Tumor Extirpation Research Articles

Multiple foci of Rosai–Dorfman disease in colon: a case report

BackgroundRosai–Dorfman disease (RDD) is an uncommon proliferative histiocytic disorder involving lymph nodes and various organs. Forty-three percent of RDD cases originate from extranodal sites; however, RDD rarely arises from the colon.Case presentationA 75-year-old man was admitted to our hospital because of intra-abdominal masses that were incidentally detected during surveillance by computed tomography (CT) after treatment for lung cancer. Enhanced CT showed two mass lesions located in the cecum to the appendix (diameter, 40 mm) and around the sigmoid colon (diameter, 24 mm). Positron emission tomography (PET)-CT revealed an apparent uptake of fluorodeoxyglucose. Intraluminal endoscopy did not reveal definite mucosal abnormalities. These findings suggest the presence of malignant neoplasms including gastrointestinal stromal tumors, lung cancer metastasis, and malignant lymphoma. Exploratory laparoscopy and/or tumor excision were planned to obtain a definitive diagnosis. Based on laparoscopic findings, ileocecal resection and sigmoidectomy were simultaneously performed to excise the tumors. Postoperative histopathological examination revealed multiple RDD originating from the mesocolon side of the cecum and the sigmoid colon. The patient did not receive any adjuvant therapy. No recurrence was observed one year after surgery.ConclusionRDD originating from the colon is extremely rare. Tumor extirpation or organ resection is sometimes required to obtain a definitive diagnosis of RDD, and minimally invasive surgery is helpful.

Staged wound reconstruction utilizing regenerative dermal matrix followed by split-thickness skin grafting in the setting of local radiation: A case series with review of the literature

The use of radiation for local control following tumor extirpation has improved outcomes across the spectrum of oncologic conditions. Reconstructive strategies that improve short-term healing rates and long-term results in these complicated wound healing environments are paramount to success. Regenerative dermal matrices (RDM) have emerged as viable options to improve reconstructive outcomes in the field of radiology. Here, we present a case series highlighting our algorithm of staged reconstruction using regenerative dermal matrix followed by split-thickness skin grafting to reconstruct skin deficits following excision of tumors either before or after radiation. A systematic review of the literature pertaining to irradiated wound closure and the application of dermal regenerative templates is presented to better understand its emerging role to manage these complex cases and impact future outcomes. Six patients underwent staged reconstruction using our algorithm, all of which went on to heal completely without additional procedures or evidence of skin breakdown in the short and long term. RDMs seem to improve the radioresistance of surgically reconstructed wounds following excision of cancer. The mechanism for this is likely related to the creation of additional tissue layers beyond those replaced with skin graft alone and should be the subject of future study.

NFS-14. INTERCEPTION TREATMENT STRATEGY FOR INCIDENTAL LESIONS IN CHILDREN, ADOLESCENTS AND YOUNG ADULTS (AYA) USING LASER INTERSTITIAL THERMAL THERAPY (LITT)

Abstract BACKGROUND Due to widespread availability and lower threshold for neuroimaging, incidental brain lesions have increased. When a high index of suspicion exists for a neoplastic process, early treatment might be beneficial. This is appealing in cases of tumor predilection such as cancer predisposition syndromes or history of therapeutic irradiation. LITT may provide a means for total tumor extirpation in these otherwise surgically inaccessible lesions and intercept eventual anatomic or pathologic evolution. The aim of this study is to evaluate our evolving experience based on an early and minimally invasive strategy using LITT. METHODS Prospective review of pediatric and AYA patients in whom incidentally discovered lesions were treated with simultaneous stereotactic biopsy and LITT. Demographic data, presenting symptoms, adverse events and outcomes are reviewed. RESULTS Mean age for 9 patients is 11.8 years. 4 patients had tumor predilection: 2 with familial tumor predisposition syndrome and 2 history of cranial-sirradiation. In 4 patients imaging was performed for surveillance of other brain tumor or focal cortical dysplasia. 3 patients had imaging for headache. Mean time from initial finding to treatment was 29.7 months. Recommendation to proceed with treatment was due to interval growth, concerning features (contrast-enhancement), or high potential for malignant transformation. 1 patient had facial weakness and 1 patient had visual field deficit that resolved. Pathological diagnoses revealed low-grade tumor in 4 patients and non-diagnostic pathology in 5. No patients received additional tumor-directed therapy during a mean follow-up of 14.7 months. There was no evidence of tumor recurrence in any patient. CONCLUSION An early therapeutic strategy aimed at tumor interception is feasible in pediatric and AYA patients for incidental lesions. Early results might influence the design of future strategies for simultaneous or sequential diagnostic and thermal therapy. Evolving tumor control rates support the therapeutic potential of LITT in central, surgically-inaccessible incidental tumors.

