Benefit in therapy of superficial rectal neoplasms objectivized: Transanal endoscopic microsurgery (TEM) compared to surgical standards

Local versus radical surgery for early rectal cancer with or without neoadjuvant or adjuvant therapy

BACKGROUND

Total mesorectal excision is the standard of care for stage I rectal cancer. Despite major advances and increasing enthusiasm for modern endoscopic local excision (LE), uncertainty remains regarding its oncologic equivalence and safety relative to radical resection (RR).

OBJECTIVES

To assess the oncologic, operative, and functional outcomes of modern endoscopic LE compared to RR surgery in adults with stage I rectal cancer.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE, Ovid Embase, Web of Science - Science Citation Index Expanded (1900 to present), four trial registers (ClinicalTrials.gov, ISRCTN registry, the WHO International Clinical Trials Registry Platform, and the National Cancer Institute Clinical Trials database), two thesis and proceedings databases, and relevant scientific societies' publications in February 2022. We performed handsearching and reference checking and contacted study authors of ongoing trials to identify additional studies.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) in people with stage I rectal cancer comparing any modern LE techniques to any RR techniques with or without the use of neo/adjuvant chemoradiotherapy (CRT).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We calculated hazard ratios (HR) and standard errors for time-to-event data and risk ratios for dichotomous outcomes, using generic inverse variance and random-effects methods. We regrouped surgical complications from the included studies into major and minor according to the standard Clavien-Dindo classification. We assessed the certainty of evidence using the GRADE framework.

MAIN RESULTS

Four RCTs were included in data synthesis with a combined total of 266 participants with stage I rectal cancer (T1-2N0M0), if not stated otherwise. Surgery was performed in university hospital settings. The mean age of participants was above 60, and median follow-up ranged from 17.5 months to 9.6 years. Regarding the use of co-interventions, one study used neoadjuvant CRT in all participants (T2 cancers); one study used short-course radiotherapy in the LE group (T1-T2 cancers); one study used adjuvant CRT selectively in high-risk patients undergoing RR (T1-T2 cancers); and the fourth study did not use any CRT (T1 cancers). We assessed the overall risk of bias as high for oncologic and morbidity outcomes across studies. All studies had at least one key domain with a high risk of bias. None of the studies reported separate outcomes for T1 versus T2 or for high-risk features. Low-certainty evidence suggests that RR may result in an improvement in disease-free survival compared to LE (3 trials, 212 participants; HR 1.96, 95% confidence interval (CI) 0.91 to 4.24). This would translate into a three-year disease-recurrence risk of 27% (95% CI 14 to 50%) versus 15% after LE and RR, respectively. Regarding sphincter function, only one study provided objective results and reported short-term deterioration in stool frequency, flatulence, incontinence, abdominal pain, and embarrassment about bowel function in the RR group. At three years, the LE group had superiority in overall stool frequency, embarrassment about bowel function, and diarrhea. Local excision may have little to no effect on cancer-related survival compared to RR (3 trials, 207 participants; HR 1.42, 95% CI 0.60 to 3.33; very low-certainty evidence). We did not pool studies for local recurrence, but the included studies individually reported comparable local recurrence rates for LE and RR (low-certainty evidence). It is unclear if the risk of major postoperative complications may be lower with LE compared with RR (risk ratio 0.53, 95% CI 0.22 to 1.28; low-certainty evidence; corresponding to 5.8% (95% CI 2.4% to 14.1%) risk for LE versus 11% for RR). Moderate-certainty evidence shows that the risk of minor postoperative complications is probably lower after LE (risk ratio 0.48, 95% CI 0.27 to 0.85); corresponding to an absolute risk of 14% (95% CI 8% to 26%) for LE compared to 30.1% for RR. One study reported an 11% rate of temporary stoma after LE versus 82% in the RR group. Another study reported a 46% rate of temporary or permanent stomas after RR and none after LE. The evidence is uncertain about the effect of LE compared with RR on quality of life. Only one study reported standard quality of life function, in favor of LE, with a 90% or greater probability of superiority in overall quality of life, role, social, and emotional functions, body image, and health anxiety. Other studies reported a significantly shorter postoperative period to oral intake, bowel movement, and off-bed activities in the LE group.

