Acellular Human Dermis Research Articles

Expanded Polytetrafluoroethylene Combined with Human Acellular Dermis Matrix for the Nasal Reconstruction in Patients with Postoperative Deformities.

Augmentation rhinoplasty is one of five aesthetic surgeries in the world. Expanded polytetrafluoroethylene (ePTFE) has been reported as a rational choice to augment the nasal dorsum and tip. However, its application for nasal tip augmentation has some debates. This study presented a technique using ePTFE grafts combined with human acellular dermis matrix (HADM) to reconstruct a deformed nose caused by previous rhinoplasties. 50 female patients who came to the hospital from 08/2022 to 09/2022 for surgical revision of their nasal deformity. ePTFE was applied to reconstruct the nasal dorsum, tip, and columella strut. HADM grafts were utilized to reinforce the reconstructed framework. Patients were evaluated for at least 12 months for both aesthetic and functional results. Postoperatively, the nasal dorsal length increased from 38.9 ± 1.32 to 43.4 ± 1.22 mm; while, the projection of the nasal tip also raised from 19.8 ± 1.16 to 23.9 ± 1.05 mm. 38 patients (76%) reported that their breathing and smelling were improved compared to preoperatively. No cases had implant reactions, extrusion, or warping columella strut. Most of the patients (84%) were satisfied with the surgical outcomes. Three patients (6%) had redness at the nasal tip. The nasal tip of ten patients (20%) was hardened for 3 months postoperatively. There were 6% of patients who developed an infection and 2% of patients had asymmetric soft tissues of the tip 3 postoperative months. This technique brought satisfactory aesthetic and functional results to patients, with no extrusion or rejection observed 12 months postoperatively. Infection was a prominent complication that should be considered and strictly monitored. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Histological and Biomechanical Analysis of Human Acellular Dermis (HAD) Created Using a Novel Processing and Preservation Technique.

Large and complex defects requiring reconstruction are challenging for orthopaedic surgeons. The use of human acellular dermal (HAD) matrices to augment large soft tissue defects such as those seen in massive rotator cuff tears, knee extensor mechanism failures and neglected Tendo-Achilles tears has proven to be a valuable tool in surgeons reconstructive armamentarium. Different methods for allograft decellularization and preservation alter the native properties of the scaffold. Traditional processing and preservation methods have shown to have drawbacks that preclude its widespread use. Some of the common issues include inferior biomechanical properties, the risk of rejection, limited customization, difficulty in storing and transporting, the requirement of pre-operative preparation, and last but not the least increased cost. We describe a novel processing and preservation method utilizing a two-step non-denaturing decellularization method coupled with preservation using a water-sequestering agent (glycerol) to remove immunogenic components while retaining biomechanical properties. The efficiency of this novel process was compared with the traditional freeze-drying method and verified by histological evaluation and biomechanical strength analysis. The absence of cellular components and matrix integrity in hematoxylin and eosin-stained glycerol-preserved HAD (gly-HAD) samples compared to freeze-dried HAD (FD-HAD) demonstrated effective yet gentle decellularization. Biomechanical strength analysis revealed that gly-HADs are stronger with an ultimate tensile load to the failure strength of 210 N compared to FD-HAD (124N). The gly-HADs were found to have an optimal suture-retention strength of 126 N. Finally, sterility testing of the resultant grafts was checked to ensure a sterility assurance level of 10-6 to establish implantability. The novel processing and preservation technique is described in this paper to create a Human Acellular Dermis with higher biomechanical strength and superior histological characteristics. The processing and preservation technique ensured high sterility assurance levels to establish implantability.

The Impact of Defect Size on Bone Healing in Critical-Size Bone Defects Investigated on a Rat Femur Defect Model Comparing Two Treatment Methods.

