Laser Ablation of Fistula Tract: A Sphincter-Preserving Method for Treating Fistula-in-Ano

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1 ORIGINAL CONTRIBUTION Laser Ablation of Fistula Tract: A Sphincter-Preserving Method for Treating Fistula-in-Ano Ersin Öztürk, M.D., Ph.D. Barış Gülcü, M.D. Uludag University School of Medicine, Department of General Surgery, Bursa, Turkey BACKGROUND: Lasers are used to treat various types of diseases, including fistula-in-ano. Until recently, the lasers used for this procedure radiated linear energy. OBJECTIVE: To assess the short-term outcomes of patients undergoing ablation of fistula in-ano tract using a new laser that radiates circumferential energy. DESIGN & SETTING: This study was approved by the local ethics committee at our institution. A 15-watt laser probe emitting at a wavelength of 1470 nm and producing joules/cm of energy, was applied to 50 patients with fistula-in-ano under general anesthesia. Short-term outcomes, including success rate, complications, pain scores and time to return to normal daily activities, were evaluated. Success was defined as cessation of either the discharge or the patient s complaints. RESULTS: Thirty-seven male and 13 female patients with a median age of 41 years (range: years) were treated on an outpatient basis. Among these patients, 10 had inter-sphincteric fistulas, 34 had low transsphinteric fistulas and 6 had high transsphinteric fistulas. None of the patients required parenteral analgesics. The return to daily activities required a median of 7 days (range: 5 17 days). The median follow-up period was 12 months (range: 2 18 months). The success rate was 82%. Patients for whom the laser treatment was unsuccessful were later treated using traditional surgical methods. LIMITATIONS: The retrospective review of the data and the fact that substantial follow-up was done by phone Financial Disclosure: The first 20 laser probes used in this study were provided by Biolitec AG (Jena, Germany). Correspondence: E. Ozturk, Uludag University School of Medicine, Department of General Surgery, Gorukle 16069, Bursa, Turkey. drozturk@uludag.edu.tr Dis Colon Rectum 2014; 57: DOI: /DCR The ASCRS 2014 and not through physical examination are the main limiting factors in this study. CONCLUSION: Laser ablation of fistula tract is a safe, effective, sphincter-preserving therapy that can be successfully performed by surgeons. KEYWORDS: Laser; Fistula-in-ano; Ablation. Fistula-in-ano has always been a challenging condition for surgeons to treat. Superficial, intersphincteric or low transsphinteric fistulas may be treated using a simple lay open technique; however, sphincter-preserving methods would be better for transsphinteric fistulas that involve a significant proportion of the sphincter and for high transsphinteric fistulas. Damage to the anal sphincter while laying open the tracts of transsphinteric fistulas that involve a significant proportion of the sphincter or high transsphinteric fistulas can lead to fecal incontinence. Therefore, much effort has gone into developing sphincter-preserving techniques. However, no ideal technique has yet been identified. The idea of burning the fistula contents using a laser is not novel, though only limited data are currently available. In most earlier studies, the laser light was emitted linearly from the end of the probe. 1 3 In 2011, however, Wilhelm 4 reported successfully treating a small series of patients using a novel laser probe that emitted energy radially to achieve a maximal effect on the surrounding tissues. In the present study, we report our initial experience with a large series of patients who presented with various types of fistula-in-ano and who underwent laser ablation of the fistula tract (LAFT) achieved through application of a circumferential laser. PATIENTS AND METHODS This report is a retrospective analysis of prospectively recorded data. Each patient in this study was treated 360 Diseases of the Colon & Rectum Volume 57: 3 (2014)

