Resection Defects Research Articles

Reopenable clip over-the-line method in endoscopic full-thickness resection of gastric submucosal tumors: A historical control study.

Endoscopic full-thickness resection for gastric submucosal tumors is gradually gaining popularity, and secure and amenable closure is key to its success. This study aimed to compare the reopenable clip over-the-line method with the purse-string method for defect closure after endoscopic full-thickness resection for gastric submucosal tumors. This historical control trial included 37 consecutive patients with 37 gastric submucosal tumors, who underwent endoscopic full-thickness resection between January 2021 and July 2024. All lesions were resected en bloc. After excluding three patients who underwent non-full-thickness resection, 34 patients were analyzed. Post-endoscopic full-thickness resection defects were closed using the purse-string method (n=18) until 2022 and the reopenable clip over-the-line method (n=16) from 2023. The median (interquartile range) time for defect closure was longer in the reopenable clip over-the-line method group of 33 (31-57) min than in the purse-string method group of 26 (24-35) min (p=0.013). The visual analog scale pain score at the umbilical region was lower (p=0.048) after the reopenable clip over-the-line method than after the purse-string method. In the reopenable clip over-the-line method group, post-procedural abdominal pain was confined to the epigastrium, whereas it extended to the umbilical or left lateral regions in the purse-string method group. The reopenable clip over-the-line method group commenced the diet (p=0.001) and discharged (p=0.024) earlier than the purse-string method group. Reopenable clip over-the-line method facilitated secure post-endoscopic full-thickness resection defect closure, reduced post-procedural abdominal pain, and shortened the fasting and hospitalization periods after endoscopic full-thickness resection in gastric submucosal tumors.

Multifunctional hydrogel scaffolds based on polysaccharides and polymer matrices promote bone repair: A review.

With the advancement of medical technology, the utilization of bioactive materials to promote bone repair has emerged as a significant research area. Hydrogels, as biomaterials, play a crucial role in bone tissue engineering. These hydrogels exhibit high biocompatibility, providing in vivo ecological conditions conducive to cell survival, and offer substantial advantages in facilitating bone repair. Different matrices of hydrogels serve distinct functions. In recent years, numerous researchers have developed a variety of novel hydrogel materials utilizing diverse matrices. These materials not only enhance the osteogenic induction capacity of hydrogels but also improve their efficacy as scaffolds in the treatment of complex bone defects, such as those resulting from trauma, tumor resection, or large bone defects due to infection. This article primarily analyzes the role of hydrogels that utilize polysaccharides and polymers as matrices in bone tissue repair, focusing on the creation of an optimal microenvironment to promote bone regeneration. These investigations deepen the understanding of the mechanisms underlying the action of hydrogels and establish a foundation for future advancements in the biomedical field.

Morphofunctional assessment of muscles of the lower leg and foot after autoneuroplasty of resection defect of tibial portion of the sciatic nerve and single intraoperative electrical neurostimulation in adult rats

INTRODUCTION: There are no data in the literature on the effect of a single intraoperative electrical stimulation (IES) on the condition of the muscles of the lower leg and foot in the long-term period after autoplasty of the sciatic nerve in adult rats. AIM: To study morphofunctional characteristics of muscles of the lower leg and foot after autoneuroplasty of a resection defect of the tibial portion of the sciatic nerve and a single IES in adult rats. MATERIALS AND METHODS: The experiment was performed on 30 Wistar rats who underwent autoneuroplasty (AN) after resection of the tibial portion of the sciatic nerve. Fourteen rats underwent a 40-munite IES session (AN + IES series). In 16 rats IES was not conducted (AN series). At 4 and 6 months after the operation, the tibial nerve function index (TFI) was calculated by analyzing rats’ paw traces on a walking track. At the same time, light microscopy and histomorphometry of paraffin and epoxy sections of gastrocnemius and plantar interosseous muscles were performed. A conventional control was muscles of intact limbs. RESULTS: Atrophy and endomysial fibrosis were less expressed in the gastrocnemius of the AN + IES series in comparison with AN series, the effect was mediated by enhancement of vascularization. In plantar interosseous muscles at 4 months after the operation, the volume density of blood vessels in the AN + IES series was 7.35 (5.49; 8.69), which was greater than in the AN series — 3.43 (2.02; 5.59), р = 0.0196. Diameters of muscle fibers and volume density of endomysium were comparable. At 6 months after the operation, endomysial fibrosis progressed in both series, but in the AN + IES series, myopathically altered muscle fibers were less common. After 6-month observation, TFI increased (-47.95) in the AN + IES series and became higher (p = 0.0339) than in the AN series, in which TFI became even lower (-93.64) than it was after 4 months (-81.95) of the experiment. CONCLUSION: A single IES permits to reduce the denervation alterations in the gastrocnemius and plantar interosseous muscles conditioned by damage to the nerve and maturation, and also to improve the tibial nerve function index in the long term after autoneuroplasty.

