7 March 2019 The rectum is the final segment of the digestive tract and is located in a bone tunnel that is difficult to access. It has a close anatomical relationship with the bladder. In men, it is also closely related to the prostate and, in women, to the uterus and the vagina. In addition to these organs, the rectum is also close to local nerves in the area. Therefore, the preservation of urinary and sexual functions should be an important element when considering surgery for the treatment of rectal cancer. What are the types of rectal surgery? Surgery for rectal cancer may be performed: Via the anus (transanal); Via the abdomen. Transanal surgery The transanal approach enables local treatment of rectal lesions , avoiding the need for incisions and the impact of abdominal surgery, but has significant oncological limitations. It was originally applied to lesions in the final 5 cm of the rectum. However, with the use of specific instruments it can now be performed on lesions that are higher up. This technique does not allow the perirectal lymphatic tissue to be removed. Its application is limited to very early and superficial lesions. It can also be used on patients who do not have the requisite health conditions of to undergo abdominal resection surgery. It may also be an option where a patient refuses to accept any form of stoma, provided they understand and accept the technique’s therapeutic limitations . Transanal resection can also be assisted by endoscopic techniques. In this case, it is known as transanal endoscopic microsurgery. Abdominal surgery When surgery is performed via the abdomen, a single large incision ( open surgery) or multiple smaller incisions may be used. Gas is inflated into these small incisions and an illuminated lens connected to a camera that allows visualisation of surgical manoeuvres (minimally invasive or laparoscopic surgery) is introduced. The laparoscopic approach can also be assisted by robotic surgery. Traditionally, abdominal surgery for rectal tumours has involved abdominoperineal resection. This consisted in the removal of the rectum, anal canal and anus, with subsequent permanent colostomy (where the intestines are brought through the skin and intestinal content is eliminated through the abdominal wall into a bag in a permanent manner). The following factors led to the development of anterior resection of the rectum: Improved oncology staging; Development of radiotherapy and chemotherapy protocols; Improved automated stitching equipment. In this case, the rectum and anal canal are removed to a distal area free from lesions, and the colon is then attached (anastomosis) to the remaining segment of the rectum or to the anus. The oncological outcomes of this type of surgery are similar to those described above, but it also allows preservation of the anal sphincter. Even with anterior resection of the rectum, there are some cases where a stoma (colostomy in the case of the large intestine, or ileostomy in the case of small intestine) is necessary: When the lesions are adjacent to the anus; When there are perforated or occluded tumours; When it is not possible to carry out anastomosis safely; When there is significant coexisting disease that rules out extensive surgery; When there is a high risk of dehiscence (bad healing of the bowel and subsequent leakage of intestinal contents into the abdomen) with anastomosis. It has been shown that the application of minimally invasive techniques in colorectal surgery allows for shorter recovery times and a better quality of life. The oncological outcomes are similar to those achieved by the open surgery route. Abdominal surgery with robotic support The complex nature of rectal cancer surgery, together with the anatomical peculiarities of this organ, makes it an ideal candidate for removal by minimally invasive robot assisted surgery (laparoscopy). In rectal cancer surgery, the aim is to: Achieve a good oncological outcome (i.e. cure the cancer); Achieve a good functional outcome: this means avoiding faecal and urinary incontinence as well as erectile dysfunction (common consequences of rectal tumour surgery); Reduce the need for a permanent ostomy in the case of tumours that are very close to the anus. The scope of these objectives depends on preservation of the pelvic nerve plexuses. Due to their location, these plexuses are difficult to visualise, identify and preserve, both in conventional open surgery and in laparoscopic surgery. Robotic surgery, which provides three-dimensional visualisation , has great capacity to enlarge images without loss of definition. In addition, the surgical instruments used for minimally invasive surgery are technologically more advanced than those available for conventional laparoscopic surgery. It also makes it possible to carry out a dissection at a lower point and makes it easier to identify and preserve the nerve plexuses referred to above. In this way, robotic surgery plays a significant