Critical-size bone defects up to 25 cm can be treated successfully using the induced membrane technique established by Masquelet. To shorten this procedure, human acellular dermis (HAD) has had success in replacing this membrane in rat models. The aim of this study was to compare bone healing for smaller and larger defects using an induced membrane and HAD in a rat model. Using our established femoral defect model in rats, the animals were placed into four groups and defects of 5 mm or 10 mm size were set, either filling them with autologous spongiosa and surrounding the defect with HAD or waiting for the induced membrane to form around a cement spacer and filling this cavity in a second operation with a cancellous bone graft. Healing was assessed eight weeks after the operation using µ-CT, histological staining, and an assessment of the progress of bone formation using an established bone healing score. The α-smooth muscle actin used as a signal of blood vessel formation was stained and counted. The 5 mm defects showed significantly better bone union and a higher bone healing score than the 10 mm defects. HAD being used for the smaller defects resulted in a significantly higher bone healing score even than for the induced membrane and significantly higher blood vessel formation, corroborating the good results achieved by using HAD in previous studies. In comparison, same-sized groups showed significant differences in bone healing as well as blood vessel formation, suggesting that 5 mm defects are large enough to show different results in healing depending on treatment; therefore, 5 mm is a viable size for further studies on bone healing.

The impact of repeated bladder surgery on successful bladder neck closure in classic bladder exstrophy: The role of mucosal violations

Restoration of genitourinary anatomy with functional urinary continence is the reconstruction aim is the exstrophy-epispadias complex (EEC). In patients who do not achieve urinary continence or those who are not a candidate for bladder neck reconstruction (BNR), bladder neck closure (BNC) is considered. Interposing layers including human acellular dermis (HAD) and pedicled adipose tissue are routinely placed between the transected bladder neck and distal urethral stump to reinforce the BNC and minimize failure due to fistula development from the bladder. The aim of this study was to review classic bladder exstrophy (CBE) patients who underwent BNC to identify predictors of BNC failure. Specifically, we hypothesize that increased operations on the bladder urothelium leads to a higher rate of urinary fistula. CBE patients who underwent BNC were reviewed for predictors of failed BNC which was defined as bladder fistula development. Predictors included prior osteotomy, interposing tissue layer use and number of previous bladder mucosal violations (MV). A MV was defined as a procedure when the bladder mucosa was opened or closed for: exstrophy closure(s), BNR, augmentation cystoplasty or ureteral re-implantation. Predictors were evaluated using multivariate logistic regression. A total of 192 patients underwent BNC of which 23 failed. Patients were more likely to develop a fistula with a wider pubic diastasis at time of primary exstrophy closure (4.4 vs 4.0 cm, p=0.0016), have failed exstrophy closure (p=0.0084), or have 3 or more MVs before BNC (p=0.0002). Kaplan-Meier analysis of fistula-free survival after BNC, demonstrated an increased fistula rate with additional MVs (p=0.0004, Figure1). MVs remained significant on multivariate logistic regression analysis with a per-violation odds ratio of 5.1 (p<0.0001). Of the 23 failed BNC's, 16 were surgically closed including 9 using a pedicled rectus abdominis muscle flap which was secured to the bladder and pelvic floor. This study conceptualized MVs and their role in bladder viability. Increased MVs confer an increased risk of failed BNC. When considering BNC, CBE patients with 3 or more prior MVs may benefit from a pedicled muscle flap, in addition to HAD and pedicled adipose tissue, to prevent fistula development by providing wellvascularized coverage to further reinforce the BNC.

The Use of Acellular Human Dermis as a Dorsal Camouflaging Graft in Rhinoplasty.

