Local heating-induced cutaneous vasodilation in reinnervated and noninnervated deep inferior epigastric perforator flaps.

INTRODUCTION: Cutaneous vascular reactivity to local heating in free flaps has not been characterized. We aimed to assess local heating-induced cutaneous vasodilation in reinnervated and noninnervated deep inferior epigastric perforator (DIEP) flaps. METHODS: We conducted a cross-sectional study of 21 female patients with an uncomplicated unilateral delayed DIEP breast reconstruction at least 2 years after surgery. DIEP flaps and contralateral breasts were subjected to direct local heating, and skin blood flow was assessed using laser-Doppler flowmetry. To evaluate sensory-nerve-fiber function, touch perception thresholds were assessed using a 20-piece Touch-test™ Sensory Evaluator, and cutaneous warm detection and heat pain thresholds were measured using a TSA-II device. RESULTS: Of the participants, 10 had a reinnervated DIEP flap with a single coapted nerve (mean flap weight, 610 ± 296 g) and 11 had a noninnervated DIEP flap (mean flap weight, 613 ± 169 g). Mean age was 58 ± 11 years, mean follow-up time was 5 ± 1 years, and mean BMI was 24 ± 3 kg/m2 . DIEP flaps exhibited significantly weaker cutaneous vasodilation in response to local heating than contralateral breasts (median peak skin blood flow, 59 [25th-75th percentile, 36-71] a.u. for DIEP flaps versus 94 [74-141] a.u. for contralateral breasts; p < .001). The magnitude of the response was similar between reinnervated and noninnervated flaps (median peak skin blood flow, 55 [25th-75th percentile, 39-68] a.u. for reinnervated DIEP flaps versus 66 [36-77] a.u. for noninnervated DIEP flaps; p = .75). Of participants with reinnervated DIEP flaps, 90% perceived heat pain below the 50°C safety threshold, as compared to 36% of participants with noninnervated DIEP flaps (two-tailed p = .02). CONCLUSION: Our results suggest that free flap transfer causes longstanding impairment, yet not complete abolition, of both the sensory nerve-mediated and nitric oxide-dependent local heating-induced cutaneous vasodilatory systems. We found no statistical evidence that flap reinnervation improves the ability to raise skin blood flow in response to local heating.

The Effect of Negative-Pressure Wound Therapy with Instillation Compared to Current Standard Care on Wound Closure Time of Infected Wounds: A Systematic Review and Meta-Analysis.

BACKGROUND: Infected wounds extend healing time and are associated with higher treatment costs than noninfected wounds. Several observational studies indicate that negative-pressure wound therapy with instillation can effectively reduce bacterial bioburden and improve wound healing. Only a few randomized trials with small sample sizes have been published, and a meta-analysis directly comparing negative-pressure wound therapy with instillation to current standard care is lacking. It is therefore uncertain whether negative-pressure wound therapy with instillation actually improves wound healing. The authors performed a systematic review and hypothesized that negative-pressure wound therapy with instillation reduces wound closure time. METHODS: The PubMed, Embase, and CENTRAL databases were searched up to December of 2020 for English studies that compare negative-pressure wound therapy with instillation-to either negative-pressure wound therapy without instillation or to other types of wound care-for the treatment of acute or chronically infected wounds. Time to wound closure was analyzed using a random effects meta-analysis in predefined subgroups according to study design and comparative wound care. RESULTS: The authors identified 14 studies describing 1053 patients. Meta-analysis of three randomized trials shows no significant difference in time to wound closure between negative-pressure wound therapy with instillation and that without (mean difference, 0.48 day; 95 percent CI, -0.70 to 1.65; I ² = 0 percent). Data from eleven observational studies indicate that negative-pressure wound therapy with instillation reduces wound closure time (from 1.6 to 16.8 days; no pooled data). Because of imprecision and risk of bias, the available evidence provides only low-level certainty. CONCLUSIONS: There is currently insufficient evidence to support or discard the use of negative-pressure wound therapy with instillation for infected wounds. More randomized trials are needed to determine whether a beneficial effect can be substantiated.

