Aho, Johnathon M.

AbstractBackgroundAcute appendicitis is a common pediatric surgical emergency; however, there are few grading systems to assign disease severity. The American Association for the Surgery of Trauma (AAST) recently developed a grading system for a variety of emergency surgical conditions, including appendicitis. The severity of acute appendicitis in younger patients in KwaZulu‐Natal (South Africa) is unknown. We aimed to describe the disease severity in this patient population using the AAST grading system hypothesizing that the AAST grade would correlate with morbidity, management type, and duration of stay.MaterialsSingle institutional review of patients <18 years old with a final diagnosis of acute appendicitis during 2010–2016 in KwaZulu‐Natal, South Africa, was performed. Demographics, physiologic and symptom data, procedural details, postoperative complications, and Clavien–Dindo classification were abstracted. AAST grades were generated based on intraoperative findings. Summary, univariate, and nominal logistic regression analyses were performed to compare AAST grade and outcomes.ResultsA total of 401 patients were identified with median [IQR] age of 11 [5–13], 65% male. Appendectomy was performed in all patients; 2.4% laparoscopic, 37.6% limited incision, and 60% midline laparotomy. Complications occurred in 41.6%, most commonly unplanned relaparotomy (22.4%), surgical site infection (8.9%), pneumonia (7.2%), and acute renal failure (2.9%). Complication rate and median length of stay increased with greater AAST grade (all p < 0.001). AAST grade was independently associated with increased risk of complications.ConclusionPediatric appendicitis is a morbid disease in a developing middle‐income country. The AAST grading system is generalizable and accurately corresponds with management strategies as well as key clinical outcomes.Level of evidenceRetrospective study, Level IV.Study typeRetrospective single institutional study.

AbstractBackgroundThe American Association for the Surgery of Trauma (AAST) anatomic severity grading system for adhesive small bowel obstruction (ASBO) has demonstrated to be a valid tool in North American patient populations. Using a multi‐national patient cohort, we retrospectively assessed the validity the AAST ASBO grading system and estimated disease severity in a global population in order to correlate with several key clinical outcomes.MethodsMulticenter retrospective review during 2012–2016 from four centers, Minnesota USA, Bologna Italy, Pietermaritzburg South Africa, and Bucharest Romania, was performed. Adult patients (age ≥ 18) with ASBO were identified. Baseline demographics, physiologic parameters, laboratory results, operative and imaging details, outcomes were collected. AAST ASBO grades were assigned by independent reviewers. Univariate and multivariable analyses with odds ratio (OR) and 95% confidence intervals (CIs) were performed.ResultsThere were 789 patients with a median [IQR] age of 58 [40–75] years; 47% were female. The AAST ASBO grades were I (n = 180, 23%), II (n = 443, 56%), III (n = 87, 11%), and IV (n = 79, 10%). Successful non‐operative management was 58%. Conversion rate from laparoscopy to laparotomy was 33%. Overall mortality and complication and temporary abdominal closure rates were 2, 46, and 4.7%, respectively. On regression, independent predictors for mortality included grade III (OR 4.4 95%CI 1.1–7.3), grade IV (OR 7.4 95%CI 1.7–9.4), pneumonia (OR 5.6 95%CI 1.4–11.3), and failing non‐operative management (OR 2.4 95%CI 1.3–6.7).ConclusionThe AAST EGS grade can be assigned with ease at any surgical facility using operative or imaging findings. The AAST ASBO severity grading system has predictive validity for important clinical outcomes and allows for standardization across institutions, providers, and future research. Disease severity and outcomes varied between countries.Level of evidence IIIStudy type Retrospective multi‐institutional cohort study.

AbstractIntroductionAppendicitis is a significant economic and healthcare burden in low‐, middle‐, and high‐income countries. We aimed to determine whether urban and rural patient status would affect outcomes in appendicitis in a combined population regardless of country of economic status. We hypothesize that patients from rural areas and both high‐ and low‐middle‐income countries would have disproportionate outcomes and duration of symptoms compared to their urban counterparts.MethodsAdults (≥18 years) with appendicitis during 2010–2016 in South Africa and USA were reviewed using multi‐institutional data. Baseline demographic, operative details, durations of stay, and complications (Clavien–Dindo index) were collected. AAST grades were assigned by two independent reviewers based on operative findings. Summary, univariate, and multivariable analyses of rural and urban patients in both countries were performed.ResultsThere were 2602 patients with a median interquartile range [IQR] of 26 [18–40] years; 45% were female. Initial management included McBurney incisions (n = 458, 18%), laparotomy (n = 915, 35%), laparoscopic appendectomy (n = 1185, 45%), and laparoscopy converted to laparotomy (n = 44, 2%). Comparing rural versus urban patient status, there were increased overall median [IQR] AAST grades (3 [1–5] vs. 2 [1–3], p = 0.001), prehospital duration of symptoms (2 [1–5] vs. 2 [1–3], p = 0.001), complications (44.3 vs. 23%, p = 0.001), and need for temporary abdominal closure (20.3 vs. 6.9%, p = 0.001).ConclusionDespite socioeconomic status and country of origin, patients from more rural environments demonstrate poorer outcomes notwithstanding significant differences in overall disease severity. The AAST grading system may serve a potential benchmark to recognize areas with disparate disease burdens. This information could be used for strategic improvements for surgeon placement and availability.

