Gasless laparoscopic assisted surgery for abdominal trauma

Background

Numerous studies have described the effectiveness of laparoscopy for trauma patients. In gas-filling laparoscopic surgery, most of the disadvantages are related to a positive pressure pneumoperitoneum that compromises the cardiopulmonary function. The main advantage of gasless laparoscopic assisted surgery (GLA) is that it does not affect the haemodynamic status, which is particularly critical for trauma patients. The purpose of this study was to investigate the feasibility and safety of GLA for abdominal trauma.

Materials and methods

This was a retrospective, 1:2 matched case–control study of all trauma gasless assisted laparoscopies performed from January 2010 until January 2013 in a Level I trauma centre. In total, 965 patients with abdominal trauma were admitted. According to the abdominal trauma protocol, a total of 93 hemodynamically stable patients required the operation; we selected fifteen patients to undergo GLA and matched 30 other patients to undergo laparotomy. Demographic information, perioperative findings, injury severity score, and postoperative recovery were recorded and analyzed.

Results

A total of fifteen patients (ten men, five women) with a mean age of 44.4, standard deviation (SD) 13.2 years underwent GLA for abdominal trauma. Eight patients had penetrating injuries, while seven had blunt injuries. Overall, 73% patients had multiple injuries. The mean time to the identified lesion was 23.1, SD 10.9 min, and the mean operative time was 109.7, SD 33.5 min. Most of the lesions were repaired concurrently by GLA. One conversion to laparotomy was done. The mean length of hospital stay (HLOS) was 9.1, SD 4.5 days. No mortality occurred in this series. The mean follow-up was 22.0, SD 7.9 months, and there were no significant events during this period. The mean operative times were comparable in the GLA and open surgery group (109.7, SD 33.5 vs. 131.2, SD 43.6 min; p = 0.076). Compared with the open surgery group, the HLOS was significantly shorter in the GLA group (9.1, SD 4.5 vs.16.3, SD 6.4 days; p = 0.030).

Conclusion

GLA offers both therapeutic and diagnostic advantages for patients with abdominal trauma. GLA shares the advantages of laparoscopy and prevents the cardiopulmonary function from being compromised due to pneumoperitoneum, which is especially critical for trauma patients.     

Fishing-rod-type abdominal wall lifter for gasless laparoscopic surgery

We have designed a new abdominal wall lifter for gasless laparoscopic surgery which consists of stainless steel rods and iron lifters. They elevate the abdominal wall up like a dome-type camping tent, which does not disturb any manipulation of scope or X-ray camera. We received a good view of the peritoneal cavity without CO₂ gas insufflation in ten patients with cholecystitis. This will be helpful for general laparoscopic surgery or laparoscopic assisted surgery with the use of conventional forceps or extracorporeal suturing through a valveless trocar.     

Comparison of immune preservation between CO2 pneumoperitoneum and gasless abdominal lift laparoscopy.

OBJECTIVE: Carbon dioxide (CO2) pneumoperitoneum has been implicated as a possible factor in early immune preservation in laparoscopic surgery. Although the current analysis was not adequate to clarify this issue, the aim of this study was to compare CO2 insufflation laparoscopic cholecystectomy to gasless abdominal wall lift laparoscopic cholecystectomy with respect to preservation of the immune system. METHOD: An analysis of the temporal immune responses was performed in 2 similar groups of patients (n = 50) who were divided randomly into the categories of gas or abdominal wall lift laparoscopic cholecystectomy. The patients were matched with respect to age, weight, and operation time. The immune parameters (serum white blood cell count, cortisol, erythrocyte sedimentation rate [ESR], tumor necrosis factor-alpha [TNF-alpha], interferon-y [INF-gamma], interleukin-6 [IL-6], interleukin-8 [IL-8]) were assessed at preoperative 24 hours and at postoperative 24 and 72 hours for the 2 groups. During the operation, the levels of cytokines that were cultured in the peritoneal macrophages were also checked. RESULTS: The serum white blood cell count, cortisol, and ESR levels were not statistically different in either of the 2 groups. Further, the serum TNF-alpha, INF-gamma, IL-6, and IL-8 levels in both groups were not significantly different from each other at preoperative 24 hours, and postoperative 24 and 72 hours. However, an immediate decrease in the cytokine levels at 24 hours after the operation was significant in both groups. The cytokine levels were particularly higher in the cultured peritoneal macrophages than in the serum, but were not statistically different between the 2 groups. CONCLUSION: Our results showed that the beneficial immune response obtained in the CO2 gas insufflation laparoscopic procedure could also be obtained in the gasless abdominal wall lift laparoscopic procedure. An immediate preservation of the immune functions in the postoperative period was detected similarly in the 2 groups.     

