Decreasing complications of pectoralis major muscle flap reconstruction with two modalities of negative pressure wound therapy.

BACKGROUND AND OBJECTIVE: Deep sternal wound infection is a feared complication of open-heart surgery. Negative pressure wound therapy has gained an important role in the treatment of deep sternal wound infection. Incisional negative pressure wound therapy has been introduced as a method to prevent wound complications after sternotomy, and lately, after flap reconstructions in the treatment of deep sternal wound infection. We aimed to study if incisional negative pressure wound therapy with PICO™ had similar beneficial effect described earlier with competing commercial devices. METHODS: This study included 82 patients treated with pectoralis major muscle flap for deep sternal wound infection during the years 2006-2020. PICO group consisted of 24 patients treated with preoperative negative pressure wound therapy and postoperative incisional negative pressure wound therapy (PICO™). Two control groups included 48 patients with conventional treatment and 10 patients with preoperative negative pressure wound therapy only. RESULTS: In the PICO group, the complication rate declined from 50.0% to 33.30%, major complication rate from 29.2% to 12.5%, and need for an additional flap from 14.6.% to 4.2% when compared to conventional treatment. The length of hospital stay decreased as well. Preoperative negative pressure wound therapy alone was associated with moderate decline in the complication rates. In addition, we described the use of split pectoralis major muscle flap reconstruction in 57 patients. To our knowledge, this is the largest published patient series describing this method in the treatment of deep sternal wound infection. CONCLUSIONS: Incisional negative pressure wound therapy with PICO™ seems beneficial after flap reconstruction. Split pectoralis major muscle flap is a versatile reconstruction option suitable to be used as a workhorse in the treatment of deep sternal wound infection.

Does Incisional Negative Pressure Wound Therapy Prevent Sternal Wound Infections?

BACKGROUND: Incisional negative pressure wound therapy has been described as an effective method to prevent wound infections after open heart surgery in several publications. However, most studies have examined relatively small patient groups, only a few were randomized, and some have manufacturer-sponsorship. Most of the studies have utilized Prevena; there are only a few reports describing the PICO incisional negative pressure wound therapy system. METHODS: We conducted a prospective cohort study involving a propensity score-matched analysis to evaluate the effect of PICO incisional negative pressure wound therapy after coronary artery bypass grafting. A total of 180 high-risk patients with obesity or diabetes were included in the study group. The control group included 772 high-risk patients operated before the initiation of the study protocol. RESULTS: The rates of deep sternal wound infections in the PICO group and in the control group were 3.9 and 3.1%, respectively. The rates of superficial wound infections needing operative treatment were 3.1 and 0.8%, respectively. After propensity score matching with two groups of 174 patients, the incidence of both deep and superficial infections remained slightly elevated in the PICO group. None of the infections were due to technical difficulties or early interruption of the treatment. CONCLUSION: It seems that incisional negative pressure wound therapy with PICO is not effective in preventing wound infections after coronary artery bypass grafting. The main difference in this study compared with previous reports is the relatively low incidence of infections in our control group.

Negative pressure wound therapy in the treatment of deep sternal wound infections - a critical appraisal.

Introduction. Negative pressure wound therapy (NPWT) has widely become the first-line option in the treatment of deep sternal wound infections. After several positive reports in comparison with conventional treatment, very recent studies comparing NPWT with early reconstruction have favored the latter. Our aim was to evaluate the effectiveness and safety of NPWT in comparison with early flap reconstruction. Materials and methods. We concluded a retrospective analysis of 125 patients with deep sternal wound infection treated in a single institution between the years 2006 and 2018. NPWT became the first-line treatment in our hospital in 2011. The study group consisted of 55 patients treated primarily with NPWT with or without subsequent flap reconstruction. The control group consisted of 60 patients treated with flap reconstruction without prior NPWT. Ten patients with an immediate re-fixation and direct wound closure were excluded. Results. There were no significant differences between the two groups concerning the type or urgency of the original open-heart surgery, age, gender, or co-morbidities. In the NPWT group there was significantly higher mortality (p = .002), longer stay in the intensive care unit (p = .028), and in the university hospital (p < .001) as well as higher number of operations (p < .001). However, there were somewhat more surgical complications in the control group as well as a higher number of distant flap reconstructions. Overall, five patients suffered from NPWT associated bleeding. Conclusion. Our results raise concerns about the wide use of NPWT as a first-line treatment of deep sternal wound infections. Further evaluative studies are warranted to confirm the results.

Modified internal mammary artery perforator flap in treatment of sternal wound complications.

