Surgical Treatment for Capsular Contracture: A New Paradigm and Algorithm.

BACKGROUND: Capsular contracture following breast augmentation is prone to recurrence with conventional surgical therapy. Adding acellular dermal matrix improves results but significantly increases operating time and cost. This study tested a new treatment algorithm that uses acellular dermal matrix selectively to optimize success rates while minimizing its drawbacks. METHODS: All patients surgically treated by the authors for Baker grade III/IV capsular contracture between 2007 and 2018 were included in this retrospective cohort study. Data were collected on patient, breast augmentation, capsular contracture, and surgical treatment characteristics, in addition to follow-up findings. Treatment success was defined as Baker grade II or better. RESULTS: One hundred eighty patients underwent 217 surgical treatments for capsular contracture. Conventional treatment was used in 185 cases and acellular dermal matrix in 32. Twenty-six patients were treated for a second occurrence and four were treated for a third. The average follow-up was 2.4 years. Conventional treatment was successful in 72.5 percent of first occurrences, 62.5 percent of second occurrences, and 50.0 percent of third occurrences. Acellular dermal matrix was successful in 96.9 percent of cases. The odds of failure were increased by bilateral capsular contracture (3.9 times) and previous treatment failure (3.5 times). When acellular dermal matrix was used selectively for bilateral capsular contracture or in unilateral cases with a previous treatment failure, the overall treatment success rate improved to 85.6 percent compared with 64.2 percent when this algorithm was not followed (p < 0.001). CONCLUSION: This study demonstrates that selective acellular dermal matrix use can increase success rate to over 85 percent in the overall treatment of capsular contracture, and to nearly 100 percent in individual cases.

Muscle Flap Closure following Complex Spine Surgery: A Decade of Experience.

BACKGROUND: Advances in surgical technology and adjuvant therapies along with an aging and increasingly morbid U.S. population have led to an increase in complex spine surgery. With this increase comes an elevated risk of complications, including those related to the surgical wound, with some studies demonstrating wound complication incidences approaching 45 percent. The authors hypothesize that immediate muscle flap closure improves outcomes in high-risk patients. METHODS: Three hundred one consecutive index cases of spinal wound closure using local muscle flaps performed by the senior author at a single institution between 2006 and 2018 were reviewed. The primary outcome was major wound complication (reoperation and/or readmission because of surgical-site infection, late infection, dehiscence, seroma, or hematoma). Logistic regression analysis was performed to identify predictors of this endpoint. RESULTS: Major wound complications occurred in 6.6 percent of patients (reoperation, 3.6 percent; readmission, 3.0 percent), with a 6.0 percent infection rate and five cases requiring instrumentation removal because of infection. Risk factors identified included radiotherapy (OR, 5.9; p = 0.004), age 65 years or older (OR, 2.8; p = 0.046), and prior spine surgery (OR, 4.3; p = 0.027). The incidence of major wound complication increased dramatically with each additional risk factor. Mean drain dwell duration was 21.1 ± 10.0 days and not associated with major wound complications, including infection (OR, 1.04; p = 0.112). CONCLUSIONS: Immediate local muscle flap closure following complex spine surgery on high-risk patients is associated with an acceptable rate of wound complications and, as these data demonstrate, is safe and effective. Consideration should be given to immediate muscle flap closure in appropriately selected patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

The Price of Aesthetics After Nipple-Sparring Mastectomy: A Cost-Minimization Analysis of Skin Banking With Deep Inferior Epigastric Perforator Flap.