ASO Visual Abstract:Effect of Early Postoperative Mobilization on Functional Recovery, Length of Hospital Stay, and Postoperative Complications After Immediate Internal Pudendal Artery Perforator Flap Reconstruction for Irradiated Abdominoperineal Resection Defects: A Prospective, Randomized Controlled Trial.

ASO Visual Abstract:Effect of Early Postoperative Mobilization on Functional Recovery, Length of Hospital Stay, and Postoperative Complications After Immediate Internal Pudendal Artery Perforator Flap Reconstruction for Irradiated Abdominoperineal Resection Defects: A Prospective, Randomized Controlled Trial.

Biological and Synthetic Materials in Mandibular Reconstruction

Mandibular reconstruction is a critical surgical procedure necessary for restoring both function and aesthetics following trauma, tumor resection, or congenital defects. Over time, a variety of biological and synthetic materials have been developed to address the challenges of reconstructing the complex anatomy of the mandible. Biological materials, such as autografts, offer superior biocompatibility and osteogenic potential, but are limited by donor site morbidity and graft availability. Allografts and xenografts provide more accessible alternatives but are associated with higher risks of immune rejection and slower integration. In contrast, synthetic materials like titanium, PEEK (polyether ether ketone), and hydroxyapatite provide excellent mechanical strength and durability but often lack osteoinductive properties, requiring surface modifications to improve tissue integration.This review aims to provide a comprehensive analysis of the current materials used in mandibular reconstruction, comparing their biocompatibility, mechanical properties, osteoinductive potential, and clinical outcomes. Additionally, the review explores the growing role of composite materials that combine the strength of synthetics with the biological activity of natural tissues, as well as the advent of tissue engineering approaches that incorporate stem cell therapies and biomaterial scaffolds to promote bone regeneration. Emerging technologies such as 3D printing of custom-made implants and the application of nanotechnology for enhanced integration and infection control are also discussed as promising directions for future clinical applications. The findings highlight the need for continued research into optimizing biomaterial design and improving regenerative therapies to enhance patient-specific outcomes, reduce complications, and foster successful long-term integration of reconstructed mandibular structures. This review provides a roadmap for advancing both material science and clinical practice in the field of mandibular reconstruction.

Effect of Early Postoperative Mobilization on Functional Recovery, Hospital Length of Stay, and Postoperative Complications After Immediate Internal Pudendal Artery Perforator Flap Reconstruction for Irradiated Abdominoperineal Resection Defects: A Prospective, Randomized Controlled Trial.

Patients undergoing perineal defect reconstruction with the internal pudendal artery perforator (IPAP) flap traditionally face 5days of postoperative bed rest (BR) to minimize surgical risks. However, prolonged BR can exacerbate postoperative physiologic changes such as increased fatigue, reduced body mass, and declining lung function, while also leading to complications such as pneumonia, delirium, deep vein thrombosis, and pressure injuries. This study assessed the effectiveness, feasibility, and safety of an adapted early mobilization (EM) program for these patients. This prospective, randomized, controlled clinical study involved 51 patients assigned to adapted EM (n = 25) or BR (n = 26). Whereas EM included core exercises, orthostasis training, gait training, muscle strengthening, and aerobic exercises after surgery, BR followed standard bed rest protocols. The primary outcome was independent ambulation for 3 m on postoperative day 5. The secondary outcomes included 6-min walk test (6MWT) distances on days 5 and 30, hospital length of stay, healing time, postoperative complications, fatigue prevalence, and quality of life. On day 5, EM improved ambulation significantly compared with BR (68.0% vs 38.5%; P = 0.035) and achieved greater 6MWT distances on days 5 (108.78 vs 47.73m; P = 0.041) and 30 (243.8 vs 166.29m; P = 0.018). The EM patients were discharged earlier (66.7% by day 10 vs 33.3% of the BR patients; P = 0.043), with comparable healing times (P = 0.06) and postoperative complication rates (68% vs 80.8%; P = 0.296). Fatigue prevalence and quality of life did not differ significantly between the two groups. Early mobilization after IPAP flap reconstruction is safe and feasible, promoting early ambulation and recovery and facilitating earlier discharge without increasing complications.