Development and clinical application of semi-loop-shaped retractor for gasless laparoscopic surgery

Background: Gasless laparoscopy has the advantage of avoiding the risk inherent in pneumoperitoneum, but has not gained widespread popularity because of limited exposure of the operative field. Improved retraction devices are therefore needed. Methods: A loop-shaped metallic retractor was designed for planar lifting of the anterior abdominal wall. Four types of retractor (5/6-, 3/4-, and 1/2-circle with rod at 90°, and 1/2-circle with rod at 97°) were studied in 15 pigs. The device was then used for 47 patients. Results: The 1/2-circle was the most smoothly inserted retractor and was significantly safer than the 5/6-circle (p < 0.05, Fishers exact probability test). The 1/2-circle with rod at 97° was utilized for clinical cases. This retractor can be readied within 1 min and was used successfully for all operations. Conclusions: This new retractor for gasless laparoscopic surgery provides good exposure and has the potential to enhance the performance of advanced laparoscopic surgery.     

Pneumoperitoneum versus abdominal wall lift: effects on central haemodynamics and intrathoracic pressure during laparoscopic cholecystectomy

BACKGROUND: It has been shown repeatedly that laparoscopic cholecystectomy using pneumoperitoneum (CO2 insufflation) may be associated with increased cardiac filling pressures and an increase in blood pressure and systemic vascular resistance. In the present study, the effects on the central circulation during abdominal wall lift (a gasless method of laparoscopic cholecystectomy) were compared with those during pneumoperitoneum. The study was also aimed at elucidating the relationships between the central filling pressures and the intrathoracic pressure. METHODS: Twenty patients (ASA I), scheduled for laparoscopic cholecystectomy, were randomised into two groups, pneumoperitoneum or abdominal wall lift. Measurements were made by arterial and pulmonary arterial catheterization before and during pneumoperitoneum or abdominal wall lift with the patient in the horizontal position. Measurements were repeated after head-up tilting the patients as well as after 30 min head-up tilt. The intrathoracic pressure was monitored in the horizontal position before and during intervention using an intraesophageal balloon. RESULTS: After pneumoperitoneum or abdominal wall lifting there were significant differences between the two groups regarding MAP, SVR, CVP, CI, and SV. Analogous to previous studies, in the pneumoperitoneum group CVP, PCWP, MPAP, and MAP as well as SVR were increased after CO2 insufflation (P < 0.01), while CI and SV were not affected. In contrast, in the abdominal wall lift group, CI and SV were significantly increased (P < 0.01), as was MAP (P < 0.01), while CVP, PCWP, MPAP, and SVR were not significantly affected. There was a significant difference in intraesophageal pressure between the two groups. In the pneumoperitoneum group, the intraesophageal pressure was increased by insufflation (P < 0.01) while, in the abdominal wall lift group, it was unaffected. In the pneumoperitoneum group the mean increases in cardiac filling pressures were of the same magnitude as the mean increase in the intraesophageal pressure. CONCLUSIONS: In healthy patients, abdominal wall lift increased cardiac index while pneumoperitoneum did not. Cardiac filling pressures and systemic vascular resistance were increased by pneumoperitoneum but unaffected by abdominal wall lift. The recorded elevated cardiac filling pressures during pneumoperitoneum may be only a reflection of the increased intra-abdominal pressure.     

