Effectiveness of Fasciocutaneous Superomedial Thigh Flap in Reconstruction of Fournier Gangrene Defects

Fournier gangrene (FG) was first described as a clinical syndrome in 1883 by Jean Alfred Fournier, a French venereal disease specialist.¹ It is a rapidly progressing necrotising fasciitis that involves the skin and subcutaneous tissues in the perineum, anal region, and abdominal wall. The clinical situation is life-threatening and requires urgent treatment. FG is a type of obliterative endarteritis involving the vascular plexus of the skin. Involvement progresses very quickly and spreads to the skin in the genital and abdominal region. Though the mortality rate is 3 to 67% in recent years, the incidence is 1:7500 to 1:750000. Diseases such as herpes simplex, gonococcal balanitis, allergic vasculitis, warfarin necrosis, and erythema gangrenosum in this region should be considered as differential diagnosis.^2,3 Although a definite etiological cause has not been determined, alcoholism, atherosclerosis, peripheral artery disease, trauma, malnutrition, immunosuppression, HIV infection, and especially diabetes can be considered as risk factors.² Based on the existing risk factors, this disease begins with polymicrobial (aerobic and anaerobic bacteria) infection and microthrombi in the subcutaneous fascia and progresses rapidly as it spreads to large vessels.^2,4 Advanced age and low socioeconomic status are among other important risk factors.⁵ Although FG affects both sexes, the male-to-female ratio is 1:10, and it is most frequently seen in the 5th and 6th decades.³ It also rarely affects children.^3,4 The disease begins with pain, redness, softness in the tissue, and shine in the skin in the affected area. Black spots, named the Brodie sign, appear on the skin when inflammation starts.² The disease begins physiopathologically due to bacterial invasion in the region as a result of a simple rupture in the skin. After this process, there are nonspecific findings such as tenderness and swelling in the soft tissue in the lesion area. Then, depending on the decrease in cutaneous defense and oxygenation, the physiopathological process accelerates. In this period, rapid diagnosis and treatment gain importance.

Among the polymicrobial agents, E coli is the most common, followed by E faecalis.³ Other common agents include B fragilis, P aeruginosa, Candida species, Streptococcus, and Cytaphylococcus species.³ Infection follows a rapidly progressing clinical course that subsequently causes sepsis and death; therefore, early diagnosis and surgical debridement are important in FG treatment.⁶ Correction of fluid deficit, a broad-spectrum antibiotic treatment protocol, and intensive care conditions are other important points in the treatment, together with rapid surgical debridement.⁷ The aim of the treatment is to cover the exposed testicle, preserve testicular functions, and provide an acceptable aesthetic result.⁵

The superomedial thigh flap was first defined by Hirschowtiz. It is a workhorse flap and has safe arterial blood flow.⁸ The flap provides blood flow from the external pudendal artery, the anterior branch of the obturator artery, and the medial femoral circumflex artery.^8,9 It provides ease of use as the flap is well adapted to the region. Maturation of the exposed tissue after deduction and ensuring adequate granulation is as important as closing the defect. Vacuum-assisted closure (VAC) therapy has been used for years to provide granulation in the wound.¹⁰ VAC treatment provides positive gains in many ways by preventing secondary infection in the wound, providing new vessel formation, accelerating epithelization, and reducing pain and edema.^7,10 Because the general clinical condition of patients with FG is unstable, the reconstruction should be short-term and should be effective. One of the important factors for achieving effective results is granulation. With VAC treatment applied after debridement, granulation accelerates.¹⁰ This case series examines the effectiveness of reconstruction with quick application of a superomedial thigh flap combined with VAC treatment.

This study included 15 patients who underwent reconstruction with a superomedial thigh flap after FG debridement at a clinic between 2016 and 2020. This study was approved by the ethics committee (review number 2021/1747). The patients were aged 32–87 years (65 ± 17 years), and all of them were men. There were no pediatric patients. The patients included 7 with diabetes, 1 with rectal and prostate carcinoma, 1 with intracranial tumour, 1 with active HIV infection, 1 with congestive heart failure, and 4 with hypertension additional diseases. No additional diseases were detected in 5 patients. The patients were referred to the clinic for reconstruction of the tissue defect present in the skin after the first intervention and adequate debridement in the urology department. Wound follow-up was performed at the clinic after debridement and reconstruction. The patients were evaluated in 2 stages. The first is the clinical evaluation with hospital admission (Table 1), and the second is the evaluation of the surgical stages (Table 2).

