Effects of pentoxifylline on experimental skin flap survival

We studied the effects of pentoxifylline on experimental skin flap survival in the domestic pig. Random skin flaps were designed using a length-width ratio of 5:1. The pigs were then given pentoxifylline (25 mg/kg/d) or placebo for seven days. Fluorescein sodium was used to help determine surviving skin flap length seven days postoperatively. Results showed no significant difference in mean surviving skin flap length between the study and control groups. We question the value of pentoxifylline in increasing skin flap survival.     

Laser Doppler velocimetry and fluorescein dye in the prediction of skin flap viability. A comparison

Laser Doppler velocimetry provides a quantitative and noninvasive measurement of cutaneous blood flow. Piglets were used to compare laser Doppler velocimetry and fluorescein with each other and as predictors of flap viability. Twenty-five random pattern rectangular skin flaps were studied with both techniques. Eighteen of the flaps were observed for two weeks and the length of viable flap documented. A reading of 100 mV on the laser Doppler corresponded with full fluorescence after dye injection. Both fluorescein and the laser Doppler underestimated flap surviving length slightly. Laser Doppler readings taken 24 hours postoperatively predicted the length of surviving flap exactly. The laser Doppler correlated well with fluorescein dye.     

Survival of myocutaneous flaps. Experimental evaluation by intra-arterial injection of a dye

Ninety-four myocutaneous island flaps of the pectoralis major were studied in the rabbit using sulfan blue (Disulphine-blue). In 13 cases, the dye was injected intra-arterially in the acromiothoracic artery before the flap was lifted, and 47 more were injected after the lifting of the flap. In 34 further cases, sulfan blue was injected intravenously once the flap had been lifted. In another 16 flaps, vascularization was studied by means of "diaphanization" (ie, making the tissue transparent or diaphenous in nature). In all groups, the surviving length of flap was observed to be greater than the stained length. Intra-arterial administration of sulfan blue was associated with reduced flap survival. Viable flap length was not related to the anatomy of the vascular base.     

The 'note flap'

A versatile local skin flap for the closure of facial defects is presented. A tangent is drawn to the edge of a circular defect parallel to the relaxed skin tension lines for a distance of 1.5 diameter (d); a second line of length d is drawn at 50 degrees to 60 degrees to the first to create a triangular flap. The final flap design when drawn resembles an eighth note. The tip of the flap is de-epithelialized to facilitate closure. Two opposing flaps can be used for a larger defect if desired. In a series of 20 consecutive patients, the mean length of the first side of the flap was 1.4d, the length of the second was 1.1d, and the mean tip angle was 50.3 degrees. The area of this average flap is approximately 75% of the area of the circular defect. Skin deformation measured on piglets showed the major tension vector to be perpendicular to the tangential side of the triangular flap.     

Retraction of skin flaps

Experiments on the pig and the human to measure retraction of skin flaps are described. Animal experiments show that it is dependent on the original length of the flap, and on the original length to breadth ratio for flaps perpendicular to the tension lines. The most important factor is the position of the flap relative to the tension lines. Flaps perpendicular to these lines do not retract and may indeed become longer, whereas flaps parallel to these lines retract by about 30%.     

Submental flap for reconstruction of anterior skull base,orbital, and high facial defects

Purpose

Large anterior skull base, orbital, and high facial defects can present a challenging reconstructive problem. Limited data exists in the literature on the use of a submental flap for reconstructing such defects. We aimed to describe the feasibility, success, and advantages of using variations of the submental flap for reconstruction of anterior skull base, orbital, and high facial defects.

Synergistic effects of pentoxifylline and hyperbaric oxygen on skin flaps

This study investigated the effects of pentoxifylline and hyperbaric oxygen (HBO) on experimental skin flaps in rats under four conditions. Sixty animals were randomly divided into one of four groups: (1) a control group, (2) a pentoxifylline- or (3) an HBO-treated group, and (4) a pentoxifylline- plus HBO-treated group. Cranially based skin flaps were elevated on the dorsum. The surviving length was evaluated with fluorescein dye seven days after the operation. Rats that were treated with pentoxifylline received 20 mg/kg intraperitoneally at 24, 12, and 1 hour(s) before flap elevation and every 12 hours after the operation for seven days. Rats that were treated with HBO received a total of 14 two-hour treatments at 2.5 absolute atmospheres in divided doses. Results indicated that the surviving length of flaps in the pentoxifylline- or HBO-treated groups was significantly greater than those in the control group, but were not significantly different from each other. Animals treated with both pentoxifylline and HBO had significantly greater flap survival than animals in any of the other three groups. This reflected a 30% to 39% improvement over pentoxifylline alone- or HBO alone-treated animals, and an 86% improvement over control animals. Mechanisms of action for this apparent synergistic effect on flap survival are discussed.     

