The biophysical characteristics of human composite flexor tendon allograft for upper extremity reconstruction.

INTRODUCTION: Devastating volar hand injuries with significant damage to the skin and soft tissues, pulley structures and fibro-osseous sheath, flexor tendons, and volar plates pose a major problem to the reconstructive hand surgeon. Despite advances in tendon handling, operative technique, and postoperative hand rehabilitation, patients who have undergone flexor tendon reconstruction are often plagued by chronic pain, stiffness, and decreased range of motion with resultant decreased ability to work and poor quality of life. In this article, we expand the technique of human composite flexor tendon allografts (CFTAs), pioneered by Dr E.E. Peacock, Jr, which consist of both the intrasynovial and extrasynovial flexor digitorum superficialis and flexor digitorum profundus tendons and their respective fibro-osseous sheath consisting of the digital pulley structures, periosteum, and volar plates procured from cadaveric donors with the use of modern tissue processing techniques. METHODS: Human cadaveric CFTAs were procured and divided into 2 groups-unprocessed CFTAs and processed CFTAs, which are cleansed and sterilized to a sterility assurance level of 10(-6). Physical length and width relationships as well as tensile strength and gliding resistance assessments were recorded pre-tissue and post-tissue processing. The histologic properties of the composite allografts were assessed before and after tissue processing. RESULTS: There was no significant difference with respect to physical properties of the composite allografts before or after tissue processing. The processed composite allografts demonstrated equivalent maximum load to failure and elastic modulus compared to unprocessed tendons. The gliding resistance of the composite tendon allografts was not significantly different between the 2 groups. CONCLUSIONS: The use of CFTAs addresses the issues of adhesion formation and lack of suitable donor material by providing a source of intrasynovial tendon in its unaltered fibro-osseous sheath without donor morbidity. This approach represents an important step toward designing an ideal material for complex flexor tendon reconstruction, which takes advantage of an intrasynovial flexor tendon in its native fibro-osseous sheath without the need for additional donor morbidity using a construct which can be engineered to have minimal tissue reactivity, negligible potential for disease transmission, and improved tendon healing properties versus standard tendon allograft.

Operative technique for human composite flexor tendon allograft procurement and engraftment.

Devastating volar hand injuries with significant damage to the pulley structures and fibro-osseous sheath, flexor tendons, and volar plates pose a major problem to the reconstructive hand surgeon. Despite advances in tendon handling, operative technique, and postoperative hand rehabilitation, patients who have undergone flexor tendon reconstruction are often plagued by chronic pain, stiffness, and decreased range of motion with resultant decreased ability to work and poor quality of life. Postoperative adhesion formation and lack of suitable donor material for tendon autograft are 2 fundamental problems that continue to challenge the hand surgeon. In 1967, Erle E. Peacock, Jr, described a technique of flexor tendon reconstruction using cadaveric composite flexor tendon allograft, which consisted of both the flexor digitorum profundus and superficialis tendons in their respective fibro-osseous sheaths consisting of the digital pulley structures and the underlying periosteum and volar plates. This technique never gained widespread acceptance due to concerns regarding tissue antigenicity, infectious disease transmission, and the rising popularity of the method of Hunter for silastic rod-based flexor tendon reconstruction initially described during the same period. With modern-day advances in tissue processing with acellularization and extensive donor screening for transmissible diseases, this technique should be revisited to address the reconstructive needs of patients with extensive volar soft tissue and tendon injury. Herein, we describe the operative technique of composite flexor tendon procurement and reconstruction with key modifications from the initial technique described by Peacock for improved composite construct elevation, soft tissue inset, and bony attachment.

The influence of absorbable subcuticular staples, continuous subcuticular absorbable suture, and percutaneous metal skin staples on infection in contaminated wounds.