AbstractBackgroundTube thoracostomy (TT) is a commonly performed procedure which is associated with significant complication rates. Currently, there is no validated taxonomy to classify and compare TT complications across different populations. This study aims to validate such TT complication taxonomy in a cohort of South African trauma patients.MethodsPost hoc analysis of a prospectively collected trauma database from Pietermaritzburg Metropolitan Trauma Service (PMTS) in South Africa was performed for the period January 2010 to December 2013. Baseline demographics, mechanism of injury and complications were collected and categorized according to published classification protocols. All patients requiring bedside TT were included in the study. Patients who necessitated operatively placed or image‐guided TT insertion were excluded. Summary and univariate analyses were performed.ResultsA total of 1010 patients underwent TT. The mean age was (±SD) of 26 ± 8 years. Unilateral TTs were inserted in n = 966 (96%) and bilateral in n = 44 (4%). Complications developed in 162 (16%) patients. Penetrating injury was associated with lower complication rate (11%) than blunt injury (26%), p = 0.0001. Higher complication rate was seen in TT placed by interns (17%) compared to TT placed by residents (7%), p = 0.0001. Complications were classified as: insertional (38%), positional (44%), removal (9%), infective/immunologic (9%), and instructional, educational or equipment related (0%).ConclusionsDespite being developed in the USA, this classification system is robust and was able to comprehensively assign and categorize all the complications of TT in this South African trauma cohort. A universal standardized definition and classification system permits equitable comparisons of complication rates. The use of this classification taxonomy may help develop strategies to improve TT placement techniques and reduce the complications associated with the procedure.Level of evidenceV.Study typeSingle Institution Retrospective review.

Abstract Background Tube thoracostomy (TT) can be an effective therapy for thoracic pathologies. Ineffective placement of TT is common and associated with significant complications. Complications require additional interventions to repair damaged tissues or replace dysfunctional TT. We hypothesize that complicated TT insertion increases cost to the hospital system. Methods Adult trauma patients requiring TT at a level 1 trauma center (2012–2013) were reviewed. Intraoperative or image‐guided TT placements were excluded. Baseline demographics and TT insertion cost (normalized and assigned by hospital billing records) were recorded. Costs included initial TT equipment, radiographs, and subsequent operative or radiologic intervention to correct TT complications. Complications were categorized using previously validated method. Secondary outcomes included: number of TT inserted, number of chest radiographs performed, and TT dwell time utilizing a standardized TT discontinuation protocol. Results A total of 154 patients with 246 TT were included. Ninety TT (37%) had complication. Complication categories are postremoval ( n = 15, 16.7%), insertional ( n = 13, 14.4%), positional ( n = 62, 68.9%). Overall median complicated TT cost was 9 times greater than uncomplicated TT insertion, p = 0.001. Insertional complications median cost 21 times greater than an uncomplicated, due to operative and radiologic interventions ( p = 0.0001). Positional and postremoval complication rates increased median cost by 3 times compared to uncomplicated TT ( p = 0.03). Operative or radiologic interventions ( n = 10) were performed for organ injury or uncontrolled hemo‐/pneumothorax. Increased dwell time median [IQR] was associated with complicated TT compared to uncomplicated 3 [1–5] versus 2 [1–3], p = 0.01. Conclusion TT is a common procedure. TT complications are often considered benign. However, patients with a complicated TT insertion, especially related to insertional subtypes, have markedly increased hospitalization costs due to need for operative or radiologic repair. Level of evidence Level V—retrospective study. Study type This is a retrospective single‐institution study.