OBJECTIVES: There are multiple treatment strategies and flap options to cover defects after deep sternal wound infections and other similar sternal defects. The choice of flap is made according to surgeons' preferences and the size and location of the defect. Our aim is to introduce a new option to cover these kinds of defects with an internal mammary artery perforator flap combined with a pectoralis major muscle flap mostly raised with a muscle-sparing technique. DESIGN: We treated 13 patients with a sternal defect after cardiothoracic operations with this technique between 2010-2016. Ten patients had a deep sternal wound infection, two had an infection of the prosthesis after carotico-subclavian bypass and one had a fragmented sternum. Nine patients were treated with an internal mammary artery perforator fasciocutaneous flap with a muscle-sparing pectoralis major muscle flap and four patients with an internal mammary artery perforator fasciocutaneous flap combined with a right pectoralis major muscle flap. RESULTS: Three patients (23%) experienced major complications and four patients (31%) had conservatively treated minor complications. There were no flap losses. CONCLUSION: This combination of flaps is a suitable option for patients with large defects in whom direct skin closure is not possible. It can be utilized for defects comprising the entire vertical length of the sternum. These are local flaps with a short operation time and are therefore most suitable for patients with comorbidities in whom major surgery is not an option.

Cost-effectiveness Analysis of Silver Delivery Approaches in the Management of Partial-thickness Burns.

INTRODUCTION: Burn injury is a common type of traumatic injury that causes considerable morbidity and mortality, resulting in about 30,000 admissions annually in specialist burn centers and costing around $1 billion per year in the United States. One percent silver sulfadiazine has been utilized widely in the management of burns and newer silver dressings are on the market, including nanocrystalline silver dressings, silver-impregnated hydrofiber dressings, and silver-impregnated foam dressings. OBJECTIVE: This study sought to determine the cost effectiveness of the newer silver dressings using clinical data from an indirect treatment comparison using silver sulfadiazine as the baseline. MATERIALS AND METHODS: A decision analytic model was developed from a US payer's perspective for burn patients with a total body surface area of < 20%. Outcomes were length of stay, infections and incidence of surgical procedures, quality adjusted life years (QALYs), and cost. RESULTS: The meta-analysis reported a statistically significant reduction in length of hospital stay and clinically important reductions in infections and incidence of surgical procedures in favor of the silver barrier dressing compared with other silver dressings. The estimated QALYs were 0.970 versus 0.969 versus 0.969 and mean cost per patient was $15,892, $23,799, and $24,269 for the nanocrystalline silver dressing, silver-impregnated hydrofiber dressing, and silver-impregnated foam dressing, respectively. The analysis showed the nanocrystalline silver dressing to be a dominant strategy (less costly with better outcomes). These findings were robust to a range of sensitivity analyses. CONCLUSIONS: According to data from an indirect treatment comparison, this analysis suggests that nanocrystalline silver dressing is the most cost-effective silver delivery system. Prospective head-to-head research on the costs and outcomes of these silver delivery systems in this patient population is necessary to validate the results of this economic evaluation.

Silver delivery approaches in the management of partial thickness burns: A systematic review and indirect treatment comparison.

Silver-containing products play an important role in the management of burn wound infections. We sought to compare the efficacy of commonly used silver delivery approaches including nanocrystalline silver, silver-impregnated hydrofiber dressing, and silver-impregnated foam dressing as the main products in the management of partial thickness burns. A systematic review was performed by searching PubMed, EMBASE, Cochrane, and other databases to identify relevant randomized controlled trials and observational studies. Due to the paucity of direct head-to-head trials, an indirect treatment comparison was performed. The use of nanocrystalline silver was associated with a statistically significant reduction in length of stay when compared to silver-impregnated hydrofiber dressing (p = 0.027) and a shorter time to healing when compared to silver-impregnated foam dressing (p = 0.0328). There were no statistically significant differences in infection rates and surgical procedures between nanocrystalline silver, silver-impregnated hydrofiber dressing, and silver-impregnated foam dressing; however, nanocrystalline silver was found to be the most beneficial for all the outcomes, including infection rates and surgical procedures, according to the Monte Carlo simulation method. In conclusion, current evidence from the published literature suggests that where the clinical and microbiological priority is to get in control of infection quickly it would seem prudent to use the most potent silver delivery system, which is nanocrystalline silver. Nanocrystalline silver may offer both clinical and economic benefits compared to alternative treatments in the management of patients with mixed burns that are at high risk of infection.

A systematic review and meta-analysis of clinical outcomes associated with nanocrystalline silver use compared to alternative silver delivery systems in the management of superficial and deep partial thickness burns.

