The Garg Classification and the Application of the TROPIS Procedure in the Management of Complex Anal Fistula
Lần đầu tiên được quan sát trùm Hậu môn trực tràng của BV mình mổ 1 ca rò hậu môn phức tạp mới thấy kinh ngạc, từ đánh giá MRI trước mổ cho đến định vị các đường rò trong mổ. Trước giờ mình chỉ biết phân loại Park và 1 số phương pháp mổ như cắt đường rò, mở đường rò, đặt seton, LIFT, dùng vạt nội mạc nhưng chưa nghe phân loại Garg và phẫu thuật TROPIS bao giờ. Tìm hiểu thử mới thấy đỉnh của chóp, phân loại Gard giúp phân định rò đơn giản và rò phức tạp, từ đó định hướng trường hợp nào có thể cắt/mở đường rò thông thường, trường hợp nào phải dùng TROPIS. Bài dưới đây sẽ cho mình biết được:
1. Đặc điểm chính giữa rò đơn giản (Garg I-II) và rò phức tạp (Garg III-V) về mặt giải phẫu và chiến lược phẫu thuật?
2. Cơ chế phẫu thuật TROPIS giúp bảo tồn cơ thắt ngoài so với fistulotomy?
3. Chống chỉ định của phẫu thuật TROPIS?
4. Tại sao tỷ lệ tiêu không tự chủ và các biến chứng khác ở TROPIS lại thấp hơn các phẫu thuật khác?
Garg Classification and Surgical Decision-Making
The Garg classification system provides a robust, anatomy-based framework for stratifying anal fistulas and is central to surgical decision-making, particularly in complex and recurrent cases. This classification divides fistulas into five grades based on the anatomical course of the tract and the proportion of external anal sphincter involved. Simple fistulas (Garg grades I and II) are defined as those involving less than 30% of the external sphincter and lacking complicating features, making them amenable to fistulotomy with minimal risk of incontinence. In contrast, complex fistulas (Garg grades III, IV, and V) are characterized by high transsphincteric tracts (involving more than 30% of the external sphincter), suprasphincteric, extrasphincteric, or horseshoe configurations, multiple tracts, supralevator extension, or association with complicating factors such as Crohn’s disease, prior radiation, malignancy, preexisting incontinence, or anterior location in women. Recurrent fistulas, defined as those that have failed previous surgical intervention, are also classified as complex due to altered anatomy and increased risk of sphincter injury and recurrence.[1-2]
The Garg classification has demonstrated superior accuracy in identifying which fistulas are truly amenable to fistulotomy. In a cohort of 650 patients, the Garg system correctly identified all 353 patients suitable for fistulotomy, whereas other systems misclassified up to 36% of these as complex, potentially leading to unnecessary use of sphincter-sparing procedures.[1] The American Society of Colon and Rectal Surgeons (ASCRS) guidelines define complex fistulas similarly, emphasizing that any fistula involving more than 30% of the external sphincter, with multiple tracts, supralevator or horseshoe extension, or associated with complicating factors, should be managed with sphincter-preserving techniques.[2] This classification is critical for guiding the choice of surgical approach, as conventional fistulotomy in complex or recurrent cases is associated with a high risk of postoperative incontinence (10–40%) and recurrence.[2-3]
Indications, Contraindications, and Patient Selection for TROPIS
The TROPIS (Transanal Opening of Intersphincteric Space) procedure is specifically indicated for patients with complex, recurrent anal fistulas as defined by the Garg classification and the ASCRS guidelines. The primary indications include high transsphincteric, suprasphincteric, extrasphincteric, horseshoe, or multiply recurrent fistulas, particularly those involving more than 30% of the external sphincter, with multiple tracts, supralevator extension, or associated abscesses.[4-7] In a prospective cohort of 325 patients undergoing TROPIS, 67.4% had recurrent fistulas, 82.8% had multiple tracts, 36.3% had horseshoe tracts, and 24% had supralevator extension, reflecting the complexity of cases for which TROPIS is most appropriate.[4]
Contraindications to TROPIS are well defined and include simple, low intersphincteric or low transsphincteric fistulas (involving less than 30% of the external sphincter), which are best managed with conventional fistulotomy or fistulectomy.[2][4-5] Absolute contraindications also include active proctitis or significant rectal mucosal disease, particularly in the context of Crohn’s disease, as healing rates are poor and recurrence is high in the presence of active inflammation.[8-10] Malignancy involving the fistula tract or adjacent tissues, uncontrolled systemic illness (such as poorly controlled diabetes or severe malnutrition), and inability to tolerate anesthesia are additional absolute contraindications.[2][4-5] Relative contraindications include previous pelvic radiation, poor baseline sphincter function, and pregnancy.[2][4-5][7]
Patient selection should be guided by detailed preoperative imaging, most commonly with pelvic MRI, to delineate the full extent of the fistula anatomy, identify all tracts and abscesses, and assess for complicating features.[4][7][11] Special populations, such as women with anterior fistulas and elderly patients, benefit from the sphincter-sparing nature of TROPIS, as these groups are at increased risk for postoperative incontinence with conventional approaches.[2][4][7] In patients with Crohn’s disease, TROPIS may be considered only in remission and in the absence of active proctitis, with multidisciplinary input and after adequate drainage of sepsis.[8-10]
TROPIS Surgical Technique and Technical Distinctions
The TROPIS procedure is a stepwise, sphincter-sparing surgical technique designed to eradicate sepsis in the intersphincteric space while preserving the external sphincter. The procedure begins with detailed preoperative planning using MRI to map the fistula anatomy and identify the internal opening and all secondary tracts.[4][6-7] Under regional or general anesthesia, with the patient in the lithotomy position, the internal opening is identified using a combination of imaging, probing, and direct visualization.[4][6] A transanal incision is made at the internal opening, extending through the mucosa and internal sphincter to enter the intersphincteric space. The incision is then extended laterally along the intersphincteric plane, deroofing the entire length of the intersphincteric tract and converting it into an open wound that communicates with the anal canal. The external sphincter is not divided at any point, preserving continence.[4][6-7]
All secondary tracts and abscesses are thoroughly curetted and cleaned via the external openings, using gentle probing and irrigation to ensure complete removal of infected tissue.[4][6-7] Meticulous hemostasis is achieved, and the wound is left open to heal by secondary intention, with no attempt to close the internal opening or the laid-open intersphincteric space.[4][6] Postoperative care includes regular wound care, sitz baths, and close monitoring for infection or delayed healing.[4][7]
TROPIS differs fundamentally from conventional drainage/incision procedures, such as simple incision and drainage or fistulotomy. Conventional approaches often do not address the intersphincteric space in its entirety, particularly in complex or high fistulas, and may leave behind residual sepsis that predisposes to recurrence.[4][6] Fistulotomy involves division of the fistula tract, which may include partial or complete division of the internal and external sphincters, especially in high or complex fistulas, resulting in a significant risk of postoperative incontinence.[2-4] TROPIS, by contrast, preserves the external sphincter and specifically targets the intersphincteric space, resulting in minimal or no deterioration in continence scores, even in patients with complex or recurrent disease.[4-7]
Technical modifications and adjuncts to TROPIS for highly complex or multiply recurrent cases include enhanced preoperative imaging (routine MRI, intraoperative ultrasound), aggressive curettage of all tracts, adjunctive seton placement for persistent infection, and repeat TROPIS for recurrence.[4-5][7] Marsupialization and topical agents may be considered in cases of delayed healing, although their role in TROPIS is not well established.[2][4][7] Integration with other sphincter-sparing techniques, such as LIFT or advancement flap, may be considered in select cases, but evidence for combined procedures is limited.[2][4-5]
Complications, Outcomes, and Postoperative Monitoring
Major, Rare, and Long-Term Complications
The TROPIS procedure is associated with a favorable complication profile, particularly regarding continence preservation and recurrence rates. In a meta-analysis of 499 patients, the one-time cure rate for TROPIS was 80%, with a recurrence rate of 20% after the first surgery and a final cure rate of 89% after reoperation.[5] In a prospective cohort of 325 patients, the initial healing rate was 78.4%, with an overall healing rate of 87.6% after repeat intervention.[4] Continence disturbance is minimal, with no statistically significant change in validated continence scores (mean preoperative 0.085 vs. postoperative 0.119, P = 0.38).[4] Similar findings were reported by Li et al., with preoperative and postoperative incontinence scores of 0.15 and 0.22, respectively (P = 0.16).[7] The risk of postoperative incontinence with TROPIS is less than 1%, compared to 10–40% with conventional fistulotomy in complex cases.[2-5][7]
Infection is rare after TROPIS, with most cases related to incomplete drainage or foreign body, and can be managed with seton placement and subsequent healing.[4][7] Delayed wound healing is uncommon and, when present, is typically attributable to persistent or recurrent fistula rather than primary wound complications.[4-5][7] Anal stenosis, chronic pain, and fistula transformation or malignancy have not been reported as significant issues in the largest published series or meta-analyses.[4-5][7] When complications do occur, they are usually related to persistent or recurrent disease and can often be managed with re-intervention or conservative measures.[4-5][7]
A summary table of major, rare, and long-term complications is provided below, highlighting the quantitative outcomes and safety profile of TROPIS in complex, recurrent anal fistulas.
Postoperative Monitoring and Follow-Up Protocols
Long-term follow-up after TROPIS requires a structured protocol integrating clinical assessment, functional evaluation, and imaging surveillance. Clinical visits are recommended at 2 weeks, 1 month, 3 months, 6 months, and annually thereafter, with thorough perianal examination at each visit to assess for wound healing, granulation tissue, persistent drainage, or signs of infection.[4][7] Continence should be objectively assessed using validated scoring systems (Wexner or Vaizey) at baseline, 1, 3, and 12 months, and annually thereafter.[2][4][7] Any new or worsening incontinence should prompt further evaluation, including anal manometry or endoanal ultrasound if indicated.[2][4][7]
MRI is the gold standard for postoperative imaging, with a baseline scan recommended at 12–16 weeks after surgery to confirm radiological healing.[12-13] Radiological healing on MRI correlates strongly with long-term clinical healing, and recurrence is rare in patients with complete radiological resolution.[12] If clinical healing is incomplete or symptoms persist, repeat MRI should be performed promptly to identify missed tracts or persistent sepsis.[13] In high-risk patients (multiple tracts, horseshoe configuration, supralevator extension, or prior recurrence), annual MRI may be considered for the first 2–3 years, although most recurrences occur within the first year.[4][12] Endoanal ultrasound is an alternative but less sensitive than MRI for complex anatomy.[11-12]
Comparative Effectiveness, Cost, and Quality of Life
Outcomes and Cost-Effectiveness Versus Conventional Surgery
TROPIS demonstrates superior outcomes compared to conventional drainage/incision procedures in patients with complex, recurrent anal fistulas. In a meta-analysis of 499 patients, the one-time cure rate for TROPIS was 80%, with a recurrence rate of 20% after the first surgery and a final cure rate of 89% after reoperation.[5] In a prospective cohort of 325 patients, the initial healing rate was 78.4%, with an overall healing rate of 87.6% after repeat intervention.[4] Continence disturbance is minimal, with no statistically significant change in validated continence scores (mean preoperative 0.085 vs. postoperative 0.119, P = 0.38).[4] Similar findings were reported by Li et al., with preoperative and postoperative incontinence scores of 0.15 and 0.22, respectively (P = 0.16).[7] The risk of postoperative incontinence with TROPIS is less than 1%, compared to 10–40% with conventional fistulotomy in complex cases.[2-5][7]
Conventional drainage/incision procedures, particularly fistulotomy and fistulectomy, have lower healing rates (69–81% in complex cases), higher recurrence rates (up to 41% after incision and drainage alone), and a substantial risk of postoperative incontinence (10–40% in complex cases).[2-3][14] The FISSIT study reported a healing rate of 69% for complex fistulas, with sphincter-cutting techniques achieving 81.1% and sphincter-sparing techniques 61.4%.[14] The American Society of Colon and Rectal Surgeons recommends sphincter-preserving procedures in patients at risk for sphincter dysfunction, underscoring the clinical value of TROPIS in this population.[2]
Cost-effectiveness analyses, while not yet widely published for TROPIS, can be inferred from the high cure rates, low recurrence, minimal incontinence, and rapid wound healing associated with the procedure.[4-5][7] Direct costs are limited to the initial procedure and routine postoperative care, with few reoperations or long-term complications. Indirect costs, such as lost productivity and long-term disability, are minimized by the rapid recovery and preservation of continence.[4-5][7] In contrast, conventional procedures are associated with higher direct and indirect costs due to increased rates of recurrence, incontinence, and need for reoperation.[2][14-16]
The following table summarizes the comparative outcomes and cost-effectiveness of TROPIS versus conventional drainage/incision procedures in complex, recurrent anal fistulas.
Quality of Life and Special Populations
Patient-reported quality of life after TROPIS is at least equivalent to, and likely superior to, other sphincter-sparing procedures such as LIFT and advancement flap. TROPIS achieves high healing rates, preserves continence, and is associated with rapid wound healing and minimal pain, all of which contribute to favorable quality of life outcomes.[4-5][7] LIFT also provides excellent quality of life, with validated improvements in FIQL and minimal continence disturbance.[17-19] Advancement flap, while effective, carries a higher risk of continence deterioration and pain, which may negatively impact quality of life, especially in patients with prior surgery or female sex.[20-22]
In special populations, such as patients with Crohn’s disease in remission, women with anterior fistulas, and elderly patients, TROPIS is preferred due to its sphincter-sparing nature and minimal impact on continence.[2][4][7-9] In Crohn’s disease, TROPIS should be reserved for patients in remission without active proctitis, and always in the context of multidisciplinary care and after adequate drainage of sepsis.[8-10] In women with anterior fistulas and in elderly patients, TROPIS is preferred over sphincter-cutting procedures due to its superior continence preservation and comparable healing rates.[2][4][7]
Conclusion
In summary, the TROPIS procedure is a highly effective, sphincter-sparing surgical option for the management of complex, recurrent anal fistulas as defined by the Garg classification. It is specifically indicated for high transsphincteric, suprasphincteric, extrasphincteric, horseshoe, or multiply recurrent fistulas, particularly those involving more than 30% of the external sphincter, with multiple tracts, supralevator extension, or associated abscesses. Contraindications include simple, low fistulas, active proctitis, malignancy, uncontrolled systemic illness, and inability to tolerate anesthesia. The TROPIS technique involves transanal deroofing of the intersphincteric space, thorough curettage of all tracts, and healing by secondary intention, with the external sphincter preserved.
TROPIS achieves high healing rates (80–90%), low recurrence (10–20% after first surgery), and minimal risk of postoperative incontinence (<1%), with rare complications and rapid wound healing. These outcomes are superior to those of conventional drainage/incision procedures, which are associated with higher recurrence, incontinence, and delayed healing in complex, recurrent cases. Cost-effectiveness is favorable for TROPIS due to reduced complications, reoperations, and disability. Patient-reported quality of life is preserved or improved after TROPIS, with outcomes at least equivalent to, and likely superior to, other sphincter-sparing procedures such as LIFT and advancement flap.
Long-term follow-up after TROPIS should include regular clinical assessment, objective continence scoring, and MRI surveillance at 12–16 weeks postoperatively to confirm radiological healing. Further imaging is indicated if symptoms recur or in high-risk patients. Continence should be monitored with validated scores at baseline and during follow-up. Technical modifications, such as enhanced imaging, aggressive curettage, adjunctive seton placement, and repeat TROPIS for recurrence, may further optimize outcomes in highly complex or multiply recurrent cases.
These recommendations are grounded in high-quality evidence from prospective studies, meta-analyses, and the clinical practice guidelines of the American Society of Colon and Rectal Surgeons and the American College of Gastroenterology.[2][4-5][7-9] The TROPIS procedure should be considered the first-line sphincter-sparing approach for complex, recurrent anal fistulas, with individualized patient selection and structured postoperative monitoring to ensure optimal outcomes.