Background: Acellular human dermis (AHD) has many uses in rhinoplasty, but its long-term use as a camouflaging graft has not been adequately described. Objective: To measure the long-term outcomes (infections/contour irregularities) of AHD used as a camouflage graft in rhinoplasty. Methods: A retrospective study of 91 patients who underwent rhinoplasty requiring AHD as a camouflage graft for a 20-year time period (2000-2020) was performed. Complications, revisions, and long-term outcomes were assessed. Surgical technique for AHD use as a dorsal and tip camouflage graft was described in detail and illustrated using intraoperative photography. Results: Of the 91 patients who required AHD in their rhinoplasties, 70 (77%) were performed in revision cases to thicken thinned and scarred skin envelopes. Only 1% had postoperative contour problems that were attributable to AHD, and only 3% had resorption of the AHD. Four percent had postoperative infections, all of which resolved with a single course of oral antibiotics. Patients were followed a mean of 3.8 years. Conclusions: AHD can be a safe, effective, and readily available option for use in thickening the nasal skin envelope in rhinoplasty.

Commentary on: "The Use of Acellular Human Dermis as a Dorsal Camouflaging Graft in Rhinoplasty" by Melancon et al.

Commentary on: "The Use of Acellular Human Dermis as a Dorsal Camouflaging Graft in Rhinoplasty" by Melancon et al.

Full-thickness lower eyelid defect reconstruction using a pedicle rotation temporal flap and Acellular Human Dermis Graft (Alloderm)

The aim of this research was to prospectively examine the combination of a pedicled temporal rotation flap with an acellular human dermal graft technique for intermediate-sized lower eyelid defect reconstruction. Pedicled temporal rotation flaps based on the orbicularis oculi muscle were used to reconstruct the anterior lamella of lower eyelid defects in six patients (five males and one female) while the posterior lamella was reconstructed using an acellular human dermis graft (Alloderm). Flap survival at 6 months was 100%. The functionality and cosmetic results of the technique were evaluated, and corneal protection was achieved. The texture and color of the reconstructed eyelid matched the surrounding skin, and neither pain nor corneal irritation was reported. The donor site scar healed well and was inconspicuous in all cases. Furthermore, no recurrence of malignancy was observed. The combination of a temporal rotational flap with an acellular human dermal graft is the key points. This technique could be ideal for the reconstruction of intermediate-sized full-thickness lower eyelid defects.

Abdominoplasty Panniculus as a Source for Human Acellular Dermis: A Preliminary Report.

In extensive deep dermal burn injuries, split-thickness skin graft (STSG) has been the most preferred treatment option for resurfacing burn wounds. A thick split-thickness skin graft is ideal for preventing graft contracture but is associated with delayed donor healing and the lack of adequate donor skin. When applied with STSG, the dermal substitutes offer better-reconstructed skin than STSG alone. Human-derived acellular dermal matrix (HADM) obtained from cadaver skin is a dermal equivalent with good clinical outcomes. However, high cost and limited cadaver donor skin availability limit its clinical utility. Developing a low-cost preparation method and finding an alternate source of human donated skin can help reduce the cost. The objective of this study was to explore the feasibility of making HADM from abdominoplasty panniculus skin. Skin samples were collected from the abdominoplasty panniculus of ten eligible donors with their informed consent. A combination of low-cost reagents-sodium chloride and hypotonic solution (water for injection) was used for decellularizing the skin. Characterization of the prepared Acellular Dermis Matrix prototype was done. The skin was deepidermized with one molar NaCl treatment at 37°C for 24h. The deepidermized dermis became acellular with hypotonic solution treatment at 4°C for two weeks. The hematoxylin and eosin staining and cytotoxicity test confirmed the acellularity and non-cytotoxicity of the prepared HADM prototype. The HADM prototype also facilitated the formation of neo-epithelium in the 3D cell co-culture model. This study confirms that abdominoplasty panniculus can be a viable alternative for HADM preparation. Further characterization studies are required to prove the concept.

Complications of Alloplast Rhinoplasty and Their Management: A Comprehensive Review.

In Asian countries, augmentation rhinoplasty is especially common, where alloplastic implants are used much more commonly than autologous tissues. In rhinoplasty, such artificial materials include silicone, expanded polytetrafluoroethylene (ePTFE), porous high-density polyethylene (pHDPE), and acellular human dermis. As the use of implants has become increasingly common in rhinoplasty, more adverse effects such as infection, extrusion, movement, irregularities, absorption, prolonged swelling, seroma, and contracture have been recognized and reported in the literature. Surgeons should be able to recognize these probable complications and manage them successfully. Early detection and prompt management of the complication are essential for minimizing the severity of the deformity. Proper management of complications is key for the success of dorsal augmentation using alloplastic implants.