Medical drains frequently become obstructed requiring removal or re-intervention. Currently, there is no widely accepted practice for maintaining drain patency. A simple device to remove obstructions from medical drains may have significant benefit. We manufactured a prototype drain clot extractor (DCE) for extracting obstructions. Fresh nonanticoagulated swine blood was instilled within drainage tubes of 16, 20, and 32 French (n = 2 for each size) to generate a 4 cm blood clot. The operator was then equipped with a 0.035 in. guidewire (GW) and given 2.5 min to attempt removal while blinded. Similarly, the operator was equipped with the DCE. Volumes removed were determined by volume displacement and by drain size and method of removal. Comparison of DCE to GW by analysis of variance and means comparison using Tukey were used for statistical analysis. The DCE facilitated mechanical removal of obstructions for 16, 20, and 32 French drainage tubes. Volumes removed: 16 French (GW mean 10% volume, DCE mean 70% volume p = 0.02); 20 French (GW mean 12.5% volume, DCE mean 75% volume p = 0.01); 32 French (GW mean 37.5% volume, DCE mean 100% volume p = 0.01). DCE volume removal had no dependence on drain size (p > 0.05). This device may have utility for reducing morbidity from early drain discontinuation or replacement. Further in vivo and clinical studies are needed to determine the safety, feasibility, and efficacy of this device as tool for removing medical drainage obstructions.

Abstract Management of recurrent bronchopleural fistula (BPF) after pneumonectomy remains a challenge. Although a variety of devices and techniques have been described, definitive management usually involves closure of the fistula tract through surgical intervention. Standard surgical approaches for BPF incur significant morbidity and mortality and are not reliably or uniformly successful. We describe the first-in-human application of an autologous mesenchymal stem cell (MSC)-seeded matrix graft to repair a multiply recurrent postpneumonectomy BPF. Adipose-derived MSCs were isolated from patient abdominal adipose tissue, expanded, and seeded onto bio-absorbable mesh, which was surgically implanted at the site of BPF. Clinical follow-up and postprocedural radiological and bronchoscopic imaging were performed to ensure BPF closure, and in vitro stemness characterization of patient-specific MSCs was performed. The patient remained clinically asymptomatic without evidence of recurrence on bronchoscopy at 3 months, computed tomographic imaging at 16 months, and clinical follow-up of 1.5 years. There is no evidence of malignant degeneration of MSC populations in situ, and the patient-derived MSCs were capable of differentiating into adipocytes, chondrocytes, and osteocytes using established protocols. Isolation and expansion of autologous MSCs derived from patients in a malnourished, deconditioned state is possible. Successful closure and safety data for this approach suggest the potential for an expanded study of the role of autologous MSCs in regenerative surgical applications for BPF. Significance Bronchopleural fistula is a severe complication of pulmonary resection. Current management is not reliably successful. This work describes the first-in-human application of an autologous mesenchymal stem cell (MSC)-seeded matrix graft to the repair of a large, multiply recurrent postpneumonectomy BPF. Clinical follow-up of 1.5 years without recurrence suggests initial safety and feasibility of this approach. Further assessment of MSC grafts in these difficult clinical scenarios requires expanded study.

Abstract Malignant esophageal pathology typically requires resection of the esophagus and reconstruction to restore foregut continuity. Reconstruction options are limited and morbid. The esophagus represents a useful target for tissue engineering strategies based on relative simplicity in comparison to other organs. The ideal tissue engineered conduit would have sufficient and ideally matched mechanical tolerances to native esophageal tissue. Current methods for mechanical testing of esophageal tissues both in vivo and ex vivo are typically destructive, alter tissue conformation, ignore anisotropy, or are not able to be performed in fluid media. The aim of this study was to investigate biomechanical properties of swine esophageal tissues through nondestructive testing utilizing sonometry ex vivo . This method allows for biomechanical determination of tissue properties, particularly longitudinal and circumferential moduli and strain energy functions. The relative contribution of mucosal–submucosal layers and muscular layers are compared to composite esophagi. Swine thoracic esophageal tissues ( n = 15) were tested by pressure loading using a continuous pressure pump system to generate stress. Preconditioning of tissue was performed by pressure loading with the pump system and pre-straining the tissue to in vivo length before data was recorded. Sonometry using piezocrystals was utilized to determine longitudinal and circumferential strain on five composite esophagi. Similarly, five mucosa–submucosal and five muscular layers from thoracic esophagi were tested independently. This work on esophageal tissues is consistent with reported uniaxial and biaxial mechanical testing and reported results using strain energy theory and also provides high resolution displacements, preserves native architectural structure and allows assessment of biomechanical properties in fluid media. This method may be of use to characterize mechanical properties of tissue engineered esophageal constructs.