Retro and prospective analysis of complex treatment of a patient with a polyostotic form of osteoclastoma of the maxillofacial region: clinical observation

In global literature there is not sufficient information on the course of the polyostotic form of osteoclastoma and methods of its treatment. For this reason, the analysis of this clinical case may be interesting for oncologists, maxillofacial surgeons and dentists of various specialties, who can reveal both the onset and recurrence of the disease. A characteristic feature of the course of this disease is the relapse of neoplasms with localization of foci in various parts of the upper and lower jaw. A clinical case of polyostotic form of jaw osteoclastoma and patient`s management tactics from 2006 to 2024 are described in the article. The disease was first diagnosed in 2006, when a neoplasm was revealed in the right part of the lower jaw. The neoplasm was removed by resection and mandibular defect was replaced by a carbon implant with further prosthesis. In 2011 a new neoplasm was detected on the left side in the frontal part of the upper jaw. At the same time a relapse of the disease was diagnosed with a new tumor focus in the lower jaw on the right. Surgical treatment was performed. Firstly, the neoplasm in the frontal area of the upper jaw was removed with replacement of the defect with a resection prosthesis. And secondly, a removal of the tumor on the lower jaw with resection of the chin within healthy tissues and replacement of the defect with an implant made of carbon-carbon material "Uglecon M" were performed. In 2023 the patient was invited to the dental hospital of the Clinical Multidisciplinary Medical Center of E.A. Vagner Perm State Medical University for dispensary observation and evaluation of the results of the treatment. The obtained results indicate the need for medical follow-up of patients after surgery for osteoblastoclastoma. The effectiveness of jaw implants made of carbon-carbon composite material " Uglecon M" was proved as well.

Pelvic and Perineal Reconstruction.

After studying this article, the participant should be able to: 1. Classify types of bony pelvic resections. 2. Outline reconstructive options for pelvic and perineal defects. 3. Identify advantages and drawbacks of various reconstructive techniques. 4. Recognize the functional benefits of bony and soft-tissue reconstruction. Defects of the pelvis and perineum arise from tumors, trauma, infection, congenital differences, and gender incongruence. Pelvic resections can result in bony instability and soft-tissue deficiency. The goals of reconstruction are maintenance of spinopelvic continuity, elimination of dead space, resurfacing of cutaneous defects, and prevention of hernias. Perineal reconstruction has important functional considerations. Abdominoperineal resection and pelvic exenteration defects benefit from flap reconstruction to decrease pelvic wound complications. Vulvovaginal reconstruction is performed with flaps from the perineum, thigh, or abdomen. Scrotal and superficial penile defects are most commonly reconstructed with scrotal flaps and skin grafts. Total penile reconstruction most commonly uses a radial forearm free flap.

Axolotl mandible regeneration occurs through mechanical gap closure and a shared regenerative program with the limb.

The mandible plays an essential part in human life and, thus, defects in this structure can dramatically impair the quality of life in patients. Axolotls, unlike humans, are capable of regenerating their lower jaws; however, the underlying mechanisms and their similarities to those in limb regeneration are unknown. In this work, we used morphological, histological and transcriptomic approaches to analyze the regeneration of lateral resection defects in the axolotl mandible. We found that this structure can regenerate all missing tissues in 90 days through gap minimization, blastema formation and, finally, tissue growth, differentiation and integration. Moreover, transcriptomic comparisons of regenerating mandibles and limbs showed that they share molecular phases of regeneration, that these similarities peak during blastema stages and that mandible regeneration occurs at a slower pace. Altogether, our study demonstrates the existence of a shared regenerative program used in two different regenerating body structures with different embryonic origins in the axolotl and contributes to our understanding of the minimum requirements for a successful regeneration in vertebrates, bringing us closer to understand similar lesions in human mandibles.

The MRE11-RAD50-NBS1 complex both starts and extends DNA end resection in mouse meiosis.