FG Severity Index (FGSI) is a scoring method that predicts survival for patients admitted to the hospital due to Fournier gangrene. The calculation uses 9 parameters, which include body temperature, heart rate, respiratory rate, serum sodium level, serum potassium level, serum creatinine level, haematocrit, leukocyte count, and serum bicarbonate level (Table 3). Each parameter was higher or lower than the normal range and is scored between 0 and 4. A higher score indicates a lower chance of survival.¹¹

The sensory evaluation of the patients was determined by measuring touch, pain, and thermal sensation 3 months postoperatively as described in the literature.¹² The superficial sense of touch, pain, and heat were performed using cotton swabs, metal forceps, and warm (40 °C) and cold (0 °C) sticks. The evaluation was repeated 3 times in each distal of the flaps. Results were considered to be positive when both were the same in each flap. Treatment of comorbidities, stabilization of the patients, and postoperative classic dressing and VAC treatments were attempted to achieve wound granulation in patients with complete debridement. After sufficient granulation was provided, a superomedial thigh flap was applied to the patients. The granulation sufficiency was measured at follow-up after the first debridement, by observing the clinically viable appearance of the wound tissue during the dressings and VAC treatment, and by the assessment of the level of bleeding when irritating the wound with gauze. Debridement, dressing, and VAC treatment were continued in the nonliving tissue of patients and did not have widespread punctate bleeding foci on the tissue surface. Viable appearance and the presence of diffuse punctate bleeding foci on the tissue surface were considered as sufficient granulation tissue.

Surgical Technique

After determining the shape and size of the defect, a pinch test was performed in the flap donor area, and a flap design was made with the capacity to be closed primarily according to the elastic structure of the donor area. The important point in flap design is to maintain the distance between the pubic tubercle and the inguinal fold, and the inguinal fold should be planned in the middle of the pedicle as much as possible. Thus, a safe pedicle is more likely to be obtained (Figure 1). One edge of the flap is such that the defect is adjacent to the defect area. The first line (line 1) was determined from the middle of the defect to the vertical line of the thigh. The most distal point of the line should be the furthest point of the defect extending to the perineal area. As seen in Figure 2a, the length of line 1 should be approximately equal to the length of XY. The XY length shows the distance between the longest point of the defect, the inguinal fold, and the perineal region. The second line (line 2) is planned from the point at which line 1 ends to the inguinal line parallel to the defect. The length of line 2 can be extended to the inguinal fold, depending on the shape and size of the defect, as far as the pinch test allows, but it should not exceed the inguinal fold line. The angle between the 2 lines was 30 to 60° depending on the degree of the primary closure of the donor site (Figure 2). In cases where the single-sided flap size is insufficient, double-sided planning can be performed. After the plan was made, the flap was elevated from the distal side, and a safe dissection was made up to the inguinal fold where the major pedicle was present. After the flap was obtained, the donor site was closed primarily. After the hemovac and/or penrose drain was placed in the donor area and the defect area, the flap was adapted to its place with skin staples and/or appropriate sutures (Figure 2). The case duration was about 1 to 2 hours for this surgery, which contained a fast plan with easy dissection.

Statistical Evaluation

Data analysis of the patients is summarised as median (minimum–maximum). In the statistical analysis, the Kruskal-Wallis test and Spearman correlation coefficient were used where appropriate. Pairwise comparisons were made using the Conover test. In this study, in addition to basic comparisons, effect sizes were calculated to evaluate the effects of each parameter on postoperative sensory groups. Effect size was defined as the size of the difference between the groups. The general interpretation of the effect size in the literature was a small effect in values from 0.01 to 0.06, a medium effect from 0.06 to 0.14, and a large effect above 0.14. Differences were considered statistically significant at P < 0.05. IBM SPSS Statistics 25.0 was used in the analyses.