A Systematic review and meta-analysis of sensate versus non-sensate flaps for the prevention of pressure ulcer recurrence among individuals with spinal cord disease.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: To identify, critically appraise, and synthesize research findings on non-sensate versus sensate flaps among individuals with spinal cord disease and pelvic pressure ulcers, with pressure ulcer recurrence as primary outcome. METHODS: PubMed, EMBASE, and Cochrane CENTRAL were screened for relevant studies. Data on surgical characteristics, ulcer recurrence, and sensory outcomes were retrieved and tabulated. Risk of bias was assessed with MINORS. The level of evidence was evaluated with GRADE. Meta-analysis was performed when possible. RESULTS: Meta-analysis of 1794 non-sensate locoregional reconstructions indicated a recurrence rate of 34% within several years (95% CI, 27-42). Twenty-one articles provided data on 75 sensate reconstructions, performed in 74 individuals. Meta-analysis of the sensate reconstructions indicated a recurrence rate of 1% (95% CI, 0-8). Sensate reconstructions were not associated with an increase of wound complications (19%; 95% CI, 7-40) compared with non-sensate ones (34%; 95% CI, 27-42). A very low level of evidence was determined with use of GRADE. CONCLUSION: Although of a very low-level, the present evidence suggests that restoration of sensory innervation may be an effective intervention for the prevention of pressure ulcer recurrence among individuals with spinal cord disease. A prospective RCT is needed to confirm or refute the results of this systematic review.

A systematic review evaluating the influence of incisional Negative Pressure Wound Therapy on scarring.

Pathological scars can result in functional impairment, disfigurement, a psychological burden, itch, and even chronic pain. We conducted a systematic review to investigate the influence of incisional Negative Pressure Wound Therapy (iNPWT) on scarring. PubMed, EMBASE and CINAHL were searched for preclinical and clinical comparative studies that investigated the influence of iNPWT on scarring-related outcomes. Individual studies were assessed using the OHAT Risk of Bias Rating Tool for Human and Animal studies. The body of evidence was rated using OHAT methodology. Six preclinical studies and nine clinical studies (377 patients) were identified. Preclinical studies suggested that iNPWT reduced lateral tension on incisions, increased wound strength, and reduced scar width upon histological assessment. Two clinical studies reported improved patient-reported scar satisfaction as measured with the PSAS (1 year after surgery), POSAS, and a VAS (both 42, 90, and 180 days after surgery). Five clinical studies reported improved observer-reported scar satisfaction as measured with the VSS, SBSES, OSAS, MSS, VAS, and POSAS (7, 15, 30, 42, 90, 180, and 365 days after surgery). Three clinical studies did not detect significant differences at any point in time (POSAS, VAS, and NRS). Because of imprecision concerns, a moderate level of evidence was identified using OHAT methodology. Preclinical as well as clinical evidence indicates a beneficial influence of iNPWT on scarring. Moderate level evidence indicates that iNPWT decreases scar width and improves patient and observer-reported scar satisfaction.

Meta-analysis, Meta-regression, and GRADE Assessment of Randomized and Nonrandomized Studies of Incisional Negative Pressure Wound Therapy Versus Control Dressings for the Prevention of Postoperative Wound Complications.

OBJECTIVE: The aim of this study was to evaluate the efficacy of iNPWT for the prevention of postoperative wound complications such as SSI. SUMMARY OF BACKGROUND DATA: The 2016 WHO recommendation on the use of iNPWT for the prevention of SSI is based on low-level evidence, and many trials have been published since. Preclinical evidence suggests that iNPWT may also prevent wound dehiscence, skin necrosis, seroma, and hematoma. METHODS: PubMed, EMBASE, CINAHL, and CENTRAL were searched for randomized and nonrandomized studies that compared iNPWT with control dressings. The evidence was assessed using the Cochrane Risk of Bias Tool, the Newcastle-Ottawa scale, and GRADE. Meta-analyses were performed using random-effects models. RESULTS: High level evidence indicated that iNPWT reduced SSI [28 RCTs, n = 4398, relative risk (RR) 0.61, 95% confidence interval [CI]: 0.49-0.76, P < 0.0001, I = 27%] with a number needed to treat of 19. Low level evidence indicated that iNPWT reduced wound dehiscence (16 RCTs, n = 3058, RR 0.78, 95% CI: 0.64-0.94). Very low-level evidence indicated that iNPWT also reduced skin necrosis (RR 0.49, 95% CI: 0.33-0.74), seroma (RR 0.43, 95% CI: 0.32-0.59), and length of stay (pooled mean difference -2.01, 95% CI: -2.99 to 1.14). CONCLUSIONS: High-level evidence indicates that incisional iNPWT reduces the risk of SSI with limited heterogeneity. Low to very low-level evidence indicates that iNPWT also reduces the risk of wound dehiscence, skin necrosis, and seroma.

A Systematic Review and Meta-Analysis of the Pressure-Induced Vasodilation Phenomenon and Its Role in the Pathophysiology of Ulcers.