AUTHORS' CONCLUSIONS

Based on low-certainty evidence, LE may decrease disease-free survival in early rectal cancer. Very low-certainty evidence suggests that LE may have little to no effect on cancer-related survival compared to RR for the treatment of stage I rectal cancer. Based on low-certainty evidence, it is unclear if LE may have a lower major complication rate, but probably causes a large reduction in minor complication rate. Limited data based on one study suggest better sphincter function, quality of life, or genitourinary function after LE. Limitations exist with respect to the applicability of these findings. We identified only four eligible studies with a low number of total participants, subjecting the results to imprecision. Risk of bias had a serious impact on the quality of evidence. More RCTs are needed to answer our review question with greater certainty and to compare local and distant metastasis rates. Data on important patient outcomes such as sphincter function and quality of life are very limited. Results of currently ongoing trials will likely impact the results of this review. Future trials should accurately report and compare outcomes according to the stage and high-risk features of rectal tumors, and evaluate quality of life, sphincter, and genitourinary outcomes. The role of neoadjuvant or adjuvant therapy as an emerging co-intervention for improving oncologic outcomes after LE needs to be further defined.

Risk of recurrence after local resection of T1 rectal cancer: a meta-analysis with meta-regression

BACKGROUND

T1 rectal cancer (RC) patients are increasingly being treated by local resection alone but uniform surveillance strategies thereafter are lacking. To determine whether different local resection techniques influence the risk of recurrence and cancer-related mortality, a meta-analysis was performed.

METHODS

A systematic search was conducted for T1RC patients treated with local surgical resection. The primary outcome was the risk of RC recurrence and RC-related mortality. Pooled estimates were calculated using mixed-effect logistic regression. We also systematically searched and evaluated endoscopically treated T1RC patients in a similar manner.

RESULTS

In 2585 unique T1RC patients (86 studies) undergoing local surgical resection, the overall pooled cumulative incidence of recurrence was 9.1% (302 events, 95% CI 7.3-11.4%; I2 = 68.3%). In meta-regression, the recurrence risk was associated with histological risk status (p < 0.005; low-risk 6.6%, 95% CI 4.4-9.7% vs. high-risk 28.2%, 95% CI 19-39.7%) and local surgical resection technique (p < 0.005; TEM/TAMIS 7.7%, 95% CI 5.3-11.0% vs. other local surgical excisions 10.8%, 95% CI 6.7-16.8%). In 641 unique T1RC patients treated with flexible endoscopic excision (16 studies), the risk of recurrence (7.7%, 95% CI 5.2-11.2%), cancer-related mortality (2.3%, 95% CI 1.1-4.9), and cancer-related mortality among patients with recurrence (30.0%, 95% CI 14.7-49.4%) were comparable to outcomes after TEM/TAMIS (risk of recurrence 7.7%, 95% CI 5.3-11.0%, cancer-related mortality 2.8%, 95% CI 1.2-6.2% and among patients with recurrence 35.6%, 95% CI 21.9-51.2%).

CONCLUSIONS

Patients with T1 rectal cancer may have a significantly lower recurrence risk after TEM/TAMIS compared to other local surgical resection techniques. After TEM/TAMIS and endoscopic resection the recurrence risk, cancer-related mortality and cancer-related mortality among patients with recurrence were comparable. Recurrence was mainly dependent on histological risk status.

First Clinical Experience With Single-Port Robotic Transanal Minimally Invasive Surgery: Phase II Trial of the Initial 26 Cases

BACKGROUND

Many transanal platforms have been developed to address the challenge of reach and vision when operating transanally. The single-port robot was specifically designed for narrow-aperture surgery and is a promising platform for minimally invasive transanal surgery.

OBJECTIVE

The purpose of this phase II trial is to evaluate the safety and feasibility of the initial clinical experience with single-port robot transanal minimally invasive surgery.

