Superior Margin Research Articles

Planned and Unplanned Sarcoma Resections: Comparative Analysis of Local Recurrence, Metastasis, and Mortality

Background: Sarcomas, a diverse group of malignant tumors arising from mesenchymal tissues, pose significant diagnostic and therapeutic challenges. This study compares the outcomes of planned resections (PEs) and unplanned resections (UEs) to inform better clinical practices. Methods: Data were analyzed from the Swiss Sarcoma Network (SSN), including patients with soft tissue and bone sarcomas treated at two major hospitals. This study utilized logistic regression and Cox regression models to examine the odds of UEs and their impact on local recurrence-free survival. Results: Among 429 patients registered by SSN members, 323 (75%) underwent PEs and 106 (25%) experienced UEs. PEs were associated with significantly larger tumors (94 mm vs. 47 mm, p < 0.001) and higher-grade tumors (Grade 3: 50.5% vs. 37.4%, p = 0.03). Despite achieving superior resection margins (R0: 78.8% vs. 12.6%, p < 0.001), PEs showed higher metastasis rates at follow-up (31.0% vs. 10.4%, p < 0.001) and greater cancer-specific mortality (16.7% vs. 6.6%, p = 0.01). UEs, while linked to higher local recurrence, did not significantly affect metastasis-free survival (MFS) or overall survival (OS). Conclusions: PEs achieve superior immediate surgical outcomes but are linked to higher metastasis and cancer-specific mortality due to the advanced stage of tumors. UEs, while associated with higher local recurrence rates, do not significantly impact MFS or OS. Early detection, comprehensive diagnostics, and timely referrals to specialized sarcoma hubs are essential to avoid UEs and reduce metastatic risk. Future research should focus on developing diagnostic tools using individual tumor and patient characteristics to improve sarcoma management.

Robot-Assisted Resection of Exposed Colon With TaTME After Heavy Ion Radiotherapy for Locally Recurrent Rectal Cancer: A Case Report

Introduction Heavy ion radiotherapy has shown promising results in treating pelvic recurrence of rectal cancer. We report a case in which a patient underwent robot-assisted low anterior resection with transanal mesorectal excision (TaTME) following heavy ion radiotherapy, owing to challenges associated with spacer placement. Case presentation A 54-year-old man was diagnosed with upper rectal cancer. He underwent robot-assisted low anterior resection. Eight courses of CapeOX were administered as postoperative adjuvant chemotherapy. Immediately after completion of adjuvant chemotherapy (8 months postoperatively), computed tomography (CT) scan revealed a 30-mm large nodule on the dorsal surface of the oral anastomotic intestine, which was detected by positron emission tomography–CT. Given that the tumor had an indistinct border with the sacrum and its superior margin extended to the second sacrum, it was concluded that a combined sacral resection was not advisable, and heavy ion radiotherapy was indicated. Robot-assisted low anterior resection combined with TaTME was performed approximately 2 months after heavy particle radiotherapy [73.6 Gy (relative biological effectiveness)/16 sessions]. CT scan conducted 3 months after irradiation revealed substantial shrinkage of the recurrent tumor. Conclusion Robot-assisted resection of exposed colon with TaTME after heavy ion radiotherapy is regarded as an effective strategy for treating locally recurrent rectal cancer.

Prognostic significance of involvement of the circumferential resection margin/surface in patients with pancreatic head cancer: A prospective evaluation of pancreatoduodenectomy specimens using the 0 and 1 mm rules