BACKGROUND: Skin necrosis after nipple-sparing mastectomy (NSM) and deep inferior epigastric perforator (DIEP) breast reconstruction impacts cosmesis and patient satisfaction. Skin grafting might mitigate these sequelae, but oftentimes creates a color and texture mismatch with native breast skin. In contrast, abdominal skin on the DIEP flap is an excellent match and can be banked. The purposes of this study are to review our experience with skin banking of DIEP flaps and determine the cost-benefit of skin banking compared with other reconstructive options. METHODS: This was a retrospective review study conducted from 2011 to 2014 to examine patients undergoing staged DIEP reconstruction immediately after NSM. Medicare reimbursement costs using Current Procedural Terminology codes, and provider and facilities fees for conventional reconstructions options versus skin banking were obtained with subsequent cost-minimization and sensitivity analyses. RESULTS: The proportion of patients who developed mastectomy skin necrosis was 12.1%, and that of those who had a positive retroareolar biopsy corresponding to an average surface area of 58.3 cm was 3.0%. Average per patient cost of skin banking was $1224, $844 more than split-thickness skin graft (STSG) without Integra, $420 more than STSG with Integra, and $839.01 more than full-thickness skin graft. Sensitivity analysis demonstrates that skin banking was less than managing mastectomy skin loss with STSG and Integra when the incidence of necrosis >10 cm exceeded 25.3%. CONCLUSIONS: Skin banking maximizes aesthetic outcomes after skin loss from either positive margins or skin flap necrosis. Use of this technique should occur especially in select patients at increased risk of mastectomy skin flap/nipple-areola complex (NAC) necrosis and/or suspicion for occult NAC carcinoma. Furthermore, among reconstructive plastic surgeons whose rate of mastectomy flap/NAC necrosis >10 cm exceeds 25.3%, sensitive analysis favors undergoing a staged reconstruction after NSM.

Intraoperative Comparison of Anatomical versus Round Implants in Breast Augmentation: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial was to determine whether anatomical implants are aesthetically superior to round implants in breast augmentation. METHODS: Seventy-five patients undergoing primary breast augmentation had a round silicone implant of optimal volume, projection, and diameter placed in one breast and an anatomical silicone device of similar volume and optimal shape placed in the other. After intraoperative photographs were taken, the anatomical device was replaced by a round implant to complete the procedure. A survey designed to measure breast aesthetics was administered to 10 plastic surgeon and 10 lay reviewers for blind evaluation of the 75 cases. RESULTS: No observable difference in breast aesthetics between anatomical and round implants was reported by plastic surgeons in 43.6 percent or by lay individuals in 29.2 percent of cases. When a difference was perceived, neither plastic surgeons nor lay individuals preferred the anatomical side more often than the round side. Plastic surgeons judged the anatomical side superior in 51.1 percent of cases and the round side superior in 48.9 percent of cases (p = 0.496). Lay individuals judged the anatomical side superior in 46.7 percent of cases and the round side superior in 53.3 percent (p = 0.140). Plastic surgeons identified implant shape correctly in only 26.5 percent of cases. CONCLUSIONS: This study provides high-level evidence supporting no aesthetic superiority of anatomical over round implants. Given that anatomical implants have important and unique disadvantages, a lack of proven aesthetic superiority argues against their continued use in breast augmentation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

Risk factors of infected sternal wounds versus sterile wound dehiscence.