Wound infection is a threatening, troublesome, and costly complication contributing to increased mortality and morbidity. The methods and materials used to close a wound significantly influence the quality of the repair process and the risk of surgical site infection. Six pigs were used to evaluate the influence of four separate skin-closure modalities on the potentiation of infection in contaminated wounds. Full-thickness skin wounds on the abdomen were contaminated with S. aureus and then closed with one of four devices: a novel absorbable staple (InsorbTM) placed in the subcuticular tissue; a braided absorbable suture (VicrylTM); a monofilament absorbable suture (MonocrylTM); percutaneous metal staples. Wound infection was assessed 7 days after closure by clinical signs and quantitative bacterial swabs. InsorbTM staples had significantly lower infection rates than continuous VicrylTM (39% vs. 100%, p=0.002) or MonocrylTM suture (39% vs. 89%, p=0.014). The InsorbTM subcuticular staple and the metal percutaneous skin staple were statistically equivalent in wound infection rate and parameters of inflammation. The combined data for both interrupted staple modalities documented less inflammation compared to the combined data for continuous sutures. These lower levels of inflammatory metrics were statistically significant for edema (p=0.018), gauze exudate observed (p=0.007) and purulent exudate in wound (p<0.0001). In conclusion, InsorbTM staples were shown to be an acceptable choice for the closure of contaminated wounds because they had a significantly lower incidence of wound infection and inflammation when compared to continuous intradermal suture.

Revolutionary advances in the management of traumatic wounds in the emergency department during the last 40 years: part I.

BACKGROUND AND OBJECTIVES: This report provides an overview of advances in wound repair devised by our research team during the last four decades. This collective review is presented in two parts. DISCUSSION: The following components are included in Part I: 1) search and treat life-threatening trauma; 2) conduct a thorough history; 3) examine the wound using aseptic technique; 4) anesthetize the wound before cleansing; 5) hair removal, skin disinfection, hemostasis, surgical debridement, and mechanical cleansing; 6) antibiotics, drains, and open wound management. CONCLUSION: On the basis of these comprehensive research studies, we have noted a marked reduction in the incidence of wound infection in traumatic wounds.

Revolutionary advances in the management of traumatic wounds in the emergency department during the last 40 years: part II.

BACKGROUND AND OBJECTIVES: During the last four decades, our research team has devised advances in wound repair that are highlighted in Part II of this collective review. DISCUSSION: There are several different methods to provide an accurate and secure approximation of the skin edges-sutures, tapes, staples, and tissue adhesives. Ideally, the selection of the wound closure technique will be based on the biologic interaction of the materials employed, tissue configuration, and biomechanical properties of the trauma wound. Selection of the appropriate wound dressing is another important consideration in the management of the trauma wound. CONCLUSION: On the basis of the comprehensive research and clinical studies, we have individualized the wound closure techniques for traumatic wounds so that healing can be achieved with more aesthetically pleasing scars.

Citizen's Petition to Food and Drug Administration to ban cornstarch powder on medical gloves: Maltese cross birefringence.

BACKGROUND: During the last 25 years, scientific experimental and clinical studies have documented the dangers of cornstarch powder on examination and surgical gloves because the cornstarch promotes wound infection, causes serious peritoneal adhesions and granulomatous peritonitis, and is a well-documented vector of the latex allergy epidemic in the world. Realizing the dangers of cornstarch on examination and surgical gloves, Germany's regulations of personal protective equipment banned the use of surgical glove powder cornstarch in 1997. In 2000, the Purchasing and Supply agency for the United Kingdom ceased to purchase any gloves lubricated with cornstarch. DISCUSSION: Realizing the dangers of cornstarch-powdered gloves, many hospitals and clinics in the United States have banned the use of cornstarch-powdered examination and surgical gloves. Hospitals that have banned cornstarch in their examination and surgical gloves have noted a marked reduction in the latex allergy epidemic in their facilities. Realizing the dangers of cornstarch-powdered examination and surgical gloves, Dr Sheila A. Murphey, branch chief, Infection Control Devices Branch, Division of Anesthesiology, General Hospital, Infection Control, and Dental Devices Office of Device Evaluation, Center for Devices and Radiological Health of the Food and Drug Administration (FDA), recommended that a Citizen's Petition be filed to the FDA to ban cornstarch on surgical and examination gloves. CONCLUSION: The 12 authors of this report have attached the enclosed petition to the FDA to ban the use of cornstarch on all synthetic and latex examination and surgical gloves used in the United States.