2 Diseases of the Colon & Rectum Volume 57: 3 (2014) 361 Fig. 1. A, Schematic of the laser probe within a transsphincteric fistula tract (presented with permission of Biolitec AG, Germany). B, Laser probe passed through the fistula tract and internal opening. and personally followed by an individual surgeon. This study was approved by the local ethics committee of our institution. A probe [FiLaC (Biolitec AG, Jena, Germany)] housing a 15-watt laser emitting at a wavelength of 1,470 nm and an energy level of joule/cm was applied to patients with fistula-in-ano under general anesthesia after obtaining informed consent. This probe was a very thin, radial laser-emitting, flexible probe that could easily be inserted through the fistulas. The laser beams from the 2-cm tip produced heat energy that dissipated over a few millimeters, burning the contents of the fistula tract without harming the surrounding muscle fibers of the sphincters (Figs. 1 and 2). In the first phase of the study, 20 consecutive unselected patients participated. During this phase, all patients who were admitted to our department with fistulain-ano and who did not have a history of prior surgical treatment for fistula-in-ano were included in the study. Patients with a history of surgical treatment for fistulain-ano or a proven history of inflammatory bowel disease were excluded. Because this method was novel, we gained experience during this phase of the study. Throughout this learning period, an abscess of any size was identified as the main obstacle to a successful ablation of the tract. During the second phase of the study, therefore, patients were selected after undergoing pelvic magnetic resonance imaging (MRI) to exclude those with abscesses prior to the surgery. An abscess of any size associated with the fistula was accepted as a contraindication for LAFT. Additionally, patients were informed that the procedure should be considered as an examination under general anesthesia and that LAFT would not be performed if undrained sepsis was identified. In those cases, a loose nylon seton was placed, and LAFT was delayed for 3 4 weeks. We then reassessed the relation of the fistula tract to the sphincters and performed another MRI analysis. During the second phase, patients paid 500 Euros to be treated with the laser probe, and the generator was provided by the company on a patient-by-patient basis. The hospital expenses totaled 1,000 Euros for each patient. In addition to use of the laser probe, we learned to curette the fistula tract with a thin plastic cytology brush, which provided a definitive curettage without enlarging the tract (Fig. 3). We also found that applying laser energy at the aforementioned dose to each 1 cm of the tract for 6 seconds yielded the maximal effect. Laser Application Technique For this procedure, the fistula tract was first identified and the external and internal openings were revealed, after which the tract was curetted using the aforementioned cytology brush. The laser probe was then passed through the external opening, along the fistula tract and through the internal opening. Next, the probe was pulled back until the tip of the probe was a few millimeters beyond the internal opening. Energy was then applied as the laser probe was withdrawn through the external opening at a speed of 1 cm/6 seconds. During the application of the energy, letting the laser probe pass spontaneously through the fistula tract as it sealed the tract yielded the desired withdrawal speed. A gentle withdrawal of the probe for a few centimeters and then pushing it again towards the inner opening was sufficient to remove any dead space in the tract. After every 3 shots, the laser probe was removed and cleaned with hydrogen peroxide-soaked gauze to prevent charcoaling of the probe s tip. Energy application was stopped when the tip of the probe was a few millimeters beyond the external opening. No sutures were placed at the internal or external openings, and no dressings or topical medications were used. Patients were discharged on the day of the surgery or the following day, after which they were followed up on a

3 362 ÖZTÜRK and GÜLCÜ ET AL: LASER ABLATION OF FISTULA TRACT TABLE 1. Summary of the results Variable Result Median age, years (range) 41 (23 83) Male/female 37/13 Types of fistulas Intersphincteric 10 Transsphincteric 34 High transsphincteric 6 Median energy consumption, joules 1,176 (320 6,843) (range) Intersphincteric 705 (320 1,780) Transsphincteric 1,190 (720 3,450) High transsphincteric 2,360 (1,174 6,843) Median number of days required to 3 (2 22) return to normal activities (range) Median follow-up, months (range) 12 (2 18) Success rate (%) 41/50 (82%) Fig. 2. Ex vivo studies demonstrating the limited penetration depth of the 1,470-nm diode laser within muscle tissue (presented with permission of Biolitec AG, Germany). regular basis. For patients who returned to our clinic in person, routine patient interviews and examinations were performed at 3-week intervals. For patients who were unable to return, phone interviews were held. The