BACKGROUND: Physiologic studies show that tissue perfusion increases during moderate amounts of tissue compression. This is attributed to sensory nerves initiating a vasodilatory cascade referred to as pressure-induced vasodilation. METHODS: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for studies investigating perfusion during pressure exposure longer than 10 minutes. Retrieved studies were assessed using the Office of Health Assessment and Translation Risk of Bias Rating Tool for Human and Animal Studies. Results were pooled with random effects models. The body of evidence was rated using the Office of Health Assessment and Translation approach. RESULTS: Twenty-nine articles were included, of which 19 articles were included in meta-analyses. The evidence indicates that moderate amounts of tissue compression have the capacity to increase perfusion in healthy humans by 46 percent (95 percent CI, 30 to 62 percent). Using the Office of Health Assessment and Translation approach, the authors found a high level of confidence in the body of evidence. Pressure-induced vasodilation blockade was associated with increased pressure ulcer formation. Pressure-induced vasodilation was impaired by neuropathy and by the drugs diclofenac and amiloride. CONCLUSIONS: This systematic review and meta-analysis indicates that healthy humans have the capacity to increase local perfusion in response to mechanical stress resulting from tissue compression. Because pressure-induced vasodilation is mediated by sensory nerves, pressure-induced vasodilation emphasizes the importance of sensory innervation for durable tissue integrity. Pressure-induced vasodilation impairment seems to provide a complementary explanation for the susceptibility of neuropathic tissues to pressure-induced lesions.

Incisional Negative Pressure Wound Therapy for Surgical Site Infection Prophylaxis in the Post-Antibiotic Era.

Background: With the prospect of antibiotic failure in the post-antibiotic era, strategies that prevent surgical site infection (SSI) are increasingly important. Current literature suggests that incisional Negative Pressure Wound Therapy (iNWPT) is a promising intervention. Methods: Based on published literature regarding iNPWT, its mechanisms of action, and clinical results, a narrative summary was built, including both the experimental as well as the clinical literature. Results: The experimental literature indicates that iNPWT provides a barrier against external contamination before re-epithelialization, increases blood flow and lymphatic clearance, and reduces edema. Meta-analyses of randomized studies indicate that iNWPT is effective in reducing SSI. We did not identify studies that assessed bacterial clearance during iNPWT in contaminated surgical sites, nor did we identify clinical studies that specified they omitted concomitant antibiotic prophylaxis. Conclusions: Moderate quality evidence indicates that iNWPT reduces SSI, although data without the concomitant use of antibiotic prophylaxis are lacking. The iNPWT is likely effective as a result of its barrier function and optimization of the surgical site micro-environment. For now, iNPWT is recommended for incorporation in SSI prevention bundles. The iNPWT as a substitute for antibiotic prophylaxis is not recommended currently. Further reduction of SSI by iNPWT will lessen the need for therapeutic use of antibiotic agents.

Documenting Combined Congenital Upper Limb Anomalies Using the Oberg, Manske, and Tonkin Classification: Implications for Epidemiological Research and Outcome Comparisons.

PURPOSE: Congenital upper limb anomalies (CULAs) exhibit a wide spectrum of phenotypic manifestations. To help the clinician evaluating this variety of CULAs, the Oberg, Manske, and Tonkin (OMT) classification was recently introduced. The OMT classification allows for documentation of combined hand anomalies. However, subsequent epidemiological and validation studies using the OMT scheme commonly registered only the main anomaly per arm. This study illustrates both the deficits of single diagnosis documentation as well as the merits of registering every anomaly for epidemiological research, outcome comparison, and overall applicability of the classification. METHODS: We retrospectively reviewed patients visiting the Erasmus MC - Sophia Children's Hospital between 2012 and 2014. All congenital anomalies of both limbs were classified according to the OMT scheme. The frequency of combined diagnoses as well as recurrent combinations were analyzed. The relation to the coregistered syndromes was studied. RESULTS: We included 746 patients, 79.5% of whom could be documented with a single OMT diagnosis. In 20.5%, a combination of OMT diagnoses was documented. We documented 149 different combinations: 102 were documented once, 47 were documented repeatedly (n = 196); for example, in patients with Greig syndrome. The prevalence of this syndrome was significantly higher in patients with a combination of radial polydactyly, ulnar polydactyly, and/or syndactyly (2.9% vs 33.3% and 60% in patients with 1 vs 2 and 3 diagnoses). CONCLUSIONS: Documentation of combined OMT diagnoses is required in a fifth of the patients. Not doing so will cause loss of phenotypic information and can hamper outcome comparison and epidemiological research. Documentation of combined OMT diagnoses can help to identify subgroups within a population, for example, patients with an underlying syndrome. Last, combined documentation of diagnoses improves flexibility of the classification and thereby better allows universal application. CLINICAL RELEVANCE: Consensus on the application of the OMT classification is critical to achieving the universal adoption of the system by hand surgeons and other medical professionals.