The use of human acellular dermis in the operative management of giant omphalocele

Purpose

The management of giant omphalocele presents a major challenge to pediatric surgeons. Current treatment modalities often result in wound infection, fascial separation, and abdominal domain loss. Human acellular dermis (AlloDerm), as a primary abdominal fascial substitute, may prevent these complications. We present our experience with its application in neonates with giant omphalocele.

Methods

Charts of patients with giant omphalocele from January 2003 to September 2004 were reviewed and data collected regarding wound healing, rate of infection, ventilatory support, and outcome.

Results

Three neonates underwent abdominal wall closure with AlloDerm (gestational ages: 38, 37, and 28 weeks; birthweights 2880, 2640, and 1160 g, respectively). All had cardiac anomalies; 1 required cardiac surgery and 1 was ventilator-dependent, secondary to pulmonary hypoplasia. Omphalocele repair was performed on day-of-life 9, 2, and 87. No fascial dehiscence or infection was encountered. Neovascularization was noted by day 7. Two died of cardiopulmonary disease (6 months and 1 year). The third exhibited normal growth and development without complication.

Conclusions

AlloDerm provides visceral coverage without compromising cardiopulmonary function, diminishing abdominal domain, or requiring multiple operations, allowing prompt treatment of associated anomalies. AlloDerm represents an exciting alternative in the treatment of giant omphalocele. Further study is required to determine long-term benefits.     

Abdominal wall repair using human acellular dermal matrix: a follow-up study

Background

The role of acellular dermal matrix (ADM) in abdominal wall reconstruction (AWR) is unclear. The aim of this study was to review the management, complications, and long-term outcomes of AWR using ADM in a large surgical cohort.

Methods

Retrospective chart review of patients undergoing AWR using ADM from 2004 to 2007 was performed. Demographic data, comorbidities, complications, and long-term outcomes were collected.

Results

There were 77 cases in 68 patients with mean age of 61.1 ± 1.4 years. The most common indication was infected fascia (n = 19 [25%]). Wound closure was achieved in 75% of the cases via primary (n = 26 [45%]), secondary intention (n = 17 [29%]), or skin graft (n = 15 [26%]). Nonprimary closure was achieved in 5.7 ± .7 months. There were 32 perioperative (39%) and 33 long-term (43%) complications. Over a mean follow-up period of 13.2 ± 1.5 months, the hernia recurrence rate was 27% (n = 21).

Conclusion

Although ADM is a viable option in AWR, the high hernia recurrence rate warrants a continued search for alternative biologic materials to improve outcomes.     

The fate of a free buried dermis graft reinforcing the anterior abdominal wall

Summary In 1937, Peer and Paddock [3] stated that the dermis graft has gained little popularity because of the theoretical possibility of cyst formation from sweat glands, hair follicles and sebaceous glands remaining in the dermis. The formation of cysts, albeit of microscopic proportions, is a common finding after the second week of insertion. The natural history of these cysts seems to be a spontaneous dissolution in the overwhelming majority of cases, as happened in the two cases presented by McGregor in 1991 [2]. In the rare case presented here, there was no such spontaneous dissolution.     

人脱细胞真皮在腹壁缺损修复中的应用

目的:探讨人脱细胞真皮(human acellular dermal marx,HADM)在腹壁缺损修复中的应用.方法:回顾我院外科自2007年5月至2008年9月14例使用HADM修复腹壁缺损病人的临床资料,分析手术效果及并发症的发生率.结果:14例均顺利重建腹壁,无感染及肠梗阻、肠瘘等并发症发生;随访1～16月,无疝复发和其他类型腹壁疝出现.结论:HADM在腹壁缺损的修复上具有一定优势,尤其是在处理感染或污染创面时,是一种值得在临床上推广应用的理想补片材料.     