The influence of intensive hyperbaric oxygen therapy on skin flap survival in a swine model.

Conflicting reports exist regarding the influence of hyperbaric oxygen therapy on random skin flap survival. The present investigation sought to demonstrate enhanced survival of experimental random skin flaps in swine using an intensive and tapering hyperbaric oxygen therapy regimen that would have direct application in human clinical trials. Random cutaneous flaps were surgically constructed on 12 domestic pigs. Flaps were designed to obtain a predictable length of necrosis. Six pigs did not undergo hyperbaric oxygen therapy and served as surgical controls. Six pigs were subjected to an intensive tapering hyperbaric regimen within 1.5 hours of completing the surgical procedure. Treatments were administered in a research hyperbaric vessel at a depth of 2.0 atm absolute (10 m of seawater) for 90 minutes of oxygen treatment in a tapering schedule over 6 days. This was structured to provide intensive therapy initially during the period of maximum tissue trauma and ischemia. Extent of flap necrosis was assessed by tracing clear plastic templates at necropsy, then converting to square centimeters using a computer digitizer tablet. The difference in flap necrosis between groups was significant, with random flaps subjected to hyperbaric oxygen therapy demonstrating a mean 35% less necrosis than surgical controls. Skin flaps treated with hyperbaric oxygen therapy demonstrated a mean survival of 77%, with a range of 56% to 100%. This reflected a 12% improvement in mean surviving area for hyperbaric oxygen therapy flaps over untreated surgical controls. We are unaware of similar studies reporting a comparable degree of enhancement in random skin flap survival using hyperbaric oxygen therapy alone. Adjunctive hyperbaric oxygen therapy in an intensive tapering schedule significantly improved flap survival in this model. Further investigations need to determine the optimum frequency of treatments and depth necessary to attain maximum tissue viability.     

Viability of skin flaps subjected to simultaneous chemical peel with occlusive taping

This study was undertaken to determine whether the application of a standardized chemical peel with an occlusive tape dressing to an acutely raised skin flap (as in combining rhytidectomy with chemical peel) affects skin flap viability. Thirty-six 4-cm x 4.cm dorsal skin flaps were raised on guinea pigs and sutured back into place. Eighteen of these flaps were simultaneously treated with a single application of Baker's solution and a 24-hour occlusive tape dressing. A mean of 3.1 cm² of the non-peeled flaps necrosed, compared with 6.3 cm² of the peeled flaps, a statistically significant increase in tissue loss in flaps that were simultaneously chemically peeled. We conclude that application of Baker's solution with an occlusive tape dressing to an acutely raised skin flap impairs skin flap viability and may result in skin flap necrosis.     

Pulmonary Atelectasis After Reconstruction With a Latissimus Dorsi Myocutaneous Flap

Atelectasis is the most common postoperative complication encountered in head and neck surgery. Risk factors include preexisting pulmonary disease, type of surgery performed, and the length of anesthetic. It is controversial whether reconstruction of defects with regional myogenous flaps predisposes to atelectasis. The latissimus dorsi myocutaneous flap requires the patient to be placed on his side for a period of time. Whether it is the position or the surgery that contributes to the development of atelectasis has not been examined. Eighteen patients underwent latissimus dorsi myocutaneous flap reconstruction following major ablative procedures for head and neck cancer. The cutaneous area transferred ranged from 70 to 225 cm² (mean, 128 cm²). The flap size ranged from 7 × 10 to 15 × 15 cm. The majority of flaps were 10 × 15 cm or greater. These patients were compared to 18 patients who did not undergo pedicled myocutaneous chest flap reconstruction. Patients were matched for age, sex, length of operation, site of primary, and stage of disease. Postoperative atelectasis was radiographically detected in 89% of flap patients vs. 79% of controls. Major atelectasis was encountered in 16% of patients undergoing flap surgery vs. 11% of patients in the control group. Patients with large cutaneous paddles on their flaps (>120 cm²) had significantly more atelectasis than patients with smaller cutaneous paddles (P<.05, chi-squared). The incidence of radiographic postoperative atelectasis in patients having a latissimus dorsi myocutaneous flap is high. The size of the skin paddle harvested as well as the position change may contribute to this.     