Statistical Results

Based on the correlation, there was a negative relationship between the debridement count and the drain time (ρ = -0.285) and the length of hospital stay (ρ = -0.455). In other words, an increase in the debridement count decreases the drain time and shortens the length of hospital stay. There is a negative relationship between the VAC session count and the duration of surgery (ρ = -0.384) and the drain time (ρ = -0.818). In other words, the more vacuums applied to the patients, the shorter the duration of surgery and the drain time. In addition, there was a positive relationship between the FGSI score and the length of hospital stay (ρ = 0.092), with higher FGSI scores showing longer length of hospital stay (Table 4).

The Kruskal-Wallis test results regarding parameters among postoperative sensory groups and the effect size estimates for each parameter are listed in Table 5. According to the results of the Kruskal-Wallis test in the postoperative sensory examination, a statistically significant difference was found between the 4 groups in terms of flap size (P = 0.01). When Table 5 is examined, the flap size area is higher in all 3 negative groups (193 [121-264]) than in all 3 positives (64 [54-100]). Therefore, the increase in flap size causes a decrease in the sensory ability of the flap. According to the effect size results, flap size had high effect size (effect size = 0.81). In other words, flap size affects the postoperative sensory groups at a high level. There was no statistical difference between the groups in terms of debridement count, VAC session count, duration of surgery, drain time, and FSGI score (P >0.05; Table 5).

Clinical Results

The patients who underwent reconstruction during the 4-year period were between the ages of 32–87 years (65 ± 17 years), and all were male. The first symptom was rash in 11 patients, swelling in 3 patients, and ecchymosis in 1 patient. Scrotal ultrasound showed air echogenicity in 12 patients, subcutaneous edema in 1 patient, fluid collection in 1 patient, and no findings in 1 patient. Broad-spectrum prophylactic antibiotic treatment was initiated from the moment of admission, and antibiotic treatment was arranged according to the wound culture results. Though no growth was detected in the wound cultures of 4 patients, Candida spp, Enterobacter spp, Citaphylococcus spp, Streptococcus spp, Acinetobacter baumannii, and especially E coli were grown from 11 patients. The FGSI scores of the patients varied from 0 to 13. In the third postoperative year, 1 patient died due to prostate carcinoma complications; in the first postoperative year, 1 patient died due to intracranial tumour complications. At the time of writing, 13 patients were still alive.

After the diagnosis was made, the patient underwent urgent surgery. All patients underwent debridement until the bleeding site was reached. Serial debridement was performed in patients who developed necrosis after the first debridement. Patients received 1-7 debridements. After the first debridement, patients underwent classic dressing twice daily for 5 days postoperatively. VAC therapy was subsequently initiated. Each VAC session was arranged for 3 days, and a gap of 2 days was left between each VAC session. Classic dressings were applied twice daily between the VAC sessions. Patients received 1-4 sessions of VAC. Between the VAC treatment sessions, serial debridements were applied to the tissues with necrosis until a haemorrhagic background was obtained, and VAC therapy was continued in patients with insufficient granulation. A superomedial thigh flap was used for reconstruction in patients with sufficient granulation. Scrotum skin defects were present in all patients. Skin defects in the scrotum that extended to the perineum were present in 8 patients, and 2 patients had a scrotal defect extending to the abdominal region. Defects extending to the abdominal area were primarily closed. Flap was applied to the defects extending to the scrotum and perineum. Bilateral flaps were applied to 3 of 15 patients, and a total of 18 flaps were created. Flaps were obtained in the fasciocutaneous plan. The smallest flap was 7 × 8 cm in area, and the largest was 15 × 10 cm in size. Colostomy was performed in 5 patients. Dead space in the wound was present in 8 patients. Drains of the patients were maintained between 3 and 10. The hospitalisation period of the patients was between 7 and 43 days. The operation time was between 1 to 2 hours. In 4 flaps, dehiscence developed in the wound lips and the wound was closed primarily with debridement. There was no flap necrosis. The flap donor areas were primarily closed. There were no other complications. The patients started to be mobilised on the third day.