Background/ObjectivesThe prognostic significance of circumferential resection margin (CRM) or circumferential surface (CS) in pancreatic head cancer is controversial. We investigated the survival outcomes according to CRM or CS involvement in pancreatoduodenectomy specimens of pancreatic ductal adenocarcinoma (PDAC). MethodsA total of 102 pancreatoduodenectomy specimens after upfront surgery for PDAC between 2014 and 2018 were prospectively collected. The superior mesenteric vein/portal vein or superior mesenteric artery margins were classified as CRM, and the anterior or posterior surfaces as CS. Survival outcomes and recurrence were compared according to the CRM/CS status, which was categorized into R10mm, R11mm, and R0 (≥1 mm) by the 0 and 1 mm rules. ResultsFor CRM, R10mm had significantly lower overall survival (OS) (P < 0.001) and disease-free survival (P < 0.001) rates than R11mm and R0, with no difference between R11mm and R0. For CS, R0 had a significantly higher OS rate (P < 0.001) than R10mm and R11mm, with no difference between R10mm and R11mm. In multivariable analysis, R10mm CRM was an independent risk factor for OS (hazard ratio 2.410, P = 0.003) and DFS (hazard ratio 5.019, P < 0.001). When CRM/CS were analyzed separately, only the R10mm superior mesenteric artery margin was significantly associated with local recurrence (P = 0.012). ConclusionsThe results suggest that CRM involvement defined by the 0 mm rule is more appropriate than the 1 mm rule for predicting survival outcomes, but CS involvement defined by the 0 or 1 mm rules is not prognostically significant.

Deep masseteric triangular area to define masseter neurovascular bundle: A cadaveric study

IntroductionFacial reanimation procedures are used in the treatment of the disorder that impairs mimetic function and jeopardizes physical and psychological health, and one of the most important instruments of these techniques is the masseteric neurovascular bundle (NVB) and proper identification at the mandibular notch level. In the current study, a triangular area (deep masseteric triangle, DMT) on the lateral surface of the masseter muscle that was identified to help reliable determination of the masseteric NVB at the mandibular notch level. Material and methods40 parotideomasseteric region dissections were performed in 10 female and 10 male donated cadavers. Structures lateral to the masseter muscle were removed. The edge length of the masseter muscle on the zygomatic arch side was measured. After the edges of the DMT were measured, the masseteric NVB was found by dissection and its distance (depth) from the skin line was measured. ResultsThe mean lengths of the superior, posterior, and anterior margins were 17.3 (±4.5) mm, 25.9 (±6.2) mm, and 26.3 (±6.5) mm, respectively. The total length of the upper edge of the masseteric muscle attached to the zygomatic arch averaged 52.7 (±5.2) mm. The masseteric neurovascular bundle was detected at a depth of approximately 17 mm from the skin of the parotideamasseteric region. DiscussionThe visualization of the DMT can be used as an important landmark for access to branch-free part of the masseteric nerve. Moreover, an specific approach for masseteric NVB localization can be established by drawing a line between the mandibular angle and the midpoint of the upper edge of the DMT. This technique can greatly improve the accuracy of both masseteric nerve harvesting and masseteric nerve block procedures.

A novel theory for rapid localization of the transverse-sigmoid sinus junction and “keyhole” in the retrosigmoid keyhole approach: micro-anatomical study, technique nuances, and clinical application

To determine a rapid and accurate method for locating the keypoint and “keyhole” in the suboccipital retrosigmoid keyhole approach. (1) Twelve adult skull specimens were selected to locate the anatomical landmarks on the external surface of the skull.The line between the infraorbital margin and superior margin of the external acoustic meatus was named the baseline. A coordinate system was established using the baseline and its perpendicular line through the top point of diagastric groove.The perpendicular distance (x), and the horizontal distance (y) between the central point of the “keyhole” and the top point of the digastric groove in that coordinate system were measured. The method was applied to fresh cadaveric specimens and 53 clinical cases to evaluate its application value. (1) x and y were 14.20 ± 2.63 mm and 6.54 ± 1.83 mm, respectively (left) and 14.95 ± 2.53 mm and 6.65 ± 1.61 mm, respectively (right). There was no significant difference between the left and right sides of the skull (P > 0.05). (2) The operative area was satisfactorily exposed in the fresh cadaveric specimens, and no venous sinus injury was observed. (3) In clinical practice, drilling did not cause injury to venous sinuses, the mean diameter of the bone windows was 2.0–2.5 cm, the mean craniotomy time was 26.01 ± 3.46 min, and the transverse and sigmoid sinuses of 47 patients were well-exposed. We propose a “one point, two lines, and two distances” for “keyhole” localization theory, that is we use the baseline between the infraorbital margin and superior margin of the external acoustic meatus and the perpendicular line to the baseline through the top point of the digastric groove to establish a coordinate system. And the drilling point was 14.0 mm above and 6.5 mm behind the top point of the digastric groove in the coordinate system.

