A 63-year-old male with a 30-year history of urinary and fecal incontinence following a fall from height presented with a one-week history of rapidly progressing perianal symptoms. On October 1, he developed a high-grade fever (peak 39.1 °C), followed by the emergence of a painful, erythematous, and edematous perianal mass. Despite transient improvement with antibiotics at a local clinic, the mass expanded rapidly, exhibiting central liquefactive necrosis. By day 7, the erythema and swelling had disseminated to the buttocks, lower back, abdominal wall, and left lower extremity. The mass subsequently ruptured, discharging malodorous, grayish-black purulent exudate. Despite multiple consultations, the diagnosis remained elusive, and empiric penicillin therapy proved ineffective.

Upon transfer to our center on October 8, the patient was in a state of septic shock and altered mental status, presenting with delirium, chest tightness, and tachypnea. Vital signs revealed a blood pressure of 95/45 mmHg and a temperature of 36.6 °C. Physical examination demonstrated extensive erythema and swelling with palpable crepitus extending from the fourth lumbar vertebra superiorly to the left ankle inferiorly, including the buttocks and left inguinal region. A 2 × 2 cm necrotic area was noted at the 3–6 o’clock perianal position with active purulent drainage.

Laboratory investigations revealed a significant inflammatory response: C-reactive protein (CRP) 261.0 mg/L, white blood cell (WBC) count 12.8 × 10⁹ /L, and procalcitonin 5.120 ng/mL. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score was 7, indicating a high probability of necrotizing fasciitis. Computed tomography (CT) confirmed diffuse soft tissue swelling and pathognomonic gas-density lesions (emphysema) tracking through the gluteal subcutaneous tissues and extending along the fascial planes of the left hip, thigh, and calf (Figures 1A–D).

The patient underwent emergency debridement on the night of admission. Intraoperatively, extensive fascial necrosis and malodorous pus were observed tracking from the perianal region to the mid-calf. The wound was meticulously irrigated with hydrogen peroxide, normal saline, and povidone-iodine until viable tissue was reached. To facilitate eventual closure, healthy skin bridges were preserved between incisions, and rubber drains were placed (Figures 2A,B). Postoperative wound cultures confirmed Escherichia coli infection, and systemic antibiotic therapy was escalated to imipenem-cilastatin.

By postoperative day 3, however, clinical symptoms persisted, with continued malodorous drainage and crepitus. Repeat imaging and laboratory tests confirmed inadequate infection control. Consequently, a second debridement was performed on hospital day 4, immediately followed by the initiation of negative pressure wound therapy (NPWT). A vacuum-assisted closure (VAC) system was integrated with a bedside irrigation-suction setup, delivering 3,000 mL of normal saline daily through an irrigation tube placed deep within the wound (Figure 3A).

The patient's postoperative course remained stable, with inflammatory markers and metabolic parameters gradually normalizing. Negative pressure wound therapy (NPWT) was maintained through the third debridement on hospital day 9, at which point the wound beds exhibited complete clearance of necrotic debris and the emergence of healthy, exuberant granulation tissue. By the fourth procedure on day 11, the absence of residual necrotic tissue allowed for the initiation of wound reconstruction.

Owing to the efficacy of early source control, extensive skin loss was averted. The wound margins were meticulously debrided and primarily approximated under acceptable tension. Drains were positioned beneath each sutured incision, and NPWT was reapplied for an additional 48–72 h to facilitate continuous drainage and ensure optimal apposition of the wound surfaces.

The majority of the incisions achieved delayed primary closure. Areas with significant skin defects or excessive tension were managed as open wounds with daily dressing changes (Figure 3B). These residual sites, supported by the preserved healthy skin bridges, healed successfully via secondary intention without the need for skin grafting. Final wound closure was performed on day 17, and the NPWT system was discontinued on day 19. Following a period of progressive suture removal and mobilized rehabilitation, the patient regained full ambulation and was discharged on hospital day 37 (Figure 4). At the one-year postoperative follow-up, the wounds remained stable and well-healed, with lower-limb motor function restored to pre-morbid levels.