Effects of perivascular Botulinum Toxin-A application on vascular smooth muscle and flap viability in the rat.

Botulinum toxin-A (BTX) has become a widely used pharmacologic agent for esthetic surgeons and those who treat neuromuscular and gastrointestinal conditions. Until recently, there has been very little basic science research related to how this powerful agent may be useful when applied to vessels. The mechanism of action of this agent suggests that it may be useful in treating vasospastic conditions and ischemic tissues. We present data from experiments conducted to establish whether perivascular application of BTX decreases skin flap necrosis in an island pedicle skin flap in the rat. Using an ischemic ventral pedicled island cutaneous flap model, 30 adult Sprague-Dawley rats were divided into groups and treated with BTX, papaverine, or saline to the intact vascular pedicle to determine the percentage of tissue necrosis and ischemia. Flaps were elevated, and the pedicle treated with 1 of the 3 agents, and the flaps reinset. Analysis of the percentage of flap necrosis and areas of flap ischemia were evaluated on postoperative day 4. There were no differences in area of flap necrosis between BTX-, papaverine-, and saline-treated animal groups. There was a significant decrease in flap ischemia in the papaverine-treated group compared with both BTX and saline (P < 0.01). When necrotic and ischemic areas were combined, papaverine again showed a protective effect when compared with the BTX- and saline-treated groups (P < 0.04). In our ischemic pedicled island cutaneous flap model, papaverine showed the greatest protective effect against skin flap ischemia compared with BTX and saline. However, our data suggest that BTX may provide a protective effect after the first several days following flap elevation.

Dangers of cornstarch powder on medical gloves: seeking a solution.

This article reviews information on the hazards of cornstarch powder on medical gloves. Dusting powders were first applied to latex gloves to facilitate donning. After 1980, manufacturers devised innovative techniques without dusting powder. It has been well documented that these powders on gloves present a health hazard to patients and health care workers by 5 different mechanisms. First, the glove cornstarch has documented detrimental effects on wound closure techniques. Second, this powder potentiates wound infection. Third, cornstarch induces peritoneal adhesion formation and granulomatous peritonitis. Finally, these powders serve as carriers as latex allergen and they precipitate a life-threatening allergic reaction in sensitized patients. These well-documented hazards of glove powder have caused the United Kingdom and Germany to ban cornstarch powder on medical gloves over 10 years ago.

Topical poloxamer-188 improves blood flow following thermal injury in rat mesenteric microvasculature.

Microvascular changes of sludging and stasis are indications of thermal injury in tissue. This study investigates whether microvascular thermal injury can be decreased via topical application of poloxamer-188. Rat mesenteric microvessels were thermally injured and topically suffused with either Ringer's solution (control) or 5% poloxamer-188 in Ringer's solution (experiment). Blood flow was characterized in microvessels as normal or abnormal (ie, sludging and stasis). Topical treatment with poloxamer-188 reduced the percentage of capillaries with abnormal blood flow from 62% to 23%. In venules, this treatment resulted in a decrease from 54% to 34%. These results demonstrated that topically applied poloxamer-188 dramatically reduces the microvascular changes of sludging and stasis because of thermal injury in rat mesenteric microvessels.

Quantitation of bacteria in clean, nonhealing, chronic wounds.

 Quantitative swabs were obtained from 30 clean, chronic wounds on 30 different patients during one visit. The number of organisms and the predominant organism were determined. All samples were processed under both aerobic and anaerobic conditions. Nineteen (63%) of the 30 clean wounds had bacterial levels that were ≥ 105 cfu/cm2. There was no correlation between ≥ 105 cfu/cm2 and delayed wound healing. The most frequently isolated predominant organism was Staphylococcus aureus. In these clean, chronic wounds, an obligate anaerobic organism was identified as predominant or co-predominant in only 2 (6.7%) of 30 wounds.

Quantitation of the Postoperative Vascular Response in Four Dorsal Bipedicle Flaps in the Rat.

