustained during correction and healed without deformity. After two years, he developed left-sided pain and two of 3 bars were removed with maintained chest correction. This case report demonstrates the feasibility of Nuss procedure in adolescents with OI and outlines improvements to the technique in future patients with OI. • The Nuss procedure is feasible in teenagers with osteogenesis imperfecta. • Bone mass density should be optimized with bisphosphonates prior to procedure. • Multiple bars and vertical sternal elevation clamp placement may decrease fractures.

Poster 263: Distance to Neurovascular Bundle During Iliotibial Band ACL Graft Passage: A Cadaveric Study

Objectives:For patients with significant growth remaining, the Micheli (iliotibial band) ACL reconstruction technique has proven to be a reliable procedure with minimal risk for growth disturbance. Recent cadaveric studies have demonstrated that graft passage over the top of the femur may bring the graft and surgical instrument close to the critical neurovascular structures. The purpose of this study was to evaluate the Micheli over-the-top, graft passage technique for ACL reconstruction using pediatric cadaveric knees, and measure the distance between surgical instrument tip and the peroneal nerve, tibial nerve, and popliteal artery.Methods:Gross dissection was performed on seventeen skeletally immature cadaveric knees (12 male and 5 female) between the ages of 4 and 12 years old. A 5.5” curved-tip hemostat clamp was used to create a path through the posterior capsule, after the posterior neurovascular structures were identified. The tip of the clamp was passed from an anterior medial portal through the notch postero-superiorly, towards the proximal lateral capsule, with the knee flexed to 90-100 degrees or more. Once passed, the clamp was positioned in the popliteal fossa and clinical photographs were taken from the posterior aspect of the dissected knee, visualizing the tip of the clamp and the neurovascular structures. A metric ruler was included in all photographs. Digital imaging software was used to measure the distance in centimeters from clamp tip to peroneal nerve laterally, and the popliteal artery and tibial nerve medially for all specimens, FIGURE 1. Distances were averaged and stratified to assess differences in age and sex FIGURE 2.Results:The average distances from clamp to neurovascular bundle were 0.875cm (range: 0.468-1.737cm), 0.968cm (range: 0.312-1.819cm), and 1.149cm (range: 0.202-2.409cm) for tibial nerve, popliteal artery and peroneal nerve, respectfully. Means were further calculated for age groups ≤8, 9-10, and 11-12 years old. The average distance from clamp tip to peroneal nerve was 1.400cm larger for 11–12-year-old patients vs. patients ≤8 after adjusting for sex (95% CI=[0.6, 2.2], p=0.005).Conclusions:Iliotibial band graft ACL reconstruction is one of the best options in the skeletally immature, as it has the lowest risk of growth plate complications and growth arrest. The neurovascular structures are very close to the path for over-the-top graft clamp placement with distances <1 cm in many subjects. When passing the graft through the posterior knee there may be greater accessibility on the lateral cortex of the knee among older patients who are closer in age to physeal closure. The current study provides detailed measurements of instrument proximity to the neurovascular bundle in the posterior compartment of the knee. This knowledge is important to help surgeons who perform the Micheli pediatric ACL reconstruction avoid damage to the nerves and vessels in this region. Careful instrument and graft passage, with awareness of proximity to critical structures, are important to reduce the risk of neurovascular injury.Figure 1.Measurements (cm) from clamp tip to neurovascular bundle structures in right Knee model.Figure 2.Average distance from clamp from tip to neurovascular bundle by age Error bars represent 95%CI,**p<0.01

Distance to Neurovascular Bundle During Iliotibial Band Acl Graft Passage: A Cadaveric Study