BACKGROUND: Sterile sternal dehiscence (SSD) and sternal wound infections (SWIs) are two complications of median sternotomy with high rates of morbidity. Sternal wound complications also carry significant economic burden, almost tripling patients' hospital costs and are considered a nonreimbursable "never event" for Medicare. Historically, SDD and SWI have been recognized as discrete entities, but nonetheless continue to be categorized as a singular complication in literature. The purpose of this study was to determine specific patient demographic and perioperative predictors of SSD and SWI. MATERIALS AND METHODS: An institutional review board-approved, retrospective study of 8098 consecutive patients who underwent cardiac surgery at Columbia University Medical Center between January 2008 and December 2013 was conducted. Patients were categorized into three groups: no sternal wound complication, SSD, or SWI. Statistical analysis was performed using univariate and multivariate logistic regression analysis. RESULTS: Of 8098 patients, there were 73 patients (0.9%) with SSD and 40 (0.5%) with SWI who required plastic surgical consultation, debridement, and flap closure. In univariate analysis of SSD, positive predictors (i.e., "risk" factors) were age >42 years, prior surgery this admission, ≥2 arterial conduits, internal mammary artery (IMA) grafting with or without previous IMA grafting, body mass index (BMI) >30 (obese), CHF, diabetes requiring medication, respiratory failure, and unplanned cardiac reoperation; negative predictors (i.e., "protective" factors) were no arterial conduits and extubation within 24 h. In univariate analysis of SWI, positive predictors were IMA grafting with or without previous IMA grafting, postoperative hematocrit urgent/emergent surgical priority, BMI >30 (obese), cardiac ejection fraction <40%, and respiratory failure; negative predictors were no arterial conduits and elective surgical priority. In multivariate regression, BMI >30, diabetes requiring medication, and respiratory failure were determined to be significant positive predictors of SSD, and IMA grafting with or without prior IMA grafting and respiratory failure were significant positive predictors for SWI; no significant negative predictors were identified. CONCLUSIONS: This study found that SSD and SWI have many common significant predictors consistent with findings that increased BMI, use of IMA grafts, poor cardiac reserve, and postoperative respiratory failure confer increased risk of sternal wound complications. Additionally, this study also found that there were predictors unique to each entity supporting that SSD and SWI may be related but are not a singular entity. Recognition and prevention of significant positive and negative predictors of SSD and SWI may be valuable in preoperative counseling, operative planning, and postoperative management. Although sternal wound complications can be successfully managed by plastic surgical intervention, preventing the development of median sternotomy complications may curb costs incurred by both patients and health care systems.

Optimizing Successful Outcomes in Complex Spine Reconstruction Using Local Muscle Flaps.

BACKGROUND: Postoperative wound complications in patients undergoing complex spinal surgery can have devastating sequelae, including hardware exposure, meningitis, and unplanned reoperation. The literature shows that wound complication rates in this patient population approach 19 percent and, in very high-risk patients (i.e., prior spinal surgery, existing spinal wound infection, cerebrospinal fluid leak, malignancy, or history of radiation therapy), as high as 40 percent and with reoperation rates as high as 12 percent. The authors investigated whether prophylactic closure of spinal wounds with muscle flaps improves outcomes. METHODS: A retrospective review was performed of 102 reconstructions (in 96 patients) in which spinal wound closure was performed by means of paraspinous, trapezius, or latissimus muscle advancement flaps by a single plastic surgeon (J.A.S.) from 2006 to 2014. Data regarding presurgical diagnosis, patient demographics, and incidence of postoperative complications were recorded. RESULTS: One hundred two reconstructions were included, with follow-up ranging from 2 to 60 months. Eighty-eight reconstructions were classified as very high-risk for wound complications, defined as those having prior spinal surgery, existing spinal wound infection, cerebrospinal fluid leak, malignancy, or prior radiation therapy. Within the very high-risk group, there were six wound complications (6.8 percent), three of which (3.4 percent) required reoperation. CONCLUSIONS: In this study, there is a markedly lower rate (6.8 percent) of postoperative wound complications compared with historical controls after closure of spinal wounds with local muscle flaps in very high-risk patients. These data encourage safe and routine use of muscle flaps for closure in this cohort of patients undergoing spinal surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Use of continuous positive airway pressure after rhinoplasty, septoplasty, and sinus surgery: A survey of current practice patterns.

