Clinical efficacy and pathological outcomes of transanal endoscopic intersphincteric resection for low rectal cancer

BACKGROUND Transanal endoscopic intersphincteric resection(ISR)surgery currently lacks sufficient clinical research and reporting.AIM To investigate the clinical effectiveness of transanal endoscopic ISR,in order to promote the clinical application and development of this technique.METHODS This study utilized a retrospective case series design.Clinical and pathological data of patients with lower rectal cancer who underwent transanal endoscopic ISR at the First Affiliated Hospital of Xiamen University between May 2018 and May 2023 were included.All patients underwent transanal endoscopic ISR as the surgical approach.We conducted this study to determine the perioperative recovery status,postoperative complications,and pathological specimen charac-teristics of this group of patients.RESULTS This study included 45 eligible patients,with no perioperative mortalities.The overall incidence of early complications was 22.22%,with a rate of 4.44%for Clavien-Dindo grade≥III events.Two patients(4.4%)developed anastomotic leakage after surgery,including one case of grade A and one case of grade B.Postoperative pathological examination confirmed negative circumferential resection margins and distal resection margins in all patients.The mean distance between the tumor lower margin and distal resection margin was found to be 2.30±0.62 cm.The transanal endoscopic ISR procedure consistently yielded high quality pathological specimens.CONCLUSION Transanal endoscopic ISR is safe,feasible,and provides a clear anatomical view.It is associated with a low incidence of postoperative complications and favorable pathological outcomes,making it worth further research and application.

Comparison between recent sphincter-sparing procedures for complex anal fistulas-ligation of intersphincteric tract vs transanal opening of intersphincteric space

Complex anal fistulas are difficult to treat.The main reasons for this are a higher recurrence rate and the risk of disrupting the continence mechanism because of sphincter involvement.Due to this,several sphincter-sparing procedures have been developed in the last two decades.Though moderately successful in simple fistulas(50%-75%healing rate),the healing rates in complex fistulas for most of these procedures has been dismal.Only two procedures,ligation of intersphincteric fistula tract and transanal opening of intersphincteric space have been shown to have good success rates in complex fistulas(60%-95%).Both of these procedures preserve continence while achieving high success rates.In this opinion review,I shall outline the history,compare the pros and cons,indications and contraindications and future application of both these procedures for the management of complex anal fistulas.

Ligation of intersphincteric fistula tract:What is the evidence in a review?

Broadly,complex fistulas are those that are not low transsphincteric or intersphincteric. The objectives of surgical management are to achieve fistula healing,prevent recurrences and maintain continence. The risk of incontinence associated with treatment ranges from10% to 57%. The objective of this manuscript is to review the current literature to date on the ligation of the intersphincteric fistula tract procedure(LIFT procedure) as a treatment option in these types of fistula.A search was conducted in Medline,PUBMED,EMBASE and ISI Web of Knowledge,and studies published from January 2009 to May 2013 were included. The primary outcomes were fistula healing rates,mean healing time and patient satisfaction with this surgical technique.Eighteen studies were included in this review. The total number of patients included was 592(65% male).The median age reported was 42.8 years. The most common type of fistula included was transsphincteric(73.3% of cases). The mean healing rate reported was74.6%. The risk factors for failure discovered were obesity,smoking,multiple previous surgeries and the length of the fistula tract. The mean healing time was5.5 wk,and the mean follow-up period was 42.3 wk.The patient satisfaction rates ranged from 72% to 100%. No de novo incontinence developed secondary to the LIFT procedure. There is not enough evidence that variants in the surgical technique achieve better outcomes(Bio-LIFT,LIFT-Plug,LIFT-Plus). This review indicates that the LIFT procedure is primarily effective for transsphincteric fistulas with an overall fistula closure of 74.6% and has a low impact on fecal continence. This procedure produces better outcomes at the first surgical attempt.