Surgical Correction of Orbital Hypertelorism With Absorbable Plate Instead of Frontal and Orbital Bar and Inverted U-Shaped Osteotomy.

The aim of the study is to investigate the effect and feasibility of using absorbable plate instead of frontal and orbital bar and inverted U-shaped osteotomy to correct the widening of orbital distance. The surgical effect and feasibility of using absorbable plate instead of frontal and orbital bridge plus inverted U-osteotomy for orbital widening syndrome in seven cases between January 2019 and February 2022 were retrospectively analyzed. First, the surgical procedure for orbital hypertelorism was inverted U-shaped orbital osteotomy, and a frontal bone flap was removed, exposing the superior orbital margin and the orbital circumference, and the orbital bone was directly cut off by inverted U-shaped osteotomy. The widened bone in the middle of the orbit was removed, and a long absorbable plate was used to replace the orbitofrontal bridge. The two sides of the orbit were fixed on the absorbable plate, and the absorbable plate was fixed on the rear skull. The clinical effect of treatment, complications (such as cerebrospinal fluid leakage and infection), safety, and feasibility of surgery were evaluated. Using absorbable plate instead of fronto-orbital bridge achieved the effect of orbitofrontal bridge, without orbital distance widening, cerebrospinal fluid leakage, and intracranial infection. Operating time was reduced. There was no metal fixation, and there was no risk of a second operation. The effect of replacing the frontal-orbital bridge with an absorbable plate and inverted U-shaped osteotomy is positive, the operation time is short, and the orbital distance is clearly improved. This approach can replace the traditional orbital-distance operation, and the incidence of postoperative cerebrospinal fluid leakage and infection is low. Long-term follow-up results are stable.

A Comparative Study Between Ultrasound-Guided Ilioingunial/Iliohypogastric Nerve Block versus Transverse Abdominis Plane Block in Patients Undergoing Oblique Inguinal Hernia Repair

Abstract Background Poorly controlled acute pain after abdominal surgery is related to somatic pain signals derived from the abdominal wall and is associated with a variety of unwanted post-operative consequences, including patient suffering, distress, respiratory complications, delirium, myocardial ischemia and prolonged hospital stay. Objective Regional anesthesia by (Ultrasound guided (US) Transversus abdominis plane block (TAP) or Ultrasound guided ilioinguinal and iliohypogastric nerves (IIN+IHN) block may be used as components of multimodal anesthesia with a comparable effect. In the present study, Bupivacaine is used to compare between them following inguinal hernia repair. Patients and Methods The study was conducted on 60 randomly chosen patients aged above 18 years, American Society of Anesthesiologists (ASA) class I or II scheduled for elective unilateral open inguinal hernia repair under general anesthesia, in Ain Shams University Hospitals after approval of the medical ethical committee. They were allocated in two groups. TAP block Group: received general anesthesia and (0.2 mL/kg of 0.25% bupivacaine per side), by midaxillary approach, under ultrasound guidance, the probe was placed transversely between the iliac crest and costal margin. Ilioinguinal/ iliohypogastric nerves block group: received general anesthesia, with (0.2 mL/kg of 0.25% bupivacaine per side). The inferior portion of linear ultrasound transducer will be placed over the anterior superior iliac spine with the superior margin of the transducer pointed directly in an oblique plane toward the umbilicus. The superior margin of the ultrasound transducer was slowly rotated superiorly and inferiorly until the fascial plane between the internal oblique and transverse abdominis muscle is identified. Results The results of the study revealed that patients received IIN+IHN block had significantly lower pain scores at 8, 12, 16, 20, and 24 hrs after operation, delayed time for rescue analgesia and decreased total need of analgesic in the first 24hrs post-operative compared to patients who received TAP nerves block. Conclusion IIN+IHN block was effective in reducing postoperative pain scores for 4-6 hours, lowering total 24-h postoperative opioid and analgesic consumption and delaying the need for rescue analgesia after inguinal hernia repair under general anesthesia, compared to TAP nerves block. It will be more useful to study in high-risk hypertensive and cardiac patients and to correlate with plasma catecholamine levels, which reflect the stress response and it is necessary to evaluate postoperative pain on movement in farther studies.

Margin clearance greater than 1 mm in nodal-positive pancreatic adenocarcinoma patients: multicentre retrospective analysis.