Mohs Micrographic Surgery for Invasive Melanoma Allows for Tissue Preservation Compared With Wide Local Excision: A Retrospective Cohort Study.

While increasing evidence supports the safety and effectiveness of immunohistochemistry-assisted Mohs micrographic surgery (MMS) for superficially invasive melanoma, there is a paucity of the literature investigating its effect on final defect size. To evaluate the tissue sparing effect of MMS for melanoma. Three hundred and twenty-eight patients with early-stage (T1a/T1b) cutaneous melanomas treated with MMS from January 2008 to December 2018 were evaluated. Measured defect sizes after Mohs tumor extirpation were compared with anticipated defect size that would result from standard-margin wide local excision (WLE). Average actual versus anticipated defect areas were compared using a paired t-test (95% confidence intervals). The following groups demonstrated a significantly smaller defect area for MMS-treated tumors when compared with anticipated standard-margin WLE defect: All tumors combined (13.8 cm2 vs 10.4 cm2, p < .001), tumors requiring 1 stage (13.6 cm2 vs 10.1 cm2,p < .001), and tumors requiring 2 stages (13.2 cm2 vs 10.5 cm2, p = .004). The majority of patients (83.5%, n = 274) achieved clear margins with 1 stage. Immunohistochemistry-assisted MMS for early-stage invasive melanoma is associated with smaller final defect size and overall tissue sparing effect compared with standard WLE margins.

Expanding the use of nipple sparing mastectomy: A review of the indications and techniques

The nipple sparing mastectomy (NSM) has allowed for targeted tumor extirpation while maintaining the breast skin envelope and nipple-areola complex. Initially, the indications for this reconstructive technique were quite narrow, but ongoing investigation have expanded the indications and safety profile of the NSM from an oncologic and reconstructive standpoint. Historically, patients with elevated body mass index, macromastia, high-grade ptosis, and ongoing tobacco use were deemed high-risk candidates for ischemic complications. Development and utilization of numerous techniques have allowed the NSM to be offered more frequently to these high-risk candidates. Specifically, many methods including single-stage and multi-stage/delay techniques have been developed for the patient with high-grade ptosis.

"To implant or not to implant": electrically evoked auditory brainstem response audiometry for decision-making in vestibular schwannoma resection with CI.

Vestibular schwannomas (VS) are often associated with debilitating hearing loss. Therefore, preservation and rehabilitation of hearing have become major therapeutic goals of VS management. Recently, cochlear implantation (CI) has been established as an effective treatment option for VS-associated hearing loss. Nevertheless, the integrity and proper function of the cochlear nerve must be evaluated before conducting CI to ensure optimal CI outcomes. Various methods to determine cochlear nerve integrity and functionality have emerged in the last few years. Of these, the use of electrically evoked auditory brainstem response audiometry (eABR) in particular has been proven to be ameaningful tool for monitoring cochlear nerve health during VS surgery. Here, the cochlear nerve can be electrically stimulated using an intracochlear test electrode before, during, and after tumor extirpation. Subsequently, the resulting brainstem responses can be measured and interpreted accordingly to obtain direct information on the cochlear nerve function. This allows for continuous monitoring of cochlear nerve function throughout the course of VS surgery and aids in the decision-making for CI candidacy. Finally, in the case of preserved brainstem responses, CI can be performed instantly after VS extirpation. This simultaneous approach offers several advantages over two-staged procedures and has been shown to be an efficient and safe procedure for restoring hearing after VS removal.