Case Reports

Case 1

A 53-year-old man was admitted to the emergency room with swelling in the scrotal region. The patient had no known comorbidities. C-reactive protein (CRP), glucose, and creatinine levels were found to be high during emergency room evaluation. Air echogenicity was determined in skin on scrotal ultrasound. The patient's FGSI score was.⁷ After urgent debridement, 2 additional debridements were performed serially, and 2 sessions of VAC were administered. With the provision of adequate granulation with VAC treatment, bilateral superomedial thigh flaps of 10 × 10 cm (R) and 12 × 10 cm (L) was performed. The patient was discharged postoperatively without any complications (Figure 3).

Case 2

A 60-year-old man was admitted to the emergency room with redness and tenderness in the scrotal area. The patient had a known history of pneumonia and was positive for HIV. In the evaluation performed in the emergency department, CRP, creatinine, and white blood cell counts were high. The patient's lymphocyte count was low. Air echogenicity was detected in the scrotal skin on abdominal computed tomography (CT) of the patient. The patient's FGSI was 6. He subsequently underwent emergency debridement. After debridement of the patient, a single-session VAC was performed. Where sufficient granulation was achieved, a superomedial thigh flap of 7 × 8 cm was planned on the left side. No complications were observed at the time the patient was discharged (Figure 4).

Since its definition in 1883, FG, which is a disease that needs to be treated quickly, is a health problem that still maintains its importance today despite being understood in more detail. FG is a life-threatening disease that involves a rapidly progressing necrotising fasciitis in the urogenital, perineum, and lower abdomen. Diagnosis of the disease first comes from clinical examination. Laboratory evaluation and imaging methods (ultrasonography, CT, and MRI) are auxiliary methods.³ Ultrasound is the first imaging method to be applied quickly. The most common findings are edema and air echogenicity in the scrotum skin. In this case series, the observation of air echogenicities during ultrasound is among the most common findings. However, CT and MRI provide more specific findings.³ The pathophysiology of this disease is not fully understood. However, the obliterative endarteritis is observed with the disruption of the microcircular flow of the skin with the microthrombi and the enlargement of this condition by affecting the larger vessels. Meanwhile, the fast-progressing situation can be considered as a fulminant transformation with the addition of the infection on this impaired blood flow.³ Microcirculation of the skin and subcutaneous fascia are the most common causes of gastrointestinal system infections. Other common sources of infection are opportunistic infections caused by the genitourinary system and skin trauma in the region.² The factors causing infection are in the form of a combination of aerobic and anaerobic microbes. Because the blood flow of the testicles and spermatic cords is provided by different source vessels, they are mostly unaffected.¹³

In this case series, rashes were the most prominent finding. After the appearance of the first symptoms of FG, 2 phases have been defined in the process leading to the invasion phase: fulminant progression (necrosis phase) and tissue regeneration (spontaneous restoration phase).³ The treatment of this disease consists of 5 principles. These include early diagnosis and rapid debridement, initiation of prophylactic broad-spectrum antibiotics, appropriate fluid resuscitation, and effective nutritional support with serial surgical debridement if necessary.¹¹ Apart from this, the treatment of additional diseases of the patient and correction of the septic picture are important. Ensuring an appropriate fluid-electrolyte balance and necessary blood replacements are important.¹¹ In addition, the use of alpha recombinant protein kinase and intravenous immunoglobulin was also previously reported.¹¹ In this disease, which progresses to sepsis and requires intensive care conditions, the chance of survival of the patient is evaluated with FGSI scoring. Hatipoğlu et al¹⁴ stated that the FGSI score is related to the duration of ICU stay. In this study, patients with high FGSI stay in intensive care longer.Similarly, in this case series, there was a statistically positive correlation between the FGSI score and length of hospital stay.

Reconstruction of a patient whose condition has stabilised is an important problem encountered after treatment. The main purpose of reconstruction should be to provide good cosmetic results, to choose a method that does not affect testicular function, and to provide sufficient mobility to the testis. In addition, the closing process should be simple, and tissue similarity should be adequate.¹⁵ Although it is not the best and optimal solution for reconstruction, an algorithm can be followed according to the defect formed and the general condition of the patient. Chen et al⁶ created a treatment algorithm that could be followed in a case series of 31 patients.According to this algorithm, the strategy can be chosen according to the size of the defect, anal or abdominal extension, the presence of dead space, and the necessity of VAC treatment.