role in reducing the risk of incontinence, erectile dysfunction and the need for permanent ostomies. Rectal cancer surgery: developments in the last 100 years The treatment of rectal cancer today is a multidisciplinary field of intervention. A common therapeutic plan could include surgical intervention, together with chemotherapy and radiotherapy treatment to be carried out before and/or after surgical intervention. In some special cases, surgery may not be indicated . However, in the vast majority of cases, surgery remains the definitive (and most powerful) weapon in the cure for rectal cancer. The greatest advancements in surgical techniques for treating rectal cancer took place during the 20th century. Beginning of the 20th century: oncological surgery begins The principles of surgery for rectal cancer were established in 1908 by surgeon William Miles. In an article published in The Lancet in 1908, after more than 150 years of slow and unsuccessful evolution, Miles recommended that, in addition to the rectum containing the tumour, surgery should remove all of the lymph nodes from the pelvic fat surrounding the rectum. He argued this technique would be more effective in preventing recurrence of the disease in the area, given that it is to these ganglia the tumour spreads first. In this way, the idea of mesorectal excision , albeit in an incipient form, was proposed for the first time. The operation proposed by Miles also presupposed excision of the anal sphincter , including the anus itself, closure of the perineum and the establishment of a permanent colostomy. Miles named this operation “radical abdominoperineal resection”. Although considered to be oncologically correct, Miles' operation would not be adopted in the following decades, as it was technically very difficult and time-consuming. It also resulted in a high rate of operative mortality. In patients who survived the intervention, control of the cancer was excellent in terms of the standards of the time. However, a large percentage of patients - 40% to 50% - died as a result of the operation itself. In 1938, surgeon Oswald Lloyd-Davies introduced some purely technical changes to Miles' operation (now known in many publications as the Miles-Davies operation) that led to notable improvements in its efficiency and safety. Moreover, after the Second World War there were substantial improvements in anaesthetic care and general supportive care (e.g. the advent of blood component transfusions and antibiotics). As a result of this progress, average mortality associated with Miles' operation dropped from 40% to 9%. Cancer control continued to be excellent, with an overall disease relapse rate of around 30% (very low for the time). Since the 1940s, the Miles or Miles-Davies operation has become the gold standard for the treatment of rectal cancer. Avoiding permanent colostomy: preservation of the anal sphincter In spite of the progress made, many surgeons remained unsatisfied. The radical nature of Miles' operation meant patients were obliged to have a permanent colostomy, and the procedure frequently resulted in urinary incontinence and sexual dysfunction. These consequences led to intensive research with the aim of overcoming these aspects. The research concluded it would be possible to preserve the anal sphincter and the anus itself. The intestine could be reconnected after resection of the segment containing the tumour without compromising the effective control of the cancer. In 1948, surgeon Claude Dixon for the first time reported a significant number of cases in which he had resected the rectum together with the ganglia from the perirectal fat. Dixon followed the principles established by Miles, but preserved the anus and the final segment of the rectum, to which he later reconnected the intestine. This preserved intestinal continuity, avoiding the need for a permanent colostomy. Dixon's data proved this option was viable, as it maintained Miles's good results in the control of oncological disease. However, Dixon's technique only applied to rectal tumours that were relatively distant from the anus. Rectal tumours that were less than 6 cm from the anus continued to be treated with Miles' radical abdominoperineal resection, and as such they invariably required a permanent colostomy. At the beginning of the 1970s, surgeon Alan Parks developed a technique, published in 1982, to connect the intestine directly to the anus. This made it possible to resect tumours located less than 6 cm from the anal sphincter apparatus and, even in these cases, to preserve the anus and restore intestinal continuity, thereby avoiding the need for a permanent colostomy. This operation would continue to be known as “anterior resection of the rectum” . From then on, Miles' operation was carried out only on tumours located less than 2 cm from the anus. Anterior resection of the rectum became the operation of choice for the treatment of rectal cancer. Total mesorectal