The Effects of Macrophages on the Survival of Random Skin Flaps in Swine

Tissue macrophages play a critical role in neovascularization by releasing angiogenic cytokines. Macrophages normally arrive into a wound bed 48 to 96 hours following an injury. ^1. Introducing macrophages into a wound bed at the time of closure would theoretically stimulate neovascularization in the traumatized tissue prior to what is normally observed. The ability to promote early angiogenesis could be an important factor in the survival of an extended skin flap. By taking advantage of advanced cell-sorting techniques, the authors developed the first study to evaluate the effect of placing a purified autologous macrophage population into an extended skin flap. We created 72 dorsally based random skin flaps in Yorkshire pigs; 48 of these wounds received autologous macrophages while 24 flaps served as controls. The macrophages were obtained by utilizing monoclonal antibodies in conjunction with flow cytometry. The skin flaps were evaluated on postoperative day 6 for their viability. Analysis of the data showed no statistically significant difference between the control and treatment flaps. There was, however, a trend of increased survival for flaps treated with macrophages. This is the first study to investigate using a purified population of cells to improve the survival of random skin flaps.     

The biomechanics of advancement and rotation flaps

An animal model (using piglets) has been developed to study the mechanical properties of simple advancement and rotation flaps. The effects of different length-width ratios and defect sizes on the tension required to close a rectangular advancement flap are described. Characteristic curves of force vs. advancement distance are presented and mechanisms discussed. The flaps should have a length-width ratio of at least 1:1; the mechanical advantage of lengthening the flap further is directly related to the measured closing tension. The distribution of tension in a standard 180° rotation flap is analyzed. Maximum tension is found between 90° and 135° (opposite the site of defect closure); this is at variance with the vector commonly pictured. The force required to close a defect with rotation flaps of varying length (45° to 180°) is measured. There is little mechanical benefit in extending the flap past 90°.     

Systemic neutrophil intrinsic 5-lipoxygenase activity and CD 18 receptor expression linked to reperfusion injury

Objective: To determine if systemic neutrophil intrinsic 5-lipoxygenase (5-LO) inhibition correlates with decreased expression of surface adhesion molecules and attenuation of ischemia-reperfusion (i/r) injury in guinea pig island skin flaps. Methods: Eighty-one adult female Hartley guinea pigs were divided into one control group, three 2-hour ischemia groups, and four 10-hour ischemia groups. Island dorsal skin flaps were developed (except in the control group), and 2 hours before reperfusion, zileutin (a 5-LO inhibitor) or vehicle was administered orally. Postreperfusion systemic neutrophil receptor expression, neutrophil flap infiltration, and flap survival were measured. Neutrophils from whole blood were analyzed for CD 18 containing surface receptor expression using monoclonal antibodies and cell associated fluorescence. Neutrophil infiltration into a distal centimeter squared of flap tissue was assessed using myeloperoxidase antibodies, and flap survival was determined within 7 days postoperatively. Results: Flaps in the treated 2? and 10-hour ischemic groups survived totally intact, while the untreated 10-hour ischemic flaps underwent total necrosis. A significant main effect of the drug was detected using analysis of variance (ANOVA) (P =.0001). Surface receptor detection and neutrophil infiltration were significantly increased in the untreated animals. Conclusions: Zileuton, a 5-LO inhibitor, reduces adhesion receptor expression on systemic neutrophils and attenuates i/r injury. Systemic neutrophil intrinsic 5-LO activity and CD18 receptor expression are linked to reperfusion injury and may be fundamental events in its pathogenesis.     