Background:For patients with significant growth remaining, the Micheli-Kocher (iliotibial band) ACL reconstruction technique has proven to be a reliable procedure with minimal risk for growth disturbance. Recent cadaveric studies have demonstrated that graft passage over the top of the femur may bring the graft and instrument close to the critical neurovascular structures.Purpose:The purpose of this study was to evaluate the over-the-top graft passage technique using pediatric cadaveric knees, and measure the distance between instruments and the peroneal nerve, tibial nerve, popliteal artery.Methods:Seventeen skeletally immature cadaveric knees between the ages of 4 and 12 years old were dissected and prepared for visualization of iliotibial band graft passage procedure. A curved hemostat clamp was used, creating a path through the posterior capsule. To avoid neurovascular injury, the tip of the instrument was kept close to the posterior and lateral cortex of the femur. Once the clamp was safely positioned in the posterior knee joint, photographs were taken. Digital imaging software was used to measure the distance in centimeters from clamp tip to peroneal nerve laterally, and the popliteal artery and tibial nerve medially for all specimens, FIGURE 1. Distances were averaged and stratified to assess differences in age, FIGURE 2.Results:The average distances from clamp to neurovascular bundle were 0.875cm (range: 0.468-1.737cm), 0.968cm (range: 0.312-1.819cm), and 1.149cm (range: 0.202-2.409cm) for tibial nerve, popliteal artery and peroneal nerve, respectfully. Means were further calculated for age groups ≤8, 9-10, and 11-12 years old.Conclusion:Iliotibial band graft ACL reconstruction is one of the best options in the skeletally immature, as it has the lowest risk of growth plate complications and growth arrest. The neurovascular structures are very close to the path for over-the-top graft clamp placement with distances <1 cm in many subjects. The current study provides detailed measurements of instrument proximity to the neurovascular bundle in the posterior compartment of the knee. This knowledge is important to help surgeons who perform the Micheli-Kocher pediatric ACL reconstruction avoid damage to the nerves and vessels in this region. Careful instrument and graft passage, with awareness of proximity to critical structures, are important to reduce the risk of neurovascular injury.Figure 1.Measurements (cm) from clamp tip to neurovascular bundle in right knee model.Figure 2.Average distance from surgical instrument to neurovascular bundle are identified with respect to age.

Mannitol Use is Renal Protective in Patients with Chronic Kidney Disease Requiring Suprarenal Aortic Clamping

Mannitol is often administered during open juxtarenal or suprarenal aortic surgery to prevent ischemic injury to the kidneys. Prior evidence evaluating the benefits of intraoperative mannitol in reducing ischemia/reperfusion injury is conflicting and largely based on small, retrospective series. The aim of this study was to evaluate the effect of mannitol in preventing postoperative hemodialysis in patients undergoing open abdominal aortic aneurysm (AAA) repair where proximal control involved temporary renal ischemia. The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing elective open AAA repair between 2003 and 2020. Patients were included in the current analysis if the proximal aortic clamp was placed above at least one renal artery. Chronic kidney disease (CKD) was defined as Cr > 1.8 mg/dL. Primary end points were 30-day major morbidity (myocardial infarction, respiratory complications, lower extremity or intestinal ischemia, and the need for temporary or permanent hemodialysis) and mortality. Comparisons were made between the mannitol and nonmannitol cohorts and stratified by the presence of preexisting CKD. During the study period, 4,156 patients underwent elective open AAA repair requiring clamp placement more than one (32.7%) or both (67.3%) renal arteries; 182 patients (4.4%) had preexisting CKD. Overall, 69.8% of patients received mannitol during their surgery. Mannitol was more frequently used in cases involving clamp placement above both renal arteries (70.3%) than one renal artery (61.5%). While prolonged ischemia time (more than 40 min) was associated with a higher risk of postoperative dialysis in patients without CKD, it was not significant in patients with baseline CKD. On a univariate analysis, mannitol use in patients with CKD was associated with a lower risk of postoperative dialysis (P = 0.005). This remained significant on a multivariate analysis (P = 0.008). Mannitol use did not appear to confer renal protective effects in patients without baseline CKD. Mannitol use was associated with a decreased risk of need for postoperative hemodialysis in patients with CKD undergoing suprarenal aortic clamping for open aneurysm repair. In appropriately selected patients, particularly those with underlying renal insufficiency, mannitol may confer a renal protective effect in open repair of pararenal AAA requiring suprarenal clamping.