Ligation of intersphincteric fistula tract and its modification: Results from treatment of complex fistula

AIM: To compare healing rates between intersphincteric fistula tract (LIFT) and LIFT plus partial fistulectomy procedures. METHODS: A study of complex fistula-in-ano patients was carried out from 1 st March 2010 to 31 th January 2012. All operations were done by colorectal surgeons at a referral center in a Ministry of Public Health hospital. Data collected included patients' demographic details, fistula type determined by endorectal-ultraso-nography, preoperative and postoperative continence status, previous operations, time between diagnosis of fistula-in-ano and operation, type of surgery, healing rates, recurrence rates, and types of failure examined by endorectal-ultrasosnography, re-operation in recurrence or failure cases, and complications. RESULTS: The study involved 41 patients whose average age was 40.78 ± 11.84 years (range: 21-71 years). The major fistula type was high-transsphincteric type fistula. The median follow-up period was 24 wk. The overall success rate was 83%: in the LIFT (Ligation intersphincteric fistula tract) group the success rate was 81% and in the LIFT plus (LIFT with partial coreout fistulectomy) group it was 85% (P = 0.529). The median wound-healing time was 4 wk in both groups (P = 0.262). The median time to recurrence was 12 wk. Neither group had incontinence (Wexner incontinence score-0) and the difference in healing rates between the two groups was not statistically significant. CONCLUSION: There was no difference in results between LIFT and LIFT plus operations. The LIFT procedure is a good option for maintaining continence in management of fistula-in-ano.

Clinical outcome of intersphincteric resection for ultra-low rectal cancer

AIM： To analyze oncological outcome of intersphincteric resection （ISR） in ultra-low rectal cancer with intent to spare colostoma. METHODS： From 1995 to 1998, patients with a nonfixed rectal adenocarcinoma （tumor stage T2） preserving the lower margin at 1-3 cm above the dentate line without distant metastasis was enrolled （period I）. ISR was practiced in eight patients, and their postoperative followup was at least 5 years. In addition, from 1999 to 2003, another 10 patients having the same tumor location as period Ⅰ underwent ISR （period Ⅱ）. Among those, 6 patients with T3-4-staged tumor received preoperative chemoradiotherapy. RESULTS： All patients received ISR with curative intention and no postoperative mortality. In these case series at period Ⅰ, local recurrence rate was 12.5% and metastasis rate 25.0%; the S-year survival rate was 87.5% and disease-free survival rate 75.0%. There was no local recurrence or distant metastases in 10 patients with a median follow-up of 30 （range, 18-47） mo at period Ⅱ. CONCLUSION： As to ultra-low rectal cancer, intersphincteric resection could provide acceptable local control and cancerrelated survival with no permanent stoma in early-staged tumor （tumor stage T2）; more- over, preoperative concurrent chemoradiotheraw would make ISR feasible with surgical curative intent in more advanced tumors （tumor stages T3-4）.

Narrow pelvic inlet plane area and obesity as risk factors for anastomotic leakage after intersphincteric resection

BACKGROUND Intersphincteric resection(ISR)has been increasingly used as the ultimate sphincter-preserving procedure in extremely low rectal cancer.The most critical complication of this technique is anastomotic leakage.The incidence rate of anastomotic leakage after ISR has been reported to range from 5.1%to 20%.AIM To investigate risk factors for anastomotic leakage after ISR based on clinicopathological variables and pelvimetry.METHODS This study was conducted at Department of Colorectal Surgery,Japanese Red Cross Medical Center,Tokyo,Japan,with a total of 117 patients.We enrolled 117 patients with extremely low rectal cancer who underwent laparotomic and laparoscopic ISRs at our hospital.We conducted retrospective univariate and multivariate regression analyses on 33 items to elucidate the risk factors for anastomotic leakage after ISR.Pelvic dimensions were measured using threedimensional reconstruction of computed tomography images.The optimal cutoff value of the pelvic inlet plane area that predicts anastomotic leakage was determined using a receiver operating characteristic(ROC)curve.RESULTS We observed anastomotic leakage in 10(8.5%)of the 117 patients.In the multivariate analysis,we identified high body mass index(odds ratio 1.674;95%confidence interval:1.087-2.58;P=0.019)and smaller pelvic inlet plane area(odds ratio 0.998;95%confidence interval:0.997-0.999;P=0.012)as statistically significant risk factors for anastomotic leakage.According to the receiver operating characteristic curves,the optimal cutoff value of the pelvic inlet plane area was 10074 mm2.Narrow pelvic inlet plane area(≤10074 mm2)predicted anastomotic leakage with a sensitivity of 90%,a specificity of 85.9%,and an accuracy of 86.3%.CONCLUSION Narrow pelvic inlet and obesity were independent risk factors for anastomotic leakage after ISR.Anastomotic leakage after ISR may be predicted from a narrow pelvic inlet plane area(≤10074 mm2).

