Non-cross-linked porcine acellular dermal matrix (Strattice Tissue Matrix) in pediatric reconstructive surgery

Acellular Bovine Pericardial Patch for Difficult Abdominal Closure in the Pediatric Population: Our Experience with Review of Literature

Aims

Closure of congenital body wall defects in children can be a challenging task for the pediatric Surgeon. Biological prosthesis has been increasingly used for high-risk wound closure in adult patients with excellent outcomes and use in the pediatric population has also been reported. Here, we aim to study the outcome of abdominal wound repair with a tissue-engineered acellular bovine pericardial patch.

Methods

Over a period of 21 months, a total of 15 children had undergone abdominal wound repair with bioprostheses, i.e., bovine pericardial patch at our institute. Patient demographics, cause of defect, an indication of patch use, rate of infection, postoperative recovery, recurrence, and outcome were studied.

Results

A total of 15 patients underwent abdominal wall closure with acellular bovine pericardial patch. Nine out of 15 patients were neonates, of whom five had gastroschisis, two had a congenital diaphragmatic hernia, and two had ruptured omphalocele major. Of the rest 6 patients, 2 were patients of bladder exstrophy, 2 were older children of congenital diaphragmatic hernia with incisional hernias, and 2 were older children with omphalocele major. Out of the five patients with gastroschisis, two died during the early postoperative period due to sepsis. The wound healed in the rest 13 patients with mild skin dehiscence in two patients. Only one child had a recurrence.

Conclusion

Reconstruction with acellular bovine pericardial patch is a viable option in children with high-risk abdominal wounds as it allows tensionless repair with excellent healing and minimal complications. Recurrence, if any, may disappear with time as remodeling of the prosthesis occurs along with the growth of the body wall of the child.

Recent advances in decellularized biomaterials for wound healing

The skin is one of the most essential organs in the human body, interacting with the external environment and shielding the body from diseases and excessive water loss. Thus, the loss of the integrity of large portions of the skin due to injury and illness may lead to significant disabilities and even death. Decellularized biomaterials derived from the extracellular matrix of tissues and organs are natural biomaterials with large quantities of bioactive macromolecules and peptides, which possess excellent physical structures and sophisticated biomolecules, and thus, promote wound healing and skin regeneration. Here, we highlighted the applications of decellularized materials in wound repair. First, the wound-healing process was reviewed. Second, we elucidated the mechanisms of several extracellular matrix constitutes in facilitating wound healing. Third, the major categories of decellularized materials in the treatment of cutaneous wounds in numerous preclinical models and over decades of clinical practice were elaborated. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues for research on decellularized biomaterials-based wound treatment.

Developments in the Surgical Approach to Staging and Resection of Rhabdomyosarcoma

Although survival after rhabdosarcoma treatment has improved over the years, one third of patients still develop locoregional relapse. This review aims to highlight developments pertaining to staging and local treatment of specific RMS tumor sites, including head and neck, chest/trunk, bladder-prostate, female genito-urinary, perianal, and extremity sites.

The Use of Acellular Dermal Matrix (Integra Single Layer) for the Correction of Malformative Chest Wall Deformities: First Case Series Reported

Introduction Autologous tissue transfers have been used in chest wall reconstruction for decades, with high morbidity. Recently, acellular dermal matrices (ADMs) have emerged as an alternative. The aim of this article is to report our initial experience in the reconstruction of malformative chest wall deformities with ADM.

Methods A prospective observational study was performed in patients with malformative chest wall deformities, who were reconstructed with ADM at our institution between 2018 and 2020. We analyzed demographic variables, surgical features, postoperative complications, and cosmetic results at 12 months' follow- up.