DESIGN

In a prospective phase II trial, patients with rectal neoplasms eligible for local excision were enrolled for single-port robotic transanal minimally invasive surgery.

SETTING

The study was conducted between October 2018 and March 2020 at a tertiary referral hospital.

PATIENTS/INTERVENTION

Twenty-six consecutive patients underwent single-port robotic transanal minimally invasive surgery resection of rectal lesions.

MAIN OUTCOME MEASURES

The primary end point of the study was the efficacy and safety of single-port robotic transanal minimally invasive surgery.

RESULTS

There were 13 men and 13 women, with an average lesion size of 2.9 cm (range, 1.0-6.0 cm) and average level of 4.8 cm from the anorectal ring (range, 0-30 cm). Ten patients had a preoperative diagnosis of adenocarcinoma, 7 of whom received neoadjuvant chemoradiation (range, 4500-5580 cGy with concurrent oral capecitabine). Eighty-eight percent of cases were completed by single-port robotic transanal minimally invasive surgery; 2 were converted to transanal endoscopic microsurgery, and 1 patient underwent a low anterior resection. There were no piecemeal extractions, and all margins were negative on final pathology. There were no mortalities, and the morbidity rate was 15.4%. There have been no local recurrences, with a mean follow-up of 5.8 months (range, 0-15.9 months).

LIMITATIONS

The study was limited by small sample size, short-term follow up, and a single-surgeon experience.

CONCLUSION

Single-port robotic transanal minimally invasive surgery procedures are safe and feasible in patients with select benign and malignant rectal lesions. Future trials will need to evaluate the long-term safety and efficacy of single-port robotic transanal minimally invasive surgery. See Video Abstract at http://links.lww.com/DCR/B605.

PRIMERA EXPERIENCIA CLNICA CON CIRUGA MNIMAMENTE INVASIVA TRANSANAL ROBTICA DE PUERTO NICO ENSAYO DE FASE II DE LOS CASOS INICIALES

ANTECEDENTES:Se han desarrollado muchas plataformas transanales para abordar el desafío del alcance y la visión cuando se opera de manera transanal. El robot de un solo puerto fue diseñado específicamente para la cirugía de apertura estrecha y es una plataforma prometedora para la cirugía transanal mínimamente invasiva.OBJETIVO:El propósito de este ensayo de fase II es evaluar la seguridad y viabilidad de la experiencia clínica inicial con la cirugía mínimamente invasiva transanal con robot de puerto único.DISEÑO:En un ensayo prospectivo de fase II, los pacientes con neoplasias rectales elegibles para la escisión local se inscribieron para la cirugía mínimamente invasiva transanal robótica de puerto único.AJUSTE:El estudio se realizó entre octubre de 2018 y marzo de 2020 en un hospital de referencia terciario.PACIENTES / INTERVENCIÓN:Veintiséis pacientes consecutivos fueron sometidos a cirugía mínimamente invasiva transanal robótica de puerto único para resección de lesiones rectales.PRINCIPALES MEDIDAS DE RESULTADO:El criterio de valoración principal del estudio fue la eficacia y seguridad de la cirugía mínimamente invasiva transanal robótica de puerto único.RESULTADOS:Hubo 13 hombres y 13 mujeres, con un tamaño de lesión promedio de 2.9 cm (rango 1.0-6.0 cm) y un nivel promedio de 4.8 cm del anillo anorrectal (rango 0-30 cm). Diez pacientes tenían un diagnóstico preoperatorio de adenocarcinoma, 7 de los cuales recibieron quimiorradiación neoadyuvante (rango 4500-5580 cGy con capecitabina oral concurrente). El 88% de los casos se completaron mediante cirugía mínimamente invasiva transanal robótica de puerto único; 2 se convirtieron a microcirugía endoscópica transanal y 1 se sometió a una resección anterior baja. No hubo extracciones parciales y todos los márgenes fueron negativos en la patología final. No hubo mortalidad y una tasa de morbilidad del 15,4%. No ha habido recidivas locales, con un seguimiento medio de 5,8 meses (rango 0-15,9 meses).LIMITACIONES:El estudio estuvo limitado por un tamaño de muestra pequeño, un seguimiento a corto plazo y la experiencia de un solo cirujano.CONCLUSIÓN:Los procedimientos de cirugía mínimamente invasiva transanal robótica de puerto único son seguros y factibles en pacientes con lesiones rectales benignas y malignas seleccionadas. Los ensayos futuros deberán evaluar la seguridad y eficacia a largo plazo de la cirugía mínimamente invasiva transanal robótica de puerto único. Consulte Video Resumen en http://links.lww.com/DCR/B605. (Traducción-Dr. Eduardo Londoño-Schimmer).

