Low Rectal Cancers: Evolution from Abdominoperineal Resection (APR) to
Sphincter Saving Procedures (SSP)
Department of Colorectal Surgery, Sher-I-Kashmir Institute of Medical Sciences, India
Submission: January 19, 2018;Published: August 27, 2018
*Corresponding author: Asif Mehraj, Department of Colorectal Surgery, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu & Kashmir, India; Email: firstname.lastname@example.org
How to cite this article: Asif Mehraj. Low Rectal Cancers: Evolution from Abdominoperineal Resection (APR) to Sphincter Saving Procedures (SSP). Adv Res Gastroentero Hepatol. 2018; 10(3): 555788. DOI: 10.19080/ARGH.2018.10.555788.
Background: Distal rectal cancers present a challenging task for surgeons in terms of providing a Sphincter Saving Procedure (SSP) as compared to Abdominal Perineal Resection (APR) and maintaining oncological safety. APR used to be commonly performed surgery for distal rectal cancers, but because of better understanding of cancer biology, better surgical techniques, newer neoadjuvant therapies & advent of surgical staplers, SSP are being preferred by both surgeons & patients. Primary aim of our study was to determine the various types of surgical treatment options in practice for distal rectal tumours & to compare the trend of Abdominal perineal resection and Sphincter saving procedures in a high-volume centre.
Methods: It was a retrospective study of 3 years, carried out a high volume colorectal surgery division at a tertiary care institute. Patients with cancers & precancerous lesions within 10cm from anal verge who underwent APR & other SSP were included. Data was collected retrospectively from patient case sheets, medical record section, operation theatre registry and outpatient department follow up register and tabulated and processed in Microsoft excel.
Results: Overall incidence of APR as compared to SSP was 17.36%. In lesions ≤6cm & ≤7.5cm APR constituted 26.4% & 22.7 % respectively. Low Anterior resection including Ultra Low Anterior Resection was the most commonly performed operation (101 patients). Trans anal excision including Transanal Minimally Invasive Surgery (TAMIS) was performed in 37 patients.
Conclusion: As a result of improved surgical skills, better technology and high volume centre the trend is shifting more towards sphincter saving procedures.
Keywords:Colorectal surgery; Sphincter; Abdominal perineal; Trans anal excision
Management of low rectal tumours is challenging for the surgeon as well as the patient as it involves subjecting the patient to a temporary, permanent or no stoma without compromising oncologic safety. Technically working in the confines of deep pelvis is a daunting task for achieving these results. The decision whether to leave a patient with a permanent stoma or save his sphincter is of utmost importance. Surgery for low rectal cancer has gradually evolved towards more sphincter saving procedures (SSP), mainly as a result of
a) Better understanding of cancer biology
b) Improved surgical techniques
c) Neo adjuvant therapy
d) Use of surgical staplers.
e) Limited distal margin,1-2 cm instead of 5 cm
f) Concept of coloanal anastamosis (TATA Surgery)
With the advent of advanced gadgets and better understanding of tumour characteristics, more and more patients are subjected to SSP instead of APR.
The importance of distal resection margin is being overshadowed by circumferential resection margin. The main limit for sphincter preservation is not the longitudinal distance between the tumour and the anal sphincter, but the circumferential distance between the tumour and the skeletal
muscles of the pelvic floor. This new concept transforms a 1 cm
discussion to a 1mm .
Low anterior resection (LAR) is the most commonly
performed SSP in distal rectal tumours, besides other options
like various forms of Transanal Excision (TAE), transanal minimal
invasive surgery (TAMIS), transanal endoscopic microsurgery
(TEMS), intersphincteric resections (ISR) and other hybrid
procedures like transanal transabdominal (TATA) surgeries.
Most studies have reported an APR to LAR ratio of 1:3 or 1:4,
suggesting that LAR may be oncologically superior to APR [2-4].
Depending of the experience of the surgeon and specialization
of the hospital, the rate of APR in rectal cancer surgery varies
from 8% to 53% .
Primary outcome measure of our study was to determine the
various types of surgical treatment options in practice for distal
rectal tumours & to compare the trend of APR and SSP in a highvolume
This is a retrospective study of 3 years (2014-2016), carried
out in the Colorectal Division of Department of General & Minimal
Access Surgery SKIMS, Srinagar, India, which is a tertiary care
institute & a high volume centre for colorectal surgery. Institute
approval was sought to collect the data for publication purpose.
Data was collected from Operation theatre record register,
Medical Record Department, Pathology Department Archives
Store and OPD follow up register. Documented carcinoma
rectum < 10 cm from AV, patients who have underwent APR and
LAR as recorded in case sheets & patients of various types of
adenomas in low and middle rectum were included in the study.
Patients undergoing Anterior resections, simultaneous surgical
procedures, unresectable tumours at laparotomy & excision
done for other benign pathologies were excluded from the study.
We allocated patients to two groups:
i. Group A including patients who underwent APR
ii. Group B including patients who underwent various
types of SSP like LAR, TAE & TAMIS.
All the data was collected & tabulated in Excel work sheet.