Results Four male patients were included (median age: 16 years). Two patients had bilateral costal anomalies, one patient had a unilateral chest deformity, and one patient had Poland syndrome. In all patients, blunt dissection of the subcutaneous cellular tissue overlying the defect was performed through 2.5 to 3 cm skin incisions, creating a pouch. Afterwards, several sheets of Integra Single Layer were placed in the pouch, to replace the volume defect. All patients were discharged same-day. No postoperative infections, hematomas, or seromas were observed. Only one patient presented with a partial surgical wound dehiscence. Revisions were performed at 1, 3, 6, and 12 months. All 4 patients were satisfied with the cosmetic outcome (Nuss Questionnaire: median score: 16 points; Q1–Q3: 22–26).

Conclusion The use of ADM in malformative chest wall deformities reconstruction has not been previously described in children. This study demonstrates that the use of ADM is a safe and reliable technique. However, more studies with long-term follow-up are warranted.

Modular Bioreactor Design for Directed Tendon/Ligament Tissue Engineering

Functional tissue-engineered tendons and ligaments remain to be prepared in a reproducible and scalable manner. This study evaluates an acellular 3D extracellular matrix (ECM) scaffold for tendon/ligament tissue engineering and their ability to support strain-induced gene regulation associated with the tenogenesis of cultured mesenchymal stromal cells. Preliminary data demonstrate unique gene regulation patterns compared to other scaffold forms, in particular in Wnt signaling. However, the need for a robust bioreactor system that minimizes process variation was also evident. A design control process was used to design and verify the functionality of a novel bioreactor. The system accommodates 3D scaffolds with clinically-relevant sizes, is capable of long-term culture with customizable mechanical strain regimens, incorporates in-line load measurement for continuous monitoring and feedback control, and allows a variety of scaffold configurations through a unique modular grip system. All critical functional specifications were met, including verification of physiological strain levels from 1–10%, frequency levels from 0.2–0.5 Hz, and accurate load measurement up to 50 N, which can be expanded on the basis of load cell capability. The design process serves as a model for establishing statistical functionality and reliability of investigative systems. This work sets the stage for detailed analyses of ECM scaffolds to identify critical differentiation signaling responses and essential matrix composition and cell–matrix interactions.

Tissue Engineering in Skin Substitute

Thermal injuries may cause significant damage to large areas of the skin. Extensive and deep burn wounds require specialized therapy. The optimal method in the strategy of treating extensive, full thickness burns (III°) is the use of autologous split thickness skin grafts STSG (Busuioc et al. Rom J Morphol Embryol 4:1061-1067, 2012; Kitala D, Kawecki M, Klama-Baryła A, Łabuś W, Kraut M, Glik J, Ryszkiel I, Kawecki MP, Nowak M. Allogeneic vs. Autologous Skin Grafts in the Therapy of Patients with Burn Injuries: A Restrospective, Open-label Clinical Study with Pair Matching. Adv Clin Exp Med. 2016 Sep-Oct;25(5):923-929.; Glik J, Kawecki M, Kitala D, Klama-Baryła A, Łabuś W, Grabowski M, Durdzińska A, Nowak M, Misiuga M, Kasperczyk A. A new option for definitive burn wound closure - pair matching type of retrospective case-control study of hand burns in the hospitalized patients group in the Dr Stanislaw Sakiel Center for Burn Treatment between 2009 and 2015. Int Wound J. 2017 Feb 21. https://doi.org/10.1111/iwj.12720 . [Epub ahead of print]; Prim et al. May 24Wound Repair Regen., 2017; Grossova et al. Mar 31Ann Burns Fire Disasters 30:5-8, 2017). The main limitation of that method is the inadequate amount of healthy, undamaged skin (donor sites), which could be harvested and used as a graft. Moreover, donor sites are an additional wounds that require analgesic therapy, leave scars during the healing process and they are highly susceptible to infection (1-6). It must be emphasized that in terms of the treatment of severe, deep and extensive burns, and there should be no doubt that the search for a biocompatible skin substitute that would be able to replace autologous STSG is an absolute priority. The above-mentioned necessitates the search for new treatment methods of severe burn wounds. Such methods could consider the preparation and application of bioengineered, natural skin substitutes. At present, as the clinical standard considered by the physicians may be use of available biological skin substitutes, e.g., human allogeneic skin, in vitro cultured skin cells, acellular dermal matrix ADM and revitalized ADMs, etc. (Busuioc et al. Rom J Morphol Embryol 4:1061-1067, 2012; Kitala D, Kawecki M, Klama-Baryła A, Łabuś W, Kraut M, Glik J, Ryszkiel I, Kawecki MP, Nowak M. Allogeneic vs. Autologous Skin Grafts in the Therapy of Patients with Burn Injuries: A Restrospective, Open-label Clinical Study with Pair Matching. Adv Clin Exp Med. 2016 Sep-Oct;25(5):923-929.; Glik J, Kawecki M, Kitala D, Klama-Baryła A, Łabuś W, Grabowski M, Durdzińska A, Nowak M, Misiuga M, Kasperczyk A. A new option for definitive burn wound closure - pair matching type of retrospective case-control study of hand burns in the hospitalised patients group in the Dr Stanislaw Sakiel Center for Burn Treatment between 2009 and 2015. Int Wound J. 2017 Feb 21. https://doi.org/10.1111/iwj.12720 . [Epub ahead of print]; Prim et al. May 24Wound Repair Regen., 2017; Grossova et al. Mar 31Ann Burns Fire Disasters 30:5-8, 2017; Łabuś et al. FebJ Biomed Mater Res B Appl Biomater 106:726-733, 2018).