The introduction of the 1 mm cut-off for resection margin according to the Leeds Pathology Protocol has transformed the concept of surgical radicality. Its impact on nodal-positive resected pancreatic ductal adenocarcinoma patients is unclear. The aim of this study was to analyse the effect of margin clearance on survival among resected, nodal-positive pancreatic ductal adenocarcinoma patients whose specimens were analysed according to the Leeds Pathology Protocol. Data were collected retrospectively from multicentre clinical databases. Resected patients with nodal involvement were included. Overall survival and disease-free survival were analysed according to minimum reported margin clearances of 0, 0.5, 1, and 2 mm. The results are reported separately for patients who had not undergone venous resection and for patients for whom data were available regarding the superior mesenteric vein-facing margin or the vein specimen. The eighth edition of TNM classification by the AJCC was used. The study comprised 290 stage IIB patients and 215 stage III patients without venous resection. The superior mesenteric vein margin analysis comprised 127 stage IIB patients and 198 stage III patients. The different resection margin distances were not associated with overall survival and disease-free survival among patients without venous resection (P > 0.050). Receiving adjuvant therapy was associated with longer overall survival among stage IIB patients (P = 0.034) and stage III patients (P = 0.003) and with longer disease-free survival among stage III patients (P < 0.001). In this study, a margin clearance greater than 1 mm showed no clear effect on overall survival in pancreatic ductal adenocarcinoma patients with nodal involvement, whereas adjuvant therapy was confirmed to be essential to ensure longer overall survival.

Quantitative orbital tightening for pain assessment using machine learning with DeepLabCut

Pain assessment in animal models is essential for understanding mechanisms underlying pathological pain and developing effective pain medicine. The grimace scale (GS), facial expression features in pain such as orbital tightening (OT), is a valuable measure for assessing pain in animal models. However, the classical grimace scale for pain assessment is labor-intensive, subject to subjectivity and inconsistency, and is not a quantitative measure. In the present study, we utilized machine learning with DeepLabCut to annotate the superior and inferior eyelid margins and the medial and lateral canthus of the eyes in animals’ video images. Based on the annotation, we quantified the eyelid distance and palpebral fissure width of the animals’ eyes so that the degree of OT in animals with pain could be measured and described quantitatively. We established criteria for the inclusion and exclusion of the annotated images for quantifying OT, and validated our quantitative grimace scale (qGS) in the mice with pain caused by capsaicin injections in the orofacial or hindpaw regions, the Nav1.8-ChR2 mice following orofacial noxious stimulation with laser light, and the oxaliplatin-treated mice following tactile stimulation with a von Frey filament. We showed that both the eyelid distance and the palpebral fissure width were shortened significantly in the animals in pain compared to the control animals without nociceptive stimulation. Collectively, the present study has established a quantitative orbital tightening for pain assessment in mice using DeepLabCut, providing a new tool for pain assessment in preclinical studies with mice.

The vertical topography of the carotid bifurcation – original study and review

PurposeThe vertical level of carotid bifurcation (CB) is commonly indicated at the superior margin of the thyroid cartilage. Few studies observed the CB vertical topography. It was aimed at studying the vertical location of the CB as referred to vertebral and anterior cervical landmarks.MethodsAn archived lot of 147 computed tomography angiograms was documented for the vertical level of CB referred to vertebral and anterior cervical landmarks. The topography of the CB in relation to anterior landmarks was classified into seven types: (1) at the superior margin of the thyroid cartilage; (2) between the hyoid and the thyroid cartilage; (3) at the hyoid level; (4) between the hyoid and mandible; (5) subgonial or supragonial CB; (6) lower cervical level; (7) intrathoracic.ResultsThe most common locations of CB were at C3 (27.21%), C3/C4 (26.19%) and C4 (25.51%). Bilateral symmetry of CB was found in 51.7%, except for C2 and C5/C6. Type 7 was not found, type 3 occurred in 39.12%, type 2 in 24.49%, type 1 in 13.95%, type 4 in 13.61%, type 5 in 6.12%, and type 6 in 2.72% (294 CBs). Bilateral symmetry of anterior types was found in 59.86%. Statistically significant correlations were found between sex and both left and right types and vertebral levels of CB.ConclusionsThe vertical topography of the CB is highly variable and has sex-related specificity. This detail should be included in the teaching of anatomy. Surgeons and interventionists should better document the carotid anatomy on a case-by-case basis.