Nucleolytic resection of DNA ends is critical for homologous recombination, but its mechanism is not fully understood, particularly in mammalian meiosis. Here we examine roles of the conserved MRN complex (MRE11, RAD50, and NBS1) through genome-wide analysis of meiotic resection in mice with various MRN mutations, including several that cause chromosomal instability in humans. Meiotic DSBs form at elevated levels but remain unresected if Mre11 is conditionally deleted, thus MRN is required for both resection initiation and regulation of DSB numbers. Resection lengths are reduced to varying degrees in MRN hypomorphs or if MRE11 nuclease activity is attenuated in a conditional nuclease-dead Mre11 model. These findings unexpectedly establish that MRN is needed for longer-range extension of resection, not just resection initiation. Finally, resection defects are additively worsened by combining MRN and Exo1 mutations, and mice that are unable to initiate resection or have greatly curtailed resection lengths experience catastrophic spermatogenic failure. Our results elucidate multiple functions of MRN in meiotic recombination, uncover unanticipated relationships between short- and long-range resection, and establish the importance of resection for mammalian meiosis.

Frontal bone tumor resection and parietal bone defect repair with immediate cranioplasty surgery using additive manufacturing–customized Ti-6Al-4V alloy implants

Frontal bone tumor resection and parietal bone defect repair with immediate cranioplasty surgery using additive manufacturing–customized Ti-6Al-4V alloy implants

Custom Endoprosthesis-Assisted Pediatric Microsurgical Jaw Reconstruction.

Surgical treatment of pediatric maxillary and mandibular tumors can cause significant postresection disfigurement, mastication, and speech dysfunction. The need to restore form and function without compromising growth at the recipient and donor sites poses a particular reconstructive dilemma. This study evaluates outcomes of the custom endoprosthesis (CE) compared with noncustom reconstruction (NCR) and introduces an algorithm using CE to optimize available soft tissue reconstructive options. An Institutional Review Board-approved retrospective review of all patients undergoing maxillary or mandibular reconstruction between 2016 and 2022 was completed. The independent variable of interest was CE utilization. Primary outcomes of interest included hardware failure/removal or exposure, major complications, and revision surgeries. Covariates of interest included patient demographics, medical comorbidities, tumor size, and pathologic diagnosis. Statistical analyses including independent t test, χ2 analyses, and univariate/multivariate logistic regression were performed using RStudio version 4.2.1. Fifty-one patients (37 mandible and 14 maxilla) underwent CE or NCR. Of patients, 37% (n = 19) received CE. Of patients who underwent mandibular reconstruction, there were significantly lower rates of hardware exposure (14.3% versus 47.8%, P = 0.018), failure (7.1% versus 43.5%, P = 0.048), major complications (28.6% versus 78.2%, P = 0.008), and revisions (11.1% versus 50.0%, P = 0.002) in the CE cohort compared with the NCR cohort. The rates of hardware failure, exposure, major complications, and revisions did not significantly differ in maxillary reconstructions, however, CE successfully reconstructed significantly larger defects (179.5 versus 74.6cm3, P = 0.020) than NCRs. Deviating from NCR, the authors propose an algorithm considering anatomical location, extent of resection, and patient age for soft tissue selection. This algorithm yielded improved mandibular reconstructive outcomes and no increase in complications rate in maxillary reconstruction despite larger resection defects. Furthermore, the authors' initial findings demonstrate that CE is a safe option for pediatric maxillary and mandibular reconstruction that may, in addition, facilitate improved form and function.

Evaluation of the resection plane three-dimensional positional accuracy using a resection guide directional guidance slot; a randomized clinical trial

AimThe study was performed to compare the mandibular resection guide with a directional guidance slot with the conventional guide regarding three-dimensional positional accuracy.Materials and methodsTwenty-six patients with lateral segmental mandibular defects were selected, and randomly allocated into two groups. All defects were managed with preoperative virtual surgical planning. Resection in the test group was conducted using a resection guide with a directional guidance slot, while a conventional resection guide design was utilized in the control group. The linear and angular deviation of the osteotomy planes was analyzed for both groups, along with the accuracy of the insertion of the reconstruction bone block in the resected defect. Data were documented, absolute deviation was calculated, statistical analysis was performed and significance was set at the 5% level.ResultsThe cases conducted with a directional guidance templet reported a statistically significant difference when compared to the conventional edge-cutting guide regarding the linear and angular spatial osteotomy plane position (P < 0.001). The defect span analysis reported excellent levels of agreement in both groups (ICC = 1.00, ICC = 0.995), however, the difference between the groups was statistically significant (P < 0.001).ConclusionThe study demonstrated the enhanced positional accuracy of the resection plane and reconstruction block placement when a directional slot is incorporated in the computer-generated resection guide.