The rodent bipedicle flap has been used in numerous permutations as a model of ischemia and to generate a compromised tissue bed. In this study 24 rats were used to investigate skin perfusion over time along the length of 4 distinct bipedicle flap designs-2 oriented cranial-caudally and 2 transverse. Traditional rectangular flaps were evaluated as well as unique elliptical geometries designed to maximize the area of the resulting ischemic bed. Perfusion was assessed by scanning laser Doppler and intravascular dye penetration. In all models, an initially ischemic bed as measured by Doppler reestablished basal perfusion rates within 2-4 days and went on to produce a hyperemic bed with perfusion levels well above baseline. Reduced perfusion areas visualized by fluorescein dye penetration completely resolved in 55% of flaps within 2 days, and 68% within 4 days. This study underscores the difficulty in developing a representative model of chronic ischemia in young healthy rats as well as their remarkable ability to recover from acute surgical insults.

A Review on the Innovative Surgical Suture and Needle Evaluation and Selection Program.

This report describes an innovative suture and needle clinical evaluation program jointly designed by hospital representatives of Consorta, Inc., a healthcare resource management and group purchasing organization, and United States Surgical/Davis & Geck Sutures (USS/D&G), manufacturer of surgical biomaterials. Nineteen Consorta shareholder hospitals enrolled 699 surgeons to participate in Phase I of this nonexperimental observational study of the clinical performance of surgical needles and sutures. Performance characteristics of the sutures and needles produced by USS/D&G, which were evaluated in 3407 surgical procedures, included packaging and ease of opening, needle strength and sharpness, tissue drag, knot security, tensile strength, and clinically acceptable and unacceptable determinations. In these 30-day studies, the surgeons concluded that the needles and sutures were clinically acceptable in 98.1% of the evaluations. 6 e general, cardiothoracic, and orthopedic surgeons, who performed 73.8% of the product evaluations, reported that the suture and needle products were clinically acceptable in 97.2% of the evaluations. More than half (50.1%) of the evaluations involved the POLISORB* braided synthetic sutures, which received a clinically acceptable rating in 98.4% of the evaluation. The next most frequently used sutures were the SOFSILK*, followed by the monofilament nylon suture. SOFSILK* was found to be clinically acceptable in 98.7% of the evaluations, whereas the monofilament nylon was noted to be clinically acceptable in 96.3% of the evaluations. Surgical needles made by USS/D&G had a 97.9% clinical acceptability rating.

Advanced Imaging Techniques for Investigation of Acellular Dermal Matrix Biointegration.

BACKGROUND: Biointegration, a concept involving a dynamic interplay among three processes-inflammation, cellular infiltration, and angiogenesis-is key to understanding the interaction between acellular dermal matrices and the host. The current standard for evaluating acellular dermal matrix biointegration involves histologic analysis at fixed time points; however, the authors' approach uses advanced imaging techniques to serially assess biointegration in real time. METHODS: The authors have adapted two advanced imaging techniques-two-photon microscopy and photoacoustic microscopy-to investigate biointegration in a murine deepithelialized dorsal skin-fold window chamber model, specifically engineered to recapitulate the host microenvironment of acellular dermal matrix-assisted breast reconstruction. Four mice per group were assessed. Two-photon imaging of dual-transgenic mice allows for detection of fluorescently labeled perivascular cells, and macrophage lineage cells. Photoacoustic microscopy noninvasively assesses oxygen and hemoglobin concentration in living tissues, generating high-resolution, three-dimensional mapping of the nascent acellular dermal matrix-associated microvasculature and metabolic consumption of oxygen. These outcomes were corroborated by confirmatory histologic analysis at the terminal time point. RESULTS: The acellular dermal matrix/host interface is characterized by robust inflammation (0 to 3 days), increased oxygen consumption and neoangiogenesis in the matrix border zone (10 to 14 days), and vascular and inflammatory cell penetration into the center of the matrix (>21 days). CONCLUSION: The data broaden the core knowledge of acellular dermal matrix biology, and serve as a potential template for elucidating the key differences among various commercially available and developmental products to guide the reconstructive surgeon to better select a reconstructive adjunct that meets their specific needs.

Complement Activation and STAT4 Expression Are Associated with Early Inflammation in Diabetic Wounds.

Diabetic non-healing wounds are a major clinical problem. The mechanisms leading to poor wound healing in diabetes are multifactorial but unresolved inflammation may be a major contributing factor. The complement system (CS) is the most potent inflammatory cascade in humans and contributes to poor wound healing in animal models. Signal transducer and activator of transcription 4 (STAT4) is a transcription factor expressed in immune and adipose cells and contributes to upregulation of some inflammatory chemokines and cytokines. Persistent CS and STAT4 expression in diabetic wounds may thus contribute to chronic inflammation and delayed healing. The purpose of this study was to characterize CS and STAT4 in early diabetic wounds using db/db mice as a diabetic skin wound model. The CS was found to be activated early in the diabetic wounds as demonstrated by increased anaphylatoxin C5a in wound fluid and C3-fragment deposition by immunostaining. These changes were associated with a 76% increase in nucleated cells in the wounds of db/db mice vs. CONTROLS: The novel classical CS inhibitor, Peptide Inhibitor of Complement C1 (PIC1) reduced inflammation when added directly or saturated in an acellular skin scaffold, as reflected by reduced CS components and leukocyte infiltration. A significant increase in expression of STAT4 and the downstream macrophage chemokine CCL2 and its receptor CCR2 were also found in the early wounds of db/db mice compared to non-diabetic controls. These studies provide evidence for two new promising targets to reduce unresolved inflammation and to improve healing of diabetic skin wounds.

A revolutionary advance in skin closure compared to current methods.

Six pigs were used to evaluate the influence of three separate modalities on contaminated wounds. Full-thickness skin wounds on the abdomen were contaminated with 10(4) or 10(5) Staphylococcus aureus and then closed with one of three methods. The three closure modalities included (1) a new absorbable staple (Insorb) placed in the subcuticular tissue, (2) a braided Vicryl suture, and (3) percutaneous metal staples. Any foreign body material implanted in tissue increases the risk of infection at that site. Wound closure always involves the use of a foreign body. Historically, sutures have been the primary material used to close tissue. The newer synthetic sutures are significangly more biodegradable and cause less infection than sutures composed of protein, such as silk and catgut. Metal staples are also associated with a low risk of infection. Recently, Incisive Surgical, Inc. (Plymouth, Minnesota) has developed an absorbable polymer staple specifically for subcuticular skin closure. The purpose of this study was to compare the new Insorb staple to both an absorbable polymer suture and a metal staple. Wound infection was assessed 7 days after closure by clinical signs and quantitative bacterial swabs. The results demonstrated that wounds closed with Insorb staples had the lowest incidence (33%) of infection, followed by percutaneous metal staples (44%). All wounds (100%) closed with Vicryl suture became infected. The incidence of wound infection directly correlated with the level of quantitative bacterial count at analysis. The Insorb staple was associated with significantly reduced closure time, less inflammation and infection, and better aesthetic result compared to Vicryl. Compared to metal staples, the Insorb subcuticular staplers demonstrated comparable closure time without the need for later staple removal. In conclusion, the closure of contaminated wounds with the Insorb staples is a superior choice to Vicryl suture because they have a significantly (p = 0.009) lower incidence of infection. The Insorb staple is a revolutionary advance in subcuticular skin stapling.

Syneture stainless STEEL suture. A collective review of its performance in surgical wound closure.