Multidisciplinary management of elderly patients with rectal cancer: recommendations from the SICG (Italian Society of Geriatric Surgery), SIFIPAC (Italian Society of Surgical Pathophysiology), SICE (Italian Society of Endoscopic Surgery and new technologies), and the WSES (World Society of Emergency Surgery) International Consensus Project

BACKGROUND AND AIMS

Although rectal cancer is predominantly a disease of older patients, current guidelines do not incorporate optimal treatment recommendations for the elderly and address only partially the associated specific challenges encountered in this population. This results in a wide variation and disparity in delivering a standard of care to this subset of patients. As the burden of rectal cancer in the elderly population continues to increase, it is crucial to assess whether current recommendations on treatment strategies for the general population can be adopted for the older adults, with the same beneficial oncological and functional outcomes. This multidisciplinary experts' consensus aims to refine current rectal cancer-specific guidelines for the elderly population in order to help to maximize rectal cancer therapeutic strategies while minimizing adverse impacts on functional outcomes and quality of life for these patients.

METHODS

The discussion among the steering group of clinical experts and methodologists from the societies' expert panel involved clinicians practicing in general surgery, colorectal surgery, surgical oncology, geriatric oncology, geriatrics, gastroenterologists, radiologists, oncologists, radiation oncologists, and endoscopists. Research topics and questions were formulated, revised, and unanimously approved by all experts in two subsequent modified Delphi rounds in December 2020-January 2021. The steering committee was divided into nine teams following the main research field of members. Each conducted their literature search and drafted statements and recommendations on their research question. Literature search has been updated up to 2020 and statements and recommendations have been developed according to the GRADE methodology. A modified Delphi methodology was implemented to reach agreement among the experts on all statements and recommendations.

CONCLUSIONS

The 2021 SICG-SIFIPAC-SICE-WSES consensus for the multidisciplinary management of elderly patients with rectal cancer aims to provide updated evidence-based statements and recommendations on each of the following topics: epidemiology, pre-intervention strategies, diagnosis and staging, neoadjuvant chemoradiation, surgery, watch and wait strategy, adjuvant chemotherapy, synchronous liver metastases, and emergency presentation of rectal cancer.

Local recurrence after local excision of early rectal cancer: a meta-analysis of completion TME, adjuvant (chemo)radiation, or no additional treatment

BACKGROUND

The risks of local recurrence and treatment-related morbidity need to be balanced after local excision of early rectal cancer. The aim of this meta-analysis was to determine oncological outcomes after local excision of pT1-2 rectal cancer followed by no additional treatment (NAT), completion total mesorectal excision (cTME) or adjuvant (chemo)radiotherapy (aCRT).

METHODS

A systematic search was conducted in PubMed, Embase and the Cochrane Library. The primary outcome was local recurrence. Statistical analysis included calculation of the weighted average of proportions.

RESULTS

Some 73 studies comprising 4674 patients were included in the analysis. Sixty-two evaluated NAT, 13 cTME and 28 aCRT. The local recurrence rate for NAT among low-risk pT1 tumours was 6·7 (95 per cent c.i. 4·8 to 9·3) per cent. There were no local recurrences of low-risk pT1 tumours after cTME or aCRT. The local recurrence rate for high-risk pT1 tumours was 13·6 (8·0 to 22·0) per cent for local excision only, 4·1 (1·7 to 9·4) per cent for cTME and 3·9 (2·0 to 7·5) per cent for aCRT. Local recurrence rates for pT2 tumours were 28·9 (22·3 to 36·4) per cent with NAT, 4 (1 to 13) per cent after cTME and 14·7 (11·2 to 19·0) per cent after aCRT.

