Transanal Versus Laparoscopic Total Mesorectal Excision: A Comparative Prospective Clinical Trial from Two Centers

Abstract

Purpose:

Laparoscopic total mesorectal excision (LapTME) faced many obstacles in obese male with narrow pelvis and bulky mesorectum with increased risk of incomplete mesorectal excision and positive circumferential resection margin (CRM) and distal resection margin (DRM). Transanal total mesorectal excision (TaTME) is reported to result in a better quality total mesorectal excision (TME) specimen, lower incidence of CRM and DRM involvement, and higher rates of sphincter preservation. To date, there is still a debate about the feasibility and efficacy of transanal versus the laparoscopic approach for TME in middle and low rectal cancer.

Materials and Methods:

This is a prospective controlled clinical trial where 38 patients of middle or low rectal cancer from two tertiary centers were nonrandomly assigned to either TaTME or LapTME.

Results:

Eighteen patients were operated by TaTME versus 20 patients by LapTME. Mean body mass index was significantly higher in the TaTME group (30.74 ± 7.79) than in the LapTME group (25.99 ± 4.68) (P = .03). TaTME was associated with more transanal specimen extraction (55.5% versus 20%, P = .06). No significant differences were detected in CRM, DRM, peri- or postoperative complications, or conversion rates with more reported Clavien–Dindo grade III complications in the TaTME group (P = .29).

Conclusions:

TaTME facilitated rectal cancer surgery in obese patients and increased the chance of transanal specimen extraction with equivalent oncological outcomes to conventional LapTME. Further studies are recommended to build better evidence.

Introduction

Worldwide, colorectal cancer is the third most commonly diagnosed cancer and the second cause of mortality.¹ Thanks to the introduction of total mesorectal excision (TME) concept by Richard Heald, local recurrence rates after rectal cancer surgery dropped to 4%. Till now, TME is considered the milestone of modern rectal cancer surgery.² Laparoscopic proctectomy with TME offered several merits of minimally invasive surgery, including less blood loss, less postoperative pain, earlier recovery, fewer wound complications, and shorter hospital stay. Moreover, it made rectal cancer surgery more feasible due to a magnified view and better manipulation of deep pelvic parts, preventing autonomic nerve injury and ensuring better functional results.³ Laparoscopic proctectomy in obese male with narrow pelvis and bulky mesorectum possesses the risk of incomplete mesorectal excision and positive circumferential resection margin (CRM) and distal resection margin (DRM).⁴ Furthermore, the rate of conversion to laparotomy in these patients is reported to be high with more complications and worse surgical outcomes.⁵

The difficulty of applying the laparoscopic staplers distal to low-lying tumors in a narrow pelvis leading to multiple firings with increased risk of anastomotic leakage and infiltrated distal margin is a major concern. Besides, the ACOSOG Z6051 and ALaCaRT trials failed to prove noninferiority of laparoscopic to open rectal cancer surgery regarding negative margins and quality of TME specimen, which raises more concerns about the quality of the oncological outcome of laparoscopic rectal resection.^6,7

That is why a “bottom to up” was suggested to overcome these drawbacks. It was first introduced by Gerald Marks under the name of transanal transabdominal proctosigmoidectomy with coloanal anastomosis for resection of low rectal cancer.⁸ Thanks to the innovation of transanal endoscopic microsurgery and natural orifice transluminal endoscopic surgery (NOTES) and their incorporation with the concept of “ bottom to up” approach, transanal total mesorectal excision (TaTME) was introduced, adopted, and gained popularity among colorectal surgeons.⁹

TaTME is reported to result in a better quality of TME specimen, lower incidence of CRM and DRM involvement, and higher rates of sphincter preservation without compromising postoperative continence.^10,11 However, this should overweigh the risks of cancer cell dissemination, bacterial contamination, and the reported unique TaTME complications such as urethral injuries.¹² It is worth mentioning that most of the evidence favoring TaTME is withdrawn from retrospective case series with few comparative analysis and meta-analysis.¹³ Moreover, a recently published meta-analysis included only 12 studies with only 2 prospective cohort studies, which was reported by the authors as one of the study limitations.¹⁴ In the present study, we prospectively compared the intraoperative, pathological, and postoperative outcomes of TaTME and laparoscopic total mesorectal excision (LapTME) for middle and low-lying rectal cancer.

Materials and Methods

This is a prospective, nonrandomized, controlled clinical trial. Patients with pathologically proven middle or low rectal cancer (i.e., located at or <10 cm from the anal verge as defined by magnetic resonance imaging [MRI] and/or rigid proctoscopy) from two tertiary centers were nonrandomly assigned into one of the two study groups either the TaTME group (interventional arm) or the LapTME group (control arm). This study was approved by the institutional review board with reference number MD/17.04.84. Patients who were included were aesthetically fit with the American Society of Anesthesiologists (ASA) score from 1 to 3. Patients with locally advanced disease stage (T3–4 or node positive) were treated by neoadjuvant chemoradiation first and then restaged again. Staging of study patients included MRI and computed tomography scanning of the chest, abdomen, and pelvis. Patients who received neoadjuvant therapy were operated within 8 weeks from cessation of radiation therapy.

The primary outcome of the study was to compare the rate of CRM and DRM involvement and lymph node retrieval between the two groups. The secondary outcome was to compare the surgical outcome (i.e., operative time, estimated blood loss, need for blood transfusion, rate of conversion. and intraoperative complications), the incidence and grading of postoperative complications (according to the Clavien–Dindo¹⁵ scale) among the two groups, and the incidence of recurrence reported in patients of both groups.

The abdominal phase of the LapTME or TaTME groups was performed in the same manner. A standard medial-to-lateral approach to ligate the inferior mesenteric vessels, lateral colonic and splenic flexure mobilization was performed and then shifting down to the holy plane after incising the peritoneal reflection. In the LapTME group, pelvic dissection is continued by laparoscopy till reaching the pelvic floor, followed by either distal stapling in middle rectal tumors or dissection in the intersphincteric plane in low-lying rectal cancer.

In the TaTME group, perineal dissection started by the application of Lone Star retractor (CooperSurgical, Trumbull, CT), followed by 2-0 prolene purse-string suture 1 cm below the tumor. This stitch could be performed either transanally in low tumors or through the platform when feasible in slightly higher tumors. Transanal platform was then introduced. In 13 cases, TEO proctoscope (Karl Storz, Tuttlingen, Germany) was used, while in the remaining 5 cases, GelPoint Path Transanal access system (Applied Medical) was used. Circumferential dissection of the rectum was initiated in the mesorectal plane after the establishment of pneumorectum till reaching the peritoneal reflection. The specimen was extracted either transanally or through Pfannenstiel incision or extension of laparoscopic port. The anastomosis was performed either in two-layered hand-sewn or by end-to-end anastomosis (EEA) circular stapler.

The statistical software SPSS (Statistical Package for Social Scientists, SPSS 24.0; IBM Corp., Armonk, NY) was used for the analysis of the results. Continuous variables are presented as mean and standard deviation (SD) if normally distributed or as median and range when nonnormally distributed. Independent samples t-test was used to compare parametric data, whereas the Mann–Whitney U test was used to compare nonparametric data. Categorical data were compared by Pearson's chi-square test or Fisher's exact test when appropriate. A P-value <0.05 was considered statistically significant.

Results

A total number of 38 patients were enrolled during the study period (April 2017–May 2019). Of these, 18 patients were nonrandomly assigned to the study group (TaTME group) and 20 patients to the control group (LapTME group). Table 1 illustrates the baseline characteristics of the two groups. There was no statistically significant difference between the two groups regarding the age, ASA, Charlson comorbidity index, the number of patients who received neoadjuvant chemoradiation, or metastasis. The median tumor distance from the anal verge in the TaTME group was lower than that in the LapTME group (4.5 versus 6 cm), but this difference was not statistically significant. In the LapTME group, there were 7 females and 13 males, whereas in the TaTME group, there were 10 females and 8 males, but this was not statistically significant. The mean body mass index (BMI) of the TaTME group (30.74 ± 7.79) was significantly higher than that of the LapTME group (25.99 ± 4.68) (P = .03).

Table 1.

Demographic and Preoperative Data of the Two Study Groups

Parameter	LapTME group (n = 20)	TaTME group (n = 18)	P
Age, years, mean ± SD	53.40 ± 11.38	53.89 ± 13.99	.13^a
Sex			.32^b
Male	13	8
Female	7	10
BMI, kg/m², mean ± SD	25.99 ± 4.68	30.74 ± 7.79	.03 ^a
ASA, median (range)	2 (1–3)	2 (1–3)	.82^c
ASA 1	5	3	.68^d
ASA 2	13	14
ASA 3	2	1
CCI, median (range)	4 (2–7)	4 (2–6)	.51^c
Distance from the anal verge, cm, median (range)	6 (4–9)	4.5 (3–10)	.55^c
Neoadjuvant therapy			.66^b
Yes	16	16
No	4	2
Metastasis			1.00^b
Yes	2	1
No	18	17

Bold indicates significance at P < 0.05.

t-Test.

Fisher's exact test.

Mann–Whitney U test.

Pearson's chi-square test.

ASA, American Society of Anesthesiologists; BMI, body mass index; CCI, Charlson comorbidity index; LapTME, laparoscopic total mesorectal excision; SD, standard deviation; TaTME, transanal total mesorectal excision.

Neoadjuvant therapy was employed in 16 of the 20 cases in the LapTME group and in 16 of the 18 cases in the TaTME group. All cases received neoadjuvant long-course chemoradiation except 1 case in each group who suffered from liver metastasis and so received the former protocol plus biological therapy. Metastasis was encountered in 2 cases in the control group (one of them was hepatic that was managed by radiofrequency ablation and the other was inguinal lymph node metastasis, which was managed by surgical resection), whereas in the TaTME group, only 1 case suffered from hepatic metastasis that was managed by surgical resection.

Regarding the operative data, the mean and SD of the operative time (in minutes) of the TaTME group were nonsignificantly higher than that of the LapTME group (320.94 ± 80.01 versus 251.45 ± 77.51, P = .74). Estimated blood loss and hospital stay were also higher in the TaTME group, but of no statistical significance. Table 2 shows the operative data of the two groups. Five cases received intraoperative packed red blood cells (RBCs) transfusion in the TaTME group versus 1 case in the LapTME group. This was not statistically significant but indeed of clinical significance. Intraoperative complications were equal among the two groups where each of the left-sided ureteric injury or posterior vaginal wall injury occurred in 1 case in each group. Two cases in the LapTME group were converted to laparotomy (due to injury of the left ureter and the other case due to anesthesia recommendation) versus 1 case in the TaTME group (due to injury of the left ureter). One case in the TaTME group was converted to laparoscopic dissection due to difficult pelvic dissection through the transanal platform. Manual coloanal anastomosis was equally used in the two groups while EEA circular stapler was used more in the LapTME group (10 versus 7 cases). Transanal specimen extraction was utilized more in TaTME than LapTME (13 versus 6 cases), while LapTME was more associated with specimen extraction through Pfannenstiel incision (10 versus 4 cases) (P = .06). All cases underwent fecal diversion, which was loop ileostomy except 1 case in the TaTME group who underwent Hartman's colostomy due to severe pelvic post-radiation fibrosis where the operating team thought that it may endanger the anastomosis vascularity.

Table 2.

Operative Parameters of the Two Study Groups

Parameter	LapTME group (n = 20)	TaTME group (n = 18)	P
Operative time, minutes, mean ± SD	251.45 ± 77.51	320.94 ± 80.01	.74^a
Estimated blood loss, mL, median (range)	230 (50–550)	335 (100–800)	.14^b
Intraoperative blood transfusion			.08^c
Yes	1	5
No	19	13
Hospital stay, median (range)	6 (4–14)	8 (3–19)	.18^b
Intraoperative complications			1.00^c
Yes	2	2
No	18	16
Conversion to open			1.00^c
Yes	2	1
No	18	17
Specimen extraction			.06^d
Pfannenstiel	10	4
Transanal	6	13
Extension of port site	2	0
Midline(converted)	2	1
Anastomosis technique			.49^d
Hand-sewn	10	10
EEA stapler	10 (Double stapling)	7 (Single stapling)

t-Test.

Mann–Whitney U test.

Fisher's exact test.

Pearson's chi-square test.

EEA, end-to-end anastomosis.

CRM was infiltrated in 1 case of TaTME, and DRM was infiltrated in 1 case of TaTME (despite being negative by intraoperative frozen section examination), while all cases in the LapTME group showed negative CRM and DRM. The case of DRM infiltration was counseled, and abdominoperineal resection was performed. Lymph node retrieval was nonsignificantly higher in the LapTME group than in the TaTME group (12 [2–42] versus 8 [2–25], P = .22). Thirty-day postoperative mortality was reported in only 1 case in the LapTME group. This was encountered in a 68-year-old diabetic female due to septic shock following necrotizing fasciitis in the Pfannenstiel incision for specimen extraction. It is worth mentioning that this patient was reluctant to her scheduled follow-up visits. Table 3 illustrates pathological and follow-up data of the study groups.

Table 3.

Pathological and Postoperative Data of the Two Study Groups

Parameter	LapTME group (n = 20)	TaTME group (n = 18)	P
Circumferential margin, mL, median (range)	10 (1–25)	15 (2–20)	.83^a
Free	20	17	.47^b
Infiltrated	0	1
Distal margin
Free	20	17	.47^b
Infiltrated	0	1
Lymph node harvest, median (range)	12 (2–42)	8 (2–25)	.22^a
Quality of TME			.55^c
Complete	17	14
Near complete	3	3
Poor	0	1
AJCC staging			.46^c
pCR	3	2
I	6	5
II	3	6
III	6	4
IV	2	1
TRG			.85^c
0	3	2
1	3	2
2	4	6
3	6	6
Hospital stay, days, median (range)	6 (4–14)	8 (3–19)	.18^a
30-Day postoperative complications	5	7	.48^c
	Vaginal infection (1)	Disrupted coloanal anastomosis (3)
	Wound infection (1)	Urinary leakage (1)
	UTI (1)	Urinary leakage + DVT (1)
	Urinary leakage (1)	Intraperitoneal hematoma (1)
	Asymptomatic anastomotic leakage (1)	UTI (1)
Clavien–Dindo classification			.18^c
I	0	1	.29^b
II	3	1
III	1	6
IV	1	0
Minor events (grade I–II)	3	2
Major events (grade III–IV)	2	6
Readmission	2 [wound infection (1), vaginal infection (1)]	4 [due to disrupted coloanal anastomosis (2), urine leakage (1), DVT (1)]	.39^b
30-Day postoperative mortality	1	0	1.00^b
Remote complications (total)	2	4	.39^b
Colovaginal fistula	0	2
Anastomotic stricture	2	1
Neurogenic bladder	0	1
Mortality all over the study follow-up period	1	2	.59^b
DRESS			.39^c
2	4	5
3	14	8
4	1	3
Not applicable	1	2
Recurrence	3 (all systemic)	2 (local+systemic)	1.00^b

Mann–Whitney U test.

Fisher's exact test.

Pearson's chi-square test.

AJCC, American Joint Committee on Cancer; DRESS, digital rectal examination scoring system; DVT, deep venous thromboembolism; pCR, pathological complete response; TRG, tumor regression grade score; UTI, urinary tract infection.

Thirty-day complications were nonsignificantly higher in the TaTME group. However, it is clinically important to report more Clavien–Dindo III complications in the TaTME group (P = .29). Disrupted coloanal anastomosis was encountered in 3 cases that necessitated refashioning under regional anesthesia, followed by urinary leakage from the drains due to ureteric injury (one was right and the other was left) that was managed by percutaneous nephrostomy drainage after urological consultation. Only one Clavien-Dindo grade III complication was reported in the LapTME group due to the right-sided ureteric injury that was managed by Double-J stenting under regional anesthesia. Asymptomatic anastomotic leakage was reported in only 1 case in the LapTME group and was managed conservatively.

During a median follow-up of 9.6 (1–29.2) months, 2 cases were complicated by colovaginal fistula in the TaTME group and was managed by transperineal repair, while anastomotic stricture was reported in only1 case and was managed by mechanical dilatation. However, anastomotic stricture was encountered in 2 cases in the LapTME group: one was managed by mechanical dilatation and the other was ultimately managed by terminal colostomy. Recurrence events were reported in 3 cases in the LapTME arm, all were systemic recurrences, while in the TaTME group, 2 cases of local and systemic recurrences were reported.

By the end of the follow-up period, 2 cases in the TaTME group died (one during receiving adjuvant chemotherapy cycles and the other after pulmonary embolism secondary to deep venous thromboembolism).

Discussion

Although rectal cancer surgery is very challenging and technically demanding, it is rapidly advancing with already available various surgical techniques and evolving new ones being introduced.¹⁶ The continuous advances in surgical technology led to the development and evolution of several minimally invasive approaches to rectal cancer from laparoscopic, hand-assisted laparoscopic, robotic surgery, and eventually NOTES, which TaTME is one of its types.¹⁷

LapTME could be technically difficult in obese patients, male gender, locally advanced tumors, narrow pelvis, and in patients with a history of downstaging chemoradiation and bulky mesorectum. This might lead to difficult distal stapling with increased risk of infiltrated distal margins and an increased incidence of anastomotic leakage due to multiple firings.¹⁸

In the present study, 10 females and 8 males were operated by TaTME versus 7 females and 13 males in the LapTME group. Although this variation was not statistically significant, it reflected the epidemiological difference among Egypt and Italy regarding the gender distribution of rectal cancer. In their study, Russo et al. reported higher incidence of rectal cancer among males (54.38% versus 45.62%), while Metwally et al. reported a comparable gender distribution (124 females versus 121 males).^19,20

TaTME was reported to overcome these obstacles, thanks to several proposed advantages. The first step of TaTME is distal transection, which ensures better distal margin and obviates the need for distal stapling.²¹ Moreover, it allows for better visualization of the perirectal tissue and obviates the need for difficult traction of bulky mesorectum, thanks to the pneumodissection and easier retraction through the transanal platform.¹³ In the present study, higher BMI was significantly reported in the TaTME group than in the LapTME group (30.74 ± 7.79 versus 25.99 ± 4.68, P = .03), which emphasizes the advantage of this technique in this cohort of patients.

Although previous studies reported TaTME to be completed in shorter operative time than LapTME,^22,23 in the current study, the mean operative time was higher in the TaTME group (320.94 ± 80.01 versus 251.45 ± 77.51, P = .74), which was not statistically significant but might have clinical importance. This could be explained by the fact that in either of two centers, TaTME was accomplished by one team, which started by the laparoscopic abdominal phase and shifted to the transanal phase, which of course could result in longer operative time. Also, in both centers, TaTME was recently introduced, which might suggest an impact of a learning curve.

In a recent meta-analysis, Wu et al. reported statistically significant less estimated blood loss volume in the TaTME group than in the LapTME group.¹² Although it was not statistically significant, estimated blood loss was higher in the TaTME group, which was reflected by more need for packed RBCs transfusion. It should be noted that unlike the meta-analysis mentioned, higher BMI was reported in our TaTME group patients, which indeed might have affected the blood loss in those patients. In a previous meta-analysis, higher BMI was correlated with longer operating time and more perioperative complications including more estimated blood loss volumes in patients who were operated by laparoscopic colorectal surgery.²⁴

Conversion to laparotomy is considered one of the major challenges of laparoscopic rectal cancer surgery. Several risk factors have been reported to increase the risk of conversion including obesity, locally advanced tumors, narrow pelvis, and iatrogenic injury to the ureters and bowels.²⁵ The rate of this conversion could reach up to 34% of cases operated by LapTME.¹⁸ In the present study, conversion to laparotomy was encountered once in the TaTME group (5.5%), whereas it occurred in 2 cases in the LapTME group (10%). This is nearly comparable with the results reported in a recent study by Sparreboom et al., where no cases were converted in the TaTME group versus 10% of cases in the LapTME group.²⁶ It is worth mentioning that the cause of conversion in the TaTME group was a ureteric injury, which is, in fact, a complication of the laparoscopic phase of the surgery.

A minimum of 1 mm circumferential resection margin is considered to be free. This is correlated in several studies with less local recurrence rates and better disease-free survival.²⁷ In their study, Detering et al. reported comparable rates of CRM involvement among cases operated by TaTME or LapTME (4.3% versus 4.0% respectively).²⁸ In a recent meta-analysis, Jiang et al. reported significantly greater CRM infiltration in cases operated by TaTME with comparable results regarding DRM, lymph node harvest, and quality of mesorectal excision among both techniques.²⁹ In the present study, although CRM infiltration was encountered in 1 case in the TaTME group versus no cases in the LapTME group, the median CRM was higher in the TaTME group than in the LapTME group (15 versus 10 mm); however, both results were not statistically significant.

The distal margin was infiltrated in 1 case in the TaTME group; although it was statistically insignificant, it is indeed of clinical importance as the case was managed by abdominoperineal resection and terminal colostomy afterward. It should be noted that in this case, the tumor was very low (≤3 cm away from the anal verge), T3 by final pathology report, and the case received neoadjuvant chemoradiation with minimal response to neoadjuvant tumor regression grade (TRG) 2. This could explain the infiltrated margin in the final pathology report by the presence of tumor cells away from the resection margin from residual tumor after preoperative chemoradiation or the presence of occult tumor cells underneath the mucosal cut edge.^30,31

It is important to highlight that either case of infiltrated CRM or DRM was operated by TaTME approach. Infiltration of CRM or DRM could be affected by several factors such as bulky tumors, proximity of the tumor to the anal verge, and narrow pelvis.³² As aforementioned CRM infiltration could be related to other predictors as obesity in our TaTME group, and the distal margin infiltration was mainly a fallacy of frozen section in post-therapy very low rectal cancer treated by intersphincteric resection initially. The false-negative margin by frozen section after chemoradiation was previously reported.³³

Comparable results were reported in terms of lymph node retrieval and quality of mesorectal excision where complete and near-complete specimens were reported in 94.4% versus 100% in TaTME versus LapTME cases. The slightly encountered lower TME quality, together with the only case of CRM infiltration in the TaTME group, can be explained by being operating in obese patients and having more blood loss, which are both reported as predictors of the quality of TME.³⁴

In the present study, the rate of 30-day postoperative complications was nonsignificantly higher among the TaTME group versus the LapTME group (38.8% versus 25%, P = .48). These results are comparable with the recent study from the Netherlands, where overall complication rates were higher in the TaTME group versus the LapTME group (42.4% versus 36.9%, P = .13).²⁸ However, it is clinically significant to mention that more Clavien–Dindo III–IV complications were reported in the TaTME group than in the LapTME group (6 versus 2 cases, P = .29), three of the reported grade III complications in TaTME cases disrupted coloanal anastomosis that were managed by refashioning under regional anesthesia.

Although laparoscopic rectal cancer surgery was reported to minimize wound-related morbidity, surgical site infection and incisional hernia could be encountered at the wounds from which specimen was extracted and/or the anvil is introduced.³⁵ The rates of wound infection are higher with Pfannenstiel and midline incisions than the right or left lower quadrant and stoma site incisions.³⁶ In our study, the only reported postoperative mortality was in the LapTME group secondary to septic shock after complicated Pfannenstiel wound infection. Interestingly, TaTME was associated with more transanal specimen extraction (P = .06), which surely obviated the need for abdominal incisions and their possible complications. It is worth mentioning that some factors could influence a surgeon's decision to extract the specimen either transanally or through an abdominal incision based on the bulk of mesorectum and the anal canal diameter. TaTME could facilitate transanal specimen extraction due to distal transection while it could be inconvenient and more time consuming to do the same in LapTME as it would be needed to reopen the distal staple line for specimen extraction.

Recurrence rates were comparable among the present study groups. However, the reported 2 recurrent cases in the TaTME group showed local recurrence events plus the systemic ones, unlike the LapTME group. Although this might reflect aggressive tumor behavior, it is worth mentioning that the final pathology of one of these cases showed complete pathological response to neoadjuvant therapy and this recurrence was reported <8 months after surgery. Larsen et al. reported local recurrence rates among 9.5% of their patients, with a median time to recurrence of 11 months. They suggested some risk factors such as the airflow during perineal dissection, incorrect dissection planes, imperfect purse-string suture, and poor surgical technique.³⁷

The present study is a prospective controlled clinical trial from two tertiary centers. However, some limitations should be stated. First, it is a nonrandomized comparative trial that surely provides weaker evidence. Moreover, the relatively small sample size might have impacted the statistical significance of some of the results. Although it should be mentioned as merit, this study was performed among two tertiary centers, which might have an impact due to the possible difference among surgeons in the two hospitals. Finally, two different transanal platforms were used in the TaTME cases.

Conclusions

TaTME is a problem-solving procedure for minimally invasive rectal cancer surgery specially in obese patients. Furthermore, TaTME facilitates natural orifice specimen extraction through the anus. However, no oncological significant differences over conventional LapTME were reported. Stronger evidence and long-term oncological results should be awaited before the standardization of its implementation in rectal cancer management.

Footnotes

Acknowledgment

The first author would like to express his appreciation to Dr. Francesca Aleotti, Dr. Gehad A. Saleh, Dr. Mai A. Abdelazez for their assistance and efforts.

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was recieved for this article.

References

Bray

, Ferlay

, Soerjomataram

, Siegel

, Torre

, Jemal

. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin, 2018; 68:394–424.

Heald

, Husband

, Ryall

. The mesorectum in rectal cancer surgery—the clue to pelvic recurrence?. Br J Surg, 1982; 69:613–616.

Cheung

, Lange

, Buunen

, Lange

. Current technique of laparoscopic total mesorectal excision (TME): An international questionnaire among 368 surgeons. Surg Endosc, 2009; 23:2796.

Penna

, Hompes

, Arnold

. TaTME registry collaborative transanal total mesorectal excision. Ann Surg, 2017; 266:111–117.

Guillou

, Quirke

, Thorpe

, Walker

, Jayne

, Smith

, et al. Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): Multicentre, randomised controlled trial. Lancet, 2005; 365:1718–1726.

Fleshman

, Branda

, Sargent

, Boller

, George

, Abbas

, et al. Effect of laparoscopic-assisted resection vs open resection of stage II or III rectal cancer on pathologic outcomes: The ACOSOG Z6051 randomized clinical trial. JAMA, 2015; 314:1346–1355.

Stevenson

, Solomon

, Lumley

, Hewett

, Clouston

, Gebski

, et al. Effect of laparoscopic-assisted resection vs open resection on pathological outcomes in rectal cancer: The ALaCaRT randomized clinical trial. JAMA, 2015; 314:1356–1363.

Marks

, Mohiuddin

, Rakinic

. New hope and promise for sphincter preservation in the management of cancer of the rectum. Semin Oncol, 1991; 18:388–398.

Atallah

, Albert

, Larach

. Transanal minimally invasive surgery: A giant leap forward. Surg Endosc, 2010; 24:2200–2205.

10.

Atallah

. Transanal total mesorectal excision: Full steam ahead. Tech Coloproctol, 2015; 19:57–61.

11.

Elmore

, Fumagalli Romario

, Vignali

, Sosa

, Angiolini

, Rosati

. Laparoscopic anterior resection with transanal total mesorectal excision for rectal cancer: Preliminary experience and impact on postoperative bowel function. J Laparoendosc Adv Surg Tech A, 2015; 25:364–369.

12.

, Zhou

, Chen

, Wang

, Feng

. Short-term outcomes of transanal versus laparoscopic total mesorectal excision: A systematic review and meta-analysis of cohort studies. J Cancer, 2019; 10:341–354.

13.

Persiani

, Biondi

, Pennestrì F, Fico V, De Simone V, Tirelli F, et al. Transanal total mesorectal excision vs laparoscopic total mesorectal excision in the treatment of low and middle rectal cancer: A propensity score matching analysis. Dis Colon Rectum, 2018; 61:809–816.

14.

Lin

, Yu

, Chen

, Hu

, Huang

, He

, et al. Transanal versus laparoscopic total mesorectal excision for mid and low rectal cancer: A meta-analysis of short-term outcomes. Videosurgery Miniinv, 2019; 14:353–365.

15.

Clavien

, Barkun

, De Oliveira

, Vauthey

, Dindo

, Schulick

, et al. The Clavien-Dindo classification of surgical complications: Five-year experience. Ann Surg, 2009; 250:187–196.

16.

Perdawood

. History of rectal cancer surgery. In: Dapri G, Marks JH (eds). Surgical Techniques in Rectal Cancer: Transanal, Laparoscopic and Robotic Approach. Tokyo: Springer Japan, 2018, pp. 3–18.

17.

Lacy

, De Lacy

, Valverde

. Transluminal cancer surgery. Surg Oncol Clin N Am, 2019; 28:101–113.

18.

Simillis

, Hompes

, Penna

, Rasheed

, Tekkis

. A systematic review of transanal total mesorectal excision: Is this the future of rectal cancer surgery?. Colorectal Dis, 2016; 18:19–36.

19.

Russo

, Andreano

, Sartore-Bianchi

, Mauri

, Decarli

, Siena

. Increased incidence of colon cancer among individuals younger than 50 years: A 17 years analysis from the cancer registry of the municipality of Milan, Italy. Cancer Epidemiol, 2019; 60:134–140.

20.

Metwally

, Abdelkhalek

, Elbalka

, Zuhdy

, Fareed

, Eldamshity

. Clinico-epidemiologic criteria and predictors of survival of rectal cancer among Egyptians in Delta region. J Coloproctol, 2019; 39:339–345.

21.

Hompes

, Arnold

, Warusavitarne

. Towards the safe introduction of transanal total mesorectal excision: The role of a clinical registry. Colorectal Dis, 2014; 16:498–501.

22.

, Xu

, Cheng

, Ying

, Cheng

, Cao

, et al. Comparison of short-term clinical outcomes between transanal and laparoscopic total mesorectal excision for the treatment of mid and low rectal cancer: A meta-analysis. Eur J Surg Oncol, 2016; 42:1841–1850.

23.

, Gao

, Song

, Zhang

, Wang

, et al. Transanal total mesorectal excision (taTME) for rectal cancer: A systematic review and meta-analysis of oncological and perioperative outcomes compared with laparoscopic total mesorectal excision. BMC Cancer, 2016; 16:380.

24.

Fung

, Trabulsi

, Morris

, Garfinkle

, Saleem

, Wexner

, et al. Laparoscopic colorectal cancer resections in the obese: A systematic review. Surg Endosc, 2017; 31:2072–2088.

25.

K-H

, Ng

DC-K

, Cheung

HY-S

, Wong

JC-H

, Yau

KK-K

, Chung

CC-C

, et al. Laparoscopic resection for rectal cancers: Lessons learned from 579 cases. Ann Surg, 2009; 249:82–86.

26.

Sparreboom

, Komen

, Rizopoulos

, van Westreenen

, Doornebosch

, Dekker

, et al. Transanal total mesorectal excision: How are we doing so far?. Colorectal Dis, 2019; 21:767–774.

27.

Lin

H-H

, Lin

J-K

, Lin

C-C

, Lan

Y-T

, Wang

H-S

, Yang

S-H

, et al. Circumferential margin plays an independent impact on the outcome of rectal cancer patients receiving curative total mesorectal excision. Am J Surg, 2013; 206:771–777.

28.

Detering

, Roodbeen

, van Oostendorp

, Dekker

J-WT

, Sietses

, Bemelman

, et al. Three-year nationwide experience with transanal total mesorectal excision for rectal cancer in the Netherlands: A propensity score-matched comparison with conventional laparoscopic total mesorectal excision. J Am Coll Surg, 2019; 228:235–244. e1.

29.

Jiang

H-P

, Li

Y-S

, Wang

, Liu

, Shen

Z-L

, et al. Pathological outcomes of transanal versus laparoscopic total mesorectal excision for rectal cancer: A systematic review with meta-analysis. Surg Endosc, 2018; 32:2632–2642.

30.

Mezhir

, Smith

, Fichera

, Hart

, Posner

, Hurst

. Presence of distal intramural spread after preoperative combined-modality therapy for adenocarcinoma of the rectum: What is now the appropriate distal resection margin?. Surgery, 2005; 138:658–664.

31.

Guillem

, Chessin

, Shia

, Suriawinata

, Riedel

, Moore

, et al. A prospective pathologic analysis using whole-mount sections of rectal cancer following preoperative combined modality therapy: Implications for sphincter preservation. Ann Surg, 2007; 245:88.

32.

Vignali

, Elmore

, Milone

, Rosati

. Transanal total mesorectal excision (TaTME): Current status and future perspectives. Updates Surg, 2019; 71:29–37.

33.

Gomes

, Bhandare

, Desouza

, Bal

, Saklani

. Role of intraoperative frozen section for assessing distal resection margin after anterior resection. Int J Colorectal Dis, 2015; 30:1081–1089.

34.

Metwally

, Coello

, Romero

, Kotb

, Hegazy

, Elnahas

, et al. Transanal total mesorectal excision for rectal cancer: Short term outcomes from two centers. J Laparoendosc Adv Surg Tech A, 2018; 28:1476–1482.

35.

Singh

, Omiccioli

, Hegge

, McKinley

. Does the extraction-site location in laparoscopic colorectal surgery have an impact on incisional hernia rates?. Surg Endosc, 2008; 22:2596–2600.

36.

Creavin

, Kelly

, Ryan

, Winter

. Meta-analysis of the impact of surgical approach on the grade of mesorectal excision in rectal cancer. Br J Surg, 2017; 104:1609–1619.

37.

Larsen

, Pfeffer

, Kørner

, Group

NCC

. Norwegian moratorium on transanal total mesorectal excision. Br J Surg, 2019; 106:1120–1121.