Addressing surgical training inequities: city-wide collaboration in gynecologic surgical skills simulation for resident education

The objectives are to 1) create and implement a novel multi-institutional minimally invasive gynecologic surgical skills simulation course for first- and second-year obstetric and gynecology residents from four different residency programs, 2) address surgical training inequities by fostering a multi-institutional collaboration among different residency programs, 3) assess the efficacy of the simulation session on improving the residents’ confidence and knowledge, and 4) assess the impact of the multi-institutional collaboration on resident and faculty education. A four-hour gynecologic surgical skills simulation course for first- and second-year residents was developed by a team of gynecology faculty. The simulation course had multiple stations that focused on essential laparoscopic, vaginal and robotic surgical skills including the laparoscopic skills required for the Fundamentals of Laparoscopic Surgery (FLS) curriculum, trocar insertion, and vaginal clamp placement and suturing. There were additional interactive stations that provided education on various surgical energy modalities, hemostatic agents, and a three-dimensional virtual reality simulator for robotic surgical skills. The simulation session was piloted in September 2021 in a stand-alone simulation center. The participating residents and faculty completed a pre- and post-simulation survey. 27 first- and second-year residents participated in the course. 21 residents (78%) completed the pre-simulation survey, and 16 (59%) residents completed the post-simulation survey. On the pre-simulation survey, 15 (71%) respondents reported that they were either not familiar or slightly familiar with the FLS requirements. On the post-simulation survey, 12 (75%) respondents reported that they were moderately familiar or very familiar with the FLS requirements. 15 (94%) respondents found that the simulation session improved their overall surgical skills. Higher confidence ratings for various surgical skills were observed on the post-simulation survey compared to the pre-simulation survey. All the residents found that working with residents and faculty from different institutions was moderately to very beneficial to their learning. 13 faculty participated in teaching and 12 (92%) completed the pre-simulation survey, and 13 (100%) completed the post-simulation survey. Nearly all the faculty (92%) found that working with faculty from different institutions was moderately to very beneficial in improving their teaching skills. This novel multi-institutional minimally invasive gynecologic surgical skills simulation increased the residents’ confidence and preparedness for gynecologic surgery. Multi-institutional collaboration is a novel aspect of this simulation session which was well received by both the residents and faculty and can improve surgical training inequities.

Evaluating proximal clamp site and intraoperative ischemia time among open repair of juxtarenal aneurysms

BackgroundThe proportion of open aneurysm repairs requiring at least a suprarenal clamp has increased in the past few decades, partly owing to preferred endovascular approaches for most patients with infrarenal aneurysms, suggesting that the management of aortic clamp placement has become even more relevant. This study evaluated the association between the proximal clamp site and intraoperative ischemia times with postoperative renal dysfunction and mortality. MethodsWe used the Vascular Quality Initiative to identify all patients undergoing open repairs of elective or symptomatic juxtarenal AAAs from 2004 to 2018 and compared outcomes by clamp site: above one renal artery, above both renal arteries (suprarenal), or above the celiac trunk (supraceliac). Outcomes evaluated included acute kidney injury (AKI), new-onset renal failure requiring renal replacement therapy (RRT), 30-day mortality, and 1-year mortality. We used multilevel logistic regressions and Cox proportional hazards models, clustered at the hospital level, to adjust for confounding. ResultsWe identified 3976 patients (median age, 71 years; 70% male; 8.2% non-Caucasian), with a median aneurysm diameter of 5.9cm (interquartile range [IQR], 5.4-6.8 cm). Proximal clamp sites were above one renal artery (31%), suprarenal (52%), or supraceliac (17%). The rates of unadjusted outcomes were 20.5% for AKI, 4.1% for new-onset RRT, 4.9% for 30-day mortality, and 8.3% for 1-year mortality. On adjusted analyses, independent of ischemia time, suprarenal clamping relative to clamping above a single renal artery had higher odds of postoperative AKI (adjusted odds ratio [aOR], 1.50; 95% confidence interval; 95% CI, CI, 1.28-1.75), but similar odds for new-onset RRT (aOR, 1.27; 95% CI, 0.79-2.06) and 30-day mortality (aOR, 1.12; 95% CI, 0.79-1.58) and hazards for 1-year mortality (adjusted hazard ratio, 1.12; 95% CI, 0.86-1.45). However, every 10 minutes of prolonged intraoperative ischemia time was associated with an increase in odds or hazards ratio of postoperative AKI by 7% (IQR, 3%-11%), new-onset RRT by 11% (IQR, 4%-17%), 30-day mortality by 11% (IQR, 6%-17%), and 1-year mortality by 7% (IQR, 2%-13%). Patients with more than 40 minutes of ischemia time had notably higher rates of all four outcomes. ConclusionsSuprarenal clamping relative to clamping above a single renal artery was associated with AKI, but not new-onset RRT or 30-day mortality. However, the intraoperative renal ischemia time was independently associated with all four postoperative outcomes. Although further studies are warranted, our findings suggest that an expeditious proximal anastomosis creation is more important than trying to maintain clamp position below one renal artery, suggesting that suprarenal clamping may be the best strategy for open AAA repair when needed to efficiently perform the proximal anastomosis.