CONCLUSION

There is a substantial risk of local recurrence in patients who receive no additional treatment after local excision, especially those with high-risk pT1 and pT2 rectal cancer. The lowest recurrence risk is provided by cTME; aCRT has outcomes comparable to those of cTME for high-risk pT1 tumours, but shows a higher risk for pT2 tumours.

Comparison of the transanal surgical techniques for local excision of rectal tumors: a network meta-analysis

BACKGROUND

In order to assess the various surgical modalities for local resection of rectal tumors, a systematic review of the current literature and a network meta-analysis (NMA) was designed and conducted.

METHODS

The present study adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions principles. Scholar databases (Medline, Scopus, Web of Science) were systematically screened up to 23/12/2019. A Bayesian NMA, implementing a Markov chain Monte Carlo analysis, was introduced for the probability ranking of the available surgical methods. Odds ratio (OR) and weighted mean difference (WMD) of the categorical and continuous variables, respectively, were reported with the corresponding 95% confidence interval (95%CI).

RESULTS

Overall, 16 studies and 2146 patients were introduced in our study. Transanal minimal invasive surgery (TAMIS) displayed the highest performance regarding the overall postoperative morbidity, the perioperative blood loss, the length of hospitalization, and the peritoneal violation rate. Transanal endoscopic microsurgery (TEM) was the most efficient modality for resecting an intact specimen. Although transanal local excision (TAE) had the highest ranking considering operative duration, it was associated with a significant risk for positive resection margins and tumor recurrence.

CONCLUSIONS

In conclusion, TEM and TAMIS display superior oncological results over TAE. Due to several limitations, validation of these results requires further RCTs of a higher methodological level.

Postoperative complications in the treatment of rectal neoplasia by transanal endoscopic microsurgery: a prospective study of risk factors and time course

PURPOSE

Transanal endoscopic microsurgery (TEM) is a safe and efficient minimally invasive treatment for rectal benign and early malignant neoplasia, but postoperative complications may be severe. We aimed to evaluate the risk factors related to the incidence, severity, and time course of postoperative complications of TEM.

METHODS

This is a prospective study of postoperative complications in 53 patients (>18 years old) with benign or early rectal neoplasia who underwent TEM with curative intention or, for higher stages, palliation. Outcome measures included age, sex, American Society of Anesthesiologists score, neoadjuvant chemoradiotherapy, lesion height and size, pathologic margins, tumor histology, and suture type.

RESULTS

Overall morbidity was 50 %. Temporary fecal incontinence was the most frequent complication (17.3 %). Complication rates of Clavien-Dindo grades I and II were 21.1 % and those of grades III and IV 3.8 %. Of patients with complications, more had lesions under the first rectal valve than over the first valve (61.54 % vs 38.46 %, p = 0.04). Patients submitted to chemoradiotherapy had a 24-fold greater chance of presenting grade II complications (p = 0.002). When the surgical defect was treated using the TEM device to perform the suture, the chance of having grade III complications was reduced 16-fold (p = 0.04). Fifty-three percent of complications occurred in the first 10 days and 95 % within 20 days.

CONCLUSIONS

Postoperative complications after transanal endoscopic microsurgery for the treatment of rectal neoplasia are frequent, acceptable, and usually controllable with pharmacologic treatment. Over time the nature of complications is continuous, centered on the first 20 days after surgery.