From two stages to one: acceleration of the induced membrane (Masquelet) technique using human acellular dermis for the treatment of non-infectious large bone defects

IntroductionThe induced membrane technique for the treatment of large bone defects is a two-step procedure. In the first operation, a foreign body membrane is induced around a spacer, then, in the second step, several weeks or months later, the spacer is removed and the Membrane pocket is filled with autologous bone material. Induction of a functional biological membrane might be avoided by initially using a biological membrane. In this study, the effect of a human acellular dermis (hADM, Epiflex, DIZG gGmbH) was evaluated for the treatment of a large (5 mm), plate-stabilised femoral bone defect.Material and MethodsIn an established rat model, hADM was compared to the two-stage induced membrane technique and a bone defect without membrane cover. Syngeneous spongiosa from donor animals was used for defect filling in all groups. The group size in each case was n = 5, the induction time of the membrane was 3–4 weeks and the healing time after filling of the defect was 8 weeks.ResultsThe ultimate loads were increased to levels comparable with native bone in both membrane groups (hADM: 63.2% ± 29.6% of the reference bone, p < 0.05 vs. no membrane, induced membrane: 52.1% ± 25.8% of the reference bone, p < 0.05 vs. no membrane) and were significantly higher than the control group without membrane (21.5%). The membrane groups were radiologically and histologically almost completely bridged by new bone formation, in contrast to the control Group where no closed osseous bridging could be observed.ConclusionThe use of the human acellular dermis leads to equivalent healing results in comparison to the two-stage induced membrane technique. This could lead to a shortened therapy duration of large bone defects.

Re: The Role of Human Acellular Dermis in Preventing Fistulas after Bladder Neck Transection in the Exstrophy-Epispadias Complex.

Re: The Role of Human Acellular Dermis in Preventing Fistulas after Bladder Neck Transection in the Exstrophy-Epispadias Complex.

Application of acellular human dermis and skin grafts for lower extremity reconstruction.

To use both acellular human dermis and skin grafting simultaneously for improved skin grafting without contracture. The study also aims to address the lack of research on the application of an acellular human dermis in diverse clinical cases. The study examined patients who had received acellular human dermis (CGDerm, CGBio, Seoul, Korea) and split-thickness skin grafting (STSG) simultaneously for lower limb, full-thickness skin defects between September 2012 and June 2014. The researchers performed chart reviews retrospectively and examined the patients based on the following factors: gender, age, injury mechanism, size, exposed structure, pre-coverage dressing method, coverage method, post-operational engraftment and total healing period, contracture development, elasticity, and infection development. A sample of 27 patients with a total of 30 wounds took part in the study. Of these wounds, 29 showed successful engraftment without infection or contracture. In one case, continued seroma was observed and, following new coverage of both the acellular human dermis and STSG, engraftment was successful. Human dermis can play an important role in securing the availability of surrounding tissue and in contracture prevention, both of which are key to lower limb reconstruction. Of the types available, acellular human dermis showed lower infection rates than other human dermis types, and its engraftment rate was higher than in STSG-only cases. These findings suggest that acellular human dermis use in STSG is effective and safe in lower limb reconstruction.