Total transvaginal endoscopic abdominal wall hernia repair: a NOTES survival study

Hypothesis Natural orifice transluminal endoscopic surgery (NOTES) has gained widespread interest as a potentially less invasive alternative to laparoscopic surgery or, else, an evolution as the next-generation surgery. The main objective of this study was to assess the safety of transluminal abdominal wall hernia repair for potential human application by specifically investigating the feasibility and challenges of using a transvaginal approach. Design NOTES ventral hernia repair via a transvaginal approach. Setting University Hospital (National University Health System, Singapore). Participants The study utilized five female pigs (30–40 kg) between 5 and 7 months of age, which underwent abdominal wall hernia repair using a transvaginal approach. Intervention The procedures were performed using a double-channel endoscope under general endotracheal anesthesia. A mesh was placed and fixed to the abdominal wall using standard laparoscopic and endoscopic equipment. The animals survived for 2 weeks and were then euthanized and a necropsy performed. Main outcome measures To assess the safety and feasibility of NOTES ventral hernia repair in a survival experimental model. Results All of the procedures could be safely performed using the standard equipment. At the necropsy, all meshes were well in place and mild adhesions were recorded in one animal with a small abscess in the subcutaneous area. Conclusion This novel approach seems technically challenging but feasible using equipment and accessories currently available for conventional laparoscopic and interventional endoscopy with low intra-abdominal contamination and sepsis. New procedure-specific instruments and equipment need to be developed to allow the surgeon safer access and more degrees of instrument freedom.     

腹腔镜巨大腹壁切口疝修补术(附1例报告)

目的:探讨腹腔镜治疗巨大腹壁切口疝的手术方法及手术要点。方法:2004年9月在完全腹腔镜下用补片法修补1例巨大腹壁切口疝,疝环12 cm×15 cm。结果:手术顺利完成,手术时间100m in,术后肺部感染,经抗感染治愈,无其他手术并发症,术后7d出院。随访7个月,术前腹胀、腹痛症状消失,无复发,工作、生活正常。结论:腹腔镜下结合带线针补片法治疗巨大腹壁切口疝具有损伤小、术后疼痛轻、并发症少、康复快、下床活动早、效果好等优点。     

腹腔镜腹壁结构分离治疗腹腔内高压的动物实验

目的 通过动物实验,研究腹腔镜腹壁结构分离技术治疗腹腔内高压的效果.方法 8头巴马香猪于全麻下手术,通过腹腔灌注CO2建立腹腔高压(IAH)模型.于腹肌平面上方建立皮下隧道,在腹腔镜的监测下以超声刀切开腹外斜肌腱膜的止点,记录术前、单侧减压和双侧减压后的腹腔内压(IAP)、腰围(WL)、中心静脉压(CVP)、平均动脉压(MAP)和心率(HR)的变化.结果 建立IAH(25 mm Hg)后,WL为(65.3±2.5)cm,MAP为(88±14)mm Hg,HR为(115±9)次/min,CVP为(10.8±2.2)cm H2O.实施腹腔镜腹壁结构分离后,IAP降至(16.0±1.5)mm Hg(P<0.01),WL升至(83.1±1.9)cm(P<0.01),MAP升至(100±12)mm Hg(P<0.01),HR降至(97±7)次/min(P<0.01),CVP降至(7.3±1.8)cmH2O(P<0.01).结论 IAP的变化可引起巴马香猪的血液动力学改变,腹腔镜腹壁结构分离技术可显著降低其IAH,从而改善血液动力学.     

手助腹腔镜外科技术在腹部外科中的应用(附113例报告)

目的:探讨手助腹腔镜外科(hand-assisted laparoscopic surgery,HALS)技术在复杂外科手术中的应用价值。方法:2002年2月至2006年12月应用HALS技术治疗113例患者,对临床相关指标,如手术时间、术中出血量、术后并发症等进行观察和分析。结果:113例患者中,110例获得成功,术后并发症发生率为5.45%,无死亡病例。结论:HALS技术可提高复杂腹腔镜手术的效率和安全性,并在一定程度上保留了微创手术创伤小、康复快的优势。     

Laparoscopic transabdominal preperitoneal approach to place a polypropylene mesh on the abdominal wall: an experimental swine model of a technique that can be used for incisional hernia repair