Anal Sphincter Function after Intersphincteric Resection for Low Rectal Cancer

Objective： To assess the anal sphincter function after intersphincteric resection for low rectal cancer by questionnaire and vectorial manometry. Methods： twenty five patients underwent intersphincteric resection, the controls contained 25 patients of rectal cancer who underwent low anterior resection and 25 healthy people. The therapeutic responses were evaluated using the Vaizey and Wexner scoring systems and vectorial manometry. Results： The Vaizey and Wexner scores after intersphincteric resection were significantly higher than those of low anterior resection controls at one month, but had no significant difference one year after. On the other hand, the indexes of vectorial manometry still had significant difference one year later. The indexes after intersphincteric resection could not reach the normal level. Conclusion： The anal sphincter function after intersphincteric resection is lower than that after low anterior resection in short term, although the long-term results can be accepted, it still can not reach the normal level.

Intersphincteric resection and coloanal anastomosis in the treatment of distal rectal cancers

Objective:In the evolving era of minimal access surgery,low rectal cancers still pose a challenge to laparoscopic or robotic surgeons.Hence,at our institute we intended to demonstrate the oncological efficacy of intersphincteric resection and coloanal anastomosis in the treatment of distal rectal cancers,performing the abdominal part of the procedure which includes rectal mobilization,laparoscopically.Methods:From February 2017 to March 2021,125 patients who had undergone intersphincteric resection and coloanal anastomosis via the perineal approach at Galaxy Care Laparoscopic Institute,Pune,were included in this study.Transabdominal mobilization of the rectum was performed laparoscopically.All patients had a diversion ileostomy and a pelvic drain.Patients were followed-up for a period of 18 months post-surgery.Data on clinical and oncological outcomes were collected and analysed.The pre-operative and post-operative Wexner incontinence scores were compared.Results:The mean time taken for surgery was 181.57±30.00 min.The mean blood loss was 119.76±42.53 mL.Most patients(103,82.4%)had their tumour at a distance of 1e2 cm from the anal verge.A loco-regional recurrence rate of 12.8%(16/125)was noted in our study.For the post-surgery Wexner score,74.4% of patients(93/125)had a score of 5 or less,depicting that three-quarters of the study population had satisfactory continence.Overall,81.6%of patients were satisfied with the functional results of surgery.Conclusion:Intersphincteric resection and coloanal anastomosis,with a 12.8%recurrence rate,can now be considered an oncological and technically feasible procedure with sphincter salvage and good continence.

Long-term outcomes and failure patterns after laparoscopic intersphincteric resection in ultralow rectal cancers