Mohs micrographic surgery challenges and new technologies to optimize care of cutaneous malignancies of the ear.

Cutaneous malignancies affecting the ear, exacerbated by extensive ultraviolet (UV) exposure, pose intricate challenges owing to the organ's complex anatomy. This article investigates how the anatomy contributes to late-stage diagnoses and ensuing complexities in surgical interventions. Mohs Micrographic Surgery (MMS), acknowledged as the gold standard for treating most cutaneous malignancies of the ear, ensures superior margin control and cure rates. However, the ear's intricacy necessitates careful consideration of tissue availability and aesthetic outcomes. The manuscript explores new technologies like Reflectance Confocal Microscopy (RCM), Optical Coherence Tomography (OCT), High-Frequency, High-Resolution Ultrasound (HFHRUS), and Raman spectroscopy (RS). These technologies hold the promise of enhancing diagnostic accuracy and providing real-time visualization of excised tissue, thereby improving tumor margin assessments. Dermoscopy continues to be a valuable non-invasive tool for identifying malignant lesions. Staining methods in Mohs surgery are discussed, emphasizing hematoxylin and eosin (H&E) as the gold standard for evaluating tumor margins. Toluidine blue is explored for potential applications in assessing basal cell carcinomas (BCC), and immunohistochemical staining is considered for detecting proteins associated with specific malignancies. As MMS and imaging technologies advance, a thorough evaluation of their practicality, cost-effectiveness, and benefits becomes essential for enhancing surgical outcomes and patient care. The potential synergy of artificial intelligence with these innovations holds promise in revolutionizing tumor detection and improving the efficacy of cutaneous malignancy treatments.

Brachiocephalic Artery Access Without Sternotomy in Older Asian Patients Undergoing Transcatheter Aortic Valve Replacement

There are numerous approaches for transcatheter aortic valve replacement (TAVR); however, access-related complications remain a point of concern. We analyzed consecutive patients who underwent TAVR for severe aortic stenosis via the brachiocephalic artery (BCA) without sternotomy (TBc group, n = 10) and via the trans-ascending aortic (TAo group, n = 8). The median BCA diameter and distance between the access point and suprasternal notch or superior margin of the clavicle were 11.3 mm and 8.3 mm, respectively. No patients in the TBc group underwent a partial sternotomy. Compared with the TAo group, the TBc group exhibited a shorter mean procedure time and lower blood loss volume as well as shorter duration of hospitalization. TAVR through the BCA may be a safe and feasible alternative for ascending aorta access. Studies with longer follow-up analysis and more patients are warranted to confirm our findings.

Extra-articular screw placement strategy in Stoppa approach based on three-dimensional reconstruction model

The study aimed to explore an extra-articular screw placement strategy in Stoppa approach. Radiographic data of patients who underwent pelvic computed tomography from January 2016 to June 2017 were imported into Materiaise’s interactive medical image control system software for three-dimensional reconstruction. Superior and lower margins of acetabulum and ipsilateral pelvic brim could be observed simultaneously through inlet-obturator view. A horizontal line from superior acetabular margin intersected pelvic brim at point “A” and another vertical line from lower margin intersected pelvic brim at point “B” were drawn, respectively. Lengths form sacroiliac joint to “A” (a), “A” to “B” (b), and “B” to pubic symphysis (c) were measured. Patients were divided into four groups depending on gender and side difference of measured hemi-pelvis: male left, male right, female left, and female right. Lengths of adjacent holes (d) and spanning different holes (e) of different plates were also measured. Mean lengths of a, b, c in four groups were 40.94 ± 1.85 mm, 40.09 ± 1.93 mm, 41.78 ± 3.62 mm, and 39.77 ± 2.23 mm (P = 0.078); 40.65 ± 1.58 mm, 41.48 ± 1.64 mm, 40.40 ± 1.96 mm, and 40.66 ± 1.70 mm (P = 0.265); 57.03 ± 3.41 mm, 57.51 ± 3.71 mm, 57.84 ± 4.40 mm, and 59.84 ± 4.35 mm (P = 0.165), respectively. Mean d length of different plates was 12.23 mm. Average lengths spanning 1, 2, 3 and 4 holes were 19.33 mm, 31.58 mm, 43.80 mm, and 55.93 mm. Our data showed that zones a and c could be safely inserted three and four screws. Penetration into hip joint could be avoided when vacant 3-hole drilling was conducted in zone b. Fracture line in zone b could serve as a landmark for screw placement.