Background The placement of intraabdominal polypropylene mesh entails risks of adhesions and fistulas that can be avoided by preperitoneal placement.Methods This comparative, open, experimental, prospective, randomized, and transversal study randomized pigs into two groups of 11 each for intraperitoneal (IPOM) or preperitoneal (TAPP) polypropylene mesh placement by laparoscopy. Diagnostic laparoscopy and tissue en-bloc resection was performed 28 days postoperatively for histopathologic analysis.Results The following data were observed for the two study groups: surgical time (IPOM: 35.73 ± 4.22 min; TAPP: 58.09 ± 6.28 min; p = <0.0001); adhesions (IPOM: 81.81%; TAPP: 27.27%; p = 0.032), grade III for IPOM and grade II for TAPP (p = 0.001); and interloop adhesions (IPOM: 81.81%; TAPP: 9.09%; p = 0.003). No fistulas were found in either group. The TAPP procedure showed better integration of mesh, without lesion to abdominal organs. Two complications, occurred with IPOM, and one with TAPP (p = 1.0, not significant).Conclusions The perperitoneal technique requires more time, but has fewer adhesions and less intraabdominal inflammatory response. It is a feasible technique that may diminish risks in the laparoscopic treatment of incisional hernias with polypropylene mesh.     

Hydro Jet dissection of abdominal wall perforator arteries: a pilot study

The Hydro Jet is a new surgical dissection instrument. Applying water to tissues under variable pressure makes selective tissue dissection possible. Larger vessels are less sensitive to water pressure and can be easily coagulated to minimize blood loss. However, the impact of the water pressure on the small blood vessels/microvasculature is not well known. These microvascular changes may be important in the future when using the Hydro Jet as a surgical tool in perforator flap surgery. The abdominal perforator arteries near the umbilicus were dissected with the Hydro Jet in five women who underwent an abdominoplasty for skin/fat excess. The inferior epigastric artery was dissected in one patient who underwent a transverse rectus abdominal musculocutaneous flap procedure for breast reconstruction. Pressure of dissection varied between 30 and 60 bar. Blood vessel specimens were taken and examined using light and electron microscopy. Eighteen samples were taken from six patients. Thirteen samples were dissected with the Hydro Jet; five samples served as controls. No vascular damage was observed microscopically from 30 to 40 bar. Clear signs of vascular damage were observed after dissection with 45 bar with swelling of the (sub)endothelium. At 50 bar dissections the edema of the surrounding stroma increased with loosening of the endothelium. At 60 bar dissections there was obvious damage to all vessel layers. Control samples showed no damage. Dissection of small vessels with the Hydro Jet up to 40 bar does not damage the structural layers histologically. Above this pressure serious damage occurs.     

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.     

腹部手术史患者行腹腔镜结直肠癌根治术的体会(附52例报告)

目的:总结为有腹部手术史的患者行腹腔镜结直肠癌根治术的应用价值及手术禁忌证.方法:回顾分析为52例腹部手术史患者行腹腔镜结直肠癌根治术的临床资料,总结手术方法和操作技巧.结果:52例均成功完成腹腔镜手术.术后1例发生小肠漏,3例超低位保肛(Dixon术)患者发生小吻合口漏,3例腹部切口感染,3例粘连性肠梗阻,经治疗均痊...     

Laparoscopic resection for rectal cancer in patients with previous abdominal surgery: A comparative study