OBJECTIVE: To explore current practice patterns in the use of continuous positive airway pressure (CPAP) following nasal or sinus surgery. STUDY DESIGN: Cross-sectional survey. METHODS: An electronic 24-question survey was created to evaluate surgeon practice patterns for restarting CPAP after nasal surgery. We also explored factors contributing to their decisions (1-5 Likert scale) and complications believed to be directly related to restarting CPAP. Factors with a median rating score greater than 3 out of 5 were deemed "important." Subgroup analyses were performed to assess the impact of practice setting and clinical experience. RESULTS: A total of 407 physicians completed the survey (27.4% response rate for those that opened the e-mail). The majority of surgeons temporarily stop CPAP after nasal surgery, generally for 1 to 2 weeks, although the range of time is wide. There are also many surgeons who do not stop CPAP after any of these procedures and who reported that complications were fairly minimal. Severity of obstructive sleep apnea (OSA) was deemed important for all procedures. There were additional patient and surgery-specific factors considered important for each individual surgery. Subgroup analysis revealed significant differences in physician practice setting and clinical experience. CONCLUSION: Regarding the use of CPAP after nasal surgery, considerable variation existed in the practice patterns of physicians. Severity of OSA was universally considered important, but the remaining factors were less consistent. A comparative study investigating the outcomes of various protocols is necessary. LEVEL OF EVIDENCE: N/A.

Normalizing dysfunctional purine metabolism accelerates diabetic wound healing.

Diabetic patients exhibit dysfunction of the normal wound healing process, leading to local ischemia by vascular occlusive disease as well as sustained increases in the proinflammatory cytokines and overproduction of reactive oxygen species (ROS). Of the many sources of ROS, the enzyme xanthine oxidase (XO) has been linked to overproduction of ROS in diabetic environment, and studies have shown that treatment with XO inhibitors decreases XO overactivity and XO-generated ROS. This study evaluates the role of XO in the diabetic wound and the impact of specifically inhibiting its activity on wound healing. Treatment of diabetic wounds with siXDH (xanthine dehydrogenase siRNA) decreased XDH mRNA expression by 51.6%, XO activity by 35.9%, ROS levels by 78.1%, pathologic wound burden by 31.5%, and accelerated wound healing by 7 days (23.3%). Polymerase chain reaction analysis showed that increased XO activity in wild-type wound may be due to XDH to XO conversion and/or XO phosphorylation, but not to gene transcription, whereas increased XO activity in diabetic wounds may also be from gene transcription. These results suggest that XO may be responsible for large proportion of elevated oxidative stress in the diabetic wound environment and that normalizing the metabolic activity of XO using targeted delivery of siXDH may decrease overproduction of ROS and accelerate wound healing in diabetic patients.

Patient preferences and bariatric surgery procedure selection; the need for shared decision-making.

BACKGROUND: Bariatric surgery is the most effective treatment for patients suffering from obesity-related comorbidities. There is little data regarding how patients choose one particular bariatric procedure over another. This study aimed to better define the relationship between preferences of patients considering bariatric surgery and the procedure patients undergo. METHODS: A bilingual questionnaire was administered to all prospective patients seen between March 1 and August 31, 2012. The questionnaire assessed basic knowledge of bariatric surgery (based on the information seminar) as well as patient preferences of the various outcomes and complications for sleeve gastrectomy, gastric bypass, and gastric banding. RESULTS: One hundred seventy-two patients completed the questionnaire. Fifty-eight percent of patients chose "maximum weight loss" as the most important outcome, and 65 % chose "leak" as the most concerning complication. Subgroup analysis of patients with diabetes revealed that 58 % chose "curing diabetes" as the most important outcome. Nineteen percent of patients were either not sure which procedure they wanted or changed their decision after consultation with the surgeon. CONCLUSIONS: The decision to choose one bariatric procedure over another is complex and is based on factors beyond absolute patient preferences. Although maximum weight loss is a commonly reported preference for patients seeking bariatric surgery, patients with diabetes are more focused on diabetes remission. Most patients have already decided which procedure to undergo prior to surgeon consultation. Patients may benefit from shared decision making, which integrates patient values and preferences along with current medical evidence to assist in the complex bariatric surgery selection process.

Thrombin and topical local anesthetic for postoperative pain management.

