Technical evolution in rectal cancer surgery
Authors:   , Koedam Thomas Willem Anton 
Published: February 2024

1 | Rectal preserving therapies
Local excision has shown to be well tolerated and oncologically safe for patients with rectal adenomas and even low-risk pT1 carcinomas. For more advanced staged rectal carcinomas, it is advised to perform a completion total mesorectal excision. Unfortunately, the diagnosis before local excision lacks precision and often both patient and physician are confronted with a locally excised lesion that turns out to be a high risk lesion based upon histopathological analyis of the locally excised specimen. In Chapter 2, we performed a retrospective analysis to compare the outcomes of mainly elderly patients unfit for surgery with a pT2-3 rectal carcinoma after local excision. In Chapter 3 we present the short term results of our case-matched analysis for 25 patients who underwent completion TaTME (cTaTME) and 25 (out of 63) patients after conventional completion TME (cTME). In Chapter 4 a trial protocol is presented introducing adjuvant chemoradiotherapy after local excision as an alternative to completion surgery in selected patients. A randomisation is made for patients with a high risk T1 or low risk T2 rectal cancer after local excision between adjuvant chemoradiotherapy limited to the mesorectum and completion TME. In addition, a registry is open for patients that have choosen a watchfull waiting after counselling. Enabling to evaluate the three possibilities after local exicison of high risk lesions; completion TME, adjuvant CRT or watchfull waiting.

2 | Transanal Total Mesorectal Excision Implementation
We evaluated this learning curve in Chapter 5, by using the data of the Gelderse Vallei Hospital in Ede, which is the first center in the Netherland that introduced TaTME, and included their first 138 patients. Using a risk-adjusted CUSUM analysis, a significant decrease in major complications was seen after 40 patients. Furthermore, the study showed a significant decrease in operating time (mean difference of 42.4 minutes) and conversion rate dropped to zero percent when comparing a one-team with two-team approach. To prevent future morbidity by the learning curve of the TaTME technique, a structured pathway was introduced to educate and proctor new surgeons.
A two-day program was set-up with e-learning, didactic courses, anatomy lessons, live TaTME procedure and hands-on cadaver workshop, followed by proctoring of the first cases by TaTME experts. In Chapter 6 a systematic review was performed to investigate the influence of high versus low volume centers. Despite the clear trend that is visible, carefull interpretation is needed since statistical significance was not obtained as we lacked the original data including standard deviations. In Chapter 7 we analyse the short-term results of the first 10 TaTME patients in each hospital that participated in our structured training pathway. A total of 120 patients was included, showing an intraoperative complication rate of 4.9% in the patients, circumferential resection margin of 5% and major postoperative complications of 19.2%. These rates are comparable to the outcomes seen in experienced TaTME centra / surgeons and conventional laparoscopic surgery. In Chapter 8 and 9 we describe the functional outcome after TaTME comparing to laparoscopic rectal surgery. We found that overall quality of life improved over time when comparing results at 1 and 6 months follow-up. These results were comparable to patients who received laparoscopic TME.

3 | Long-term consequences of TME surgery
In Chapter 10 we analyse the COLOR II data on long-term morbidity after open and laparoscopic rectal cancer surgery. No significant differences were found comparing open and laparoscopic surgery, including the need for admission or re-operation. In Chapter 11 we use the COLOR and COLOR II data to evaluate the influence of anastomic leakage on long-term oncological outcome after colorectal cancer surgery.