TaTME Versus Open Intersphincteric Resection After Neoadjuvant Concurrent Chemoradiotherapy.
TaTME Versus Open Intersphincteric Resection After Neoadjuvant Concurrent Chemoradiotherapy.
The two surgical options for lower 1/3 rectal cancer is APR and sphincter sparing procedures.
 Intersphincteric resection is procedure to treat very low rectal cancer within 2 cm from the
 dentate line to avoid permanent colostomy,improves the quality of life with better
 genitourinary function. Neoadjuvant chemo-radiotherapy is routine for T3 cases.
During the period between April 2013 and July 2019, a non-randomized controlled study was
 performed at two tertiary centers; Oncology Centre of Mansoura University and Policlinico
 Umberto Primo surgery department of SAPIENZA university of Rome after referral from the
 clinical oncology and nuclear medicine department. After diagnosis of ultralow rectal cancer,
 a written informed consent was obtained from patients after full explanation of the
 procedure, the likely outcome and the potential complications that may occur. Digital rectal
 examination was conducted to assess the distance of lower tumor margin from the anal verge
 and the anal tone. Anesthetic fitness and tumour markers (CEA) were assessed. Pelvis MRI
 and/or endorectal ultrasound (EUS), abdomen and chest CT scan and colonoscopy with biopsy
 were done for all cases. Re-evaluation after neoadjuvant chemo-radiotherapy by MRI and EUS.
 Inclusion criteria included a very low rectal cancer below 5 cm from the anal verge with
 normally continent and tumor-free external anal sphincter. Neoadjuvant treatment was given to
 all patients with T3 or node positive tumors. Exclusion criteria were T4, metastatic tumors
 and fecal incontinence. Fifty patients were excluded from the study (Fig.1). One hundred and
 ten patients with ultralow rectal adenocarcinoma, with matched age and sex (table 1), were
 non-randomly classified into two equal groups: the control group included 55 patents that
 underwent sphincter sparing by open ISR with TME (O-ISR Group) and the 2nd group included 55
 patents that underwent Transanal minimally invasive ISR with TME (TAMIS Group).

 Surgical technique:

 In open ISR, the inferior mesenteric vessels were highly ligated. After full mobilization of
 the left colon and splenic flexure was done, the plane for TME was followed down in the
 pelvis superficial to the hypogastric fascia as low as possible to enter into the posterior
 intersphincteric plane. A non-endoscopic perineal phase was then initiated using an anal
 lone-star retractor to expose the anal canal. Both the mucosa and the muscular layer were
 incised 1cm below the tumor margin to transect the internal anal sphincter (IAS) and then
 closed by purse string sutures. The dissection continued between IAS and the external anal
 sphincter (EAS) starting posteriorly then laterally, where EAS is easier to identify, then
 anteriorly where the plane presented more adhesions with the urethra in male or vagina in
 female till reaching the abdominal dissection. Proximal division of the specimen started just
 below the site of inferior mesenteric vessels ligation and continued till division of the
 marginal artery at the site of the required anastomosis. The Specimen extraction and division
 was done extra-anal. A defunctioning ileostomy was done in all cases.

 In TAMIS-TME, using a lone star retractor, the 1st step was to divide and close the anal
 canal by purse-string suturing to enter the intersphincteric plane. Using TEo platform (Karl
 Storz, Tuttilingen, Germany) (fig. 2) with a 4 cm size operating proctoscope diameter,
 Transanal endoscopic dissection was initiated and continued in the intersphincteric plane
 starting posteriorly then laterally. Partial or high ISR started at the dentate line to
 remove the upper half of IAS for ultralow tumors at 3 to 4.5 from anal verge. Total or low
 ISR started 1 cm below the dentate line, removing the whole of IAS for tumours below 3 cm
 from the anal verge. The endoscopic dissection continued in the same sequence as the control
 group along the levator ani. Then continue posteriorly till reaching as much as possible,
 then dissection continued laterally and anteriorly to reach the peritoneal reflection. Then,
 the laparoscopic phase was initiated to ligate the inferior mesenteric vessels and mobilize
 the splenic flexure and left colon. The peritoneal reflections were then divided to connect
 to the transanal part. The specimen was then extracted transanally and the Colo-anal
 anastomosis was done in two layers. A defunctioning ileostomy was done in all cases.
Inclusion Criteria:

 -  Patients with low rectal carcinoma(The lowest margin of tumor located 3 cm from anal
 verge ; ≤ 2 cm from dentate lines; 1 cm from anorectal rings.

 -  Local spread restricted to the rectal wall or the internal anal sphincter.

 -  Adequate preoperative sphincter function and continence.

 -  Absence of distant metastasis.

 Exclusion Criteria:

 -  Contraindications to major surgery and American Society of Anesthesiologists (ASA)
 Physical Status scoring 4.

 -  Metastatic rectal cancer.

 -  Those in Dukes stage D (T4 lesion).

 -  Undifferentiated tumours.

 -  Local infiltration of external anal sphincter or levator ani muscles.

 -  Tumor located more than 2 cm above the dentate line.

 -  Presence of fecal incontinence.

 -  Patients unwilling to take part in the study.