PURPOSE: Local anesthetic is often used for perioperative pain control. Thrombin serves as a carrying medium for sustained release of antibiotics, chemotherapy, and growth factors. We tested the hypothesis that local anesthetic pain relief can be prolonged with the adjunct use of thrombin. METHODS: A prospective single-blinded clinical study was performed. Patients undergoing elective hand surgery inclusive of carpal tunnel release, excision of ganglion cyst, trigger finger release, and excision of mucous cyst under local block were enlisted. Before closure, patients received 1 of the following combinations: (1) control with oral analgesics, (2) 5 mL of 2% xylocaine, (3) 5 mL of 0.5% bupivacaine, (4) 2.5 mL of 2% xylocaine with 2.5 mL of 0.5% bupivacaine (XB), (5) thrombin with 5 mL of 2% xylocaine (XT), (6) thrombin with 5 mL of 0.5% bupivacaine (BT), and (7) thrombin with 2.5 mL of 2% xylocaine and 2.5 mL of 0.5% bupivacaine (XBT). There were 7 patients in each group, and patient demographics were similar between groups. Outcome measures included postanesthesia care unit (PACU) time, pain level, and number of pain pills required. RESULTS: Compared with oral analgesics alone, mean (SD) postoperative pain levels were reduced by 33.3% (8.9%) by xylocaine, 69.1% (8.7%) by bupivacaine, and 45.7% (9.4%) by XB. When thrombin was added, pain levels were further reduced by 69.9% by XT (P < 0.001), 23.1% by BT (P = 0.071), and 50.5% by XBT (P < 0.001) compared with their nonthrombin counterparts. In addition, PACU time was decreased by 34.8% by XT (P = 0.003) and 19.7% by XBT (P = 0.013) compared with xylocaine and XB, respectively. However, there was no difference in total pain pills needed between xylocaine, bupivacaine, and XB when administered with and without thrombin. CONCLUSIONS: The addition of topical thrombin to local anesthetic at the end of elective hand surgery provides for sustained postoperative pain control. Patients in this study who received thrombin and local anesthetic before wound closure had lower pain levels and were discharged from the PACU sooner than those who received local anesthetic alone. LEVEL OF EVIDENCE: Therapeutic level 2.

A prospective analysis of the association between indwelling surgical drains and surgical site infection in plastic surgery.

INTRODUCTION: Many surgeons fear that closed-suction drains serve as a portal for bacterial entry into surgical spaces. Despite a lack of supporting evidence, postoperative antibiotics are often prolonged while drains remain in place. METHODS: Medical records of all patients who underwent intraoperative Jackson-Pratt drain placement and sterile removal over a 12-month period were prospectively analyzed. RESULTS: Fifty-four patients with 101 drains were included. Drains were in place for 5 to 43 days [mean (SD), 13.5 (6.3) days]. Sixty-three percent of drains had positive cultures. All patients received perioperative antibiotics. Thirty-nine patients received postoperative antibiotics [mean (SD), 13.8 (13.8) days]. There were 2 cases of cellulitis. One patient required reoperation. CONCLUSIONS: Sixty-six drains (65.3%) were placed in the presence of prosthetic material. Although nearly two thirds of drains were colonized with bacteria, our wound infection rate was extremely low (5.6%). Thus, closed-suction drains may be left in place for an extended period without increasing the risk of infection, even in the presence of prosthetic material.

The use of acellular dermal matrix in immediate two-stage tissue expander breast reconstruction.