First, the most important factor in the success of the reconstruction treatment of patients with adequate surgical debridement is to obtain sufficient granulation.¹⁵ Classic dressing, Dakin's solution, potassium permanganate, enzymatic agents, raw honey, hyperbaric oxygen, growth hormone, and growth agents were used to provide granulation.^7,16 Another effective method for granulation is the VAC treatment.⁷ VAC therapy has been used for many years and has been shown to be effective for complex wound management and granulation.¹⁰ In a study conducted by Cuccia et al,¹⁷ significant improvement in patient management was achieved in the treatment of FG with hyperbaric oxygen combined with VAC treatment.In a study by Yanaral et al⁷ that compared classical dressing and VAC treatment, positive effects of VAC treatment on the wound, namely the number of classic dressings applied daily, decreased the need for narcotic analgesics, contributed to the rapid mobilisation of the patient, and increased the quality of life of the patient.Similarly, in the present case series, the increase in the number of VAC sessions was found to be negatively correlated with the duration of the operation and drain duration. In other words, as the number of VAC sessions increased, the duration of the operation was shortened by providing the planning of the flap directly and closing the wound without loss of time with the debridement of the dead tissues in the reconstructed operation because of the provision of sufficient granulation. In this case series, the operation time was between a minimum of 1 and a maximum of 2 hours. In addition, the postoperative drain time was reduced by VAC treatment. In this way, the drain was kept in the operation area for a shorter period, secondary wound infection was prevented, and the amount of discharge was reduced by preparing granulation ground with sufficient blood supply. In addition, in 8 patients with dead space, fusion of the tissues was more effective owing to the granulation in the pouch. In this way, the muscle flaps used to close the dead space were not required, and the defect was effectively closed without causing any secondary damage that would affect the muscle function in the patient.

Many methods have been used for reconstruction. Considering the reconstructive ladder, though secondary healing and primary closure can be applied in defects that are not large, skin grafts, local flaps, pedicled flaps, and free flaps can be used in larger defects. Each method has its own advantages and disadvantages. With granulation sufficient for reconstruction in patients with tissue defects, the first method of closure is skin grafts. Skin grafts are a method that has been used for many years and is still valid. Although the application is simple, the disadvantages of this method include the high risk of infection due to the proximity of the defect to the anal area, the risk of graft loss due to the moisture in the area, and the risk of exposed testicles with an insufficient tissue volume, turning the testicle into an organ that can be easily traumatised. Orchiectomy due to chronic pain resulting from graft closure has also been reported in the literature.¹⁵ The scrotal advancement flap is another simple method applied in patients who do not have much tissue loss. The point to be considered when performing the scrotal advancement flap is to move the advancement easily without tension. Other methods should be considered in closures that cause tension.¹⁵ In addition, poor skin quality and edema in the area have disadvantages in performing scrotal advancement.¹⁸ Local and pedicled flaps are the most used methods in FG reconstruction.

With the understanding of the vascular structure of the region and the perforator network continuing to improve, the variety and methods of flap in the region are increasing. The caudal thigh flap, superomedial thigh flap, medial circumflex femoral artery perforator flap, anterolateral thigh flap, gracilis flap, superficial circumflex iliac artery perforator flap, and other defined perforator flaps are commonly used flaps.^4,6,10,18-22 Closing the defect using foreskin as a flap has also been reported in the literature.²³ Also, it can be used to close defects in free flaps. However, it is not a preferred method because of the large variety of flaps mentioned earlier in the region, the technical difficulty of the free flap in this region, and the high risk of flap loss.²² Nevertheless, a case related to the use of free flaps has also been reported.²⁴