excision: a giant step towards a cure for oncological disease During the 1980s, a new development in surgical technique resulted in an innovative and important advancement in the control of oncological disease. Surgeon Richard John ("Bill") Heald developed a new technique of resection, with results published successively in scientific magazines - British Journal of Hospital Medicine in 1979, British Journal of Surgery in 1982 and The Lancet in 1986. In this technique, excision of the rectum (containing the tumour) and the fat surrounding the rectum (containing the lymph nodes) - the area known as the mesorectum - was carried out en bloc . This was an embryonic plan that was taken up by Heald and described in greater precision than by his predecessors: together with the rectum, the mesorectum is removed as a whole and wrapped in a fine membrane providing clear delimitation through which the surgeon should not pass. For proper implementation of this technique, the entire dissection of the rectum and the mesorectum has to be performed under direct visualisation . Until then, surgeons were performing a large part of the intervention via blunt dissection, that is, using their hands and their sense of touch, but without direct visual contact. Heald called his technique “total mesorectal excision” and his results showed a relapse rate for the local disease of 3.6% - the lowest obtained . Equally notable were the rates of overall disease-free survival, which were 80% at 5 years and 78% at 10 years. Anterior resection of the rectum with total mesorectal excision has since become the treatment of choice for rectal cancer. This operation is widely performed and is carried out these days by surgeons specialising in colorectal disease. The notable oncological results initially reported by Heald have been reproduced over the last 20 years pretty much all over the world — which confirms the excellence of the technique he developed. Quite rightly, RJ ("Bill") Heald is now considered the father of modern rectal cancer surgery. Minimally invasive surgery Minimally invasive surgery is a giant step towards the preservation of sexual function and faecal and urinary continence. Laparoscopic surgery The mid-1980s brought about the advent of minimally invasive surgery, as a consequence of the development of laparoscopic surgery. This new route of access, less invasive than traditional laparotomy (the opening of the abdominal cavity with a long incision) quickly showed multiple advantages: Reduced pain during the post-operative period; Reduced amount of time spent in hospital; Faster return to work; Reduced rate of infection in abdominal wall surgical wounds; Reduced incidence of incisional hernia in the medium term; Fewer visible surgical scars. In the case of oncological disease, a very significant additional effect has been suggested and investigated, which is a result of the lower overall aggression of the technique and a less intense inflammatory response. Less immunological disturbance , leading to a more vigorous immune response after intervention (which could be important in the fight against cancer). However, in the early days, the movement towards laparoscopic procedures did not affect surgery of the colon and rectum, as it was considered too complex to be approached by this route. There were legitimate doubts about the feasibility of laparoscopic rectal surgery. There were particular doubts as to the possibility of total mesorectal excision being performed correctly and safely without affecting the control of the oncological disease. This was all changed by the enhanced experience and performance of surgeons who dedicated themselves to laparoscopic techniques, together with technological advancements in the field. During the second half of the 1990s, the first reports of anterior resection of the rectum with total mesorectal excision correctly carried out by laparoscopy started to appear. At an international congress in Brussels in the late 1990s, surgeon Joel Leroy carried out one of these interventions live. Bill Heald, who was present at the congress, acknowledged for the first time that the intervention he had just witnessed was a technically perfect reproduction of the one he had described himself and carried out by conventional open surgery. Since 2000, several published studies have emerged that report on a series of cases in which laparoscopic surgery was applied to the treatment of rectal cancer, with excellent results. In this way the oncological principles were observed in their entirety, with oncological outcomes similar to those seen in conventional open surgery. In addition to this, all the advantages of minimally invasive surgery mentioned above were observed. In the specific case of rectal cancer surgery, in addition to the central concerns of oncological control and patient survival, there is also an ongoing concern with regard to the functional outcomes. This is a mutilating surgery, carried out in the