Classification of the Volume of Tumor Lesion of the Chest Wall as A Prerequisite for Planning Surgical Treatment

Tumors of the chest wall are a heterogenous group of neoplasms per nosology, clinical progression, and treatment methods. Primary tumors of this location, according to some authors, comprise between 1 and 5 %, and 60 % of them are malignant. Tumors of the chest wall can have not only various nosological forms but also varying volume, location, affect different structures of the chest wall which are determined during physical exam. Despite the progress in drug therapy, radical surgical intervention is a prerequisite for successful treatment of patients with malignant tumors of the chest wall. One of the most important prognostic factors is sufficient margin during chest wall resection. The international tumor classification system Tumor, Nodus and Metastasis (TNM) does not give a complete understanding of the volume of lesions and therefore does not allow to correctly plan resection volume and defect reconstruction based on its data.The article presents a classification of tumor volume of the chest wall proposed by the Sarcoma Research Association which allows to expand indications for surgical treatment and select the optimal type of defect reconstruction.

Evaluation of long-term results of single intraoperative electrical neurostimulation after autologous plastic surgery of a resection defect of the tibial portion of the sciatic nerve in adult rats

Introduction World literature data indicate the effectiveness of single intraoperative electrical stimulation (IES) of the proximal segment of the damaged nerve to stimulate its regeneration, but there is no data on its effect on the long-term results of autoplasty of resection defects.The purpose of the work was to evaluate the long-term results of a single IES after autologous plastic surgery of the tibial portion of the sciatic nerve in rats.Materials and methods Thirty rats after autologous repair of the resection defect of the tibial portion of the sciatic nerve were divided into series 1 (unstimulated control, n = 16) and series 2 (single IES for 40 minutes, n = 14). At 4 and 6 months after surgery, the static sciatic functional index (SFI) and morphometry of epoxy transverse semithin sections of the tibial nerve at the level of the middle third of the leg were assessed. For comparison with the normal values, the corresponding data from 7 intact rats were used.Results The number of animals with excellent results of SFI restoration was 12.5 % in series 1 and 50 % in series 2 (p = 0.05). The numerical density of regenerated myelinated fibers (MF) exceeded the norm: in series 1 — by 63 % (p &lt; 0.01) and 34 % (p &lt; 0.01), in series 2 — by 58 % (p &lt; 0.01) and 47 % (p &lt; 0.01), respectively. In series 2, there were greater values in comparison with series 1: the median diameters of MFs were by 11.7 % and 15.7 %, the median diameters of their axons were by 5.4 % and 11.9 %, the median thickness of the myelin sheath was by 17.0 % and 24.1 %, respectively (p &lt; 0.05 4 months and p &lt; 0.01 6 months after surgery). Four months after surgery in series 1 and 2, the numerical densities of endoneurial vessels exceeded the intact control by 134 % (p &lt; 0.05) and 156 % ( 0.05), their average diameters by 18 % and 16 % (p &lt; 0.01) respectively, and lumen diameters increased only in series 2 by 8 % (p = 0.07). After 6 months of the experiment in series 1 and 2, the numerical densities of microvessels decreased, but significantly exceeded the control by 66 % (p &lt; 0.05) and 83 % (p &lt; 0.05), the average diameters — by 14 % and 36 % (p &lt; 0.05), lumen diameters — by 26 % (p &lt; 0.05) and 50 % (p &lt; 0.01), respectively.Discussion The difference between stimulated and unstimulated animals in all MF size parameters 6 months after surgery was greater than after 4 months, indicating a persistent neuroregenerative effect.Conclusions A significant increase in the diameters of regenerating nerve fibers in the tibial nerve, as well as the diameters of their axons and the thickness of the myelinated sheaths 4 and 6 months after autoplasty of the tibial portion of the sciatic nerve in the group of animals with a single 40-minute IES of the proximal portion of the sciatic nerve indicates the promoting effect of the applied additive effect on regenerative axono- and myelinogenesis. Increase in the lumens and improvement of blood flow of the endoneurial vessels of the tibial nerve in the series with IES ensured the stability of the neuroregenerative effect. The functional significance of the effects of a single IES is confirmed by a significantly higher percentage of animals with excellent results in restoring the static functional index.