Perforator flaps and pedicled flaps have been used frequently in recent years. These methods have both advantages and disadvantages. Coşkunfırat et al¹⁸ and Hong et al²² have published case series on perforator flaps. Hong et al²² developed a perforator flap planning algorithm for the closure of large defects.However, the disadvantage of this method is the difficulty of dissection of the perforator flaps, the selection of the appropriate perforator, and the long operation time. Bilateral planning of the superomedial thigh flap in large defects eliminates this problem. In our case series, this problem was overcome with bilateral planning in 3 patients with more than 50% defects. Likewise, pedicled flaps such as anterolateral thigh flap, superficial circumflex iliac artery perforator flap, and gracilis create disadvantages due to the long operation time and difficulty in dissection. However, these flaps are advantageous in filling dead space with a large tissue volume. In 8 patients with dead space in this case series, granulation within the dead space was provided with effective VAC treatment, and effective treatment was provided without any complications with the effect of negative pressure and postoperative drains.

The superomedial thigh flap was first described by Hirschowtiz^8,9 in 1980, who used it to close tissue defects after perineal tumor excision. It has been used for many years as a useful and reliable flap for the closure of many defects in the perineal and inguinal regions. The flap receives blood flow from 3 sources. These are the external pudendal arteries, which provide major blood flow. Other vessels providing arterial blood flow are the anterior branch of the obturator artery and medial femoral circumflex artery.^8,9 In a cadaver study, Wang et al²⁵ stated that 3 rows of blood flow were provided to the thigh superomedial. He stated that the anterior row was provided by branches coming from the superficial femoral artery, the medial row with perforators coming from the gracilis and adductor longus muscles, and the posterior row with perforators coming from the gracilis and adductor magnus muscles. In this study, it was stated that the external pudendal artery, which is the dominant pedicle, received branches between the pubic tubercle and the ischial arm. Veins follow a course similar to that of the arteries.¹⁹ It provides sensation to the flap with branches coming from the ilioinguinal and genitofemoral nerves.¹³ Femoral and obturator nerves innervate the skin sensation of the distal part of the skin island in the flap plan area. Therefore, enlarging the flap distally will reduce the sensory ability in the flap. Similarly, as seen in the present study, the sensory ability decreases as the flap size increases. In the following years, this flap has been used safely for the closure of many defects in the region. There are case reports in which the superomedial thigh flap was used to close the FG defect.^9,19

Blood supply is provided from many sources, and rapid planning can occur. Furthermore, the operation time is short, the dissection is practical, and there is a lower possibility of pedicle injury during dissection. Additionally, the pedicle is less exposed to pressure, and the risk of circulatory disturbance is less. It is a flap with sensation, and the tissue in the same area is used. It has many advantages, including obtaining an aesthetically acceptable result. As seen in this case series, none of the patients experienced flap loss or even partial tissue loss. Complications occur in the form of wound dehiscence due to excess moisture in the skin in the area. This complication can be closed with local debridement and new suturing. Considering the general clinical condition of the patients with FG, these patients cannot tolerate excessive and long operations. With this flap, a rapid plan can be made and the operation can be completed in a short time without the need for long-term dissections such as microsurgery.

Based on clinical experience, this method is a quick and practical approach for the closure of the superomedial thigh flap FG defect when it is applied with VAC therapy to provide sufficient granulation and serial debridement required from the time of hospitalization. This case series can contribute to methods that will be more useful than other combined therapies.

The treatment and reconstruction of FG is challenging. Because the general clinical condition of patients with this disease is impaired, planning should provide fast and effective solutions. Considering the treatment principles of plastic surgery, the treatment should be effective with good tissue compatibility and no loss of function and should provide practical solutions for reconstruction. In this case series, we believe that the superomedial thigh flap combined with VAC treatment provided a fast and effective solution for the closure of the tissue defect after FG.

Future studies can be conducted for the development of more effective solutions by applying different combined therapies. The purpose of this study was to shed light on such methods and share the clinical experience in this case series.

Affiliations: ¹Department of Plastic Reconstructive and Aesthetic Surgery, İnönü University, Medical Faculty, Malatya, Turkey; ²Department of Biostatistics and Medical İnformatics, İnönü University, Medical Faculty, Malatya, Turkey;

Correspondence: Özcan Öcük, MD: ozcanocuk@gmail.com

Ethics: This study was approved by the ethics committee (review number 2021/1747).

Disclosures: The authors have no relevant financial or nonfinancial interests to disclose.