A nationwide phase II study of delayed local treatment for children with high-risk neuroblastoma: The Japan Children's Cancer Group Neuroblastoma Committee Trial JN-H-11.

Survival rates of patients with high-risk neuroblastoma are unacceptable. A time-intensified treatment strategy with delayed local treatment to control systemic diseases has been developed in Japan. We conducted a nationwide, prospective, single-arm clinical trial with delayed local treatment. This study evaluated the safety and efficacy of delayed surgery to increase treatment intensity. Seventy-five patients with high-risk neuroblastoma were enrolled in this study between May 2011 and September 2015. Delayed local treatment consisted of five courses of induction chemotherapy (cisplatin, pirarubicin, vincristine, and cyclophosphamide) and myeloablative high-dose chemotherapy (melphalan, etoposide, and carboplatin), followed by local tumor extirpation with surgery and irradiation. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), response rate, adverse events, and surgical complications. Seventy-five patients were enrolled, and 64 were evaluable (stage 3, n=8; stage 4, n=56). The estimated 3-year PFS and OS rates (95% confidence interval [CI]) were 44.4% [31.8%-56.3%] and 80.7% [68.5%-88.5%], resspectively. The response rate of INRC after completion of the treatment protocol was 66% (42/64; 95% CI: 53%-77%; 23 CR [complete response], 10 VGPR [very good partial response], and nine PR [partial response]). None of the patients died during the protocol treatment or within 30days of completion. Grade 4 adverse effects, excluding hematological adverse effects, occurred in 48% of patients [31/64; 95% CI: 36%-61%]. Major Surgical complications were observed in 25% of patients [13/51; 95% CI: 14%-40%]. This study indicates that delayed local treatment is feasible and shows promising efficacy, suggesting that this treatment should be considered further in a comparative study of high-risk neuroblastoma.

In vitro evaluation and characterization of cisplatin loaded nanofibers for local chemotherapy

Cancer is a disease that affects the quality of life of the patients that are treated with Cisplatin (CDDP), which is needed for adjuvant therapy, however it leads to many secondary and adverse effects. In this study, we manufactured and characterized poly-(lactic acid) (PLA) non-woven fibers loaded with Cisplatin (CDDP) by electrospinning technique to evaluate their cytotoxicity in in vitro assays on HeLa cells (cervical carcinoma cell line). PLA–CDDP solutions with increasing concentrations of CDDP (0.5, 1 and 2% w/w) were used in a TL-01 electrospinning equipment with the same system parameters. We analyzed the chemical, thermal and morphological characteristics of PLA and PLA–CDDP fiber mats. Furthermore, hydrolytic degradation, hemolysis and toxicity in HeLa cells were evaluated. By adding the CDDP to the fibers, the degradation, glass transition and melting temperatures were modified; the 3 µm fiber diameter of pristine PLA fibers was decreased in half the size and the degradation time was extended over 5 months. However, the hemocompatibility of the material with and without CDDP was maintained, while cytotoxicity in HeLa cells increased in the three concentrations of fiber mats of PLA–CDDP compared to the intravenous drug at 24 h (p < 0.01). We concluded that the fiber mats PLA–CDDP could be used for localized therapy in the adjuvant treatment when resection panels are expose after a surgical extirpation of solid tumors.

Weishaar's classification system for nodal metastasis in sentinel lymph nodes: Clinical outcome in 94 dogs with mast cell tumor.