BACKGROUND Intersphincteric resection(ISR),the ultimate anus-preserving technique for ultralow rectal cancers,is an alternative to abdominoperineal resection(APR).The failure patterns and risk factors for local recurrence and distant metastasis remain controversial and require further investigation.AIM To investigate the long-term outcomes and failure patterns after laparoscopic ISR in ultralow rectal cancers.METHODS Patients who underwent laparoscopic ISR(LsISR)at Peking University First Hospital between January 2012 and December 2020 were retrospectively reviewed.Correlation analysis was performed using the Chi-square or Pearson's correlation test.Prognostic factors for overall survival(OS),local recurrence-free survival(LRFS),and distant metastasis-free survival(DMFS)were analyzed using Cox regression.RESULTS We enrolled 368 patients with a median follow-up of 42 mo.Local recurrence and distant metastasis occurred in 13(3.5%)and 42(11.4%)cases,respectively.The 3-year OS,LRFS,and DMFS rates were 91.3%,97.1%,and 90.1%,respectively Multivariate analyses revealed that LRFS was associated with positive lymph node status[hazard ratio(HR)=5.411,95%confidence interval(CI)=1.413-20.722,P=0.014]and poor differentiation(HR=3.739,95%CI:1.171-11.937,P=0.026),whereas the independent prognostic factors for DMFS were positive lymph node status(HR=2.445,95%CI:1.272-4.698,P=0.007)and(y)pT3 stage(HR=2.741,95%CI:1.225-6.137,P=0.014).CONCLUSION This study confirmed the oncological safety of LsISR for ultralow rectal cancer.Poor differentiation,(y)pT3 stage,and lymph node metastasis are independent risk factors for treatment failure after LsISR,and thus patients with these factors should be carefully managed with optimal neoadjuvant therapy,and for patients with a high risk of local recurrence(N+or poor differentiation),extended radical resection(such as APR instead of ISR)may be more effective.

Intersphincteric Resection Is the Optimal Procedure for Very Low Rectal Cancer: Techniques, Morbidity, Oncologic and Functional Outcomes

Background: The intersphincteric resection the most extreme form of a sphincter-preserving alternative for the abdominoperineal resection. Aim of the Work: We investigated oncological, functional outcomes and morbidity after ISR. Methods: This retrospective study included 164 patients who underwent ISR with between 2010 and 2015, Male 56.1%, Female 43.9%, with a median age was 54.5 years, Median follow-up time was of 48 months, Average surgical time was 230 min, Median blood loss was 700 mL and median hospital stay was nine days. Mean tumour size was34 mm. The surgical procedure through a laparotomy (72.6%), laparoscopically (27.4%). Neoadjuvant radiotherapy 89.6% {long-course radiotherapy 74.4%, short-course radiotherapy 15.2%}, neoadjuvant chemotherapy 28.7% and adjuvant chemotherapy 70.1%. Colonic J-pouch 16.5%, Transverse coloplasty 15.9%, a side-to-end anastomosis 26.8% and straight coloanal anastomosis 40.9%. Partial-ISR 36.6%, subtotal-ISR 37.2%, total-ISR 26.2%, diverting ileostomy 6.7%. Results: Operative mortality 1.2%, morbidity 14.6% (anastomotic leakage 3.7%, anastomotic stenosis 1.8%, a recto-vaginal fistula 2.4% bowel obstruction 3%, surgical site infection 3%. Respiratory tract infection 1.2%, local 7.9%, distant recurrence 15.2%, 5-year overall 79.8%, disease-free survival 75.8%, R0 resection 95.1%. Pathologic complete response 11%. Circumferential margin involvement 2.4%. Median number of lymph nodes 17. Mean distal margin20 mm, after 12 months Median Wexner score 6. Incontinence for (flatus 11%, liquid 4.9%, solid 4.3%). Median bowel motions in a 24-h were 3. Faecal urgency 17.7%. Stool fragmentation 18.9%. Difficult evacuation 17.7%, lifestyle alteration 14.6%. Difficulty Feces/flatus discrimination 43.3%. Nocturnal soiling in 17.1%. Daytime soiling 11%. Pad wearing 23.8%. Anti-diarrhoea medication loperamide 14%. Conclusion: ISR is a feasible surgical procedure for low rectal cancer. Oncologic and functional, outcomes after are acceptable.