猪脱细胞真皮基质修复兔腹壁缺损的实验研究

目的研究猪脱细胞真皮基质修复兔腹壁缺损的效果,探讨异种脱细胞真皮基质应用的可行性。方法健康小白猪1头,取背部及两侧皮肤制备脱细胞真皮基质。26只日本大耳白兔,雌雄不限,体重2.2～2.3 kg,随机分为对照组(n=6)和实验组(n=20)。对照组制备5.0 cm×0.5 cm腹壁缺损,单纯缝合关闭缺损。实验组制备5.0 cm×2.5 cm腹壁缺损,用同样大小的猪脱细胞真皮基质补片(简称"补片")修复,补片基底膜面朝向肠管。术后观察是否有疝形成,比较两组腹腔内脏器粘连情况,以及对照组腹壁肌筋膜单纯缝合处和实验组补片-腹壁肌筋膜吻合处的最大张力,组织学观察补片是否有纤维血管组织长入及其在体内的生物学转归。结果实验动物均无疝形成。术后5周,实验组补片和腹壁融为一体,补片皮肤面和脏器面均有纤维血管组织长入,补片处于新生组织掺入重建过程。实验组1只动物补片和腹腔内脏器粘连较重(2级),5只发生了轻微粘连(1级),12只无粘连(0级);对照组1只轻微粘连(1级),5只无粘连(0级);两组粘连分级比较差异无统计学意义(Z=—0.798,P=0.425)。术后5周,实验组补片-腹壁肌筋膜吻合处的最大张力为(13.0±5.5)N,对照组腹壁肌筋膜单纯缝合处为(13.6±4.0)N,差异无统计学意义(t=—0.410,P=0.683)。组织学观察显示,术后5周,实验组补片中有大量小血管,并有中性粒细胞及淋巴细胞为主的炎性浸润,补片边缘偶见巨噬细胞,补片-腹壁肌筋膜吻合处由纤维结缔组织连接;术后6个月,补片及周围炎性反应消退,胶原纤维结构发生了改建,补片和肌筋膜层由有纤维结缔组织愈合。结论补片修复兔腹壁缺损取得了较好效果,补片-腹壁肌筋膜层愈合,其吻合处的力学强度达到了自体腹壁单纯缝合吻合的力学强度,补片胶原纤维结构发生了改建。     

Laparoscopic paraesophageal hernia repair with acellular dermal matrix cruroplasty

Background:

Laparoscopic paraesophageal hernia repair (LPEHR) has been shown to be both safe and efficacious. Compulsory operative steps include reduction of the stomach from the mediastinum, resection of the mediastinal hernia sac, ensuring an appropriate intraabdominal esophageal length, and crural closure. The use of mesh materials in the repair of hiatal hernias remains controversial. Synthetic mesh may reduce hernia recurrences, but may increase postoperative dysphagia and result in esophageal erosion. Human acellular dermal matrix (HADM) may reduce the incidence of hernia recurrence with reduced complications compared with synthetic mesh.

Methods:

A retrospective review of all cases of laparoscopic hiatal hernia repair using HADM from December 2008 through March 2010 at a single institution was performed evaluating demographic information, BMI, operative times, length of stay, and complications.

Discussion:

Forty-six LPEHRs with HADM were identified. The mean age of patients was 60.3 years (±13.9); BMI 30.3 (±5.3); operative time 182 minutes (±56); and length of stay 2.6 days (±1.9). Nine of 46 (19.6%) patients experienced perioperative complications, including subcutaneous emphysema without pneumothorax (n=2), urinary retention (n=1), COPD exacerbation (n=2), early dysphagia resolving before discharge (n=1), esophageal perforation (n=1), delayed gastric perforation occurring 30 days postoperatively associated with gas bloat syndrome (n=1), and PEG site abscess (n=1). There were 2 clinically recurrent hernias (4.3%). Radiographic recurrences occurred in 2 of 26 patients (7.7%). Six of 46 (13%) patients reported persistent dysphagia.