The therapeutic role and prognostic relevance of lymphadenectomy in mast cell tumor (MCT) has historically been evaluated on regional rather than sentinel lymph nodes. To update information about the association of histological nodal (HN) classes with clinical outcome in dogs with MCT after tumor excision and extirpation of normal-sized sentinel nodes (SLN) guided by radiopharmaceutical. Ninety-four dogs with histologically-confirmed treatment-naïve MCT (71 cutaneous, 22 subcutaneous and 1 conjunctival MCT) were included if without: distant metastases, lymphadenomegaly, concurrent mixed cutaneous, and subcutaneous MCT. This was a monoistitutional cohort study. Tumors characteristics were retrieved and SLNs were classified according to Weishaar's system. Incidence of MCT-related events (local, nodal, distant relapse), de novo MCT or other tumors and death (MCT-related and non-MCT-related), were recorded. Incidence curves were compared among the HN classes. Twenty-seven dogs had HN0, 19 HN1, 37 HN2, and 11 HN3 SLN. Thirteen (2 HN0, 4 HN2, and 7 HN3) received adjuvant chemotherapies. Kiupel high grade, increasing number of SLN and lymphocentrums were associated with higher HN classes. Five dogs died for MCT-related causes: 1 low-grade (HN0) and 1 subcutaneous (HN3) had a local relapse, 2 high-grade had distant relapse (HN3-HN0) and 1 dog developed disease progression from a de novo subcutaneous MCT. No nodal relapse was registered. Fourteen dogs developed de novo MCTs. Low grade/low-risk MCT with nonpalpable and normal sized SLN have a favorable outcome independently from the HN. Result should be considered strictly related to the successful SLN detection guided pre- and intraoperative by radiopharmaceutical markers.

Expanding the Armamentarium of Donor Sites in Microvascular Head and Neck Reconstruction.

The field of microsurgical head and neck reconstruction has witnessed tremendous advancements in recent years. While the historic goals of reconstruction were simply to maximize flap survival, optimizing both aesthetic and functional outcomes has now become the priority. With an increased understanding of perforator anatomy, improved technology in instruments and microscopes, and high flap success rates, the reconstructive microsurgeon can push the envelope in harvesting and designing the ideal flap to aid patients following tumor extirpation. Furthermore, with improvements in cancer treatment leading to improved patient survival and prognosis, it becomes increasingly important to have a broader repertoire of donor sites. The present review aims to provide a review of newly emerging soft tissue flap options in head and neck reconstruction. While certainly a number of bony flap options also exist, the present review will focus on soft tissue flaps that can be harvested reliably from a variety of alternate donor sites. From the upper extremity, the ulnar forearm as well as the lateral arm, and from the lower extremity, the profunda artery perforator, medial sural artery perforator, and superficial circumflex iliac perforator flaps will be discussed, and we will provide details to aid reconstructive microsurgeons in incorporating these alternative flaps into their armamentarium.

Anatomical Variations of the Ascending Pharyngeal Artery: Implications for Endoscopic Surgery in the Parapharyngeal Space.

Objectives: The ascending pharyngeal artery (APA) travels with the parapharyngeal internal carotid artery (pICA) in the parapharyngeal space (PPS). This study aimed to investigate the anatomical variations of the APA, and to explore their implications for endoscopic surgery in the PPS. Methods: Dissection of the APA in the PPS was performed on 10 cadaveric specimens (20 sides). The relationship between APA and PPS tumors was retrospectively reviewed in 20 patients, attempting to ascertain the APA during the resection of 10 pre-styloid and 10 retro-styloid PPS tumors. Results: During the cadaveric dissections, the APA was identified at the medial, posteromedial, or bilateral aspects of the pICA in 12 (60%) and 4 (20%) sides, respectively. In the remaining 4 sides (20%), the APA branched into several subcategory arteries lying at the medial and lateral aspects of the pICA. Branches of the APA were observed in 13/20 sides (65%). Two branches were found in 9/13 sides and 3 branches in 4/13, respectively. The APA was only identifiable in 1/10 (10%) of pre-styloid tumors, a patient with basal cell adenoma. In contrast, the APA was encountered surrounding the pICA in 8/10 (80%) of patients with retro-styloid tumors, all of which were schwannomas. No inadvertent injury of the APA or the pICA occurred in this cohort. Conclusions: With identification of the ascending pharyngeal artery on preoperative magnetic resonance imaging, it may serve as an additional landmark during the endoscopic extirpation of tumors arising in the PPS.