Objective: In laparoscopic colorectal procedures, the presence of peritoneal adhesions caused by previous surgery is one of the most common reasons for conversion and is often associated with increased postoperative morbidity. However, improvements in laparoscopic technique and instruments might, to some extent, help to overcome the adverse effects of peritoneal adhesions. Therefore, the present study was designed to compare and evaluate laparoscopic rectal cancer excision in patients who had had and who had not had previous abdominal surgery. Methods: The present study was a non‐randomized comparison of patients who have had and have not had previous abdominal surgery. Data were extracted from a prospective cohort of patients who had undergone laparoscopic anterior resection for rectal cancer in one particular unit between January 1996 and May 2000. For the purpose of standardization, data on laparoscopic low anterior resection and laparoscopic abdomino‐perineal resection were not used for analysis. The measured outcomes included operation time, blood loss and length of hospital stay as well as complications and conversions. Results: Of the 91 patients recruited for analysis, 26 patients had had previous abdominal surgery (study group), whereas 65 patients had not had previous abdominal surgery (control group). The two groups had a similar age and gender distribution as well as tumour staging. The median operating times of the study group and control group (115 vs 123 min, P = 0.34), their blood loss (122 vs 144 mL, P = 0.30) and lengths of hospital stay (10 vs 11 days, P = 0.66) were similar. The complication rates (23 vs 23%, P = 0.79) and conversion rates (15.4 vs 7.7%, P = 0.55) were also similar between the two groups. Conclusion: Laparoscopic resection for rectal cancer in patients who have had previous abdominal surgery is technically safe and produces similar results to those who have not had previous abdominal surgery.      

Giant pseudocyst of the anterior abdominal wall following mesh repair of incisional hernia: a rare complication managed laparoscopically.

Giant pseudocyst formation of the anterior abdominal wall, following on-lay polypropylene mesh repair for incisional hernia is an under reported complication. We report an unusual case of a 56-year-old female who underwent a polypropylene mesh repair of incisional hernia 2 years back. Subsequently she developed a giant pseudocyst of the anterior abdominal wall, which was occupying the whole of the abdomen from the xiphisternum to the pubic bone, and over both the flanks. Over a period of one year, the cyst had defied multiple attempts at aspiration. The patient underwent a laparoscopic drainage of the collection with piecemeal excision of the entire cyst wall. Histopathology of the cyst wall revealed necrotic material with intervening areas of hemorrhage. No epithelial lining was seen. There has been no recurrence in the two years of follow-up. Conclusion: giant pseudocyst of the anterior abdominal wall is a rare complication following mesh repair of an incisional hernia. Such pseudocysts can be managed successfully by laparoscopic procedures.     

Prior abdominal open surgery does not impair outcomes of laparoscopic colorectal surgery: a case–control study in 367 patients

Aim This prospective case‐matched study was conducted to compare the outcome of laparoscopic colorectal surgery in patients with and without prior abdominal open surgery (PAOS). Method From June 1997 to December 2010, 167 patients with PAOS (including midline, Pfannenstiel, subcostal, right upper quadrant or transverse incision) were manually matched to all identical patients without PAOS from our prospective laparoscopic colorectal surgery database. Matching criteria included age, gender, American Society of Anesthesiology (ASA) score, body mass index, diagnosis and surgical procedure performed. Primary end‐points were postoperative 30‐day mortality and morbidity. Secondary end‐points included operating time, conversion rate and length of stay. Results A total of 367 patients (167 with PAOS and 200 without PAOS) were included in this study. PAOS was associated with a significantly increased mean operating time (229 ± 66 min vs 216 ± 71 min, P = 0.044). The conversion rate was significantly higher in patients with PAOS, compared with patients without PAOS (22%vs 13%, P = 0.017). There was one (0.3%) postoperative death. The overall postoperative morbidity rate was similar in both groups (22%vs 19%, P = 0.658), including Grade 3 or Grade 4 morbidity, according to Dindo’s classification (5%vs 5%, P = 0.694). Mean hospital stay showed no difference between both groups (10 ± 7 days vs 9 ± 5 days, P = 0.849). Conclusion This large case–control study suggests that PAOS does not affect postoperative outcomes. For this reason, a systematic laparoscopic approach in patients with PAOS, even with midline incision, should be considered in colorectal surgery.     