Conclusion:

LPEHR with HADM crural reinforcement is an effective method of repairing symptomatic paraesophageal hernias with low perioperative morbidity. Recurrences occur infrequently with this technique. No mesh-related complications were seen in this series.     

Reconstruction of complex abdominal wall hernias using acellular human dermal matrix: a single institution experience

Background

Acellular human dermal matrix (AHDM) has mechanical properties suitable for complex abdominal wall reconstructions and physiologic properties that allow more resistance to infection in contaminated fields. The purpose of this study was to determine which patient and technical factors lead to optimal surgical outcomes.

Methods

A retrospective review was conducted of 144 abdominal wall reconstructions using AHDM over a 33-month period. Data were recorded and analyzed.

Results

Fifty-three percent were women. The average age was 55 years, with an average body mass index of 35 kg/m². Thirty percent were smokers at the time of repair, and 24% had diabetes. Forty-three percent of the operative fields had some degree of contamination. The indication for operation in half the patients was to reconstruct a previously failed hernia repair. The recurrence rate was 27.1%. The significant factors that affected the recurrence rate were female gender (P = .02), reconstructing a failed prior repair (P = .025), and high body mass index (P = .004). An underlay mesh placement trended to a lower recurrence rate (P = .053). Average follow-up time was 23 weeks (range, 0-100 weeks).

Conclusions

Three patient factors contributed significantly to the recurrence rate in this study: gender, above-normal body mass index, and repairing a recurrent hernia. Placing the matrix as an underlay appears to decrease recurrence rates. Long-term follow-up is needed to further determine the durability of hernia repairs with AHDM. AHDM offers a viable option with acceptable morbidity in complex abdominal wall reconstructions in high-risk patient populations.     

脱细胞异体真皮在烧伤后期瘢痕畸形整复中的应用

目的：评价脱细胞异体真皮在烧伤后期瘢痕畸形整复中的应用价值。方法：对32例烧伤后期瘢痕畸形病人整复后继发创面进行脱细胞异体真皮与自体刃厚皮片复合移植。结果：32例病人复合移植皮片全部成活，成活率为100％。成活的复合移植皮片具有外观平整，颜色与邻近正常皮肤相近似，无明显收缩，触之柔软，耐磨，弹性好等特点。结论：脱细胞异体真皮是烧伤后期瘢痕畸形整复中比较理想的材料。     

Peritoneal regeneration induced by an acellular bovine pericardial patch in the repair of abdominal wall defects

BACKGROUND: This study was to evaluate the feasibility of using an acellular bovine pericardium fixed with genipin (AGP) to repair an abdominal wall defect created in a rat model. MATERIALS AND METHODS: The glutaraldehyde-fixed acellular pericardium (AGA), the genipin-fixed cellular pericardium (GP), and a commercially available polypropylene mesh were used as controls. RESULTS: Gross examination at 3-month post-operatively revealed that dense adhesions to the visceral organs were observed for the polypropylene mesh and the AGA patch, while a filmy to dense adhesion was seen for the GP patch. In contrast, no adhesion to the visceral organs was observed for the AGP patch. Histologically, inflammatory cells were found mainly surrounding the GP patch. In contrast, host cells (inflammatory cells, fibroblasts, and neo-capillaries) were able to infiltrate into the AGA and AGP patches. Unlike the AGA patch, the AGP patch retrieved at 1-month post-operatively became well integrated with the host tissue near the suture line. Additionally, there were some mesothelial cells, identified by the van Gieson stain, observed on the AGP patch. At 3-month post-operatively, a neo-peritoneum was observed on the AGP patch. The neo-peritoneum consisted of organized vascularized connective tissues covered by an intact layer of mesothelial cells. The calcium contents of the polypropylene mesh and the AGA patch increased significantly at 3-month post-operatively, while those of the GP and AGP patches stayed minimal throughout the entire course of the study. CONCLUSIONS: The results obtained in the study revealed that the AGP patch effectively repaired abdominal wall defects in rats and successfully prevented the formation of post-surgical abdominal adhesions.     