The Pedicled Anterolateral Thigh Flap as a Versatile Option for Resurfacing Extensive Lower Trunk Defects.

The resurfacing of large abdominal and perineal defects is a major concern, and it poses a great challenge to the reconstructive surgeon. The main target in the reconstruction of the abdomen is to ensure a stable soft-tissue cover, and a strong and reliable fascia to prevent hernia recurrence and fecal contamination. The pedicled anterolateral thigh flap (ALT) either in the myocutaneous or fasciocutaneous form is a work-horse for the closure of abdominal and perineal defects. There is a paucity of studies on the use of the anterolateral thigh flap among black Africans especially in Nigeria; hence, we present our experience with the use of this flap for extensive abdominal and perineal defects. The folders of all patients who had pedicled anterolateral thigh flap between January 2019 and July 2022 in our institution were reviewed. The patients' demographic data and the available details about the flap reconstruction were extracted from the folders. There were three males and two females, and the age range was between 22 and 48 years. Four cases resulted from tumor extirpation, while one was following extensive necrotizing fasciitis of the lower anterior abdominal wall. No gross anatomical variations were encountered intraoperatively. Four flaps had full survival, while one had marginal flap tip loss. The pedicled anterolateral thigh flap is an excellent reconstructive tool for the coverage of extensive abdominal and perineal defects.

Horner syndrome: Clinical image

A 34-year-old man was referred by his primary care physician for left blepharoptosis, ipsilateral miosis, and left facial anhidrosis (Figure 1). His medical history included a recent thoracotomy of the upper left hemithorax for extirpation of a neurogenic mediastinal tumor. A diagnosis of Horner syndrome was made.

Narrative review of patient-reported outcomes of breast reconstruction.

The treatment of breast cancer encompasses both the elimination of malignancy as well as reconstruction after tumor extirpation. Although the patient may have had successful treatment of her breast cancer, the resulting disfigurement and deformity can have a substantial impact on her physical and mental well-being. Breast reconstruction affords these patients the opportunity to correct these deformities and potentially to improve their quality of life. The current literature review evaluates patient-reported outcomes for the various options of breast reconstruction that are most commonly performed. A literature review on PubMed with the key words "patient-reported outcomes", "breast reconstruction", and "breast cancer" yielded 738 results, which were screened. Articles that specifically focused on patient-reported outcomes after various types of breast reconstruction were evaluated and included in this literature review. The main options of alloplastic reconstruction, autologous tissue reconstruction, and oncoplastic reconstruction were reviewed and found to demonstrate high levels of patient satisfaction. Although there is no clear superior option, patient-reported outcomes demonstrate improved well-being compared to no reconstruction. Breast reconstruction provides the opportunity to correct the deformities after breast cancer treatment making it a crucial component of comprehensive cancer care. A variety of reconstructive options are available which can be tailored to each individual patient to achieve the optimal results for that particular patient. Therefore patient-reported outcomes are paramount to gauge the true success of not only breast cancer treatment but also reconstructive aspects after treatment.