OBJECTIVE: The purpose of this systematic review and meta-analysis was to assess the clinical effectiveness of nanocrystalline silver compared to alternative silver delivery systems (silver sulphadiazine [SSD] and silver nitrate) in adults and children with superficial and deep partial thickness burns. METHODS: PubMed, EMBASE, Cochrane and other databases were searched to identify relevant randomised controlled trials and observational studies. RESULTS: Eight studies that assessed both nanocrystalline silver and SSD and one study that compared nanocrystalline silver vs. silver nitrate were identified. Nanocrystalline silver compared to SSD/silver nitrate was associated with a statistically significant reduction in infections (odds ratio [OR] 0.21, 95% CI 0.07-0.62, p=0.005), length of stay in hospital (mean difference -4.74 (95% CI -5.79 to -3.69, p=0.00001) and surgical procedures (OR 0.40, 95% CI 0.28-0.56, p=0.00001). Three studies that reported on pain had lower pain scores with nanocrystalline silver use than with SSD/silver nitrate; a high level of heterogeneity precluded pooling estimates. CONCLUSION: This comprehensive systematic review and meta-analysis of the available evidence suggest that the use of nanocrystalline silver dressings results in shorter length of stay in hospital, less pain, fewer surgical procedures and reduced infection rates compared to silver sulphadiazine/silver nitrate.

Sympathetic innervation does not contribute to glycerol release in ischemic flaps.

BACKGROUND: Extracellular glycerol as detected by microdialysis has been used as a surrogate marker for (ischemic) tissue damage and cellular membrane breakdown in the monitoring of free microvascular musculocutaneous flaps. One confounding factor for glycerol as a marker of ischemic cell damage is the effect of lipolysis and associated glycerol release as induced by sympathetic signalling alone. We hypothesized that extracellular glycerol concentrations in a microvascular flap with sympathetic innervation would be confounded by intact innervation per se as compared to denervated flap. Clinical relevance is related to the use of both free and pedicled flaps in reconstructive surgery. We tested the hypothesis in an experimental model of microvascular musculocutaneal flaps. METHODS: Twelve pigs were anesthetized and mechanically ventilated. Two identical rectus abdominis musculocutaneal flaps were raised for the investigation. In the A-flaps the adventitia of the artery and accompanying innervation was carefully stripped, while in the B-flaps it was left untouched. Flap ischemia was induced by clamping both vessels for 60 minutes. The ischemia was confirmed by measuring tissue oxygen pressure, while extracellular lactate to pyruvate ratio indicated the accompanying anaerobic metabolism locally. RESULTS: Intramuscular and subcutaneal extracellular glycerol concentrations were measured by microdialysate analyzer. Contrary to our hypothesis, glycerol concentrations were comparable between the two ischemia groups at 60 minutes (p = 0.089, T-test). CONCLUSIONS: In this experimental model of vascular flap ischemia, intact innervation of the flap did not confound ischemia detection by glycerol. Extrapolation of the results to clinical setting warrants further studies.

The effects of hypotension and norepinephrine on microvascular flap perfusion.

Microvascular flap surgery is a common technique in reconstructive surgery. The wide indications and variable patients provide challenge also for anesthesiologist. Both hypotension and hypoperfusion can be harmful to the flap. Hypotensive patients are treated with fluid resuscitation and vasopressors (e.g., norepinephrine), if needed. As vasoconstrictors, vasopressors might impair microvascular flap perfusion. In this experimental pig model we studied the effect of sevoflurane-induced hypotension on the perfusion of microvascular and superiorly pedicled rectus abdominis myocutaneous flaps. In addition, we evaluated the effect of norepinephrine on flap perfusion when it was used for correction of hypotension. Microdialysis (MD) was used to detect metabolic changes, as it is a sensitive method to detect early changes of tissue metabolism and ischemia in different tissue components of soft tissue flaps. The main finding of this study was that moderate degree of normovolemic hypotension or the use of norepinephrine for the correction of this hypotension did not affect flap perfusion as assessed by MD. More studies are clearly needed to confirm the safety of norepinephrine in clinical use in microsurgery.

Cost analysis of 109 microsurgical reconstructions and flap monitoring with microdialysis.

Few studies have examined the cost-effectiveness of microsurgery, and little is known about the cost-effectiveness of flap monitoring. We studied the costs related to microsurgery during 2004 to 2006 in Kuopio University Hospital. A total of 99 patients were reconstructed with 109 flaps. Primary success was achieved in 64% of cases. Reoperation for anastomosis was conducted in 25% and for other surgical complications in 27%. The intended result was achieved in 94% of cases. The mean total cost of hospital care was 20,000 euro in head and neck cancer surgery, 15,500 euro in defects of the lower extremities, and 9200 euro in breast reconstruction. The costs were greatly influenced by surgical complications (i.e., if the primary reconstruction failed, then the secondary microvascular flap almost doubled the expense involved; mean expenses per case 27,900 euro). Microdialysis was used in flap monitoring with an additional cost of 535 euro per patient. We found that microdialysis provided an early diagnosis of perfusion failure and helped to save the flap. It was estimated that if one or two flaps per year are saved due to more effective monitoring, then the extra costs of using microdialysis are covered.

Veno-venous extracorporeal membrane oxygenation in surgery for bronchial repair.