异种(猪)脱细胞真皮与自体表皮复合移植研究

目的 为深度烧伤、瘢痕切除控制瘢痕增生与组织凹陷等寻求良好、廉价的覆盖与充填材料。方法 健康的白色小猪,活杀后剥其皮肤,用固定剂对异种（猪）皮肤细胞外基质固定交联,盐水法去除表皮,保留基底膜,用酶化学剂去除异种（猎）皮肤细胞,使其失去抗原性,保留完整的基底膜和细胞外基质的形态,制成网状异种（猪）脱细胞真皮支架。结果 对２３例病人进行异种（猪）脱细胞真皮支架移植７ｄ左右,再植自体刃厚大张皮的二步法复     

Abdominal wall repair using a biodegradable scaffold seeded with cells

Background/Purpose

The repair of large abdominal wall defects is still a challenge for pediatric surgeons. Synthetic materials, however, may lead to high complication rates. This study was aimed at applying tissue-engineering methods to abdominal wall repair.

Methods

3T3 mouse fibroblasts were expanded in vitro. In the next step, a biodegradable material—polyglycolic acid (PGA)—was actively seeded with 10⁷ cells/scm of PGA scaffold. Culture medium (Dulbecco's Modified Eagle's Medium with 10% fetal bovine serum) was changed every 6 hours after seeding cells on PGA fibers. Under general anaesthesia, C57BL/6J black mice underwent creation of a 2 × 3-cm abdominal wall defect (60%-70% of abdominal surface). The defect was repaired in the experimental group with the fibroblast-seeded PGA scaffold. In the first control group, the defect was covered with acellular PGA, and in the second control group, by skin closure. Animals were killed after 30 days to assess the histologic and gross findings.

Results

No abdominal hernia was found in animals repaired with cell-seeded and acellular scaffolds. All animals with skin closure died within 7 days. In every case, tissue-engineered construct was thicker then in controls. Histologic and gross examination revealed a good neovascularisation in tissue-engineered abdominal walls comparing to the acellular matrix. There was no intensive scar formation between abdominal wall and skin.

Conclusions

Engineered soft tissue constructs can provide structural replacement of severe and large abdominal wall defects. Tissue engineering in the near future will possibly enter clinical practice.     

Reconstruction of the abdominal wall for incisional hernia repair

BACKGROUND: Abdominal wall reconstruction with mobilization of autologous tissue has evolved as a reliable option for patients with incisional hernias. METHODS: With the aim of evaluating morbidity and recurrence rates in patients who underwent abdominal wall reconstruction for incisional hernia repair, we retrospectively reviewed the charts of 188 patients treated between 1996 and 2003. RESULTS: Primary approximation of the fascial defect was achieved in 77% and was reinforced by either mesh placement or rectus muscle advancement. The remaining 23% were reconstructed either by mesh placement, components separation, or distant flap mobilization. Median follow-up was 15 months. Overall morbidity rate was 38%; recurrence rate was 13%. Dimensions of the hernia and intraoperative enterotomies were associated with postoperative complications. Lack of complete restoration of the myofascial abdominal wall continuity was associated with recurrence. CONCLUSIONS: In patients with incisional hernias, techniques involving autologous tissue mobilization are safe and associated with low recurrence rates.     

异体去细胞真皮基质重建真皮的实验研究

目的　通过不同形式去细胞真皮 (acellulardermalmatrix ,ADM )与单纯自体刃厚皮片移植的比较研究 ,探讨异体ADM作为真皮替代物的机制及效果。方法　猪全层皮肤缺损创面分别行颗粒状 (实验组 1)及网状异体ADM (实验组 2 )结合自体刃厚皮移植 ,以单纯自体刃厚皮移植作对照 ,观察各组移植术后皮片存活率、创面收缩率、组织学变化及血管化程度等。结果　移植术后 ,各组皮片均全部存活 ;与对照组相比 :两实验组创面收缩较小 ,弹性较好 ,创面充血程度轻 (P <0 .0 1) ,瘢痕增生程度也明显小于对照组。结论　网状及颗粒状异体ADM结合自体刃厚皮移植较好地封闭了全层皮肤缺损创面 ;其愈后功能优于单纯自体刃厚皮移植 ;颗粒状ADM制作简单 ,使用方便 ,值得进一步探索研究。     