Ileal Interposition for Ureteral Reconstruction Following Treatment for Abdominopelvic Malignancy: Complications and Outcomes From a Comprehensive Cancer Center

To characterize the outcomes of ileal interposition for the management of ureteral obstruction from tumor and ureteral stricture following treatment for abdominopelvic malignancy. A retrospective database analysis was performed for all cases of ileal interposition performed by 5 surgeons from January 2013 to December 2020. Patients were ≥18years of age and included if undergoing ileal interposition in either the primary setting of a surgical procedure for tumor extirpation or in the delayed setting. In total, 23 patients who underwent repair of 27 ureteral units were included. The mean age was 60.2years. Median follow-up was 21.6months. The most common primary diagnoses were urothelial (35%), colorectal (31%), and cervical (22%) cancer. The etiologies of ureteral obstruction were malignant in 48% and ureteral stricture in 52%. Types of repairs included unilateral interposition in 13 patients, bilateral interposition in 1 patient, interposition to an ileal conduit in 3 patients, and interposition with cystoplasty in 6 patients. There was a statistically significant difference between the mean preoperative (Creatinine 1.05mg/dL, Estimated Glomerular Filtration Rate 77ml/min/1.73m2) renal function and postoperative (Creatinine 1.26mg/dL, Estimated Glomerular Filtration Rate 67mL/min/1.73m2) renal function at the most recent follow-up (P=.024). Eight minor (grade 1-2) and 6 major (grade ≥3) complications developed for a minor and major complication rate of 35% and 26%, respectively. Ileal interposition is successfully utilized as a reconstructive technique at the time of enbloc resection involving the ureter and to address ureteral stricture in the delayed setting.

A Systematic Review on Prosthodontic Rehabilitation of Hemimandibulectomy Defects.

Restoration of hemimandibulectomy defects following tumour extirpation to restore oral function is a herculean task for practitioners. Prosthetic treatment alternatives available for rehabilitation of acquired hemimandibulectomy defects according to mandibular reconstruction type and extent (Cantor-Curtis classification) are unclear. This systematic review aims to assess the spectrum of prosthodontic rehabilitation approaches with regard to reconstruction type and extent of mandibular surgical defects.The databases incorporated for literature search were Google Scholar and Medline (PubMed). Relevant search terms for hemimandibulectomyand reconstruction with prosthetic rehabilitation were used. Two reviewers independently assessed the articles using eligibility criteria; published case reports and case series in the English language anddepicting prosthodontic treatment modality of patients greater than 15 yearswere included. A total of 202 records were identified from the database search of which 19 duplicates were removed. The remaining articles were assessed for eligibility, and 55 articles (comprising58 cases) were finally included in the study. This review revealed various prosthetic alternatives ranging from guide flange, twin occlusion, palatal ramp, conventional to hybrid partial and complete dentures to implant-supported prosthesis including a few innovative prosthetic approaches. This systematic review provides a plethora of prosthodontic rehabilitation approaches according to the extent of hemimandibular surgical defect and type of reconstruction. This will facilitate practitioners and prosthodontists in sequential treatment planning and management of hemimandibulectomy cases in their routine practice.

Whipple Resection for Benign Tumors and Premalignant Neoplasms of the Pancreatic Head: Surgery-Associated Risk for Complications and Late Metabolic Morbidity Matters.

Benign and premalignant neoplasms of the pancreas are increasingly detected and recommended for surgical treatment. For tumors of the pancreatic head, the challenging decision is: multiorgan resection or local tumor extirpation? Compared with pancreaticoduodenectomy, duodenum-preserving pancreatic head resection is associated with significantly fewer surgery-related serious and severe complications and lower in-hospital mortality. The decisive advantage of duodenum-preserving pancreatic head resection is the maintenance of endocrine and exocrine pancreatic and upper gastrointestinal tract functions.

