Scientific Abstract Presentations: Top Residents Abstract Session 4 (Pediatric, Reconstruction / Burn / Microsurgery) Friday, October 27 Fri, Oct 27 8:00-9:00 a.m. CDT

Background A teratoma is a true neoplasm, containing tissue from the ectodermal, mesodermal and endodermal layers. Teratoma of the oropharynx is found in 1:35,000-1:200,000 live births. Teratoma of the oropharynx is usually associated with cleft palate as the teratoma hampers palatal closure during in-utero development. Management of these cases are challenging with respect to handling of airway at birth and during surgery.

Methods A retrospective review of all cases presenting to our institution with an oropharyngeal teratoma were analysed. The inclusion criteria were patients of any age with oropharyngeal teratoma and velopalatine cleft. The diagnosis of teratoma was confirmed by histological analysis. Data regarding the following characteristics were collected: antenatal history, radiological and pathological characteristics, surgical treatment, tumour recurrence, and length of follow-up.

Results Six patients were included: 5 with a palatal teratoma and 1 with a tongue teratoma. In 2 cases with the largest tumour size, the lesions were diagnosed antenatally and both patients required neonatal resuscitation due to respiratory distress. All patients underwent early surgery in the first 6 months, and 2 with complete excision. All patients with an initial incomplete excision eventually presented with recurrence and therefore repeat excision. No malignant transformation was noted. After a mean follow-up of 5 years, no sign of tumour recurrence had been detected.

Conclusion Palatal teratoma has a benign disease process and has an excellent long term prognosis following surgery. In the situation of incomplete resection, careful meticulous follow-up with radiological imaging, tumour markers and a multidisciplinary team approach is a safe and viable alternative.

Introduction: Gortex-mesh (GT) is commonly used to reconstruct bony defects created in chest wall reconstruction (CWR) following tumor resection. GT can be used with or without flap coverage for CWR. Mesh infection (MI) is a serious complication of GT-CWR. Little is known on outcomes and management after MI.1-3 The purpose of this study was to evaluate outcomes in patients undergoing CWR who developed MI.

Methods: This was a single-institution retrospective review of adults who underwent GT-CWR. Clinical outcomes were evaluated. Salvage therapy (ST) was defined as complete mesh explant after MI. Uni and multivariate analysis was used to evaluate differences.

Results: 244 patients met inclusion (1994 to 2021). Forty-six (18.9%) had MI and 198 (81.1%) did not. There was no difference in mean follow-up period (MI 6.8 yrs.± 7.0 vs 5.8 yrs. ±5.6). Analysis revealed that MI was more frequent in patients with prior CW-radiation (39.1% vs 20.7%, p <0.02; OR 4.89, p <0.01), higher body mass index or BMI (30.6±6.9 vs 27.48± 5.6, p < 0.015; OR 1.09, p <0.02), and greater quartile defect area (OR 1.85, p < 0.012). Fifty-two percent (104/198) of the control group had flaps compared to 62.5% (30/46) with MI. Although more patients with MI had flaps (muscle flap 60.9% vs 51%; omental flap 4.3% vs 0%; p <0.01), flap coverage did not alter risk of MI after controlling for other variables (OR 1.05, p= 0.91). Complications within 3-months were higher in those with MI, including more empyema (11.1% vs 0%, p <0.001), flap-complications (43.3% vs 8.9%, p <0.001), hematomas (11.1 % vs 2.1%, p <0.015), seromas (26.7% vs 8.3%, p <0.001), readmission (77.8% vs 7.8%, p <0.001), and surgical-site infections (75.6% vs 3.6%, p <0.001). Three (7.7%) with MI expired due to postop complications (vs 0 % in control, p <0.002), although no difference in time-to-death postop was seen (4.76yrs ± 4.7 vs 4.75yrs ± 4.5). A majority (41/46) of patients with MI were managed surgically; 78% (36/46) had ST, 11% (5/46) had chronic antibiotics (ABX) only, 6.5% (3/46) had debridement surgeries without explanting the mesh, and the remaining 4.3% (2/46) had partial explant of the mesh. There were no differences in days to MI diagnosis or death due to post-op complications amongst the ABX versus surgical group. Ninety-six percent (44/46) had cultures sent returning as either Staph aureus (31%) or polymicrobial (28.6%) compared to coagulase negative Staph (14.3%), Enterobacter/Enterococcus (9%), other (11.9%), or no-growth (4.8%). Of those who received ST, the reconstruction was either simple (55.6%), complex (36.1%), or mesh-based (8.3%). Sixty-one percent (22/36) had a muscle flap at time of ST; there were no differences in time-to-explant or history of prior CW-radiation had a muscle flap been used. Seventy-five percent (27/36) had staged debridement followed by reconstruction, which correlated with a longer hospital stay (mean 20.6 days± 19.1 vs 6.1 days± 3.7, p <0.05). Following ST, 69.4% (25/36) had complete wound healing, and 22% (8/36) developed a future-hernia at the prior CWR; 3 of these patients were symptomatic. Thirteen percent (5/36) required a future reconstruction of which 3 were mesh-based.