Ethical Publication Standards in Articles Reporting on Novel Surgical Methods: Analysis of Three Pediatric Surgical Journals

INTRODUCTION

 According to the Declaration of Helsinki, medical research and new therapeutic interventions involving human subjects require prior informed consent and ethical approval. In 2010, 46% of pediatric surgical publications lacked documentation of ethical approval and 84% lacked documentation of informed parental consent with lowest rates of ethical adherence found in articles concerning novel methods. The aim of this study was to investigate whether adherence to ethical standards has improved in pediatric surgical publications.

MATERIALS AND METHODS

 All 3,093 consecutive articles published in Journal of Pediatric Surgery, European Journal of Pediatric Surgery, and Pediatric Surgery International over the last 5 years were systematically reviewed for publications describing novel surgical methods. Novel methods were defined as surgical methods not published before or not considered common practice. The publications were reviewed as to whether ethical approval and informed consent to participate was documented.

RESULTS

 In total, 105 articles describing novel surgical methods were identified (61 Journal of Pediatric Surgery, 16 European Journal of Pediatric Surgery, and 28 Pediatric Surgery International). Authors reported on new operative techniques (62%), modified techniques (31%), or use of new materials (7%). Ethical approval was documented in 52% of the articles with almost half reporting approval for retrospective data analysis only but not the application of the novel method. Informed consent was documented in 21% of publications. Complications were reported in 48% of the studies, including recurrences and reinterventions for the unsuccessful novel methods. Two authors reported mortalities due to underlying disease, one of which failed to report prior ethical approval or informed consent.

CONCLUSION

 Adherence to ethical publication principles in pediatric surgery has improved over the last years but is still lacking in many publications. When implementing new methods, prior ethical approval and informed consent and their documentation are mandatory, specifically in the light of potential hazard to patients.

Complex abdominal wall reconstruction combined with bladder closure in OEIS complex

PURPOSE

Due to the large abdominal defect from the omphalocele and extreme pubic diastasis in cloacal exstrophy (CE), bioprosthetic material may be used to bridge this gap during abdominal closure in CE. This study examined presurgical factors associated with the use of bioprosthetic materials in CE closure and complications in these patients.

METHODS

An institutional database of exstrophy-epispadias complex patients was reviewed for CE. Inclusion criteria included CE and primary closure performed at the host institution from 1998 to 2018. Data collection included demographics, presurgical factors, use of bioprosthetic material, complications, and outcomes.

RESULTS

All 32 patients had a staged closure and pelvic osteotomy prior to bladder closure. Ten of the 32 patients incorporated a bioprosthetic material during abdominal wall closure. There is at least 3 months follow up for all patients, all had successful bladder closure without any postoperative hernias. Those who underwent closure without bioprosthetic material were younger at the time of closure (565 vs 693 days, p = 0.043). The differences in complication rates and mean pubic diastasis was not statistically significant, p = 0.079 and p = 0.457 respectively.

CONCLUSIONS

The use of bioprosthetic material is associated with older age at abdominal wall and bladder closure. The use of bioprosthetic material is a useful adjunct for secure abdominal wall closure in the reconstruction of CE.

TYPE OF STUDY

Prognostic.

LEVEL OF EVIDENCE

III.

Ruptured omphalocele: Diagnosis and management

Omphalocele is an abdominal wall defect which can be classified as small, giant, or ruptured. Ruptured omphaloceles require prompt diagnosis and management to prevent associated morbidity and mortality and represent a challenging surgical condition. This review serves to define the etiology, diagnosis, initial resuscitation, and surgical therapy employed in the treatment of ruptured omphalocele. Resuscitation should focus on maintaining hydration and normothermia. Broad spectrum antibiotics should be initiated. Similar to giant omphaloceles, procedural intervention includes primary closure, silo, synthetic and biologic mesh, negative pressure wound therapy, and topical agents. Despite advances in neonatal care, the prognosis remains guarded and mortality is high.

Acellular dermal matrix contributes to epithelialization in patients with chronic sinusitis

BACKGROUND

Nasal endoscopic surgery is widely used for nasal diseases, including sinusitis and tumors. However, scar hyperplasia, nasal irritation, scab, and nasal obstruction delay nasal mucosal recovery, with prolonged cleaning exacerbating the patient's financial burden. Here, we presented a novel approach for the treatment of nasal mucosal defects, termed acellular dermal matrix.

METHODS

A total of 31 patients with bilateral chronic sinusitis (maxillary sinusitis and ethmoid sinusitis) underwent nasal surgery and nasal mucosal repair in September-October 2016. We divided the nasal cavities of each patient into control and acellular dermal matrix groups, randomly selected one side for nasal mucosal repair by surgery. A suitable acellular dermal matrix size was selected according to the defect in each patient. After pruning, the acellular dermal matrix was placed on the wound surface and filled with gelatin sponge. All patients were followed up for 14 weeks to compare nasal mucosal epithelialization between the control and acellular dermal matrix groups. Results：No obvious complications and adverse reactions were observed after nasal surgery. Lund-Kennedy scores in the acellular dermal matrix group were significantly decreased compared with the control group at 8 (0 (0, 1) vs. 2 (2, 4); P<0.05) weeks. Epithelialization time of eight weeks in the acellular dermal matrix groups was significantly decreased than the control group of 14 weeks.

CONCLUSION

Acellular dermal matrix provides a growth framework for the healthy mucosa on the wounded surface and reduces postoperative epithelialization time.

Reconstruction of the Thoracic Wall With Biologic Mesh After Resection for Chest Wall Tumors: A Presentation of a Case Series and Original Technique

INTRODUCTION

Synthetic materials have traditionally been used for tissue reconstruction in thoracic surgery. New biomaterials have been tested in other areas of surgery with good results. Non-cross-linked swine dermal collagen prosthesis has been used to reconstruct musculofascial defects in the trunk with low infection and herniation rate.

MATERIAL AND METHODS

Retrospectively, we analyze our initial experience of chest wall reconstruction on large defects using a non-cross-linked swine dermal collagen matrix mesh with a thickness of 1.4 mm. A total of 11 consecutive patients were included. Preoperative, intraoperative, and postoperative data were taken into consideration.

RESULTS

Eleven sarcoma patients with a mean age of 58.25 ± 12.9 years underwent chest wall resections. Complete thoracic wall defects ranged from 6 · 9 to 16 · 25 cm in size. In all cases, we used a porcine collagen matrix mesh, and in all patients, it was covered by transposition of myocutaneous flap. The complications occurred in 5 (45%) patients, 1 (9%) pneumonia, 1 atrial fibrillation (9%), and 3 (27%) wound healing difficulty because of hematoma or infection. There was no respiratory impairment, and the pulmonary function (total lung capacity, vital capacity, and forced expiratory volume in 1 second) was not statistically different before and after surgery. The 30-day mortality was 0%, 1-year mortality and 2-year mortality was 27.2%. The collagen material resulted in a durable and good to excellent chest wall stability in clinical follow-ups, and on computer tomography scans spanning over 2 years.

CONCLUSION

Non-cross-linked acellular porcine dermal collagen matrix is a feasible and reliable biological patch material for reconstruction of the thoracic wall. Excellent wound healing, long-term stability, low complication, and good pulmonary function are achieved even in large defects.

Non-crosslinked porcine acellular dermal matrix in pediatric abdominal wall reconstruction: a case series

INTRODUCTION

The use of biologic mesh where native tissue deficiencies limit reconstructive options has been well documented in the adult population, with increasing use to address the special requirements of complex abdominal wall reconstruction. There is, however, little documented evidence as to the safety and efficacy of these products in the pediatric population.

METHODS

This retrospective case series details 5 pediatric cases of complicated abdominal hernia repair with Strattice®, a non-crosslinked porcine acellular dermal matrix. Outcomes measured include recurrence, infection, seroma formation, symptomatic bulging, and need for mesh removal. Defect size, mesh size, and history of prior abdominal operations and infection were also recorded.

RESULTS

Patients received Strattice® with an average area of 132.2 (24-250)cm² and primary closure was achieved over a mesh underlay in three (60%) patients, while the remaining required a bridging approach secondary to lateral defects. Complications included suture extrusion, requiring suture removal, hernia recurrence without bulge, noted incidentally, and seroma formation, requiring placement of drains.

DISCUSSION/CONCLUSIONS

In conclusion, the use of porcine ADM in pediatric patients appears to be potentially safe and efficacious in the context of complex abdominal wall defects, including those with substantial contamination. Our small series builds on previous reports in this difficult patient population. Although additional study, with larger subject pools, would assist in solidifying the observations seen in this and other series, initial findings suggest that porcine ADM is a valuable tool in the treatment of these complex patients.

LEVEL OF EVIDENCE

Case series: Treatment study, Level IV.

The impact of detergents on the tissue decellularization process: A ToF-SIMS study

Biologic scaffolds are derived from mammalian tissues, which must be decellularized to remove cellular antigens that would otherwise incite an adverse immune response. Although widely used clinically, the optimum balance between cell removal and the disruption of matrix architecture and surface ligand landscape remains a considerable challenge. Here we describe the use of time of flight secondary ion mass spectroscopy (ToF-SIMS) to provide sensitive, molecular specific, localized analysis of detergent decellularized biologic scaffolds. We detected residual detergent fragments, specifically from Triton X-100, sodium deoxycholate and sodium dodecyl sulphate (SDS) in decellularized scaffolds; increased SDS concentrations from 0.1% to 1.0% increased both the intensity of SDS fragments and adverse cell outcomes. We also identified cellular remnants, by detecting phosphate and phosphocholine ions in PAA and CHAPS decellularized scaffolds. The present study demonstrates ToF-SIMS is not only a powerful tool for characterization of biologic scaffold surface molecular functionality, but also enables sensitive assessment of decellularization efficacy.

STATEMENT OF SIGNIFICANCE

We report here on the use of a highly sensitive analytical technique, time of flight secondary ion mass spectroscopy (ToF-SIMS) to characterize detergent decellularized scaffolds. ToF-SIMS detected cellular remnants and residual detergent fragments; increased intensity of the detergent fragments correlated with adverse cell matrix interactions. This study demonstrates the importance of maintaining a balance between cell removal and detergent disruption of matrix architecture and matrix surface ligand landscape. This study also demonstrates the power of ToF-SIMS for the characterization of decellularized scaffolds and capability for assessment of decellularization efficacy. Future use of biologic scaffolds in clinical tissue reconstruction will benefit from the fundamental results described in this work.