Biodegradable hyaluronan hydrogel coatings on acellular dermis grafts—A potential strategy to improve biologic graft durability in hernia repair application

Biologic grafts used in hernia repair undergo rapid cellular infiltration and remodeling, but their premature degradation often results in hernia recurrence. We hypothesize that a temporary barrier that prevents infiltration of acute inflammatory cells into the graft during the initial 4 weeks of implantation could mitigate graft degradation. The purpose of this study is to design tyramine-substituted hyaluronan (THA) hydrogel coatings with tunable degradation properties, as a means to develop a resorbable barrier for human acellular dermis grafts (HADM). THA plugs prepared at different cross-linking densities, by varying cross-linking agent concentration (0.0001-0.0075% H2 O2 ), demonstrated varying rates of in vitro degradation (25 U/mL hyaluronidase, 48 h). Based on these results, HADM grafts were coated with THA at three cross-linking densities (0.0001%, 0.00075%, and 0.003% H2 O2 ) and THA coating degradation was evaluated in vitro (25 U/mL hyaluronidase, 48 h) and in vivo (rat intraperitoneal implantation, 1-4 weeks). THA coatings degraded in vitro and in vivo with the lowest cross-linking density (0.0001% H2 O2 ), generally showing greater degradation as evidenced by significant decrease in coating cross-sectional area. However, all three coatings remained partially degraded after 4 weeks of in vivo implantation. Alternate strategies to accelerate in vivo degradation of THA coatings are required to allow investigation of the study hypothesis. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2664-2672, 2019.

Evaluating the Impact of Technique and Mesh Type in Complicated Ventral Hernia Repair: A Prospective Randomized Multicenter Controlled Trial

To our knowledge, there is an absence of prospective randomized multicenter controlled trials evaluating both the impact of technique and mesh type on outcomes in complicated ventral hernia repair. A prospective randomized multicenter controlled trial of 120 patients at 3 sites was conducted in which patients were randomized to either overlay (anterior component separation) or underlay mesh placement (posterior component separation) and mesh type (human acellular dermis [HADM] vs porcine acellular dermis [PADM]). Key inclusion criteria included hernia size (>200 cm2), BMI < 40 kg/m2, hemoglobin A1C < 7%, tobacco free > 6 weeks and primary fascial closure. Primary outcome was hernia recurrence at 1 year, determined by independent examiner/imaging. Secondary outcomes included complications and patient satisfaction (short form [SF]-36v2). Standardized investigator training included a porcine model followed by a proctored first case by the lead investigator. There were no significant differences in demographics between the 4 groups (age 60 ±12 years, BMI 32 ± 5 kg/m2, 51% female). The overall 1-year recurrence rate was 10.8%. There was no significant difference in recurrence rate by location of mesh placement (overlay 9.8%, underlay 11.9%) or mesh type (HADM 10.3%, PADM 11.3%). Overlay patients had a significantly lower surgical site infection rate (1.6% vs 11.9% p= 0.03), reported better physical functioning (p= 0.001) and role limitation scores (p= 0.04) in the early postoperative period, and achieved the highest physical functioning score during the 12-month period (p < 0.03). Recurrence rates were not affected by either anatomic location or type of mesh used. To our knowledge, this represents the first prospective randomized multicenter controlled trial that demonstrates similar clinical outcomes using HADM vs PADM (not inferiority, contrary to previously published literature), with several advantages identified using the overlay technique.

Simplified Technique for Superior Capsular Reconstruction Using an Acellular Dermal Allograft

Superior capsular reconstruction is a powerful tool for the treatment of massive irreparable rotator cuff tears. Several authors have described this evolving technique. Issues of graft sizing, graft passage, graft tensioning, and suture management make this a challenging procedure even in the hands of experienced shoulder surgeons. We describe our arthroscopic technique for superior capsular reconstruction using nonirradiated human acellular dermis. We introduce several techniques for graft passage and tensioning that may help to simplify this challenging procedure and make it more reproducible.

Human Acellular Dermis as Spacer for Small-Joint Arthroplasty: Analysis of Revascularization in a Rabbit Trapeziectomy Model.

Carpometacarpal joint osteoarthritis affects 8 to 12 percent of the general population. Surgical management provides symptomatic relief for 78 percent of patients who fail conservative therapy, but little consensus exists regarding which surgical procedure provides superior patient outcomes. Recent human trials substituted exogenous acellular dermal matrices in the bone space, but there are no quantitative histologic data on the outcome of acellular dermal matrices in this environment. The authors aimed to quantify the revascularization and recellularization of acellular dermal matrices in the joint space using a rabbit model. Bilateral lunate carpal bones were surgically removed in New Zealand rabbits. Acellular dermal matrix and autologous tissue were implanted in place of the lunate of the right and left wrists, respectively. Acellular dermal matrix was also implanted subcutaneously as a nonjoint control. Histologic and immunofluorescence analysis was performed after collection at 0, 6, and 12 weeks. Quantitative analysis of anti-α-smooth muscle actin and CD31 immunofluorescence revealed a sequential and comparable increase of vascular lumens in joint space and subcutaneous acellular dermal matrices. In contrast, autologous tissue implanted in the joint space did not have a similar increase in α-smooth muscle actin-positive or CD31-positive lumens. Semiquantitative analysis revealed increased cellularity in both autologous and acellular dermal matrix wrist implants at each time point, whereas average cellularity of subcutaneous acellular dermal matrix peaked at 6 weeks and regressed by 12 weeks. Trichrome and Sirius red staining revealed abundant collagen at all time points. The trapeziectomy joint space supports both cellular and vascular ingrowth into human acellular dermal matrix.

Human acellular dermis increases surgical site infection and overall complication profile when compared with submuscular breast reconstruction: An updated meta-analysis incorporating new products✰

BackgroundHuman acellular dermal matrix (HADM) is an increasingly used adjunct to breast reconstruction. Previous meta-analyses demonstrate increased risks of complications, but these studies largely represent one product. The purpose of this study is to stratify outcomes on the basis of a meta-analysis of complications incorporating all new studies after 2012 and their associated new human-based products. MethodsA query of the MEDLINE database for articles on HADM and breast reconstruction from January 2012 to October 2015 yielded 172 citations. Two levels of screening identified 47 relevant studies. Thirteen studies were used in comparative meta-analysis. ResultsComplication rates were higher in HADM patients: total complications, 17.7% versus 6.1%; seroma, 8.3% versus 5.4%; infection, 7.2% versus 5.9%; and flap necrosis, 14.7% versus 7.1%. Meta-analysis revealed a statistically significant increased risk of total complications in patients who underwent reconstruction with HADM when compared with their submuscular reconstruction cohort (p = 0.03; relative risk (RR) = 1.46; confidence interval (CI): 1.04–2.04). Patients who underwent reconstruction with HADM demonstrated a significantly increased risk of flap necrosis (p < 0.01; RR = 2.39; CI: 1.8–3.16) and infection (p = 0.02; RR = 1.5; CI: 1.07–2.09) when compared with those who underwent submuscular reconstruction. There was no significant difference in seroma, hematoma, or implant explantation between these two groups. ConclusionsThis study suggests an increased risk of overall complications, specifically infection and flap necrosis, in patients who underwent tissue expander/implant breast reconstruction with HADM when compared with those who underwent submuscular placement. This must be weighed against the advantages in enhancing aesthetic outcomes, increasing intraoperative fill volume, and ameliorating capsular contracture.

The Role of Human Acellular Dermis in Preventing Fistulas After Bladder Neck Transection in the Exstrophy-epispadias Complex