depths of the pelvic cavity, where the nerve plexuses regulating faecal and urinary continence functions, and sexual function, are located. As a result, changes in continence and sexual function disorders are relatively common following this type of surgery. Therefore, the surgeon who carries out a surgical procedure for the treatment of rectal cancer is not only concerned with curing the cancer, but also with preserving continence and sexual function. In this sense, minimally invasive surgery has an additional advantage. The high definition optical systems currently available for laparoscopic surgery, together with the fact the laparoscope can access areas, such as the pelvic cavity, in a way that is impossible for human sight, enables better visualisation and preservation of these nerve plexuses, enabling a better functional outcome. In a presentation for the IRCAD (Institut de Recherche contre les Cancers de l'Appareil Digestif) WebSurg website in May 2005, Heald (who does not perform laparoscopic surgery) noted that laparoscopic surgery has the potential to allow "better visualisation of the area of dissection". Not only this, but a "better view of the nerves, with less morbidity and less impotence". He added that "the potential for the perfect operation is enormous” using this surgical route. He ended with an example of prescience (as will be seen below) when he said that with the foreseeable evolution of technology, "the sky’s the limit!" Robotic surgery During the 2000s, the first robotic surgical system adapted for abdominal surgery appeared on the market: the Da Vinci Surgical System , produced and marketed by Intuitive Surgical, Inc. This opened up a whole new field of robotic surgery: essentially, this is laparoscopic surgery carried out with the intermediary of a robotic device. However, this device brings significant advantages to laparoscopic surgery: Amplified, high-definition three-dimensional visualisation (in conventional laparoscopy, visualisation is two-dimensional); Complete camera stability; Instruments with internal articulation, which allow greater freedom of movement; Elimination of natural human tremor and optimal ergonomics. Although studies that could prove this definitively are still under way, it is natural to assume these advantages will have a major influence on the outcomes of rectal cancer surgery. This has already been widely demonstrated in the case of prostate cancer surgery, which is performed in the same area and deals with similar oncological and functional concerns. In the Manual of Total Mesorectal Excision, one of the most recent publications on the topic (2013; ed. Brendan Moran and RJ Heald), M. Chadwick writes on robotic surgery. He says this is: “...the vision that enables identification and preservation of pelvic nerves" and that it "has enormous potential for improving the quality of mesorectal dissection", believing that "this is a new step forward in the surgical treatment of rectal cancer". In short, robotic surgery has the potential to: Obtain oncological control that is at least similar to that which can be obtained by open or laparoscopic surgery; Provide significant progress in preserving continence and sexual function as a result of more precise and thorough dissection, with clearer identification of the area of dissection; Reduce the amount of blood loss; Enable pelvic dissection with preservation of the sphincters in tumours that are ever closer to the anus, further reducing the need for permanent colostomies. To date, several reports on the individual experiences of various surgeons and preliminary findings of ongoing institutional investigations point in this direction. Conclusion Over the last 100 years, mortality associated with rectal cancer has decreased from around 90% to less than 4%. To this end, a great deal of progress has been made in the development of surgical techniques and other cancer therapies , such as radiotherapy and chemotherapy. No less important has been the progress made in general medical care (blood component transfusion, antibiotic therapy, intensive care) and anaesthetics. The search for increasingly effective and less invasive solutions has not ended. New techniques in the research and development stage have shown promising results. Among these are: Laparoscopic or robotic surgery through a single entry or through natural orifices; Local excision of early stage tumours (accompanied by chemotherapy and/or radiotherapy); The use of radiotherapy without surgery. At the moment the gold standard for the surgical treatment of rectal cancer is anterior resection of the rectum with total mesorectal excision. If the individual experience of the surgeon and/or institutional experience so permits, patients should be offered laparoscopic surgery or, ideally, robotic surgery. This article was written with the support of physicians and other clinical professionals from the Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