Percutaneous Endoscopic Suprapedicular Decompression in the Treatment of Down-Migrated Lumbar DiscHerniation

[OBJECTIVE]: This study aimed to investigate the clinical efficacy of percutaneous endoscopic suprapedicular decompression in treatment of down-migrated lumbar disc herniation. [METHODS]: The clinical data of 43 patients with down-migrated lumbar disc herniation treated with endoscopic surgery at our hospital between January 2022 and January 2023 were retrospectively analysed. Twenty-two and 21 patients underwent percutaneous endoscopic decompression using the suprapedicular and TESSYS approaches, respectively. The perioperative, follow-up, and imaging data of the groups were compared. [RESULTS]: Surgery was uneventful in both groups. The number of intraoperative fluoroscopies and duration of surgery were significantly lower in the suprapedicular group (p<0.05). The patients in both groups were followed up for at least 12 months. At the last follow-up, lumbar pain and leg pain visual analogue scale (VAS), Oswestry Disability Index (ODI), and 36-Item Short Form Health Survey (SF-36) scores were significantly improved in both groups compared with preoperative values (p<0.05); the differences in these indexes between the two groups were not significant preoperatively (p>0.05). However, at the last postoperative follow-up, lumbar pain VAS scores were significantly better in the suprapedicular group (0.83±0.85 vs. 2.54±1.32, p<0.05). There was no significant change in intervertebral space height or lumbar lordotic angle compared with preoperative values in either group at the last follow-up (p>0.05). However, the spinal canal cross-sectional area significantly increased (p<0.05). [CONCLUSION]: The treatment of down-migrated lumbar disc herniation via a suprapedicular approach enabled the incision of the superior margin of the pedicle as needed under direct vision, involved less fluoroscopy while preserving facet joint stability, and enabled targeted removal of the herniated nucleus pulposus, thus greatly reducing residual nucleus pulposus. This surgical procedure was safe, rapid, and showed satisfactory therapeutic efficacy.

Abstract 6340: Novel conditionally active tetravalent B7-H3 x CD3 T-cell engagers targeting solid tumors

Abstract B7-H3, also known as CD276, is an immune-checkpoint molecule and a type 1 transmembrane protein that exerts a variety of biological functions. In cancer biology, the overexpression of B7-H3 is correlated with tumor cell invasion and metastasis, decreased T-cell infiltration and function, poor prognosis, and resistance to therapy. As B7-H3 is expressed in multiple solid tumors and plays an important role in modulating anti-tumor immune response as well as promoting cancer cell formation, it became an important target for the development of antibody-based immunotherapy. Many forms of bispecific antibodies targeting B7-H3 have shown antitumor response in preclinical studies. However, bispecific T-cell engagers (TCE) targeting B7H3 and CD3 have been correlated with cytokine release syndrome and hepatic adverse events, a common toxicity observed using TCEs which has limited the development of this immunotherapeutic in clinic. We leveraged BioAtla’s Conditionally Active Biologic (CAB) platform (1) to develop a DualCAB T-cell engager targeting B7-H3 and CD3. This DualCAB-TCE molecule, BA3142, was engineered to bind with high affinity to both recombinant B7-H3 and CD3 receptor/antigens under conditions that mimic the acidic tumor microenvironment, but with low affinity in alkaline physiological conditions. In vitro and in vivo efficacy and toxicity data for the clone BA3142 will be presented. Our data demonstrated that BA3142 promotes cytotoxicity of B7-H3-expressing cancer cells in vitro and induces significant tumor regression in vivo. In Non-Human Primates BA3142 bispecific antibody was tolerated up to 25 mg/kg with minimal cytokine release and no clinical and histopathological signs of toxicities. The CAB technology offers the opportunity to expand the number of targets suitable for drug development in a new class of DualCAB TCEs with superior safety margin and potency in the clinic. (1) Chang HW, Frey G, Liu H, Xing C, Steinman L, Boyle WJ, and Short, J.M. Generating tumor-selective conditionally active biologic anti-CTLA4 antibodies via protein-associated chemical switches. Proc Natl Acad Sci U S A 2021;118. Citation Format: Ana Paula Cugnetti, PhD, Haizhen Liu, Patricia McNeeley, Kathryn Woodard, Cathy Chang, Gerhard Frey, William J. Boyle, Jay M. Short. Novel conditionally active tetravalent B7-H3 x CD3 T-cell engagers targeting solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6340.

