desmoid tumors , desmoid type fibromatosis or aggressive fibromatosis are designations of a benign mesenchymal neoplasm with monoclonal proliferation , which belongs to a family of myofibroblastic fibromatosis characterized by aggressive local infiltration of surrounding tissues , with uncertain growth and increased chances of recurrence , despite no metastatic potential . although first described by macfarlane in 1832 , the designation desmoid was given in 1838 by muller in berlin , who first used the term  desmos  relating to the greek word  which means incidence is estimated in 24 per million population , with 900 new cases per year in the us . some 70% of patients diagnosed with desmoid type fibromatosis have tumors related to familial adenomatous polyposis ( fap ) , including a mutation in the apc gene . in most of the patients with sporadic desmoid type fibromatosis ( which are not related to fap ) , the tumorigenesis is related to endocrine and physiologic factors , including estrogen hormonal stimulus and pregnancy , , . in those cases , up to 25% of the patients have previous history of trauma or surgical incisions , which are related to the topography of these tumors , , , . surgery was the first line of treatment , consisting of radical therapy with wide resection of the tumor and adjoining tissues . despite that aggressive approach more recently , additional treatments such as radiotherapy , chemotherapy , hormonal inhibitors and non - hormonal anti - inflammatories have been used as complement or even as the first approach , , , , , , , . whenever radical resection is indicated , the abdominal wall defect closure remains an important challenge to the surgical team and there is no defined consensus regarding the best choice of abdominal wall reconstruction . therefore , the aim of this study is to analyze the experience in abdominal wall reconstruction as a result of sporadic desmoid type fibromatosis resection at a single center in so paulo , brazil , specifically focusing on the surgical technique . this case series was conducted based on a comprehensive retrospective analysis of charts from patients submitted to radical therapy of abdominal wall desmoid type fibromatosis treated between 1982 and 2013 in the general surgery service in the division of surgical clinic iii of the hospital das clnicas of the university of sao paulo , school of medicine . all patients had preoperative abdominal ct scan or magnetic resonance for surgical planning , and underwent operative procedure in a supine position with urinary catheterization and prophylactic antibiotics . the surgery comprised radical resection , with three centimeters free surgical margins , intraoperative frozen section of margins , and further resection in case of residual neoplasm . despite the period of this cohort , all surgeons involved in the study belonged to sarcoma and melanoma group of the general surgery service of hospital das clnicas wide resection was achieved in all procedures , comprising the tumor , all layers of the abdominal wall and healthy adjacent tissues . table 1 summarizes demographic data of the cohort . from the three patients diagnosed during their pregnancies , one was able to start treatment six months after the beginning of gestation , and another had to undergo surgery while in her 16th week of pregnancy , because the tumor 's mass effect was compromising the development of the fetus ( fig . 1 , fig seven patients had undergone previous abdominal procedures and 18% of those had tumors arising within surgical scars , in line with the desmoid type fibromatosis pathophysiology . tumor weight varied from 15 to 2.125  g , and tumor diameter from 2 to 25  cm . 4 ) . resection encompassed removal of the neoplasm , subcutaneous tissue , muscles , peritoneum and , in more superficial lesions , skin parts . after radical resection , the abdominal wall defect was addressed , and surgeons faced two reconstruction scenarios , summarized in fig . 5 . first , and more frequent , were abdominal wall defects that allowed primary closure . in this scenario , the use of relaxing gibsos incisions granted successful approach of the wound edges with no tension , followed by a midline fascial closure using polyglactin continuous suture ( fig . this technique was used in 22 of 27 patients ( 81,5% ) . in the remaining cases , edge - to - edge fascial closure and relaxing incisions were not possible , either due to the size or the location of the defect , usually at upper or lower lateral quadrants . in such cases , the technique consisted of using synthetic material that could be in contact with the bowel and , when possible , using the greater omentum as an interface between the mesh and the abdominal organs ( fig . one of them required a local advancement flap after a 11  cm tumor excision ( fig . 8) , and the other , a deep inferior epigastric perforator ( diep ) flap following the resection of a 6  cm desmoid tumor . postoperative complications were classified according to clavien - dindo grading system ( table 2 ) . there was one case of small bowel erosion due to intestinal contact with a cellulose - based mesh diagnosed on follow - up . from the two patients who presented incisional hernias as a late complication , one had no mesh placed during the surgery , and the other was morbidly obese . after a mean follow up of 5 years ( ranging from 20 to 360 months ) , 24 out of 27 ( 89% ) patients remained disease - free . the other three had desmoid local recurrences with a mean disease - free survival of 22 months . resection encompassed removal of the neoplasm , subcutaneous tissue , muscles , peritoneum and , in more superficial lesions , skin parts . after radical resection , the abdominal wall defect was addressed , and surgeons faced two reconstruction scenarios , summarized in fig . 5 . first , and more frequent , were abdominal wall defects that allowed primary closure . in this scenario , the use of relaxing gibsos incisions granted successful approach of the wound edges with no tension , followed by a midline fascial closure using polyglactin continuous suture ( fig . this technique was used in 22 of 27 patients ( 81,5% ) . in the remaining cases , edge - to - edge fascial closure and relaxing incisions were not possible , either due to the size or the location of the defect , usually at upper or lower lateral quadrants . in such cases , the technique consisted of using synthetic material that could be in contact with the bowel and , when possible , using the greater omentum as an interface between the mesh and the abdominal organs ( fig . one of them required a local advancement flap after a 11  cm tumor excision ( fig . 