Single-lung ventilation using a double-lumen endobronchial tube is often performed for surgical procedures involving the thorax. Tracheobronchial rupture during use of an endobronchial tube is an uncommon and serious complication. We present the case of a patient undergoing a right pneumonectomy who experienced a bronchial rupture due to a double-lumen endobronchial tube. Institution of veno-venous extracorporeal membrane oxygenation allowed removal of the endobronchial tube, and the repair was successfully performed. We hope that this information can provide further insight into the management of such a complication.

Deep sedation with dexmedetomidine in a porcine model does not compromise the viability of free microvascular flap as depicted by microdialysis and tissue oxygen tension.

BACKGROUND: Deep sedation is often necessary after major reconstructive plastic surgery in the face and neck regions to prevent sudden spontaneous movements capable of inflicting mechanical injury to the transplanted musculocutaneous flap(s). An adequate positioning may help to optimize oxygenation and perfusion of the transplanted tissues. We hypothesized that dexmedetomidine, a central alpha2-agonist and otherwise potentially ideal postoperative sedative drug, may induce vasoconstriction in denervated flaps, and thus increase the risk of tissue deterioration. METHODS: Two symmetrical myocutaneous flaps were raised on each side of the upper abdomen in 12 anesthetized pigs. The sympathetic nerve fibers were stripped from the arteries in one of the flaps (denervated flap), while nerve fibers were kept untouched in the other (innervated flap). After simulation of ischemia and reperfusion periods, the animals were randomized to deep postoperative sedation with either propofol (n = 6) or dexmedetomidine (n = 6). Flap tissue metabolism was monitored by microdialysis and tissue-oxygen partial pressure. Glucose, lactate, and pyruvate concentrations were analyzed from the dialysate every 30 min for 4 h. RESULTS: Mean arterial blood pressure was higher in the dexmedetomidine group (P = 0.036). Flap tissue metabolism remained stable throughout the experiment as measured by lactate-pyruvate and lactate-glucose ratios (median ranges 14.3-24.5 for lactate-pyruvate and 0.3-0.6 for lactate-glucose) and by tissue-oxygen partial pressure, and no differences were found between groups. CONCLUSIONS: Our data suggest that dexmedetomidine, even if used for deep sedation, does not have deleterious effects on local perfusion or tissue metabolism in denervated musculocutaneous flaps.

Microdialysis detects postoperative perfusion failure in microvascular flaps.

In microvascular tissue transfers, it is essential postoperatively to follow-up on the perfusion of the transferred flap because of the risk of anastomotic failure. The diagnosis of pedicle obstruction is usually made by clinical observation, but some techniques have been reported as more reliable than clinical observation in detecting perfusion failure. The authors used microdialysis (MD), a method developed to assess in situ tissue metabolism, in the follow-up of 80 consecutive microvascular flaps from October, 2001 to October, 2003. Of the 78 flaps with postoperative data, 58 flaps were uneventful clinically and using MD, and served as the reference material for normal postoperative metabolism. Twenty flaps showed some abnormality in the clinical course or with MD. Of these, 13 flaps were reoperated for anastomosis thrombosis (9 arterial, 4 venous). All thromboses were clearly recognized by MD via a decrease in the glucose concentration in the tissue (< 2.7 mmol/l) and an increase in the lactate concentrations (> 5.7 mmol/l). In some cases, MD indicated a pathological trend in glucose and lactate concentrations hours before there were any clinical signs. A system of alarm levels was developed for the staff: when the limits were reached, a critical evaluation of the situation was undertaken, and the need for reoperation was considered. In the series, the salvage rate of all thrombosed flaps was 77 percent, with a final success rate in microvascular reconstruction of 95 percent. No flap was lost due to a delay in the diagnosis of secondary ischemia, if on-line MD monitoring was available. Microdialysis is a clinically feasible and sensitive monitoring method for all kinds of microvascular flaps, especially for those in which clinical observation is difficult or impossible. The performance of the analysis is easy and can be done by even less experienced nursing staff working in institutes with a low frequency of microsurgery.

Repair of right ventricular free wall defect with a de-epithelized pedicled myocutaneous latissimus dorsi muscle flap.

Rupture of the right ventricle may occur because of sternal dehiscence or mediastinitis after cardiac surgery. Direct suture, polytetrafluoroethylene patch, fasciae, and muscle flaps have been used to close a right ventricular rupture. A unique occurrence of repair of a full-thickness right ventricle defect with a de-epithelized myocutaneous flap is presented. Our patient experienced a rupture of the right ventricle complicating sternal wound infection. The rupture was reconstructed with a polytetrafluoroethylene patch, but the patch needed to be removed because of infection. The defect was reconstructed with a de-epithelized myocutaneous latissimus dorsi flap. The patient indicated no signs of complication during follow-up.