Standard techniques involving multiple small incisions and counter-drainage may suffice for localized infections. However, in cases where PNF tracks along deep fascial layers, these methods often leave “drainage blind spots,” predisposing the patient to refractory infection and sepsis. The extensive longitudinal debridement utilized in this case was designed to circumvent these issues. Its primary advantages are twofold: (1) it provides comprehensive exposure of the infected anatomy, facilitating meticulous debridement under direct visualization to minimize retained necrotic debris; and (2) it transforms a complex, infected space into an open, manageable wound bed. The surgical objective here shifts from merely “draining an abscess” to disrupting the anatomical pathways of infection and establishing a controllable wound environment.

The therapeutic efficacy of Negative Pressure Wound Therapy (NPWT) in managing PNF is well-documented (5–7). In the context of such fulminant infections, the therapeutic window is exceptionally narrow. Based on our clinical experience and a review of the literature, we propose that NPWT should be initiated immediately following the definitive diagnosis and the completion of the primary radical debridement. Early implementation facilitates rapid source control through continuous physical drainage, potentially circumscribing the infection's spread. This creates an optimal environment for subsequent interventions, potentially shortening the clinical course and mitigating patient morbidity.

However, the application of NPWT in the complex perineal region is frequently hampered by anatomical irregularities that complicate secure fixation and increase the risk of contamination. The success of this case was rooted in the systematic integration of NPWT following extended debridement. By utilizing the “clean” surgical foundation achieved through radical debridement, NPWT was able to effectively obliterate dead space and attenuate systemic toxin absorption.

Furthermore, the occlusive nature of the NPWT dressing served as a vital temporary barrier in an anatomically challenging zone, significantly decreasing the incidence of fecal contamination and markedly enhancing patient comfort (8). This integration establishes a synergistic model defined by “early radical debridement coupled with immediate NPWT support.” This dual-modality approach does more than merely accelerate granulation; it provides a stabilized local environment essential for definitive infection control. Our findings align with recent studies advocating for NPWT in the management of complex, infected abdominal and pelvic wounds (9).

The favorable outcome was supported by a multidisciplinary team (MDT) approach, integrating intensive care, targeted antimicrobial therapy, and optimized nutrition. A pivotal point of discussion in PNF management is the role of prophylactic fecal diversion via colostomy (10). We advocate for an individualized strategy. While a diverting stoma may be necessary for patients with extreme contamination risk or anatomical barriers to NPWT fixation, our case demonstrates a viable stoma-sparing alternative. Through the use of indwelling rectal tubes and a strict elemental diet, we achieved effective fecal diversion without the morbidity of a stoma or the need for secondary reversal surgery. This approach, however, requires high-level perioperative vigilance and meticulous nursing care.

This case suggests that for rapidly progressive and extensive PNF, the combination of thorough initial debridement and immediate NPWT application may be more decisive than traditional, staged conservative debridement. This integrated strategy facilitated rapid source control and mitigated the systemic inflammatory response, thereby significantly improving the patient's prognosis.

A notable observation in this case was that early containment of the infection limited the extent of skin and soft tissue necrosis. Furthermore, because necrotizing fasciitis primarily tracks along fascial planes, the underlying deep musculature remained viable. Consequently, the reconstruction phase did not require complex tissue transfers, such as fasciocutaneous flaps or muscle grafts. Instead, definitive closure was achieved through delayed primary suturing and direct approximation of the remaining healthy tissue—a result of the favorable wound environment created by the initial aggressive management.

Despite the successful outcome, several limitations must be acknowledged. First, as a single case report, this study lacks comparative data against established standard protocols; thus, the perceived superiority of this integrated approach requires validation through larger, prospective clinical trials. Second, the application of NPWT in the perineal and gluteal regions involves a specific technical learning curve and higher material costs, which may restrict its adoption in resource-limited clinical settings. Finally, while the one-year follow-up was positive, long-term outcomes regarding the quality of scar tissue and nuanced functional recovery warrant continued investigation.

For PNF patients presenting with more substantial dead spaces or massive tissue loss following debridement, more invasive reconstructive techniques—such as gracilis muscle flap interposition—have demonstrated potential in obliterating dead space and accelerating recovery (11). We advocate for an individualized treatment hierarchy based on the depth of the defect and the quality of the local tissue. The protocol of “radical debridement + early NPWT” presented here serves as a foundational framework. It stabilizes the patient and optimizes the local wound bed, providing clinicians with a “therapeutic bridge” to decide whether simple approximation is sufficient or if a transition to complex reconstructive procedures is necessitated.