BACKGROUND: Acellular dermal matrix is commonly used in implant-based breast reconstruction to allow for quicker tissue expansion with better coverage and definition of the lower pole of the breast. This study was performed to analyze complications associated with its use in immediate two-stage, implant-based breast reconstruction and to subsequently develop guidelines for its use. METHODS: A retrospective analysis of 628 consecutive immediate two-stage tissue expander breast reconstructions at a single institution over a 3-year period was conducted. The reconstructions were divided into two groups: reconstruction with acellular dermal matrix and reconstruction without it. Demographic information, patient characteristics, surface area of acellular dermal matrix, and complications were analyzed and compared. RESULTS: A total of 407 patients underwent 628 immediate two-stage, implant-based breast reconstructions; 442 reconstructions (70.3 percent) used acellular dermal matrix and 186 (29.6 percent) did not. The groups had similar patient characteristics; however, major complications were significantly increased in the acellular dermal matrix group (15.3 versus 5.4 percent; p = 0.001). These complications included infection requiring intravenous antibiotics (8.6 versus 2.7 percent; p = 0.001), flap necrosis requiring excision (6.7 versus 2.7 percent; p = 0.015), and explantation of the tissue expander (7.7 versus 2.7 percent; p = 0.004). CONCLUSIONS: Use of acellular dermal matrix in immediate two-stage, implant-based breast cancer reconstruction is associated with a significant increase in major complications. Therefore, it should only be used in specific patients and in minimal amounts. Indications for its use include single-stage permanent implant reconstruction and inadequate local muscle coverage of the tissue expander. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Fat grafting accelerates revascularisation and decreases fibrosis following thermal injury.

BACKGROUND: Fat grafting has been shown clinically to improve the quality of burn scars. To date, no study has explored the mechanism of this effect. We aimed to do so by combining our murine model of fat grafting with a previously described murine model of thermal injury. METHODS: Wild-type FVB mice (n=20) were anaesthetised, shaved and depilitated. Brass rods were heated to 100°C in a hot water bath before being applied to the dorsum of the mice for 10s, yielding a full-thickness injury. Following a 2-week recovery period, the mice underwent Doppler scanning before being fat/sham grafted with 1.5cc of human fat/saline. Half were sacrificed 4 weeks following grafting, and half were sacrificed 8 weeks following grafting. Both groups underwent repeat Doppler scanning immediately prior to sacrifice. Burn scar samples were taken following sacrifice at both time points for protein quantification, CD31 staining and Picrosirius red staining. RESULTS: Doppler scanning demonstrated significantly greater flux in fat-grafted animals than saline-grafted animals at 4 weeks (fat=305±15.77mV, saline=242±15.83mV; p=0.026). Enzyme-linked immunosorbent assay (ELISA) analysis in fat-grafted animals demonstrated significant increase in vasculogenic proteins at 4 weeks (vascular endothelial growth factor (VEGF): fat=74.3±4.39ngml(-1), saline=34.3±5.23ngml(-1); p=0.004) (stromal cell-derived factor-1 (SDF-1): fat=51.8±1.23ngml(-1), saline grafted=10.2±3.22ngml(-1); p<0.001) and significant decreases in fibrotic markers at 8 weeks (transforming growth factor-ß1(TGF-ß): saline=9.30±0.93, fat=4.63±0.38ngml(-1); p=0.002) (matrix metallopeptidase 9 (MMP9): saline=13.05±1.21ngml(-1), fat=6.83±1.39ngml(-1); p=0.010). CD31 staining demonstrated significantly up-regulated vascularity at 4 weeks in fat-grafted animals (fat=30.8±3.39 vessels per high power field (hpf), saline=20.0±0.91 vessels per high power field (hpf); p=0.029). Sirius red staining demonstrated significantly reduced scar index in fat-grafted animals at 8 weeks (fat=0.69±0.10, saline=2.03±0.53; p=0.046). CONCLUSIONS: Fat grafting resulted in more rapid revascularisation at the burn site as measured by laser Doppler flow, CD31 staining and chemical markers of angiogenesis. In turn, this resulted in decreased fibrosis as measured by Sirius red staining and chemical markers.

Dupuytren's disease in the Hispanic population: a 10-year retrospective review.