8) , and the other , a deep inferior epigastric perforator ( diep ) flap following the resection of a 6  cm desmoid tumor . . there was one case of small bowel erosion due to intestinal contact with a cellulose - based mesh diagnosed on follow - up . from the two patients who presented incisional hernias as a late complication , one had no mesh placed during the surgery , and the other was morbidly obese . after a mean follow up of 5 years ( ranging from 20 to 360 months ) , 24 out of 27 ( 89% ) patients remained disease - free . the other three had desmoid local recurrences with a mean disease - free survival of 22 months . although the low incidence , aggressive infiltration and growth towards healthy adjacent tissue implicates in high morbidity associated with radical resection . this represents a major difference when comparing surgical treatment of desmoid tumors to soft tissue sarcomas with well - defined pseudo capsules . surgical radical therapy used to be the first and unique choice of treatment , despite local relapse or high morbidity . over the last years , chemotherapy and hormonal adjuncts have been the first option , especially when the location of the neoplasm predicts difficult reconstruction after resection . surgery is now considered a final step to a multimodal approach , after all other options have been exhausted . when radical resection is indicated our group has preferably chosen the primary fascial closure with onlay polypropylene mesh reinforcement , associated with subcutaneous drainage , as the first choice of reconstruction . however , when the defect is too extensive or the resection margins do not favor primary closure of the wound , alternative options should exist in the surgeon 's armamentarium . in such cases , our group prefers to place a synthetic mesh in inlay position to both close the defect and prevent complications such as fistula . the literature review about desmoid type fibromatosis within the abdominal wall showed no consensus regarding the surgical technique to close the abdominal defects . reconstruction was performed using two layers of polypropylene mesh , and , when possible , with suturing of the greater omentum to create a the experience from the memorial sloan kettering cancer center , described by stojadinovic et al . , regards the treatment of 39 patients whose lesions had a mean size of six centimeters . the authors stated that 10% of the patients had primary closure of their wounds without mesh use while 85% of patients required the use of some prosthesis as an adjunct in the reconstruction procedure . that series , which lasted for 53 months , showed 8% of morbidity , especially wound complications . in 2004 , phillips and his collaborators analyzed the resection of 23 desmoid type fibromatosis within the abdominal wall , 20 of which were primary lesions . mean tumor size was eight centimeters , and a two - centimeter margin of palpable normal tissue was obtained . in addition to that , in 2009 bertani et al . described the experience with 14 patients in the milan institute . tumors had a mean diameter of 4.7  cm and patients were followed by a mean of 55 months . in two cases , neo - peritoneum  , while in five patients , two layers of mesh were used , one with polyglactin and a superficial one with polipropylen . in the seven remaining cases , lightweight low profile the series neither describes closure of the midline nor any acute complication , with the exception of two cases of abdominal wall bulging diagnosed during the follow - up . the use of e - ptfe mesh and acellular dermal matrix for abdominal wall closure after desmoid resection was also reported in other series with good results , . in 2013 , garvey et al . retrospectively analyzed 164 patients with desmoid tumors , being 47 operated on because of lesions within the abdominal wall . the average size of the specimens were between 14 and 16.6  cm among patients who underwent resection without reconstruction of the abdominal wall and those who needed skin flap reconstruction . surgical approach was different from the other studies , since component separation was used in 54% of the cases . midline fascial closure was achieved in 68% of the patients , 10.6% required bridged prosthesis and 38% of them underwent concomitant flap reconstruction for skin replacement and soft - tissue coverage . the large experience with desmoid type fibromatosis treatment from the royal marsden hospital was reported by wilkinson et al . from 50 patients who underwent surgery , mean tumor diameter was 8  cm and 56% had r1 resection ( microscopically involved margins ) . mesh was used in 96% of abdominal closures , although there was no description of type of mesh or surgical technique . apart from abdominal wall reconstruction primary closure and mesh placement , bridged or not , it is also possible to use single - stage myocutaneous free flaps to close the defect . described the closure of a 25    25  cm abdominal wall defect using a single - stage latissimus dorsi myocutaneous flap in combination with a synthetic mesh with no complications in 15  days of hospitalization . full - thickness reconstruction of the abdominal wall can also entail using a tensor fascia lata pedicled flap . in 2005 , rifaat et al . described 11 patients in whom the technique was applied without acute complications , except for one case of incisional hernia and one of abdominal wall bulging . another option to be considered is the use of myofascial flaps with microsurgical end - to - end anastomosis . brenner and rammelt reported the management of anterior abdominal wall defects using calcaneus microvascular soft tissue autologous flap . the complications described included hyperkeratosis in the donated area , and one patient required reconstructive plastic surgery . potential biases or imprecision could be related to different surgeons performing the procedures , despite sharing the same surgical background , and the 30-year length of the study , during which novel research on management course emerged . after such retrospective analysis , we have concluded that surgical treatment of the desmoid type fibromatosis and reconstruction of the abdominal wall defect is feasible , although challenging . it requires multidisciplinary approach including a surgical team with expertise in resection and reconstruction of the abdominal wall . despite the need to implement extensive margins , fascial and skin closure can be achieved in the majority of the procedures without the need of complex reconstructions . our groups suggests that , in light of the results presented , midline fascial closure and adjunct onlay polypropylene mesh placement should be performed whenever possible . further prospectively designed studies focusing on the surgical technique of abdominal wall reconstruction after desmoid resection should enhance our understanding of the subject . ethical approval was given by ethical comission for research projects analysis ( cappesq ) under the reference number 115/16 . this work has been stated according to the process guidelines as described in agha ra , fowler aj , rajmohan s , barai i , orgill dp , for the process group .
highlightsdesmoid type fibromatosis , although benign and rare tumors , pose significant challenge to surgeons due to their high morbidity and recurrence rate.after radical resection , closure of the abdominal wall defect requires the surgeos expertise and an accurate technique.primary abdominal wall reconstruction using onlay mesh achieves high closure rate and low risk of significant complications .