Accuracy of intraoperative approximation of pelvic tilt using preoperative standing radiographs

BackgroundAnterior approach surgeons who utilize intraoperative fluoroscopy often try to match a preoperative radiograph as a reference for intraoperative cup position. Every degree of inaccuracy in tilt leads to a roughly 0.7° change in anteversion. This study aimed to determine how closely pelvic tilt (PT) is approximated intraoperatively when compared to preoperative anteroposterior (AP) radiographs. MethodsThis was a retrospective review of 193 primary THA's done by 2 surgeons at an academic tertiary referral center between September 2021–January 2023. There were 24 patients excluded for distorted anatomy, post-traumatic arthritis, insufficient x-rays, or a sacroiliac joint that could not be visualized on film. Data collected included age and BMI. PT was calculated using the formula, Tilt = -(ln((B/A) x (1/0.483)))/0.051. Value A is the distance from the base of the SI joint to the superior margin of the obturator foramen; value B is the height of the obturator foramen. ResultsMean preoperative PT was 0.2° versus intraoperative PT was 3.4° (p < 0.001). Mean absolute difference was 6.5°. 48% of patients (n = 81) had an absolute difference less than 5°, 31% (n = 52) between 5° and 10°, 14% (n = 24) between 10° and 15°, and 7% (n = 12) greater than 15°. There was no correlation between BMI or age and PT discrepancy. ConclusionOf the patients, 21% had a discrepancy of 10° or greater between their preoperative radiographs and intraoperative fluoroscopic images. Surgeons should be aware of potential errors in cup positioning and be particularly diligent in high-risk cases.

Spontaneous Blinking Kinematics After Frontalis Muscle Flap Advancement.

To measure the spontaneous blinking metrics after blepharoptosis correction with frontalis muscle flap advancement. A video system was employed to measure the amplitude and velocity of spontaneous blinking of 24 eyelids after the frontalis muscle flap surgery for blepharoptosis correction. A control group with no eyelid disorders was also measured. The data of 13 eyelids who had frontalis slings with autogenous fascia, which were previously collected with the same method in another study, were used for comparison. Digital images were used to measure the superior margin reflex distance and the presence of lagophthalmos during a gentle closure of the palpebral fissure. Superficial keratitis was assessed by corneal biomicroscopy. The mean amplitude of spontaneous blinking was 6.3 mm in controls, 2.6 mm in the frontalis flap patients, and 2.1 mm in the fascia sling group. The mean blink velocity was 133.8 mm/second in controls, 39.0 mm/second (3.7 standard error) after the frontalis flap, and 36.3 mm/second in patients with frontalis sling with fascia. For these 2 parameters, there was no statistical difference between the surgical groups, but a significant reduction when compared with the control group. No significant association was found between lagophthalmos and keratitis and the surgical procedure. There is no difference between the blinking metrics of eyelids operated using the frontalis muscle flap advancement technique or frontalis sling with autogenous fascia. The presence of lagophthalmos and keratitis also does not differ between the 2 procedures.