BACKGROUND: Dupuytren's disease is a common benign fibroproliferative disorder of the hand. Epidemiologic studies have reported significant variation in disease prevalence among races, focusing primarily on those of northern European descent. In contrast, Dupuytren's disease in the Hispanic population has received little attention. Thus, in this study, the authors aimed to determine the prevalence and operative rate of Dupuytren's disease in the Hispanic, black, white, Asian, Native American, and other races and to characterize the disease presentation in Hispanics who required surgical treatment. METHODS: A retrospective review was conducted to identify the racial distribution of Dupuytren's disease patients seen at Bellevue Hospital between July of 2000 and August of 2010. In Hispanic patients requiring surgical treatment for their disease, data were collected on the following parameters: age, sex, ethnicity, hand dominance, hand affected, and digits operated on. Epidemiologic factors including smoking, alcoholism, diabetes mellitus, hypercholesterolemia, epilepsy, and hypertension were also evaluated. RESULTS: Dupuytren's disease prevalence was found to be 533 per 100,000 in Hispanics. Of these patients, 1.8 percent required surgical treatment, and this group was characterized by the following comorbidities: smoking (57.1 percent), hypertension (57.1 percent), alcoholism (52.4 percent), diabetes mellitus (47.6 percent), and hypercholesterolemia (19.0 percent). CONCLUSIONS: The authors' results indicate that Dupuytren's disease is more prevalent in the Hispanic population than previously reported. Although the epidemiologic factors identified in Hispanics with Dupuytren's disease are similar to those in other races investigated, there are important differences with respect to clinical presentation and surgical treatment.

Therapeutic delivery of hydrogen sulfide for salvage of ischemic skeletal muscle after the onset of critical ischemia.

BACKGROUND: Recent evidence suggests that hydrogen sulfide is capable of mitigating the degree of cellular damage associated with ischemia-reperfusion injury (IRI). METHODS: This study evaluated the potential utility of hydrogen sulfide in preventing IRI in skeletal muscle by using in vitro (cultured myotubes subjected to sequential hypoxia and normoxia) and in vivo (mouse hind limb ischemia, followed by reperfusion) models to determine whether intravenous hydrogen sulfide delivered after the ischemic event had occurred (pharmacologic postconditioning) conferred protection against IRI. Injury score and apoptotic index were determined by analysis of specimens stained with hematoxylin and eosin and terminal deoxynucleotide transferase-mediated deoxy-uridine triphosphate nick-end labeling, respectively. RESULTS: In vitro, hydrogen sulfide reduced the apoptotic index after 1, 3, or 5 hours of hypoxia by as much as 75% (P = .002), 80% (P = .006), and 83% (P < .001), respectively. In vivo, hydrogen sulfide delivered after the onset of hind limb ischemia and before reperfusion resulted in protection against IRI-induced cellular changes, which was validated by significant decreases in the injury score and apoptotic index. The timing of hydrogen sulfide delivery was crucial: when delivered 20 minutes before reperfusion, hydrogen sulfide conferred significant cytoprotection (P < .001), but treatment 1 minute before reperfusion did not provide protection (P = NS). CONCLUSIONS: These findings confirm that hydrogen sulfide limits IRI-induced cellular damage in myotubes and skeletal muscle, even when delivered after the onset of ischemia in this murine model. These data suggest that when given in the appropriate dose and within the proper time frame, hydrogen sulfide may have significant therapeutic applications in multiple clinical scenarios.

Therapeutic metabolic inhibition: hydrogen sulfide significantly mitigates skeletal muscle ischemia reperfusion injury in vitro and in vivo.

BACKGROUND: Recent evidence suggests that hydrogen sulfide is capable of mitigating the degree of cellular damage associated with ischemia-reperfusion injury. The purpose of this study was to determine whether it is protective in skeletal muscle. METHODS: This study used both in vitro (cultured myotubes subjected to sequential anoxia and normoxia) and in vivo (mouse hind-limb ischemia followed by reperfusion) models in which hydrogen sulfide (0 to 1000 µM) was delivered before the onset of oxygen deficiency. Injury score and apoptotic index were determined by analysis of specimens stained with hematoxylin and eosin and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, respectively. RESULTS: In vitro, hydrogen sulfide reduced the apoptotic index by as much as 99 percent (p=0.001), with optimal protection conferred by raising intravascular hydrogen sulfide to 10 µM. In vivo, 10 µM hydrogen sulfide delivered before 3 hours of hind-limb ischemia followed by 3 hours of reperfusion resulted in protection against ischemia-reperfusion injury-induced cellular changes, as evidenced by significant decreases in injury score and apoptotic index (by as much as 91 percent; p=0.001). These findings were consistent at 4 weeks after injury and reperfusion. CONCLUSION: These findings confirm that the preischemic delivery of hydrogen sulfide limits ischemia-reperfusion injury-induced cellular damage in myotubes and skeletal muscle and suggests that, when given in the appropriate dose, this molecule may have significant therapeutic applications in multiple clinical scenarios.