Effects of Activated Macrophages and Fibroblast Growth Factor on Random Skin Flap Survival in Swine

Objective: To examine the effect of application of activated autologous macrophages and basic fibro-blast growth factor (FGF) on random skin flap survival in swine. Design: A randomized nonblinded controlled trial. According to a standard design, six dorsally based, random-pattern skin flaps were raised in each of 12 Yorkshire pigs. Methods: Twenty-five milliliters of blood is harvested from each animal 20 to 24 hours prior to flap creation. Monocytes are isolated, placed in culture medium, and then activated by the addition of platelet-derived growth factor (PDGF) and tissue growth factor beta (TGF-β). Following an 18-hour incubation period, the monocytes are decanted and quantified, and their viability confirmed. These cells are then infused into the wound bed of the treatment flaps immediately following flap creation, and FGF is added prior to flap closure. The position of treatment and control flaps is systematically varied with regard to anterior-to-posterior and side-to-side flap positions within each animal. The area of superficial flap necrosis is evaluated on postoperative day 7, digitally scanned, and analyzed using graphics software. Control flaps are elevated similarly, but receive no placebo treatment. Results: Two-way analysis of variance (ANOVA) demonstrated nonsignificant differences between pig side and anterior, middle, and posterior flap positions within treatment and control flap groups. Using side and position pooled data, a one-way ANOVA showed no statistically significant differences between treatment and control flaps. Conclusions: The cellular and biochemical events following creation of a surgical wound are complex and incompletely understood. Our attempt to augment the natural role of the macrophage in wound healing by employing cytokines to activate these cells and to accelerate their arrival by implanting them into the wound bed failed to enhance flap survival. Further study is warranted to ascertain the details of wound healing, particularly with respect to cytokine concentrations and the timing of their roles, if we are to find a clinically applicable means of enhancing flap survival.     

Grundtechniken der Lappenbildung und ihre Anwendungsmöglichkeiten

Summary The different type of soft tissue defect in the face can be rehabilitated by means of classical local flaps, either by advancement, rotation or transposition. The excellent blood supply of the face permits to create a flap by its length which may extended up to 5 times of its diameter, and secondarily, may be turned up to an angle of 180 degree (median forehead flap).Typical donor areas besides the forehead are the nasolabial and submandibular area with the advantage of closure in correlation to the skin tension lines. By using a flap and transposing to the neighbourhood disfigurement of natural apertura, like mouth, nose and eyes, can be easily avoided. Typical smaller and larger defects are demonstrated on patients following excisional tumor surgery in the forehead, naso-frontal-orbital angle, at the nose, the naso-labial-buccal region. Different ways of flap rehabilitation are analyzed for the same or similar type of defect, which is followed by the surgical and functional end-result. Attention is paid to the W-plasty, whereby a rhomboid defect is created and which can be eliminated with additional W-type incision lines. The results are excellent.Combinations of different types of flaps are possible, when f.e. a total loss of the upper lip and a most subtotal loss of the nose is present.

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Erscheint ausführlich in Z. Laryngol. Rhinol. Otol.     

The Thirty Degree Transposition Flap

The rhomboid and other 60° transposition flaps have theoretical and practical disadvantages for many applications. A better flap for these is one having an angulation of 30° at its distal end. When this 30° flap is combined with the M-plasty, a versatile and cosmetically favorable repair is provided for many surface defects. In fact, over the years, it has become our most useful method of closure with flaps. Fundamentally, it allows sharing of tensions of closure better than does the rhomboid flap, produces less level disparities or protrusions than does any 60° flap, and its resulting scar length is only fractionally longer than that of the rhomboid flap. Rhomboid and other 60° angle flaps have been exceedingly valuable tools to many surgeons; the 30° flap combined with M-plasty should be significantly more useful.     

鼻翼恶性肿瘤切除并鼻唇沟带蒂皮瓣Ⅰ期修复11例疗效分析

目的:探讨鼻唇沟带蒂皮瓣在修复鼻翼恶性肿瘤术后缺损的临床实用性和可行性。方法:对11例鼻翼恶性肿瘤患者行手术切除肿瘤,并根据鼻唇沟面部血供特点及缺损区大小设计出需要修复区域的长度、角度和体积,设计鼻唇沟面部带蒂皮瓣。经鼻侧移至缺损区修复鼻翼缺损区。结果:所有患者术后伤口均Ⅰ期愈合,皮瓣全部成活,血液循环良好,色泽良好,供区无明显瘢痕。术后随访1～5年,肿瘤无复发,外鼻美容修复效果满意。结论:鼻唇沟带蒂皮瓣血运丰富,易成活,可提供足够的组织量用以修复较大面积鼻翼缺损,且血管蒂长,转移灵活,操作简便,供区无明显瘢痕。鼻唇沟带蒂皮瓣是修复鼻翼恶性肿瘤切除术后较大面积缺损的最佳皮瓣。     