Statistical analysis of data was done using Microsoft Excel and
Data of 167 patients was included in the study. More than 50
% of patients were above 50 years of age and almost 25% were
younger than 40 years. Mean (±SD) age was 46.1(±7.89) years
Surgical operations performed included 29 APR’s, 101 LAR’s
and 37 local excisions (LE) Figure 1.
The two groups were comparable in terms of age & gender.
Out of 167 total patients, 143 were operated for rectal
adenocarcinoma and 24 for adenomas with high grade dysplasia.
APR was performed in 29 (17.36%), LAR in 101 (60.48%) and LE
in 37 (22.16%) patients, hence SSP in 138 (82.64%). In case of
cancer rectum only i.e. 143 patients, 29 (20.28) were subjected
to APR & 114 (79.72%) were subjected to SSP (LAR+LE). We
further did subgroup analysis of patients whose growths were
within 6cm & 7.5cm from anal verge. Rate of APR was 26.4 and
22.7% respectively (Table 3). In further sub group analysis,
we compared the rate of APR vs. LAR in patients with growths
within 6 cm & 7.5 cm and the rate of APR was 35.8 and 29.6%
respectively (Table 4).
The standard approach of curative treatment in rectal cancer
is surgery. Early stage cancers may be successfully treated with
local excision. However, the vast majority of rectal cancers
present at advanced stages and need more extensive surgery
in the form of LAR or APR. Treatment of distal rectal tumours
is challenging in providing a continent anal opening. Sphincter
preservation with coloanal anastomosis in LAR has become an
established option for low rectal cancers, however most patients
with rectal cancer involving anal canal are routinely treated with
Colorectal cancer generally tends to be more common in
elderly, but the incidence among younger patients is increasing.
Both the incidence and mortality rates of CRC have been
decreasing in the United States . The observed decline in
incidence is largely attributed to an increase in screening,
specifically colonoscopy, which is recommended for all adults
50 years or older . Conversely, the incidence of CRC in
adults younger than 50 years, for whom CRC screening is not
recommended, appears to be increasing, and these patients are
more likely to present with advanced disease [8,9].
Several individual studies from Indian subcontinent
consistently document a relatively high proportion of young age
rectal cancer, with a mean age of around 40-45 yr [10-12]. In our
study proportion of patients younger than 40 years was 26.4%
and mean age of presentation was 50.27 years.
In a retrospective study of 153 patients of rectal cancer
involving lower and middle rectum, Shapour Omidvari et al
reported that out of 138 patients subjected to surgery 96
(70%) underwent LAR and 42 (30%) were subjected to APR
. Thus LAR to APR ratio was close to 1:3. In our study the
overall incidence of APR as compared to other sphincter saving
procedures was 17.36% which is close to 1:6. In 2007 data from
Tata Memorial Hospital, Mumbai , one of the largest centres
catering to colorectal cancer surgeries in India (2005 data)
revealed the rate of APR being 45% as compared to 55% for
LAR in low rectal cancers . If we look at some of the largest
clinical trials in rectal surgery, the aggregate percentage of
patients subjected to APR is 39 % (Table 5) .
In tumours located ≤ 6cm 26.4 % of patients underwent APR
as compared to 73.6% who were subjected to various SSPs. At
Cleveland Clinic (1995 to 2009) out of 153 low rectal cancer
(< 5cm) patients, sixty-eight (44 %) underwent APR and 85 (56
%) patients underwent LAR. Five of the 85 LAR operations were
inter sphincteric resections (<5cm) .
Jonas Geohl from a cancer centre in Germany reported their
data from1985 to 2007 (Table 6), wherein they performed
surgeries on 725 low rectal cancers within 7.5cm from anal
verge. SSP were performed in 379 (52.3%) patients including
LAR in 275 and inter sphincteric resection in 104 patients. APR
was done on 346 (47.7%) patients . In our series 29.6%
patients who had their tumours within 7.5% were subjected to
One of the reasons for a low rate of APR in our study is the
volume of rectal surgeries we perform at our centre. On an
average we perform more than 100 rectal cancer surgeries and
along with colon almost 250-300 colorectal cancer surgeries
every year. In this study we have included only low and middle
rectal cancers over a period of 3 years and the number is 167
for 3 years. A high-volume centre has been defined as a centre
where >24 (17-35) rectal cancer surgeries or >126 (85-167)
colon surgeries are performed per year . In a meta-analysis
by Talya Salz et al.  they reported that many studies that
measured hospital volume and surgery type, found a positive
association between higher hospital volume and higher rate of
sphincter-sparing procedures. The significant odds ratios were
0.44, 0.55, and 0.73. Significant differences between APR rates
for high and low volume hospitals were reported as 26.4% vs.
29.8% for high and low volume, respectively, in one study, and
47% vs. 49% for high and low volume hospitals, respectively, in
another study [20,21].
Low rectal cancer continues to be a challenge for the surgeon
in maintaining balance between oncological clearance and
sphincter preservation. Most of such patients can be offered
continent sphincters as a result of improvement in knowledge
and skills besides innovations in technology. The case volume
of the centre plays a pivotal role in performing sphincter
preserving operations. Ideally all low volume centres should
preferably refer these cases to high volume centres for giving
the maximum possible benefit to the patients in the form of
sphincter preservation and better quality of life.