Therapeutic, IV.

Background Specific antimicrobial breast pocket irrigations have been proven over the past 20 years to reduce the incidence of capsular contracture by a factor of 10, and the emergence of breast implant–associated anaplastic large cell lymphoma (BIA-ALCL) and its link to bacteria/technique has created renewed interest in different antimicrobial breast pocket preparation agents. Our previous studies have identified that both Betadine-containing and non-Betadine-containing antimicrobial irrigations provide excellent broad-spectrum bacterial coverage. The current science of BIA-ALCL has implicated the Gram-negative microbiome as a key in pathogenesis. Objectives The aim of this study was to revisit the antimicrobial effectiveness of clinically utilized Betadine and non-Betadine solutions, along with other antimicrobial agents that have not yet been tested, against multiple organisms, including additional common Gram-negative bacteria associated with chronic breast implant infections/inflammation. Methods Current and new antimicrobial breast irrigations were tested via standard techniques for bactericidal activity against multiple Gram-positive and Gram-negative strains. Test results are detailed and clinical recommendations for current antimicrobial irrigations are provided. Results Betadine-containing irrigations were found to be superior according to the testing performed. Conclusions There are quite few misconceptions with regard to antimicrobial breast pocket irrigation. These are discussed and final evidence-based recommendations for practice are given.

Background Incisional hernia is the most common complication of abdominal surgery leading to reoperation. In the United States, 200,000 incisional hernia repairs are performed annually, often with significant morbidity. Obesity is increasing the risk of laparotomy wound failure. Methods We used a validated animal model of incisional hernia formation. We intentionally induced laparotomy wound failure in otherwise normal adult, male Sprague-Dawley rats. Radio-opaque, metal surgical clips served as markers for the use of x-ray images to follow the progress of laparotomy wound failure. We confirmed radiographic findings of the time course for mechanical laparotomy wound failure by necropsy. Results Noninvasive radiographic imaging predicts early laparotomy wound failure and incisional hernia formation. We confirmed both transverse and craniocaudad migration of radio-opaque markers at necropsy after 28 d that was uniformly associated with the clinical development of incisional hernias. Conclusions Early laparotomy wound failure is a primary mechanism for incisional hernia formation. A noninvasive radiographic method for studying laparotomy wound healing may help design clinical trials to prevent and treat this common general surgical complication.

Background Obesity increases the risk of laparotomy dehiscence and incisional hernia. The aim of this study was to measure the biological effect of obesity on laparotomy wound healing and the formation of incisional hernias. Methods Normal-weight Sprague–Dawley (SD) and obese Zucker rats were used in an established laparotomy wound healing and incisional ventral hernia model. Mechanical testing was performed on abdominal wall strips collected from laparotomy wounds. Hernia size was measured by digital imaging. Picrosirius staining for collagen isoforms was observed with polarized microscopy. Abdominal wall fibroblasts were cultured to measure collagen matrix remodeling and proliferation. Results Laparotomy wound healing was significantly impaired in obese rats. Mechanical strength was lower than in normal-weight rats. Yield load was reduced in the obese group at all time points. Picrosirius red staining showed increased immature type III collagen content and disorganized type I collagen fibers within laparotomy wounds of obese rats. Wound size was significantly larger in the obese group. Collagen matrix remodeling was impaired with fibroblasts from obese rats, but there was no difference in fibroblast proliferation between the obese and normal-weight groups. Conclusions We observed for the first time that laparotomy wound healing is impaired in obese rats. The recovery of laparotomy wound strength is delayed due to abnormal collagen maturation and remodeling, possibly due to a defect in fibroblast function. Strategies to improve outcomes for laparotomy wound healing in obese patients should include correcting the wound healing defect, possibly with growth factor or cell therapy.

Background Laparotomy wound load forces are reduced when dehiscence and incisional hernia formation occur. The purpose of this study is to determine the effects of strain loss on abdominal fascial fibroblast proliferation, orientation and collagen compaction function. Methods Cultured rat linea alba fibroblasts were subjected to continuous cyclic strain (CS), cyclic strain interrupted at 24 or 48 hours followed by culture at rest (IS-24 and IS-48) or were cultured without mechanical strain (NS). Cell number was measured and images analyzed for cell orientation. Fibroblasts from these groups were seeded onto the surface of (FPCL-S) or mixed into (FPCL-M) a collagen gel matrix and gel area was measured over time. Results Continuous strain stimulated proliferation when compared to the non-strained cells. The loss of strain (IS) delayed proliferation compared to CS throughout (P<0.05). CS fibroblasts aligned perpendicular to the direction of strain within 12 hours. Within 12 hours of strain loss, IS-48 fibroblasts became significantly less aligned (P<.0001), and appeared similar to the randomly organized NS fibroblasts 48 hours after strain removal. The CS and IS-24 groups demonstrated faster and greater overall FPCL-M compaction than both the IS-48 and NS groups (P<.0002). The CS group contracted the gel faster than the NS group in FPCL-S (P=.029). Conclusions Mechanical strain rapidly induces a proliferative, morphological and functional response in abdominal wall fibroblasts that is dependent on the continued presence of the strain signal and quickly lost when the load force is removed. The loss of wound edge tension that occurs during laparotomy wound separation and hernia formation may contribute to impaired wound healing through loss of a key stimulatory mechanical signal with important implications for abdominal wall reconstruction.