Full thickness resection device (FTRD) for endoluminal removal of large bowel tumours: development of the instrument and related experimental studies

We describe a novel device for full thickness resectioning of large bowel lesions. The device has been assessed in experimental studies. Tumours of the large bowel are a frequent disease with increasing incidence figures. If detected at an early stage, local treatment of colon tumours is possible through an endoluminal access. Currently, full thickness resection can only be performed in the rectum with the TEM technique, while snare resection through the flexible endoscope will only allow mucosa resection. We have developed a new device which allows full thickness bowel wall resections up to the splenic flexure. The device, called full thickness resection device (FTRD) has a flexible shaft and a multifunctional front-end. It can be inserted into the colon over a flexible endoscope. After the device is advanced to the tumour, the head can be opened and the tumour, including safety margins, is pulled into the resection chamber inside the device head by means of two tissue graspers. The bowel wall invagination can be visualised with the endoscope to ensure that the tumour is completely pulled into the resection head. The head is then closed and the resection mechanism is activated. A semicircular stapling suture is fired through the bowel wall and a rotary knife is used to cut the tissue. Specimens of > 3 cm can be harvested with FTRD. Prototypes of the device have been successfully tested in a series of animal experiments in parallel to the technical development of the instrument. These experiments could demonstrate that full thickness bowel wall resection is feasible using a flexible instrument and endoscopic visualisation.

Local excision and transanal endoscopic microsurgery in the management of rectal cancer with a focus on early carcinoma

Transanal endoscopic microsurgery (TEMS) will play an even greater role in the treatment of rectal cancer as the UK national colorectal cancer screening program becomes national. With more rectal tumors being uncovered at earlier stages, a greater emphasis will be placed on treatment options that do not involve radical surgery and the possibility of a stoma. This article reviews the data surrounding TEMS, focusing on its current role in the treatment of early rectal cancer but with a view on how this option may develop in the future, particularly with regards to the more advanced rectal cancers and in view of the improved chemoradiotherapy regimens available. The data is reviewed and some of the more controversial issues discussed.

Transanal endoscopic microsurgery: risk factors for local recurrence of benign rectal adenomas

OBJECTIVE

Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for excision of selected benign and malignant rectal neoplasms. It is considered a safe and effective treatment but recurrence rates of 1-13% are reported for benign lesions. The aim of this study was to assess risk factors for local recurrence of benign rectal lesions and to evaluate mortality and morbidity following TEM.

METHOD

Data were prospectively collected from all patients undergoing TEM for benign adenomas from January 1998 to March 2005. The procedure was performed by a single surgeon and patients were regularly followed up.

RESULTS

One hundred and forty-six procedures were included, with a median patient age of 74 years (range 22-92 years). The mean lesion area was 16 cm(2) (range 0.3-150 cm(2)) and the median distance from the dentate line was 9 cm (range 0-17 cm). Immediate complications included bleeding (six) and acute urinary retention (six). There has been one (0.68%) procedure-related death. After a median follow up of 39 months (range 4-89 months) there have been seven recurrences (4.8%), recurring at a mean time of 23.3 months (range 5-48 months). Only microscopic involvement of the circumferential resection margin was found to be significantly associated with recurrence (P = 0.0059). Recurrence was not associated with age, size of lesion, previous treatment, severity of dysplasia or use of the harmonic scalpel.

CONCLUSION

TEM is a safe and effective treatment for benign rectal adenomas. Circumferential resection margin involvement is associated with recurrence, which tends to occur late. Therefore extended follow up is recommended.

Transanal endoscopic microsurgery: a systematic review

PURPOSE

The aim of this study was to systematically review the evidence relating to the safety and efficacy of transanal endoscopic microsurgery, a relatively new technique used to locally excise rectal tumors, compared with existing techniques such as anterior resections and abdominoperineal resections or local excisions.

METHODS

We conducted a systematic review of comparative studies and case series of transanal endoscopic microsurgery from 1980 to August 2002.