Hydrogen sulfide attenuates intestinal ischemia-reperfusion injury when delivered in the post-ischemic period.

BACKGROUND AND AIM: To investigate whether pharmacologic post-conditioning of intestinal tissue with hydrogen sulfide (HS) protects against ischemia reperfusion injury (IRI). METHODS: In vitro, enterocytes were made hypoxic for 1, 2, or 3 h, treated with media containing between 0 and 100 µM HS 20 min prior to the end of the hypoxic period, then returned to normoxia for 3 h. An apoptotic index (AI) was determined for each time point and (HS). In vivo, jejunal ischemia was induced in male Sprague-Dawley rats for 1, 2, or 3 h; 20 min prior to the end of the ischemic period animals were given an intravenous injection of NaHS sufficient to raise the bloodstream concentration to 0, 10 µM, or 100 µM HS. This was followed by jejunal reperfusion for 3 h, histologic processing, and measurement of villus height. RESULTS: In vitro, there was a significant decrease in AI compared with non-HS-treated control at all time points after treatment with 10 µM HS, and at the 2 h time point with 100 µM HS (P < 0.017). In vivo, after 1 h ischemia, qualitative reduction of injury was noted with 10 µM and 100 µM; after 2 h ischemia, reduction was noted with 10 µM but not 100 µM; and after 3 h ischemia, there was no injury reduction. HS treatment resulted in significant quantitative preservation (P < 0.05) of villus height at all time points and doses, except for 3 h ischemia and delivery of 100 µM (P = 0.129). CONCLUSIONS: Hydrogen sulfide provides significant protection to intestinal tissues in vitro and in vivo when delivered after the onset of ischemia.

Development of an acellular bioengineered matrix with a dominant vascular pedicle.

BACKGROUND: This study assessed the feasibility of creating a tissue engineering platform by decellularization of fasciocutaneous tissue. MATERIALS AND METHODS: A fasciocutaneous flap based upon the superficial inferior epigastric artery was harvested from the abdominal wall of 8-wk-old male Sprague-Dawley rats. All cellular components were removed by sequential treatment with sodium azide, DNAse, and sodium deoxycholate. The degree of decellularization was qualitatively assessed by histology and quantitatively assessed by spectrophotometry. Persistence of relevant extracellular matrix proteins was shown following staining with orcein and hematoxylin. The duration of circuit patency was determined by continuous perfusion with a peristaltic perfusion pump. RESULTS: Gross and histologic examination demonstrated removal of cellular constituents with preservation of tissue matrix architecture, including macrochannels and microchannels. This was confirmed by the application of spectrophotometry to DNA isolates, which showed that the decellularized flap retained 4.04 ng/µL DNA, compared with the non-processed control, which retained 37.03 ng/µL DNA, and the acellular control, which was read as having 0.65 ng/µL DNA. The extracellular matrix of vessel walls was shown to remain intact. Peristaltic perfusion of the cannulated pedicle inflow channel with phosphate buffered saline at a rate of 200 µL/min confirmed circuit patency for 6 h. CONCLUSION: Fasciocutaneous flaps harvested with an intact vascular pedicle and associated tissue vascular network can be successfully decellularized and perfused ex vivo. This methodology, which is scalable to human size tissues, provides promise as a technique for the production of customizable engineered tissues.