Free flap combined with pectoralis major flap for reconstruction after total laryngopharyngectomy in patients with advanced hypopharyngeal carcinoma

Conclusion: The findings suggest that a pectoralis major flap combined with a free flap is a safe and reliable method of reconstruction after total pharyngolaryngectomy; with this technique, one can help these patients remain disease free, with normal swallowing function, for a relatively acceptable survival duration. Objectives: To determine the functional and oncological outcomes of a combined flap for the extensive defects after total pharyngolaryngectomy in patients with advanced squamous cell carcinoma of the hypopharynx (SCCHP). Method: This study determined the perioperative morbidity and functional and oncologic outcomes of 21 patients with advanced SCCHP who underwent total laryngopharyngectomy and reconstruction using a combination of a pectoralis major flap and a free flap. Results: The free flap and pectoralis major flap were used to reconstruct the defects for all 21 patients. Fourteen patients were reconstructed with jejunal free flaps and pectoralis major flaps; in the remaining seven patients, anterolateral thigh flaps and pectoralis major flaps were used. All the combined flaps worked well, and patients recovered normal swallowing function a mean 19.4 days after surgery. After an overall mean follow-up time of 31.3 months, 30% of patients were still alive at the time of this analysis, with no evidence of disease.     

Clinical implications of anterolateral thigh flap shrinkage

OBJECTIVE: To evaluate anterolateral thigh flap shrinkage after elevation and to develop a predictive model for flap design. METHOD: A prospective study was conducted in a university teaching hospital. The skin islands from anterolateral thigh flaps were outlined on a transparent sheet before and after the reconstruction procedure. Dimensions of the stretched flaps were also recorded. These three outlines were scanned and the surface areas computed and compared by tracing and use of AutoCAD. Age, sex, flap dimension, and flap thickness were investigated for association with flap shrinkage. RESULTS: Forty-five anterolateral thigh flaps harvested for head and neck soft tissue reconstruction after tumor resection were studied. Flap size ranged from 4 to 14 cm in width and 8 to 22 cm in length; flap area ranged from 30.6 to 151.0 cm. On average, the flaps shrunk by 25.0% (6.2%-52.6%), a highly significant change (P < .01). Flap width and thickness correlated with the reduction in flap size. The average stretched-flap area was 10.1% (0.4%-29.4%) less than the preflap area, a significant reduction (P < .01). The difference between stretched-flap and preflap areas was independent of all variables. We developed a predictive model using a stepwise multiple linear regression method with a coefficient of determination of 0.495. CONCLUSIONS: Anterolateral thigh flaps shrink after harvesting, and flap width and thickness are significant contributing variables. These findings indicate that flap size must take shrinkage into account to ensure sufficient coverage.     

Reconstruction of soft-tissue defects of the head and neck: radial forearm flap or anterolateral thigh flap?

This study compared the reliability, practicability and impact to donor site functionality of radial forearm (RF) and anterolateral thigh (ALT) flaps used for the reconstruction of head and neck soft-tissue defects. The clinical data of patients who underwent reconstruction using RF flaps (n = 53) and ALT flaps (n = 21) after tumour ablation were reviewed. Pedicle length, skin area harvested and flap survival rate were compared between the two flap types. A questionnaire was used to compare the patients’ perceptions of donor site functionality. Pedicle length did not significantly differ between RF and ALT flaps (7.5 vs. 9 cm, p = 0.733). A significantly larger mean area of skin was harvested in the ALT group than in the RF group (65 vs. 38 cm², p = 0.001). Flap survival rates did not differ between the two groups (p = 0.554). Patients in the ALT group were more satisfied with the appearance of the donor sites than were those in the RF group (p = 0.029). Significantly more patients in the RF group complained of donor site numbness than in the ALT group (p = 0.014). No ALT group patients complained of movement impairment or weakness at the donor sites, but 10% of RF group patients experienced impairment (p = 0.014) and 35% felt weakness (p = 0.001). The ALT and RF flaps showed similar practicability and reliability for the reconstruction of soft-tissue defects, but ALT flaps had fewer impacts to donor site functionality than RF flaps.