RESULTS

Three comparative studies (including one randomized, controlled trial) and 55 case series were included. The first area of study was the safety and efficacy of adenomas. In the randomized, controlled trial, no difference could be detected in the rate of early complications between transanal endoscopic microsurgery (10.3 percent) and direct local excision (17 percent) (relative risk, 0.61; 95 percent confidence interval, 0.29-1.29). Transanal endoscopic microsurgery resulted in less local recurrence (6/98; 6 percent) than direct local excision (20/90; 22 percent) (relative risk, 0.28; 95 percent confidence interval, 0.12-0.66). The 6 percent rate of local recurrence for transanal endoscopic microsurgery in this trial is consistent with the rates found in case series of transanal endoscopic microsurgery (median, 5 percent). The second area of study was the safety and efficacy of carcinomas. In the randomized, controlled trial, no difference could be detected in the rate of complications between transanal endoscopic microsurgery and direct local excision (relative risk for overall early complication rates, 0.56; 95 percent confidence interval, 0.22-1.42). No differences in survival or local recurrence rate between transanal endoscopic microsurgery and anterior resection could be detected in either the randomized, controlled trial (hazard ratio,1.02 for survival) or the nonrandomized, comparative study. There were 2 of 25 (8 percent) transanal endoscopic microsurgery recurrences in the randomized, controlled trial, but no figures were given for recurrence after anterior resection. In the case series, the median local recurrence rate for transanal endoscopic microsurgery was 8.4 percent, ranging from 0 percent to 50 percent. The third comparison was cost of the procedures. Transanal endoscopic microsurgery had both a lower recurrence rate and a lower cost than local excision or anterior resection for adenomas. Although the effectiveness of transanal endoscopic microsurgery could not be established for carcinomas, costs were lower than those for either anterior resection or abdominoperineal resection.

CONCLUSIONS

The evidence regarding transanal endoscopic microsurgery is very limited, being largely based on a single relatively small randomized, controlled trial. However, transanal endoscopic microsurgery does appear to result in fewer recurrences than those with direct local excision in adenomas and thus may be a useful procedure for several small niches of patient types--e.g., for large benign lesions of the middle to upper third of the rectum, for T1 low-risk rectal cancers, and for palliative, not curative, use in more advanced tumors.

The Role of Transanal Endoscopic Microsurgery for Rectal Tumors

PURPOSE

The management of rectal tumors is complex, because of the balance between preserving rectoanal function and curing the patient. Transanal endoscopic microsurgery (TEM) is both an effective treatment for benign rectal tumors and early cancers, and a diagnostic tool for determining tumor depth, or for residual tumors of post endoscopic mucosal resection. In the present study, we evaluated the role of TEM in the management of rectal tumors.

METHODS

Twenty-six patients with rectal tumors underwent TEM from December 2000 through March 2005 in our department. The operations were performed by a single surgeon, and the indications were mainly limited to a) benign tumors for which endoscopic resection was difficult, b) early cancers that had invaded the submucosa within 500 microm of the muscularis mucosae, c) submucosal tumors, i.e., gastrointestinal stromal tumor, carcinoid tumors, d) local excision for diagnosis, and e) palliative resection for high-risk cases. Anesthesia, operation time, sizes of the tumor and of resected specimens, postoperative complications, length of hospitalization, pathological results, and postoperative recurrence rate were reviewed.

RESULTS

The mean age of patients was 61.9 years, and the cases included 14 rectal cancers, 7 adenomas, 1 gastrointestinal stromal tumor, and 3 rectal carcinoid tumors. The mean operation time was 96 min (range, 40 approximately 235 min.). The average postoperative hospital stay was 4.8 days. All tumors were resected with horizontal and vertical safety margin. The mean size of the resected specimens was 9.0 cm(2). In one case, the tumor had infiltrated the proper muscle layer, as shown by intraoperative frozen sectioning, which necessitated abdominoperineal resection. In 3 cases, pathological examination revealed massive infiltration into the submucosal layer. 2 patients underwent low anterior resection, and the remaining patient refused additional surgery despite our recommendation. No deaths occurred. No major postoperative complications were noted. The mean follow-up period was 27.2 months. Only one case of lymph node metastasis was observed, in the left iliac lymph node 3 years after TEM.

CONCLUSIONS

TEM is a minimally invasive surgical procedure for rectal tumors, which allows the whole depth of the rectal wall to be resected with a safety surgical margin. Although TEM requires technical skill and accurate preoperative diagnosis, the procedure is safe, facilitates accurate diagnosis of tumor depth, and limits the need for additional surgery.