既往腹部手术史对腹腔镜结直肠癌手术影响的临床非随机对照研究

目的 探讨既往腹部手术史对腹腔镜结直肠癌手术的影响及腹腔镜的再次手术技术在结直肠癌治疗中的可行性及安全性.方法 按纳入、排除及剔除标准,将2002年3月至2009年3月期间连续收治的653例腹腔镜结直肠癌手术病例分成3组,即上腹部手术组(n=48)、中下腹部手术组(n=110)和无既往腹部手术史组(n=495).比较组间人口统计学、病理解剖学及手术相关数据上的差异.结果 上腹部手术组、中下腹部手术组和无既往腹部手术史组间在人口统计学、病理解剖学及术后相关并发症方面比较差异均无统计学意义.中下腹部手术组(11.8%)较其他两组存在更高的中转开腹率(上腹部手术组和无既往腹部手术史组分别为4.2%、3.8%),其差异与腹腔内粘连相关.三组在手术时间[(132±36)、(141±42)、(132±36)min]、术中失血量[(58±50)、(81±99)、(57 ±57)ml]、输血率(6.3%、10.9%、7.9%)、低位保肛(47.1%、44.7%、55.2%)、肛门排气时间[(2.5±1.4)、(2.9±1.7)、(2.5±2.1)d]、摄食时间[(5±4)、(5±4)、(4 ±3)d]、术后住院时间[(17±9)、(15±8)、(16±10)d]等方面差异均无统计学意义(P均>0.05).结论 既往腹部手术史因素并不是再手术时运用腹腔镜技术治疗结直肠癌的禁忌证,腹腔镜的再次手术技术在结直肠癌的治疗中安全、可行.     

加速康复外科方案和标准治疗方案对腹部手术患者术后急性肾损伤影响的比较Meta分析

目的 通过Meta分析比较加速康复外科(ERAS)方案和标准治疗方案对腹部手术患者术后急性肾损伤(AKI)的影响.方法 通过PubMed、Embase、Cochrane Library数据库和参考文献列表进行检索,识别从建库至2020年9月符合纳入标准的相关研究.采用风险比(RR)、均数差(MD)和相应的95％可信区间...     

A comparative study of adhesion formation and abdominal wall ingrowth after laparoscopic ventral hernia repair in a porcine model using multiple types of mesh

Background The ideal mesh for laparoscopic ventral hernia repair is not yet identified.Methods We laparoscopically placed polypropylene (PPM), expanded polytetrafluoroethylene (ePTFE), and polyester with antiadhesive collagen layer (PCO) in eight pigs using sutures and tacks for fixation. After 28-day survival, we compared adhesion formation, fibrous ingrowth, and shrinkage among the types of mesh.Results Mean area of adhesions to PCO (8.25%) was less than that to ePTFE (57.14%, p < 0.001) or PPM (79.38%, p < 0.001). Adhesions peel strength was less for PCO (2.3 N) than for PPM (16.1 N, p < 0.001) or ePTFE (8.8 N, p = 0.02). Peel strength of mesh from the abdominal wall was less for ePTFE (1.3 N/cm of mesh width) than for PCO (2.8 N/cm, p = 0.001) or PPM (2.1 N/cm, p = 0.05). ePTFE area (94.4 cm²) was less than that for PCO (118.6 cm², p < 0.001) or PPM (140.7 cm², p < 0.02).Conclusion PCO had fewer and less severe adhesions than ePTFE or PPM while facilitating excellent ingrowth of the adjacent parietal tissue.     

Comparison of polypropylene and polyethylene terephthalate (Dacron) meshes for abdominal wall hernia repair: A chemical and morphological study

For the first time, by scanning electron microscopy (SEM), polypropylene (PP) excised meshes (ethylene oxide sterilized) for abdominal wall hernia repair have been shown to be greatly damaged physically, independently of the implantation time, while the polyethylene terephthalate (PET), or Dacron, ones (gamma radiation sterilized), did not undergo alterations due to the sterilization process and were not damaged, even after long implantation periods. Fourier-Transform Infrared Spectroscopy (FTIR) study of PP and PET excised meshes, as well as of their extracts with cyclohexane, has shown the presence of species, such as squalene, palmitic and stearic acid, in some cases, cholesterol, transferred from the surrounding tissues to the polymer during the implantation period. In the case of PP meshes, these small organic molecules would reduce physical and mechanical properties of the material. A hypothesis is presented to account for the better behavior (not in the clinical sense) of PET meshes.