Syneture (division of U.S. Surgical, division of Tyco Healthcare, Norwalk, Connecticut, USA) STEEL sutures are monofilament stainless steel sutures composed of 316L stainless steel conforming to ASTM Standard F138 grade 2 (" Stainless steel bar and wire for surgical implant"). STEEL sutures meet all requirements established by the United States Pharmacopeia (USP) for nonabsorbable surgical sutures. Steel sutures are for use in abdominal wound closure, intestinal anastomosis, hernia repair, sternal closure, and skin closure. They are attached to the following types of surgical needles: Roto-Grip Needles and SCC Needle. The sutures and needles are packaged in a Mylar/Tyvek outer envelope. The purposes of this clinical review are two fold. First, we will report the performance of the Syneture STEEL suture product in the largest studies of suture performance ever reported in the literature. In addition, we will provide comprehensive information from the surgical literature that highlights the unique benefits of stainless steel sutures for the following wound closure techniques: sternal fixation, abdominal wound repair, inguinal hernia repair, and skin wound closure. Consorta Inc. (Rolling Meadows, Illinois), a leading healthcare resource management group purchasing organization, and Syneture, jointly with a clinician task force, designed a reproducible surgical evaluation program for needles and sutures in a large cooperative of healthcare systems. Because of the subjective nature of the more commonly used suture selection techniques, a nonexperimental observational study approach was designed to replace perception of performance characteristics with actual clinical experience. In a report involving 19 Consorta shareholder hospitals, they discussed the preliminary part (Phase I) of a large nonexperimental observational study of the clinical performance of surgical needles and sutures. Performance characteristics of the sutures and needles produced by Syneture that were evaluated in 3407 surgical procedures included packaging/ease of opening, needle strength and sharpness, tissue drag, knot security, tensile strength, clinically acceptable determinations, and clinically unacceptable determinations. In this preliminary study, the surgeons concluded that the needles and sutures were clinically acceptable in 98.1% of the evaluations. Armed with this favorable experience, we wanted to expand this observational study to an entirely new group of shareholder hospitals that had a larger number of participating hospitals (Phase I, 19 hospitals; Phase II, 42 hospitals). This more than doubling of hospital observational base dramatically increased the number of patients and performance evaluations. In the Phase II expanded program involving 42 hospitals, the number of patients (8939) and the number of evaluations (25,545) were more than twofold the preliminary study. In the phase I multicentric evaluation of Syneture surgical sutures, the performance of 9266 sutures was evaluated. Of these performance evaluations, 130 evaluations focused on Syneture STEEL sutures. The surgeons were especially pleased by the performance of this suture product, with 129 Syneture STEEL products being judged as clinically acceptable in their performance. Only one Syneture STEEL suture was judged to be unacceptable in its performance, resulting in a 99.2% acceptability rating. In the expanded phase II evaluation of Syneture suture products, the performance evaluation involved 25,545 surgical suture evaluations. The performance of Syneture STEEL sutures was judged in 215 cases. Of these product performance evaluations, 207 were judged to be clinically acceptable in their performance (96.3%). It is important to emphasize that the phase I and phase II observational studies evaluated the performance of other sutures besides monofilament steel sutures. These comprehensive suture and needle performance evaluations included the following additional sutures: Plain Gut, Mild Chromic Gut, Chromic Gut, DEXON II, DEXON S, MAXON, BIOSYN, SOFSILK, SURGILON, BRALON, MONOSOF, DERMALON, SURGIDAC, POLY-SORB, TI.CRON, SURGIPRO, SURGIPRO II, NOVAFIL, VASCUFIL, and FLEXON. Finally, we provide a collective review of the literature that shows the reliable performance of monofilament stainless steel sutures in the following wound closure techniques: sternal fixation, abdominal wound closure, inguinal hernia repair, and skin wound closure.

Use of the PUSH tool to measure venous ulcer healing.

Currently, no instrument is available to provide an accurate and simple method of monitoring venous ulcer healing in clinical practice. The Pressure Ulcer Scale for Healing (PUSH) tool was developed and validated to monitor the healing of pressure ulcers. During a 2-month study involving 27 venous ulcer patients visiting a chronic wound clinic of a major university, the feasibility of using the PUSH tool to monitor healing was evaluated. The patients were assessed by two Wound Ostomy Continence Nurses using the PUSH tool, where 0 = healed and 17 = worst possible score. The mean score at the initial clinic visit was 12. One month and 2 months later, the mean scores were 9 and 8, respectively. Of the 27 participating patients, 23 had a decrease in their PUSH score over the 2-month period of the study; four of the 23 patients had PUSH scores of zero after 2 months because their venous ulcers had healed. One ulcer did not change and three ulcers worsened and their PUSH scores increased. Based on this study, the PUSH tool appears to be an effective way to monitor healing trends in venous ulcers as well as pressure ulcers.