Preservation of the continence function after intersphincteric resection using a prolapsing technique in the patients with low rectal cancer and its clinical prognosis

Background The technique of intersphincteric resection of tumors combined with coloanal anastomosis has been used to avoid permanent colostomy for patients with a rectal cancer located 〈5 cm from the anal verge. This study aimed at assessing the preservation of continence function of the residual rectum and the clinical prognosis of patients with lower rectal cancer after intersphincteric resection using a prolapsing technique. Methods This study included patients with the following inclusion criteria： （1） pathological evidence of rectal cancer and the tumors within distal margins located 5 cm or less from the anus by preoperative endoscopic examination; （2） no evidence by MRI of infiltration of either the external sphincter, puborectalis or the levator muscle; （3） the patients are eligible for intersphincteric resection and lower coloanal anastomosis with a preoperative biopsy showing the tumors with well-to-moderate differentiation. From January 2000 to June 2004, 23 patients with low rectal cancer were included in this study. We used the standard abdominoperineal approach to perform radical resection of tumors with excision of the mesorectum and total or part of the internal sphincters. The patients were followed for assessment of the function of the residual rectum and of cancer recurrence after the operations. Results The median tumor distance from the anal margin was 4.5 （range 3.5-5.0） cm and the mean distal surgical margin 1.6 （range 1.0-2.0） cm. Cancer was classified into Stage Ⅰ （30.4%）, Stage Ⅱ （47.8%）, and Stage Ⅲ （21.7%） according to the TNM classification. Two patients developed anastomotic fistula after the surgical resection and 2 patients （8.7%） developed later stages of anastomotic stricture at the site of coloanal anastomosis. The median follow-up period was 31.5 months （range 12-54） and 2 patients （8.7%） developed local recurrence. Three deaths were associated with distal organ metastasis. Twenty patients （87.0%） have maintained competence to control solid or liquid stool and the capacity of flatus continence after the surgery. Among these patients, 2 patients were able to control solid stool and occasionally lose continence of liquid stool. And only 1 patient （4.4%） has retained partial rectum function with good continence of solid stool but not liquid after the operations. Average times of defecation per day of 3, 6, 12, 24 and 36 months after the surgery were 13.1, 4.7, 3.1, 2.9, and 3.2 times/day. Anal manometer measurements showed a decrease of pressure during the resting time after intersphincteric resection and this change remained during the period of follow-up. The maximum squeeze pressure was improved after an initial decrease after the surgery. Conclusions More residual rectum function after the surgery may be preserved by intersphincteric resection of low rectum cancer. At the same time this technique is safe with few postoperative complication and low tumor recurrence after the surgery.

Why do we have so much trouble treating anal fistula?

Anal fistula is among the most common illnesses affecting man.Medical literature dating back to 400 BC has discussed this problem.Various causative factors have been proposed throughout the centuries,but it appears that the majority of fistulas unrelated to specific causes (e.g.Tuberculosis,Crohn’s disease) result from infection (abscess) in anal glands extending from the intersphincteric plane to various anorectal spaces.The tubular structure of an anal fistula easily yields itself to division or unroofing (fistulotomy) or excision (fistulectomy) in most cases.The problem with this single,yet effective,treatment plan is that depending on the thickness of sphincter muscle the fistula transgresses,the patient will have varying degrees of fecal incontinence from minor to total.In an attempt to preserve continence,various procedures have been proposed to deal with the fistulas.These include: (1) simple drainage (Seton);(2) closure of fistula tract using fibrin sealant or anal fistula plug;(3) closure of primary opening using endorectal or dermal flaps,and more recently;and (4) ligation of intersphincteric fistula tract (LIFT).In most complex cases (i.e.Crohn’s disease),a proximal fecal diversion offers a measure of symptom-atic relief.The fact remains that an "ideal" procedure for anal fistula remains elusive.The failure of each sphincter-preserving procedure (30%-50% recurrence) often results in multiple operations.In essence,the price of preservation of continence at all cost is multiple and often different operations,prolonged disability and disappointment for the patient and the surgeon.Nevertheless,the surgeon treating anal fistulas on an occasional basis should never hesitate in referring the patient to a specialist.Conversely,an expert colorectal surgeon must be familiar with many different operations in order to selectively tailor an operation to the individual patient.