Conclusion: This is the largest study to evaluate MI following GT-CWR. We report a 19% MI rate. Flap coverage did not influence the risk of MI. Instead, a higher BMI, greater defect size, and history of prior CW-radiation increased the likelihood of developing a MI. This suggests that these factors predispose patients to a higher risk of MI irrespective of flap coverage. Although those with MI had higher complications, it did not alter the time-to-death postop. Over 90% of the patients who received ST were reconstructed safely with either a complex or simple reconstruction suggesting that once the mesh is removed, an immediate replacement of mesh does not need to be performed.

Reference: 1. Petrella F, Casiraghi M, Mariolo AV, et al. Rigid Prosthesis Removal Following Chest wall resection and reconstruction for cancer. Shanghai Chest. 2018; 2(8): 1-5. 2. Deschamps C, Tirnaksiz BM, Darbandi R, et al. Early and Long-term Results of Prosthetic Chest wall reconstruction. Journal of Thoracic and Cardiovascular Surgery. 1999; 1117(3): 588-92. 3. Weyant M, Bains M, Venkatraman E, et al. Results of Chest Wall Resection and Reconstruction with and without Rigid Prosthesis. Annals of Thoracic Surgery. 2006; 81: 279–285

Purpose: Pediatric reduction mammaplasty has become increasingly common due to the obesity epidemic. While obesity remains the leading cause of macromastia leading to surgery, it may also be a risk factor for postoperative complications. The objective of this study was to assess the safety and complication rate of pediatric (Age <18) reduction mammaplasty in relation to the obesity risk factor,

Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP Peds) was queried to obtain all reduction mammaplasty cases from 2012 to 2020. Univariate & multivariate logistic regression analyses controlling for confounders were carried out to assess the relationship between BMI and rates of complication.

Results: 1589 patients having primary CPT code 19318 were included in the final analysis. The mean age was 16.6 years (SD 1.1) & the mean Body Mass Index (BMI) was 30.5 kg/m2 (SD±6.2). Notably, 49% of the patients were obese and 31% were overweight, while only 0.4% were underweight. A total of 43 patients (2.7%) sustained a superficial surgical site infection (SSI) postoperatively. Other complications were less prevalent, including deep SSI (4 patients, 0.3%), dehiscence (11, 0.7%), reoperation (21, 1%), and readmission (26, 1.6%).

Independent variables analyzed included age, sex, BMI, diabetes mellitus, American Society of Anesthesiologists (ASA) class, and operative time, of which only BMI and ASA class were found to be significantly associated with SSI on univariate analysis. On multivariate logistic regression while controlling for ASA class and the false discovery rate, there was a strong association between increasing rates of superficial SSI and increasing BMI (Unit Odds Ratio (OR) 1.05, 95% CI [1.01, 1.09], p=0.02). The OR indicates that for each 1-unit increase in BMI, the odds of SSI increases by 1.05x.

Conclusions: Complications following pediatric reduction mammaplasty are uncommon, demonstrating the safety of this procedure. However, higher BMI was found to have a significantly higher risk for superficial SSI. With the growing obesity epidemic, our data suggest that higher infection control and awareness should be practiced when performing reduction mammaplasty on obese pediatric patients.

Introduction Over the last 20 years, the use of the surgical robot has seen an exponential increase throughout many surgical specialties. Proving to be advantageous in intraabdominal operations, its role in plastic and reconstructive surgery was initially limited due to the diversity of tissues and superficial spaces often involved. As reconstructive microsurgery requires the use of fine instrumentation and precise magnification, incorporation of the robot into the field has been explored. With advances in robotic surgical instrumentation over the years, this systematic review aims to identify the current utilization of the surgical robot in plastic and reconstructive surgery.

Methods An electronic database search of Pubmed, EMBASE, and CINAHL was performed using pertinent search terms to identify applications of robot-assistance in plastic and reconstructive surgery. Inclusion criteria included studies where the robot was used in a clinical setting for reconstruction. Exclusion criteria included systematic reviews, preclinical/cadaveric studies, and studies where plastic surgeons were not involved.

Results A total of 71 out of 675 studies met inclusion criteria; 26 case reports, 25 case series, 14 retrospective reviews, and 6 randomized controlled trials. Robot assistance was utilized in breast reconstruction (18 papers, 25.4%), head and neck reconstruction (15 papers, 21.1%), gender-affirmation (7 papers, 9.9%), abdominal/pelvis reconstruction (6 papers, 8.5%), upper extremity/peripheral nerve reconstruction (6 papers, 8.5%), lymphedema (5 papers, 7%), latissimus dorsi harvest (4 papers, 5.6%), cosmetic (4 papers, 5.6%), craniofacial (3 papers, 4.2%), and lower extremity reconstruction (1 paper, 1.4%).

Cumulative, the robot was used in 1041 reconstructive procedures with complications reported in 161 cases (15.5%). Higher complication rates were seen in abdominal and pelvis reconstruction (28.6%), gender-affirming surgery (16.7%), and breast reconstruction (13.9%). Lower complication rates were seen in craniofacial operations (11.1%), head and neck reconstruction (8.22%) and latissimus dorsi harvest (3.7%). Operative times varied based on procedure performed.

Robotic-assisted microsurgical anastomosis was performed in 19 papers (27%). Microsurgical cases had an average operative time of 361 minutes and a complication rate of 7.97%.

Conclusion Utilization of the robot in plastic and reconstructive surgery has allowed for improved precision, minimal scarring, and a low complication rate. With an initial learning curve, longer operative times were later reduced with more experience in robotics. Furthermore, in robotic-assisted microsurgery, the superior magnification and additional degrees of freedom provided by the robot are especially advantageous; however, the cost, learning curve, and lack of haptic feedback are some of the current limiting factors of its use. With many studies describing pre-clinical applications for robotic microsurgery and reconstruction, we expect to see continued growth of its utilization in the field.

Background: Vasoactive medications are essential agents in the management of sepsis and are commonly administered via peripheral intravenous lines in the pediatric acute care setting. Vasopressor extravasation is an infrequent but well-described complication that may result in severe tissue ischemia and is a common reason for hand surgery consultation. Although local injection of phentolamine is the pharmacological standard of care, phentolamine has recently been subject to national shortages and is not universally available.

Methods: We present a case of a neonate with upper extremity tissue ischemia secondary to dopamine extravasation who was successfully treated with topical 2% nitroglycerin ointment alone. Additionally, we conducted a literature review of nitroglycerine ointment as a treatment modality for tissue ischemia in the setting of extravasation.

Results: Although topical nitroglycerine is commonly referenced in treatment algorithms for dopamine extravasation, to the authors' knowledge this recommendation is based on only two case reports published over 30 years ago. Our case adds to the limited published reports supporting the efficacy of topical nitroglycerin in reversal of local tissue ischemia resulting from vasopressor extravasation.

Conclusions: In the absence of phentolamine, topical nitroglycerin ointment may represent a safe and effective treatment alternative.

Introduction Intraoperative vasopressors play a key role in preserving hemodynamic stability in the trauma setting during soft tissue microvascular reconstruction.1,2 Historically, their use has been proposed to adversely affect flap survival due to concerns for hypoperfusion.1,3 Though previous studies have reviewed the impact of vasopressors on flap outcomes in the head and neck, their effects on lower extremity (LE) reconstruction have yet to be investigated. This study aims to analyze the impact of intraoperative vasopressor use on postoperative outcomes in patients undergoing traumatic LE reconstruction.

Methods A retrospective review was performed evaluating patients who sustained LE trauma and underwent operative reconstruction with soft tissue coverage at a level 1 trauma center from 2015-2022. Data on patient demographics, mechanism of injury, flap characteristics, intraoperative pressor use, intraoperative fluids, and postoperative complications were collected. Primary outcomes included partial flap necrosis, complete flap necrosis, flap loss, and amputation. Chi-squared analysis and independent t-tests were used for categorical and continuous data, respectively. Multivariate logistic regressions were performed to model the association of vasopressor use and total fluids received intraoperatively with the primary outcomes while controlling for the following covariates: age, sex, comorbidities, Gustilo-Anderson fracture classification, and flap composition and movement.

Results Upon review, 142 LE flaps were placed over an 8-year period, of which 30 (21.2%) received pressors and 112 (78.9%) did not. Overall flap survival and limb salvage rates were 93.7% and 97.9%, respectively. The mean fluid administered in the pressor and non-pressor group were 3598.1±314.8 mL and 3886.6±531.8 mL, respectively. The amount of intraoperative fluids did not differ significantly between the two groups (p=0.782). The patients who received vasopressors intraoperatively did not significantly differ in rates of partial flap necrosis (23.3% vs. 12.5%; p=0.138), flap loss (3.3% vs. 7.1%; p=0.447), and amputation (6.7% vs. 0.9%; p=0.051) compared to those who did not receive vasopressors intraoperatively. Multivariate regression determined that vasopressor use was not associated with the likelihood of partial or complete flap necrosis (Odds Ratio [OR]: 1.27; p=0.663) or amputation (OR: 3.06; p=0.443). Similarly, total intraoperative fluids did not independently contribute to partial/full flap necrosis (OR: 1.00; p=0.478) or amputation (OR: 1.00; p=0.733).

Conclusion Our findings demonstrated no significant correlation between intraoperative vasopressor use or total fluids received and flap outcomes in LE reconstruction. Vasopressor use with adequate fluid management can optimize hemodynamic stability when necessary during traumatic LE microvascular reconstruction without concern for increased risk of flap ischemia.

References 1. Zheng G, Liu J, Yu P. Intraoperative Fluid Management Implies Insignificant Influence to Surgical Outcomes in Head and Neck Microvascular Reconstruction Cases. Plast Reconstr Surg. Apr 1 2021;147(4):627e-633e. doi:10.1097/PRS.0000000000007777 2. Al Saied G, Almutairi HM, Alharbi Y, Almohanna M, Almutairi A. Comparison Between the Impact of Vasopressors and Goal-Directed Fluid Therapy on the Management of Free Flap Reconstruction of Head and Neck and Monitoring in ICU. Cureus. Dec 16 2020;12(12):e12108. doi:10.7759/cureus.12108 3. Brinkman JN, Derks LH, Klimek M, Mureau MA. Perioperative fluid management and use of vasoactive and antithrombotic agents in free flap surgery: a literature review and clinical recommendations. J Reconstr Microsurg. Jul 2013;29(6):357-66. doi:10.1055/s-0033-1343955

PURPOSE: The current standard of care for the coverage of large wounds often involves split thickness skin grafts (STSGs) which have numerous limitations. One promising technique that has gained traction is fractional autologous skin grafting using full-thickness skin columns (FTSC). Harvesting occurs orthogonally by taking numerous individual skin columns containing the epidermis down through the dermis and transferring them to the wound bed. The purpose of this porcine study was divided into two objectives. The first was to investigate the efficacy of implanting FTSCs directly into deep partial-thickness burn wounds, maintaining their inherent orientation, instead of previous scattered methods. The second objective was to examine donor site healing at the maximal harvest density. Our hypothesis was that by implanting FTSCs, the speed of healing can be improved at low expansion ratios and harvested at a high harvest density without incurring donor morbidity, minimizing the amount of donor site needed.

METHODS: For the first objective, fifty deep-partial thickness burns were created on three anesthetized Red Duroc swine. FTSCs were harvested at 7-10% harvest density and implanted evenly across varying expansion ratios (1:50, 1:100, 1:200). Burned, untreated skin was utilized as a negative control. For the second objective, ten donor sites were created on one anesthetized Red Duroc swine with the highest possible harvest ratio of sixteen skin columns/cm2 (28%). Split thickness skin graft (STSG) donor sites were harvested with a dermatome as comparison. In both studies, healing was assessed via re-epithelialization, contraction, superficial blood flow, pigmentation, and scar thickness out to day 90.

RESULTS: On day 14, wounds treated with 1:50 expansion ratio showed significantly faster re-epithelialization than the control and 1:200 expansion (p=0.032 and 0.042, respectively). At day 90, wounds treated with 1:50 expansion ratios visually appeared to contract less than the burned, untreated control; however, these results were not significant. When studying donor site morbidity, low harvest densities of 7-10% were 100% re-epithelialized by day 7. Maximal harvest density was determined to be 28% ex-vivo, and applied to a porcine model with STSG donor sites as comparison. At maximal harvest density, no significant differences were observed in re-epithelialization, contraction, or blood flow were noted, with STSGs significantly more hypopigmented, and FTSC donor scarring significantly thicker at maximal harvest density. Damage to the vascular tree was observed in one donor site at maximal harvest density.

CONCLUSIONS: In conclusion, implantation directly into deep partial thickness burns is a viable option for the application of FTSCs, favoring lower expansion ratios such as 1:50 showing fast re-epithelialization and visually less contracture. The major limitation with implantation is that it is a time consuming and tedious technique compared to other methods of applications. The potential to damage the native vascular tree at maximum harvest density, along with observing little difference between FTSC at a maximal harvest density and STSG donor sites, concludes the optimal harvest density was exceeded. We favor a lower harvest density around 7-10% where donor sites are completely re-epithelialized in a week or less.

Background: A multidisciplinary approach to limb salvage has become the standard of care for soft tissue sarcoma (STS) of the extremities.1-4 Lower extremity reconstruction has notoriously higher complication rates compared to other anatomical regions.2,5 While orthoplastic collaboration appears beneficial in lower extremity reconstruction, existing literature fails to effectively synthesize outcomes after plastic surgery involvement.5 Our study aims to elucidate the benefits of orthoplastic collaboration in lower extremity soft tissue sarcoma reconstruction by performing a systematic review to describe clinical and functional outcomes at the global level.

Methods: A systematic review of adult lower extremity STS excision with plastic surgery involvement was conducted according to PRISMA guidelines searching the Pubmed, Embase, and Web of Science databases from inception to April 2023. Screening was independently conducted by two authors (ML and SD) using Covidence systematic review software. Conflicting inclusion decisions were discussed until the authors reached a consensus. Study cohorts were included based on predefined inclusion criteria, which excluded groin malignancies, tumors of bony origin, and pediatric cases. Case reports were also excluded. Primary outcome measures were rates of surgical complications, reoperation, limb amputation, and postoperative ambulation.

Results: Following removal of duplicates, 778 records were identified through the database searches. Subsequent screening of the title and abstract excluded 715 records, leaving 63 studies for eligible full-text review. During screening, the most common reason for exclusion was a lack of differentiated data for the lower extremity compared to other sarcoma sites. Ultimately, 26 articles were accepted for inclusion, published between 1992 and 2023, with an eligible cohort ranging from 1 to 181 (40.8 +/- 54.2) and totaling 1060 patients.

In the pooled cohort, mean age was 55.2 +/- 6.3 (20 studies). 51.6% (397/770) of patients were male (17 studies). Total mean follow-up duration was 32.0 +/- 24.3 months (15 studies). 67.9% (673/991) of patients received adjuvant radiotherapy (18 studies). Mean duration of hospital stay was 23.38 +/- 19.8 (5 studies) and 85.8% (307/358) ambulated postoperatively (11 studies). 21% (77/374) of patients required a reoperation during their respective follow-up periods (16 studies). Of studies that did not exclude amputations (25 studies), the limb salvage rate was 93.4% (958/1026). Amongst pooled surgical outcomes, 22.2% (225/1012) of patients experienced a perioperative complication (20 studies). Of those 553 patients with specific outcomes provided, patients experienced delayed wound healing at a rate of 5.6%, partial flap necrosis at 5.6%, total flap loss at 4.2%, wound dehiscence at 8.0%, seroma formation at 5.8%, hematoma formation at 2.0%, and infection at 11.9%.

Conclusion: Soft tissue sarcoma of the lower extremity represents a complex disease process which affects patients in profound ways. The inclusion of plastic surgery for lower extremity reconstruction optimizes outcomes and leads to high rates of limb salvage and functional markers. Here we provide a strong benchmark to evaluate clinical outcomes of an orthoplastic approach to lower extremity reconstruction following soft tissue sarcoma resection at the global level.

References: 1. Thomas B, Bigdeli AK, Nolte S, et al. The Therapeutic Role of Plastic and Reconstructive Surgery in the Interdisciplinary Treatment of Soft-Tissue Sarcomas in Germany-Cross-Sectional Results of a Prospective Nationwide Observational Study (PROSa). Cancers (Basel). 2022;14(17):4312. Published 2022 Sep 2. doi:10.3390/cancers14174312 2. Fujiki M, Kimura T, Takushima A. Limb-salvage surgery with vascular reconstruction after lower extremity sarcoma resection: A systematic review and meta-analysis. Microsurgery. 2020;40(3):404-413. doi:10.1002/micr.30553 3. Lucattelli E, Lusetti IL, Cipriani F, Innocenti A, De Santis G, Innocenti M. Reconstruction of upper limb soft-tissue defects after sarcoma resection with free flaps: A systematic review. J Plast Reconstr Aesthet Surg. 2021;74(4):755-767. doi:10.1016/j.bjps.2020.10.065 4. Götzl R, Sterzinger S, Arkudas A, et al. The Role of Plastic Reconstructive Surgery in Surgical Therapy of Soft Tissue Sarcomas. Cancers (Basel). 2020;12(12):3534. Published 2020 Nov 26. doi:10.3390/cancers12123534 5. Slump J, Bastiaannet E, Halka A, et al. Risk factors for postoperative wound complications after extremity soft tissue sarcoma resection: A systematic review and meta-analyses. J Plast Reconstr Aesthet Surg. 2019;72(9):1449-1464. doi:10.1016/j.bjps.2019.05.041

Approximately 70-80% of the greater than 2 million patients in the US who undergo major limb amputations develop chronic pain of varying etiologies. Targeted muscle reinnervation (TMR) has been shown to have remarkable success in multiple outcome metrics for patients with neuropathic or phantom limb pain following major limb amputation. Additionally, many amputations are performed without eventual prosthesis-wearing in mind, especially those performed emergently for trauma, infection, or limb ischemia. Revision surgery to address mechanical issues with the amputation stump such as bony contour, soft tissue coverage, or heterotopic ossification can make patients more comfortable with prosthetic devices and can be life-changing. Depending on the site of amputation, revision rates can approach 30%. Targeted muscle reinnervation at the time of stump revision is an approach that offers the combined advantages of addressing the patient's neuropathic pain while improving their stump quality and ability to wear a prosthetic device.
We performed a retrospective review of a single surgeon's experience over five years performing TMR at the time of stump revision in major limb amputees. The patients were managed using a multi-disciplinary approach with plastic surgery, physiatry, and physical therapy. Six patients in total were analyzed between 2017-2022. Ages ranged from 24-66, including 4 men and 2 women. Amputation sites include three below the knee and three above the knee amputations. Primary outcomes include safety of the combined procedures, prosthetic use, and pain level after surgery. Secondary outcome measurements include opioid use and quality of life before and after surgery. The six patients included were surveyed using the Houghton Scale to quantify perceived functional outcomes and the McGill Pain Questionnaire. Mobility was calculated using the AMPro and Timed Up and Go Test (TUG) when available.
Targeted muscle reinnervation can be safely and successfully done at the time of amputation revision. Combining procedures results in decreased post operative pain, improved time of prosthetic use, and decreased narcotic requirements.