Nanoengineered 3D-printing scaffolds prepared by metal-coordination self-assembly for hyperthermia-catalytic osteosarcoma therapy and bone regeneration

The integration of functional nanomaterials with tissue engineering scaffolds has emerged as a promising solution for simultaneously treating malignant bone tumors and repairing resected bone defects. However, achieving a uniform bioactive interface on 3D-printing polymer scaffolds with minimized microstructural heterogeneity remains a challenge. In this study, we report a facile metal-coordination self-assembly strategy for the surface engineering of 3D-printed polycaprolactone (PCL) scaffolds with nanostructured two-dimensional conjugated metal–organic frameworks (cMOFs) consisting of Cu ions and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP). A tunable thickness of Cu-HHTP cMOF on PCL scaffolds was achieved via the alternative deposition of metal ions and HHTP. The resulting composite PCL@Cu-HHTP scaffolds not only demonstrated potent photothermal conversion capability for efficient OS ablation but also promoted the bone repair process by virtue of their cell-friendly hydrophilic interfaces. Therefore, the cMOF-engineered dual-functional 3D-printing scaffolds show promising potential for treating bone tumors by offering sequential anti-tumor effects and bone regeneration capabilities. This work also presents a new avenue for the interface engineering of bioactive scaffolds to meet multifaceted demands in osteosarcoma-related bone defects.

Developing A Temporary External Fixator (TEF) for Mandibular Reconstruction using Two-Phase QFD and TRIZ Approach

A temporary external fixator (TEF) is a device used to bridge resection defects after sequestrectomy and before secondary mandibular reconstruction surgery. A well-designed TEF should be customizable and adjustable to accommodate individual patient needs. This study developed a TEF for mandibular reconstruction using the quality function deployment (QFD) and the theory of inventive problem-solving (TRIZ). Customer needs (CNs) were investigated from literature reviews and a survey. Subsequently, a questionnaire was developed, refined, and delivered to 22 experts to identify the essential principles of TEF. Afterwards, the QFD priorities were analyzed based on the acquired CNs and technical requirements (TRs), and the top priorities were found to be safety and adequate operational space. The guidelines for developing a TEF with TRIZ were established as follows: First, using carbon fiber epoxy composite and Ti-6Al-4V as the material for TEFs is recommended Second, permanent magnet should be inserted into the clamp lock bolts to prevent them from falling off during surgery. Last, replacing one Schanz screw with three Bicortical screws is recommended for the fixator pins. Additionally, it was also found that changing the screw size from 2.5–4.0 mm to 2.0–2.4 mm could reduce hole defects in the mandible.

Prosthetic Rehabilitation of a Maxillectomy Patient with Restricted Mouth Opening Using an Altered Cast Technique: A Case Report

Deformity in the maxillofacial region caused by surgical resection of a tumor have an adverse effect on the patient's ability to swallow, masticate, phonate, and psychological state. These patients may have restricted mouth opening capacity due to several surgical procedures and scar contracture resulting from radiation therapy. Therefore due to restricted access to the oral cavity prosthetic rehabilitation of these patients becomes a challenging task. A precise impression of the resection defect is necessary for accurate obturation. This is not practical for patients who have restricted mouth opening, hence this crucial first step in the making of a good prosthesis is frequently accomplished by altering the conventional impression method. This clinical report details the prosthetic rehabilitation of a patient who was diagnosed with Adenoid cystic carcinoma of the left maxillary sinus. Patient underwent maxillectomy for tumor removal, which was worsened by trismus as a result of the procedure and radiation therapy. For orofacial rehabilitation and defect obturation, the patient was restored with a removable dental prosthesis with a hollow bulb obturator. An altered cast technique was used in the final impression making. This rehabilitation approach was successful in restoring lost function and appearance of the patient. Keywords: Maxillectomy, Hollow Obturator, Altered cast technique