Low rectal cancer:Sphincter preserving techniques-selection of patients,techniques and outcomes

Low rectal cancer is traditionally treated by abdominoperineal resection. In recent years, several new techniques for the treatment of very low rectal cancer patients aiming to preserve the gastrointestinal continuity and to improve both the oncological as well as the functional outcomes, have been emerged. Literature suggest that when the intersphincteric resection is applied in T1-3 tumors located within 30-35 mm from the anal verge, is technically feasible, safe, with equal oncological outcomes compared to conventional surgery and acceptable quality of life. The Anterior Perineal Plan E for Ultra-low Anterior Resection technique, is not disrupting the sphincters, but carries a high complication rate, while the reports on the oncological and functional outcomes are limited. Transanal Endoscopic Micro Surgery(TEM) and Trans Anal Minimally Invasive Surgery(TAMIS) should represent the treatment of choice for T1 rectal tumors, with specific criteria according to the NCCN guidelines and favorable pathologic features. Alternatively to the standard conventional surgery, neoadjuvant chemo-radiotherapy followed by TEM or TAMIS seems promising for tumors of a local stage T1sm2-3 or T2. Transanal Total Mesorectal Excision should be performed only when a board approved protocol is available by colorectal surgeons with extensive experience in minimally invasive and transanal endoscopic surgery.

Current management of cryptoglandular fistula-in-ano

Fistula-in-ano is a difficult problem that physicians have struggled with for centuries.Appropriate treatment is based on 3 central tenets: (1) control of sepsis;(2) closure of the fistula;and (3) maintenance of continence.Treatment options continue to evolve-as a result,it is important to review old and new options on a regular basis to ensure that our patients are provided with up to date information and options.This paper will briefly cover some of the traditional approaches that have been used as well as some newer promising procedures.

Efficacy of Kegel exercises in preventing incontinence after partial division of internal anal sphincter during anal fistula surgery

BACKGROUND The transanal opening of intersphincteric space(TROPIS)procedure,performed to treat complex anal fistulas,preserves the external anal sphincter(EAS)but involves partial incision of the internal anal sphincter(IAS).AIM To ascertain the incidence of incontinence after the division of the IAS as is done in TROPIS and to evaluate whether regular Kegel exercises(KE)in the postoperative period can prevent incontinence due to IAS division.METHODS Patients operated on for high complex fistulas and having no preoperative continence problem(score=0)were included in the study.All patients were operated on by the TROPIS procedure and were recommended KE(pelvic contraction exercises)50 times/day.KE were commenced on the 10^(th)postoperative day and continued for 1 year.Incontinence was evaluated objectively(by modified Vaizey’s scores)in the immediate postoperative period(Pre-KE group)and on long-term follow-up(Post-KE group).The incontinence scores in both groups were compared to evaluate the efficacy of KE.RESULTS Of 102 anal fistula patients operated on between July 2018 and July 2020 were included in this study.There were 90 males,the mean age was 42.3±12.8,and the median follow-up was 30 mo(18-42 mo).Three patients were lost to follow-up.There were 65 recurrent fistulas,92 had multiple tracts,42 had associated abscess,46 had horseshoe fistula and 34 were supralevator fistulas.All were magnetic resonance imaging-documented high fistulas(>1/3 EAS involved).Overall incontinence occurred in 31%patients(Pre-KE group)with urge and gas incontinence accounting for the majority of cases(28.3%).The mean incontinence scores in the Pre-KE group were 1.19±1.96(in 31 patients,solid=0,liquid=7,gas=8,urge=24)and in the Post-KE group were 0.26±0.77(in 13 patients,solid=0,liquid=2,gas=3,urge=10)(P=0.00001,t-test).CONCLUSION Division of the IAS led to incontinence,mainly urge incontinence,and also to a mild degree of gas and liquid incontinence.However,regular KE led to a significant reduction in incontinence(both in the number of affected patients and the severity of scores in these patients).