Spinal Dural Arteriovenous Fistula in a Pediatric Patient with History of Endovascular Therapy Failure: A Case Report

Spinal Dural Arteriovenous Fistula (SDAVF) cases in children are extremely rare and pose a high risk for intraoperative hemorrhage. The clinical manifestation and imaging results may be vague and deceptive, frequently mistaken for other conditions such as demyelinating or spinal degenerative illnesses. SDAVF's cause is not well understood. Here, we present the case of a 10-year-old male patient with SDAVF who did not improve after endovascular therapy. The patient complained of weakness in the lower extremities, skin thickness, tingling sensations, and painful bowel movements and urination. The patient underwent endovascular embolization due to spinal AVF from the 9th thoracic vertebrae until the sacral vertebrae one month earlier. But no significant clinical improvement was found. The vital signs of the patient were within normal limits. An MRI showed a flow-void lesion with tortuosity in the dorsal spinal area at the 9th and 10th thoracic vertebrae. Because an embolization procedure was performed on the patient, which resulted in no significant improvement, it was planned for the patient to undergo an MRI and MRA evaluation. An MRI and MRA later showed the formation of an extramedullary intradural cyst at levels T9 to T10 of the thoracic vertebrae. Decompression surgery (left hemilaminectomy) and tumor extirpation were thereafter carried out on the patient after the routine laboratory test was performed. After the procedure, the patient showed improvement and could carry out everyday activities independently at 10 months post-operatively. The failure of endovascular therapy can be attributed to several factors, such as the surgeon’s experience, tools, and embolization technique, and follow-up treatment by surgery.

McGregor Versus Stepped Lower Lip Split Incision for Extirpation of Tumor in Oral Squamous Cell Carcinoma Patients: Does It Affect the Functional and Esthetic Outcomes? A Comparative Study

McGregor Versus Stepped Lower Lip Split Incision for Extirpation of Tumor in Oral Squamous Cell Carcinoma Patients: Does It Affect the Functional and Esthetic Outcomes? A Comparative Study

A Ready-To-Use Purified Exosome Product for Volumetric Muscle Loss and Functional Recovery.

Large skeletal muscle defects due to trauma or following tumor extirpation can result in substantial functional impairment. Purified exosomes are now available clinically and have been used for wound healing. The objective of this study was to evaluate the regenerative capacity of commercially available exosomes on an animal model of volumetric muscle loss (VML) and potential translation to human muscle injury. An established VML rat model was used. In the in-vitro experiment, rat myoblasts were isolated and co-cultured with 5% purified exosome product (PEP) to validate uptake. Myoblast proliferation and migration was evaluated with increasing concentrations of PEP (2.5%, 5%, and 10%) in comparison to control media(F10) and myoblast growth media (MGM). In the in-vivo experiment, a lateral gastrocnemius-VML defect was made in the rat hindlimb. Animals were randomized into four experimental groups; defects were treated with either surgery alone, fibrin sealant, fibrin sealant and PEP, or platelet rich plasma (PRP). The groups were further randomized into four recovery timepoints (14, 28, 45, or 90 days). The isometric tetanic force (ITF), which was measured as a percentage of force compared to normal limb, was used for functional evaluation. Florescence microscopy confirmed that 5% PEP demonstrated cellular uptake around 8-12 hrs. Compared to control, myoblasts showed faster proliferation with PEP irrespective of concentration. PEP concentrations of 2.5 and 5% promoted myoblast migration faster compared to control (<0.05). At 90 days postop, both the PEP and fibrin sealant and PRP groups showed greater ITF compared to control and fibrin sealant alone (<0.05). At 45 days postop, PEP with fibrin sealant had greater cellularity compared to control (<0.05). At 90 days postop, both PEP with fibrin sealant and the PRP treated groups had greater cellularity compared to fibrin sealant and control (<0.05). PEP promoted myoblast proliferation and migration. When delivered to a wound with a fibrin sealant, PEP allowed for muscle regeneration producing greater functional recovery and more cellularity in vivo compared to untreated animals. PEP may promote muscle regeneration in cases of VML, further research is warranted to evaluate PEP for the treatment of clinical muscle defects.