Abstract PO2-20-12: Breast Implant-associated Squamous Cell Carcinoma

Abstract A 54-year-old female with a history of bilateral breast implants presented with intermittent left breast pain for 6 months. She first had bilateral breast implants placed in 1996 and had no reported issues until 2010, when she had bacteremia and seeding infection with subsequent removal of both implants. She then had a second set of silicone-based implants placed in 2012 with no issues for 10 years. Family history was negative for breast cancer or any other malignancy. She had no prior smoking history. Vital signs and laboratory values were unremarkable. On exam, the left breast appeared larger than the right, dense, thickened, and slightly edematous. No lymphadenopathy was palpated. Both mammogram and ultrasound of bilateral breasts, done at the onset of her pain, were normal. Given the patient’s symptoms, an MRI of the breasts was done, with findings concerning an infection or lymphoma. It revealed an irregular fluid collection in the left breast. The fluid collection was rim-enhancing with frond-like areas of enhancing tissue, extending through the inferior aspect of the capsule into the subcutaneous tissue of the lower outer quadrant of the left breast. Enhancement and edema extended off of the superior and posterior aspect of the prosthesis into the pectoralis muscle. It was particularly prominent along the medial aspect of the prosthesis where it extended in the chest wall between the sternum and the costal cartilage. There were 3 mildly enlarged left intramammary lymph nodes measuring up to 7 mm in short axis, with diffuse edema seen within the breast. No axillary adenopathy was seen in the MRI. She was referred to surgery and had both right and left breast implants removed, and a left breast JP drain was placed. The pathology from the left breast capsule excision revealed squamous cell carcinoma, well-differentiated and invasive, associated with a scar and extending to the surgical margin. She was diagnosed with a rare case of breast implant-associated squamous cell carcinoma (BIA-SCC). Subsequent staging imaging showed postsurgical inflammatory changes with no nodal metastatic disease. She continued to follow up outpatient with plans of multidisciplinary meeting to discuss long-term treatment options. Most patients undergoing breast augmentation experience no serious complications. Previously, rare incidences of breast-implant-associated anaplastic large cell lymphoma (BIA-ALCL) had been reported, with 1234 cases as of 2022. More recently, cases of BIA-SCC have been seen. Primary SCC of the breast is extremely rare in both augmented and non-augmented women. 19 cases of BIA-SCC are reported in the literature as of 2022, all seen in females, typically arising from capsular tissue around the breast implant. It is a rare and potentially aggressive malignancy, with unclear etiology and undefined therapy regimen due to a paucity of data. Suggested treatments include resection with a negative margin, although this could require an extensive and complex reconstruction, including plastic surgery soft tissue coverage of the resection defect. Definitive radiation to obtain local control can be considered in an organ-sparing approach. Consideration can also be given to either chemosensitization with agents such as cisplatin or combining radiation with immunotherapy. Citation Format: Farhan Azad, Ajay Siva, Prutha Patel, Clive Miranda, Matthew Gravina. Breast Implant-associated Squamous Cell Carcinoma [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-20-12.

Audit of hemostatic clip use after colorectal polyp resection in an academic endoscopy unit.

Background and study aims Prophylactic closure of endoscopic resection defects reduces delayed hemorrhage after resection of non-pedunculated colorectal lesions ≥ 20 mm that are located proximal to the splenic flexure and removed by electrocautery. The risk of delayed hemorrhage after cold (without electrocautery) resection is much lower, and prophylactic clip closure after cold resection is generally unnecessary. The aim of this study was to audit clip use after colorectal polyp resection in routine outpatient colonoscopies at two outpatient centers within an academic medical center. Patients referred for resection of known lesions were excluded. Patients and methods Retrospective chart analysis was performed as part of a quality review of physician adherence to screening and post-polypectomy surveillance intervals. Results Among 3784 total lesions resected cold by 29 physicians, clips were placed after cold resection on 41.7% of 12 lesions ≥ 20 mm, 19.3% of 207 lesions 10 to 19 mm in size, and 2.8% of 3565 lesions 1 to 9 mm in size. Three physicians placed clips after cold resection of lesions 1 to 9 mm in 18.8%, 25.5%, and 45.0% of cases. These physicians accounted for 8.1% of 1- to 9-mm resections, but 69.7% of clips placed in this size range. Electrocautery was used for 3.1% of all resections. Clip placement overall after cold resection (3.9%) was much lower than after resection with electrocautery (71.1%), but 62.4% of all clips placed were after cold resection. Conclusions Audits of clip use in an endoscopy practice can reveal surprising findings, including high and variable rates of unnecessary use after cold resection. Audit can potentially reduce unnecessary costs, carbon emissions, and plastic waste.