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目的总结脱细胞异体真皮基质(ADM)补片修补复杂性腹壁疝的经验。方法 2008-2010年首都医科大学附属北京朝阳医院普外疝和腹壁外科采用ADM修补36例复杂性腹壁疝,对其临床资料进行回顾性分析。结果 36例均采用ADM补片进行修补,术后Ⅰ期愈合,无术后腹壁血肿、肠梗阻、肠漏等并发症。随访时间6～34个月,平均16个月,无术后切口感染、腹壁疼痛、腹壁僵硬感、腹壁膨隆等并发症,无术后复发。结论 ADM补片修补复杂性腹壁缺损安全、有效。     

The effect of skin expansion on acellular dermis in an experimental model

Objective: Although acellular dermis is widely used in prosthesis-based breast reconstruction, there is no study evaluating its expandability and histological, ultra-structural related changes. The purpose of this study is to determine whether acellular dermis could be expanded and whether the histological changes occurring in the skin with tissue expansion is different from normal when acellular dermis is used.

Methods: Twenty-two male Wistar rats were used in this study. In group 1 (n?=?6), a rectangular-shaped tissue expander with final volume of 35?ml was placed subcutaneously. In group 2 (n?=?6) tissue expander was placed submuscularly. In group 3 (n?=?6), a 4?×?5?cm, acellular dermis was inserted and sutured in place, tissue expander was placed underneath acellular dermis. Group 4 (n?=?4) was control, no procedure was done after creation of a pocket. After day 30, tissue expanders were inflated with 2?ml every 2 days with saline solution. On day 66, midvertical, midhorizontal surface expansion measurements were recorded. Samples were examined macroscopically. Biopsies were taken from mid-point of the expanded full-thickness flap. Histological evaluation, total skin thickness, epidermal thickness, and the amount of vascularisation were measured.

Results: There was no expansion noted on the acellular dermis; however, acellular dermis increased vascularity and decreased the thinning of the overlying skin and thickening of the epidermis when compared to other groups.

Conclusion: Acellular dermis use can be beneficial in implant-based breast reconstruction in terms of morbidity and its tissue support.     

Ventral hernia repair using allogenic acellular dermal matrix in a swine model

Background This study was designed to assess the long-term efficacy of allogenic acellular dermal matrix (ADM) used as an interpositional graft for ventral hernia repair in a swine model.Methods We created 12×4-cm full-thickness abdominal wall defects in 22 Yucatan miniature pigs. The defect was repaired with either two 6×4-cm pieces of AlloDerm (acellular dermal matrix processed from pig skin in order to avoid a xenogenic response, LifeCell Corporation, Branchburg, NJ USA) (n=12), or expanded polytetrafluoroethylene mesh (ePTFE) (Gore-Tex, W.L. Gore & Associates, Inc., Newark, DE USA) (n=10). In six pigs, a separate 3-cm fascial incision was made, which was then suture repaired as a control for tensiometry testing. The surgical sites were evaluated at either 3 months or 9 months for the presence of a hernia, stretching of the implant, adhesions, vascularity, and biomechanical strength.Results Two hernias occurred in both the ADM and the ePTFE groups. There was minimal stretching of the implants and minimal adhesions in both groups. Fluorescein testing and histology indicated vascular ingrowth into the ADM. There was no statistical difference between the mean breaking strengths of the ADM-fascial interface (106.5 N±SD 40.1), the interface between two pieces of ADM (149.1 N±SD 76.7), and the primary fascial repair (108.1 N±SD 20.9) at 9 months. The ADM-fascial interface had a significantly higher breaking strength than that of the ePTFE-fascia interface (66.1 N±SD 30.1) (P=0.017, t-test, P=0.043 Wilcoxon rank sum test).Conclusions In this study, we were unable to demonstrate a difference between ADM and ePTFE in their ability to repair ventral hernias at 9 months in a swine model. The ADM additionally supports vascular ingrowth and exhibits increased breaking strength at the fascia-implant interface.This paper won the Fruchaud prize for best poster presentation at the American Hernia Society meeting in Orlando, Fla., USA, on February 27, 2004.This study was funded in part by an unrestricted donation to the University of Maryland Division of Plastic Surgery research fund from LifeCell Corporation. Dr. Ronald P. Silverman also has received honoraria from LifeCell Corporation as a speaker.     