Simple instruments facilitating achievement of transanal total mesorectal excision in male patients

AIM To assess the efficacy of a modified approach with transanal total mesorectal excision(ta TME) using simple customized instruments in male patients with low rectal cancer.METHODS A total of 115 male patients with low rectal cancer from December 2006 to August 2015 were retrospectively studied. All patients had a bulky tumor(tumor diameter ≥ 40 mm). Forty-one patients(group A) underwent a classical approach of transabdominal total mesorectal excision(TME) and transanal intersphincteric resection(ISR), and the other 74 patients(group B) underwent a modified approach with transabdominal TME,transanal ISR, and ta TME. Some simple instruments including modified retractors and an anal dilator with a papilionaceous fixture were used to perform ta TME. The operative time, quality of mesorectal excision, circumferential resection margin, local recurrence, and postoperative survival were evaluated.RESULTS All 115 patients had successful sphincter preservation. The operative time in group B(240 min, range: 160-330 min) was significantly shorter than that in group A(280 min, range: 200-360 min; P = 0.000). Co m pa r e d w it h g r o up A, m o r e c o m p le t e d is t a l mesorectum and total mesorectum were achieved in group B(100% vs 75.6%, P = 0.000; 90.5% vs 70.7%, P = 0.008, respectively). After 46.1 ± 25.6 mo followup, group B had a lower local recurrence rate and higher disease-free survival rate compared with group A, but these differences were not statistically significant(5.4% vs 14.6%, P = 0.093; 79.5% vs 65.1%, P = 0.130). CONCLUSION Retrograde ta TME with simple customized instruments can achieve high-quality TME, and it might be an effective and economical alternative for male patients with bulky tumors.

Progress in the surgery of rectal cancer

The treatment of rectal cancer has been improved a great deal within the last 20 years. Major progress has been made in the preoperative evaluation by introducing MRI- imaging as a basis for the further management. Neoadjuvant radiochemotherapy has been shown to be effective in downstaging of advanced tumours. The surgical technique has been improved in many respects.- Total mesorectal excision has reduced local recurrences, sphincter saving techniques such as low anterior resection and intersphincteric resection reduced the need for a permanent stoma to 10%-20%. Recently the introduction of minimal invasive techniques and the application of robotic systems have reduced the surgical trauma.

Modern management of anal fistula

Ideal surgical treatment for anal fistula should aim to eradicate sepsis and promote healing of the tract,whilst preserving the sphincters and the mechanism of continence.For the simple and most distal fistulae,conventional surgical options such as laying open of the fistula tract seem to be relatively safe and therefore,well accepted in clinical practise.However,for the more complex fistulae where a significant proportion of the anal sphincter is involved,great concern remains about damaging the sphincter and subsequent poor functional outcome,which is quite inevitable following conventional surgical treatment.For this reason,over the last twodecades,many sphincter-preserving procedures for the treatment of anal fistula have been introduced with the common goal of minimising the injury to the anal sphincters and preserving optimal function.Among them,the ligation of intersphincteric fistula tract procedure appears to be safe and effective and may be routinely considered for complex anal fistula.Another technique,the anal fistula plug,derived from porcine small intestinal submucosa,is safe but modestly effective in long-term follow-up,with success rates varying from 24%-88%.The failure rate may be due to its extrusion from the fistula tract.To obviate that,a new designed plug(GORE BioA ) was introduced,but long term data regarding its efficacy are scant.Fibrin glue showed poor and variable healing rate(14%-74%).Fi La C and video-assisted anal fistula treatment procedures,respectively using laser and electrode energy,are expensive and yet to be thoroughly assessed in clinical practise.Recently,a therapy using autologous adiposederived stem cells has been described.Their properties of regenerating tissues and suppressing inflammatory response must be better investigated on anal fistulae,and studies remain in progress.The aim of this present article is to review the pertinent literature,describing the advantages and limitations of new sphincterpreserving techniques.