To evaluate human acellular dermis (HAD) as an adjunct during bladder neck transection (BNT) by comparing surgical outcomes with other types of tissue interposition. A prospectively maintained institutional database of exstrophy-epispadias complex (EEC) patients was reviewed for those who underwent a BNT with at least 6 months follow-up. The primary outcome was the occurrence of BNT-related fistulas. In total, 147 EEC patients underwent a BNT with a mean follow-up time of 6.9 years (range 0.52-23.35 years). There were 124 (84.4%) classic exstrophy patients, 22 (15.0%) cloacal exstrophy patients, and 1 (0.7%) penopubic epispadias patient. A total of 12 (8.2%) BNTs resulted in fistulization, including 4 vesicoperineal fistulas, 7 vesicourethral fistulas, and 1 vesicovaginal fistula. There were 5 (22.7%) fistulas in the cloacal exstrophy cohort and 7 (5.6%) fistulas in the classic bladder exstrophy cohort (P = .019). Using either HAD or native tissue flaps resulted in a lower fistulization rate than using no interposed layers (5.8% vs 20.8%; P = .039). Of those with HAD, the use of a fibrin sealant did not decrease fistulization rates when compared to HAD alone (6.5% vs 8.8%, P = .695). There was no statistical difference in surgical complications between the use of HAD and native flaps (8.6% vs 5%, P = .716). Use of soft tissue flaps and HAD is associated with decreased fistulization rates after BNT. HAD is a simple option and an effective adjunct that does not require harvesting of tissues in patients where a native flap is not feasible.

Reconstruction of parotidectomy and lateral skull base defects

The purpose of this review is to summarize the options for reconstruction of parotid and lateral skull base defects based on the size and functional requirements of the defect. Free grafts with dermal fat or acellular human dermis, superficial musculoaponeurotic system flaps, and sternocleidomastoid flaps have been successful in preventing Frey's syndrome and restoring facial contour defects after superficial and total parotidectomy. Lateral skull base resections often require reconstruction with pedicled or free flaps to restore extensive soft tissue and dural defects. Supraclavicular artery island flaps and submental flaps have been recently been gaining popularity for use for these purposes. Free tissue transfer remains the best reconstructive option for repair of large soft tissue and/or dural defects. The most reliable free flap for lateral skull base reconstruction is the anterolateral thigh flap, which is highly versatile because of its large skin paddle and potential for harvest with varying amounts of fascial and muscle tissue. Here we will summarize the most appropriate and widely used reconstructive options for parotid and lateral skull base defects of various sizes, discussing the most recent evidence pertaining to each technique along with advantages and limitations of each reconstructive strategy.

Transplanted fibroblasts proliferate in host bronchial tissue and enhance bronchial anastomotic healing in a rodent model.

Healing of airway anastomoses after preoperative irradiation can be a significant clinical problem. The augmentation of bronchial anastomoses with a fibroblast-seeded human acellular dermis (hAD) was shown to be beneficial, although the underlying mechanism remained unclear. Therefore, in this study we investigated the fate of the fibroblasts transplanted to the scaffold covering the anastomosis. 32 Fisher rats underwent surgical anastomosis of the left main bronchus. In a 2 × 2 factorial design, they were randomized to receive preoperative irradiation of 20 Gy and augmentation of the anastomosis with a fibroblast-seeded transplant. Fibroblasts from subcutaneous fat of Fischer-344 rat were transduced retrovirally with tdTomato for cell tracking. After 7 and 14 days, animals were sacrificed and cell concentration of transplanted and nontransplanted fibroblasts in the hAD as well as in the bronchial tissue was measured using RT-PCR. Migration of transplanted fibroblasts from dermis to bronchus were demonstrated in both groups, irradiated and nonirradiated. In the irradiated groups, there was a cell count of 7 × 104 ± 1 × 104 tomato+-fibroblasts in the bronchial tissue at day 7, rising to 1 × 105 ± 1 × 104 on day 14 (p <0.0001). Tomato+-cell concentration in hAD increased from 6 × 103 ± 1 × 103 at day 7 to 6 × 104 ± 1 × 104 at day 14 (p <0.0001). In the nonirradiated groups, tomato+-cell concentration in bronchus was 4 × 103 ± 1 × 103 on day 7 and 4 × 103 ± 1 × 103 at day 14. In the hAD tomato+ cell concentration rising from 1 × 104 ± 1 × 103 at day 7 to 2 × 104 ± 3 × 103 cells at day 14 (p = 0.0028). Transplanted fibroblasts in the irradiated groups proliferate and migrate into the irradiated host bronchial tissue, but not in the nonirradiated groups.