Blood vessel matrix: a new alternative for abdominal wall reconstruction

BACKGROUND: Biologic matrices offer a new approach to the management of abdominal wall defects when the use of other foreign material is not ideal. A member of our team (GEA) developed a biological decellularized matrix generated from harvested blood vessels of swine blood vessel matrix (BVMx). The aim of our study was to investigate whether this novel collagen-based biological matrix is safe and effective for the repair of abdominal wall hernia defects in a rat model. METHODS: Full thickness abdominal wall defects were created in rats and repaired with our BVMx. After implantation as an underlay for 30 and 90 days, animals were sacrificed and the implanted material evaluated for herniation, adhesions, breaking strength, inflammation, and revascularization. RESULTS: No evidence of herniation was noted at 30 (n = 7) or 90 (n = 7) days after repair. Adhesions, if present, were filmy and easily separated. The mean area of visceral adhesions to the BVMx was 18.9 +/- 11.0% at 30 days and 7.1 +/- 3.1% at 90 days post implantation (P = 0.33). The breaking strength of the BVMx-fascial interface was 4.5 +/- 0.8 N at 30 days and 4.5 +/- 2.4 N at 90 days post implantation (P = 0.98). Histologic analysis demonstrated that the BVMx elicited a mild transient inflammatory response and supported fibroblast migration, deposition of newly formed collagen, and neovascularization. CONCLUSIONS: These data confirm that this BVMx supports vascular ingrowth and provides adequate strength for the repair of abdominal wall defects. Future studies in a large animal model are required to assess its validity for human application.     

Abdominal wall endometriomas

BACKGROUND: The diagnosis of abdominal wall endometriomas is often confused with other surgical conditions. METHODS: A retrospective study was made of 12 patients presenting with an abdominal wall mass, which proved to be endometrioma. RESULTS: Of a total of 297 patients of endometriosis treated in our hospital over a 7-year period, 12 (4%) had isolated abdominal wall endometriomas. Their mean age was 29.4 years. The presenting symptoms were abdominal mass (n = 12), cyclical (n = 5) or noncyclic pain (n = 7), dyspareunia and dysmenorrhea (n = 1). All patients had a history of gynecologic operations and presented, after an average of 1.9 years, with a tender mass (average 4 cm) at the previous incision site. Preoperative diagnosis was correct in 4 patients (33%) who presented with a cyclically painful abdominal mass. The others were diagnosed as incisional hernia (n = 4), "abdominal wall tumor" (n = 2), and inguinal hernia (n = 2). All patients underwent wide excision of their endometrioma; 2 required polytetrafluoroethylene patch grafting for the resulting fascial defect. The diagnosis was confirmed at frozen section or conventional histological examination in all patients. At follow-up, ranging from 4 months to 3 years, there was no recurrence of endometrioma. CONCLUSIONS: Scar endometrioma commonly presents as an abdominal mass with noncyclical symptoms. Imaging techniques are nonspecific and needle biopsy may confirm the diagnosis. Wide excision is the treatment of choice for abdominal wall endometrioma as well as for recurrent lesions.