primary endpoint was cessation of either discharge through the fistula tract or the patients complaints. For patients who returned to the clinic, the scar tissue at the former outer opening was also accepted as part of the healing. In this report, the demographics of the patients, the types of fistulas (determined using Park s classification), 5 the amount of energy used to seal the tracts and the patient follow-ups are presented. Fig. 3. Plastic brush used for curettage of the fistula tract. RESULTS All patients were discharged after uneventful hospitalizations of one or 2 days. No patients required opiates. All the patients were able to drive or fly home on the day after the procedure. No additional medications were administered, except to patients in whom pus was identified during curettage of the tract. These patients received oral antibiotics for an additional week. Patient demographics and the LAFT data on the patients are presented in Table 1. The median age of the patients was 41 years, and approximately 75% of the patients were male. The majority of patients had transsphinteric fistulas. The energy required for ablation increased as the fistulas became higher and deeper. The median follow-up period was 12 months (range: 2 18 months). Among the 50 patients followed up, 12 (24%) were interviewed at the clinic, and the others were interviewed by phone. The LAFT failed to close the fistula tract in 7 of the 50 patients. In addition, two patients experienced anal fistulas at different locations than those treated with LAFT (one patient after 3 months, one patient after 5 months). Of the patients whose fistula tracts failed to close, 5 were among the 20 unselected cases treated in the first phase of the study. The 2 patients who experienced anal fistulas at different locations were also from that group. The remaining 2 patients were from the second phase, and they developed anal abscesses 2 weeks after the LAFT, even though the preoperative MRI showed no related abscess. Their procedures were classified as failures. Among the patients with unsuccessful LAFT procedures, one had a high transsphinteric fistula, 4 had transsphinteric fistulas and 2 had intersphincteric fistulas. The overall success rate with LAFT was 82%. The rate of persistent fistula was 25% (5/20) in the first phase and

4 Diseases of the Colon & Rectum Volume 57: 3 (2014) % (2/30) in the second phase. When LAFT failed, the failure usually occurred during the first one or 2 weeks after surgery. No recurrence at the original fistula site occurred during the follow-up period. The loose seton technique was used for the patients with failed LAFT. After 3 4 weeks, they underwent surgery for definitive treatment. The patient with high transsphinteric fistula underwent a mucosal advancement flap. The remaining 8 patients underwent fistulotomy. All of these patients were then relieved of their symptoms. DISCUSSION Anal fistula repair is a challenging undertaking, with up to 30% of fistulas persisting postrepair. 4 The simple lay open technique is an effective and efficient method for treating fistula-in-ano; however, it sacrifices part of the anal sphincter. And because anal fistulas tend to persist or reoccur, repeated sphincter assaults can lead to incontinence. Therefore, sphincter-preserving methods for the repair of fistula-in-ano have always been a critical topic for surgeons. Various types of lasers, plugs and other sophisticated procedures have been studied. 1 3,5 Among these techniques, laser treatment is an especially promising approach due to its easy application, minimal safety issues and practicality. Previous laser ablation attempts had major limitations. Ellison et al. 1 used an ND:YAG laser to treat perianal fistulas in dogs and reported a success rate of 80% with one laser treatment and 95% with more than one laser treatment. Later, in 1998, Bodzin 2 used CO 2 laser ablation of complex fistulas in patients with Crohn s disease. Although there were only 7 patients in the study, 4 showed complete recovery, and the remaining 3 showed improvement of their symptoms. Subsequently, the same group reported on 27 patients, and a fine clinical response was described. 