Defining Reference Values for the Anatomical Axis of Syndesmosis and Landmark for the Clamp Placement to Minimize Malreduction

Category:Ankle; Sports; TraumaIntroduction/Purpose:Malreduction of the fibula within the incisura is often caused by an eccentric clamp or screw placement and short fibular length. Weightbearing computed tomography (WBCT) has proven to be a reliable method to diagnose syndesmotic instability and can be used as a template to determine the syndesmotic axis and optimal position to place the clamp. We aimed to determine the anatomic axis of the syndesmosis, or the trans-syndesmotic angle (TSA) in healthy individuals on WBCT, and to see if side-to-side and gender based variations exist. We also aimed to determine the clamp's medial tine placement along the trans-syndesmotic axis.Methods:The study group was made up of patient population without ankle injury who underwent bilateral foot and ankle WBCT imaging (n = 100; 200 ankles). Measurements on bilateral WBCT images included: 1) TSA at 1cm, 2cm, and 3cm proximal to tibial plafond, respectively; 2) Medial tine of the clamp positioning at 1cm and 2 cm along the syndesmotic axis. The medial tine clamp position was described in terms of the percentage of anterior to posterior tibial diameter from the anterior cortical boundary. In addition, the aforementioned TSA measurements were compared to historically defined 30 degrees of syndesmotic axis. Paired t-test was used to compare side to side and gender based differences. A p-value < 0.05 was considered statistically significant.Results:In the uninjured healthy population, the mean trans-syndesmotic angles were 17.60, 21.60, and 24.10 at 1cm, 2cm, and 3cm proximal to the tibial plafond respectively. The clamp's medial tine should be positioned 24.7% and 21.3% of the AP tibial cortical distance, posterior to the anterior tibial cortex at 1cm and 2 cm proximal to the tibial plafond. There was no significant side to side or gender based differences for any of the measurements. Additionally, all three weightbearing TSA measurements were significantly larger than the historically defined syndesmotic angle of 30 degrees (p<0.001).Conclusion:Preoperative WBCT imaging provides a reliable template to determine TSA and to plan optimal clamp tine positioning along the syndesmotic axis. Our study has established normal ranges for cross-sectional syndesmotic axis measurements during weight-bearing and established that no differences exist between laterality and gender in patients without syndesmotic injury.

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Does Proximal Placement of the Syndesmotic Reduction Clamp Affect the Optimal Position for the Medial Tine? A Cadaveric Pilot Study

Sagittal plane syndesmotic malreduction is associated with off-axis, eccentric reduction clamping and preferential placement of the medial tine anteriorly has been proposed to minimize the malreduction risk. Although clamp placement 1cm proximal to the plafond is recommend, no previous study has assessed whether differences in the anatomic position of the fibula within the incisura (eccentric 1cm superior and concentric 2 cm superior to the tibial plafond) affect the optimal position for the clamps medial tine during reduction of the syndesmosis. The purpose of the present cadaveric pilot study was to evaluate and compare the sagittal syndesmotic malreduction rate with various clamping vectors, 1cm and 2cm from the tibial plafond, respectively. Six through the knee cadaveric specimens were obtained. Kirschner wires and a surgical maker were used to denote placement of the reduction clamp laterally on the peroneal ridge of the fibula, and medially within the anterior, middle, and posterior thirds (Zones A, B, C) of tibia's width; 1 cm and 2 cm from the plafond. CT scans were obtained as controls, followed by destabilization of the syndesmosis. Reductions were then performed sequentially at each level (1 cm, 2 cm) and zone (A, B, C); and CT scans repeated for assessment. In most specimens (n = 5), an eccentric (1 cm) to concentric (2 cm) positional transition was observed within incisura fibularis. The transition altered the resulting fibular displacements in some specimens (2A anterior, vs 2B posterior), resulting in a higher malreduction rate with anterior (zone 2A, 33%) vs central (Zone 2B, 17%) positioning of medial tine. Although no definitive conclusions can be reached from the present pilot study, future studies with a greater number of specimens and clamping vectors are warranted to determine whether positional transitions of the fibula within the incisura fibularis affect the optimal position for the clamps medial tine.