Transpression or polyphase deformation along craton margins: Insights from the Archean–Proterozoic boundary near Sudbury, Canada

Continental margins vary in composition and configuration, resulting in complex structural geometries during deformation. One example is the Archean–Proterozoic boundary near Sudbury, Canada, where the Creighton-Victoria Deformation Zone (CVDZ) contains both reverse dip-slip and dextral strike-slip kinematic indicators. To resolve if these structures formed during a single transpression event or multiple overprinting events, the orientation, relative timing and style of the CVDZ are compared to those of adjacent regional structures. Regional fold axes and their axial planar foliation are subparallel to the steeply-plunging stretching lineation and steeply-dipping foliation, respectively, along the CVDZ. Phase equilibria modelling of syn-tectonic staurolite-chloritoid assemblages indicates that the regional folds and foliation formed at 480–565 °C, similar to temperatures estimated for the formation of dip-slip quartz crystallographic preferred orientations (CPO) along the CVDZ. This suggests that the CVDZ, regional folds and foliation formed during the same regional folding and reverse shearing event. Major lateral lithological changes and inflections in the orientation of the craton margin controlled the formation of structures, and evidence for regional transpression, such as strike-slip kinematic indicators, steeply-plunging stretching lineation, and obliquity of regional folds with respect to major shear zones, resulted from polyphase deformation and transcurrent reactivation of the Superior craton margin.

Inverted Internal Limiting Membrane Flap Coverage With Autologous Blood Technique After Air-Fluid Exchange and Silicone Oil Tamponade for Extensive Macular Hole Retinal Detachment in Highly Myopic Eyes.

To report a technique consisting of inverted internal limiting membrane (ILM) flap coverage with autologous blood after air-fluid exchange and silicone oil tamponade in treating extensive retinal detachment secondary to a myopic macular hole (MH). This was a retrospective case series. 18 eyes with MHRD extending beyond the equator were included in this study with a minimum follow-up of 6 months. The procedures for pars plan vitrectomy (PPV) included the following: 1) The ILM was peeled to the superior and inferior arcade margins and, except for the ILM in the temporal region, was hinged toward the edge of the MH. 2) Air-fluid exchange was then performed to drain the subretinal fluid through the MH with a flute needle, ensuring that a small amount of subretinal fluid remained to facilitate ILM flap inversion. 3) The ILM flap was used to cover the MH with the assistance of autologous blood. Six months after surgery, the MH was successfully anatomically closed, and retinal reattachment was observed in all 18 eyes of 18 patients. The mean best-corrected visual acuity logarithm of the minimum angle of resolution (logMAR) improved from 2.03 ± 0.61 (ranging from hand motion [2.6] to finger counting [2.3]) to 1.23 ± 0.63 (ranging from hand motion [2.6] to 20/28 [0.15]) ( P < 0.01) at 6 months. This surgical technique using an inverted ILM flap combined with autologous blood provides an option for the treatment of extensive MHRD.

Intra- and Interimage Reliability of Inter-Rectus Distance Measurements Determined via Ultrasound Imaging by the Same or Different Testers in Women in the Early Postpartum Period.

No consensus regarding the optimal position and location for the measurement of the inter-rectus distance (IRD) via ultrasound (US) has been reached. By investigating the intra- and interimage reliability of IRD measurements taken in different positions and at different locations within and between testers, this study provides a theoretical basis for the current situation. The IRD was measured via US in 46 women at 42-60 days after delivery at the superior margin of the umbilicus and 3 cm above, 5 cm above and 3 cm below the umbilicus while the women were in the supine, crunch and standing positions. In the interimage test, every participant was tested 2 times by Physician X and 1 time by Physician Y; in the intraimage test, the images collected by Physician X during the first test were saved in the machines, and two measurements were performed by Physician X and one measurement was performed by Physician Y. Paired t tests and intraclass correlation coefficients (ICCs) were calculated. Only the first IRD measurements by tester X and tester Y at 3 cm below the umbilicus in the crunch position were significantly different (9.56 ± 6.00 versus 11.00 ± 5.55) (P < .05). All the ICCs were greater than .75, and the intratester ICCs were greater than or equal to the corresponding intertester ICCs. The ICCs at 3 cm below the umbilicus were the smallest in the supine and crunch positions and the largest in the standing position due to the increased frequency of IRD values of 0. The ICCs for the crunch position were greatest according to the intraimage test but smallest according to the interimage test. The interimage ICCs between the two testers in the supine position at the superior margin, 3 cm above, 5 cm above, and 3 cm below the umbilicus were .972, .974, .975, and .956, respectively. Ultrasound imaging (USI) is a reliable method for measuring the IRD in women in the early postpartum period. The dynamic measurement of the IRD at or above the umbilicus in the supine position by different testers in real time showed the highest reliability.