3 The reported use of a laser to ablate perianal fistulas is limited to those 3 studies, and it is noteworthy that the laser probes used in those studies radiated energy linearly, which limited the probes utility. This is because the fistula tract is a cylindrical tunnel, and the linear energy produced by the laser probes had minimal circumferential effects. On the other hand, newer laser probes produce radial energy, which maximizes the circumferential heating. In addition, the effect occurs over only a few millimeters (Fig. 2), which minimizes the collateral damage to the surrounding sphincter muscle fibers. Heat produced from the laser probe denatures proteins in the surrounding tissue. Following cessation of the laser application, the melted proteins refold, sealing the tract. It is thus the protein refolding that ablates the fistula tract. 4 A few important considerations and recommendations are as follows. First, hemoglobin is the ideal protein for sealing the tract. We therefore recommend using a thin plastic sterile brush to curette the fistula tract immediately before LAFT. This curettage cleans out the infected content of the fistula tract and causes blood to accumulate within the tract. Second, the laser should be applied just inside the inner opening, and the application should be ceased just before the tip reaches the surface of the external opening. A successful application can be easily recognized by palpating the thickened fistula tract just after LAFT. Based on our experience with LAFT, this technique may be more effective for fistulas that primarily involve a significant amount of external anal sphincter. During the initial phase of the study, all patients with (or believed to have) crypto-glandular-originated anal abscess underwent LAFT. By the end of this phase, we realized that any form of associated anal abscess was the main obstacle to success with LAFT. Therefore, during the second phase of the study, we selected patients for LAFT. All patients who had an anal fistula underwent an MRI, and those without detectable abscesses, without a previous history of fistula surgery, and without inflammatory bowel disease were accepted as suitable candidates for LAFT. The rate of persistent fistula fell dramatically after the selection criteria were implemented (from 25% to 6.6%). LAFT can be performed as an outpatient procedure. Our patients were under laryngeal mask anesthesia during the LAFT procedure, but this technique could be performed with regional or local anesthesia. In contrast to the conventional procedures, the patients were able to return to normal daily activities and work 2 or 3 days after the operation, and pain was not a problem. The only complaint was of a serous discharge that sometimes contained minimal amounts of blood or black charcoal-like particles, which seeped through the external opening. This discharge usually resolved within 3 to 4 weeks and did not cause discomfort or interfere with the patients normal daily lives. When LAFT was unsuccessful, the fistulas widened slightly, and failure was apparent within the first one or 2 weeks. However, the failure of LAFT neither prevented conventional methods from working nor worsened the symptoms. Because this procedure does not damage the anal sphincter, its failure delays the healing process but is not accompanied by any complications. On its own, LAFT is an efficient procedure for most patients with uncomplicated fistula-in-ano. It can also be used as one component of a treatment regimen for complex cases. It has no known or proven complications, and we identified no complications in the present study. The retrospective review of the data and the fact that substantial follow-up was done by phone and not

5 364 ÖZTÜRK and GÜLCÜ ET AL: LASER ABLATION OF FISTULA TRACT through physical examination are the main limiting factors in this study. In conclusion, LAFT is a promising, minimally invasive, sphincter-preserving technique for the treatment of fistula-in-ano. It is an efficient procedure that can heal the fistulas in most patients with simple fistulas. REFERENCES 1. Ellison GW, Bellah JR, Stubbs WP, Van Gilder J. Treatment of perianal fistulas with ND:YAG laser results in twenty cases. Vet Surg. 1995;24: Bodzin JH. Laser ablation of complex perianal fistulas preserves continence and is a rectum-sparing alternative in Crohn s disease patients. Am Surg. 1998;64: Moy J, Bodzin J. Carbon dioxide laser ablation of perianal fistulas in patients with Crohn s disease: experience with 27 patients. Am J Surg. 2006;191: Wilhelm A. A new technique for sphincter-preserving anal fistula repair using a novel radial emitting laser probe. Tech Coloproctol. 2011;15: Vasilevsky CA, Gordon PH. Benign anorectal: abscess and fistula. In: Wolff BG, Fleshman JW, Beck DE, Pemberton JH, Wexner SD, eds. The ASCRS Textbook of Colon and Rectal Surgery. New York, NY: Springer LLC; 2007: