The rectum is the final straight portion of the large intestine in humans and some other The rectum is a part of the lower gastrointestinal tract. The rectum is a continuation of the sigmoid colon, and connects to the anus. The rectum follows the shape. In regards to the upper rectum, Benzoni et al found that the relation . for that we add a levator ani insertion as a parameter for lower rectal classification. Rectal washouts are performed to decompress the lower intestine and deflate the gastrointestinal contrast study; Upper gastrointestinal contrast study; Rectal biopsy Orders should include specific size, and length of catheter to be inserted.
and Lower Rectum Insertion Upper
Involvement of circumferential margin by tumor is the main cause of local recurrence after rectal cancer surgery[ 46 , 48 ]. Circumferential margin is the nonperitonealized surface of the rectal specimen created by mesorectal dissection at surgery. Circumferential margin is considered positive if the distance between the deepest extent of the tumor and closest surgical clearance around the tumor, i. CRM is an independent predictor of outcome in patients with rectal cancer[ 49 - 51 ].
However, other investigators have considered 2 mm as the cutoff point. Although the ideal CRM has not been universally accepted, resection with as wide of a CRM margin as possible must be accomplished.
Circumferential margin for distal tumors is problematic since the mesorectum encases the rectum as a thick cushion mainly posteriorly and laterally proximally and inferiorly it thins out and tapers down to the anorectal junction making it impossible to obtain a 2 cm cuff of marginal tissue circumferentially.
Lymph node involvement is the most important prognostic factor and a major determining factor whether a patient is candidate for adjuvant therapy. The overall survival is determined by number of LN involved. Violation of the perirectal fascia and transmesorectal dissection is associated with high local recurrence rate[ 24 ].
Local recurrence after rectal cancer surgery is associated with incomplete excision of circumferential margin, presence of isolated deposits in the mesorectum and tumor in regional LN and incomplete LN clearance[ 43 , 53 , 54 ].
To eradicate the primary rectal tumor and control regional disease, the rectum, first area of LN drainage mesorectal LN and surrounding tissue must be completely excised while maintaining an intact fascial envelope around the rectum and protecting and preserving surrounding structures, including the ureters, gonado iliac vessels, sacral venous plexus and pelvic autonomic nerves. To achieve such a radical resection, thorough knowledge of the pelvic structures and fascial planes is paramount.
Total mesorectal excision TME , originally described by Abel[ 55 ] in and later adopted by other surgeon, implies removal of the entire mesorectum including portion distal to the tumor within its enveloping fascia as an intact unit[ 27 , 30 , 45 , 53 , 56 , 57 ].
For mid- to low-rectal cancer, LAR with TME has been demonstrated to minimize locoregional recurrences[ 30 , 56 - 61 ]. With, APR, the operative plane follows the mesorectum to the muscular tube of the rectal wall stopping at the puborectalis sling.
The anus is removed by perineal approach and dissection is performed outside the edge of the EAS and leaving the ischioanal fat. With ELAPR, abdominal dissection stops at the rectosacral ligament and the anus, coccyx and most of the levator muscle are removed by perineal approach[ 19 ]. Lateral LN dissection may be performed with TME as part of an extraregional dissection lateral clearance for lower rectal cancer but the reported outcome is no different than that with TME[ 40 , 57 , 65 ].
Sharp dissection facilitates identification and preservation of the autonomic nerves, allows adequate hemostasis and avoids tearing of the fascial envelope around the mesorectum. The inferior mesenteric vessels are divided and retracted with the rectosigmoid junction anteriorly, and extrafascial dissection is commenced. Identification and preservation of the hypogastric nerves is discussed later. Dissection is performed between the fascia propria of the rectum and the presacral fascia posteriorly in the retrorectal space that contains loose areolar tissue and is devoid of vessels and nerves and pelvic wall laterally.
Sharp dissection is performed under vision down to the rectosacral ligament posteriorly and lateral rectal ligaments laterally. The rectosacral ligament is divided so as to gain access and mobilize the last cm of the rectum and the anorectal junction[ 21 ]. The mesorectal fascia is not detached from the parietal pelvic fascia and the levator muscle is not separated from the sacrococcygeal junction[ 19 ].
The sacrococcygeal junction is disconnected through the perineal phase to detach the coccyx that is the insertion of the midline raphe of the levator muscle.
The parietal pelvic fascia is divided in the midline through the disconnected sacrococcygeal junction and the levator is divided laterally at both sides[ 19 ]. The anterior plane of dissection to separate the rectum from the prostate gland and vagina is controversial and is discussed later.
However, dissection is performed inside the pelvic autonomic nerves down to the top of the anorectal junction where the rectum has little mesorectal fat and appears as a bare tube[ 25 , 31 , 32 ].
Laterally the lateral rectal ligaments are divided detailed discussion to follow. Damage to the accessory branches rather than the main of the MHA may occur MHA during division of the lateral ligaments. The point of insertion of the MHA into the rectum is cm from the anus. Damage to the main MHA occurs during dissection of the rectum anteriorly and anterolaterally on the pelvic floor, when it is being dissected off the seminal vesicle and prostate gland or vagina vide infra.
Down ward spread is uncommon. Lateral spread to lateral pelvic LN is more clinically important in tumors with lower margin below 5 cm from the dendate line and the incidence becomes significantly higher with lower margin below 3 cm above the dendate line[ 14 , 36 , 40 ].
With extended resection, i. The number of LN removed with extrafascial mesorectal excision depends on level of the tumor. Canessa et al[ 39 ] in a study in formalin-fixed cadavers noted that the mean number of LN was 8. The LN ranged in size from 2 to 10 mm. It is shown that LN must be examined to accurately determine node negativity and any less limits the predictive value of the pathologic examination[ 68 , 69 ]. The role of extended resections is controversial since randomized studies on survival benefits from the procedure are still missing.
Opponents of lateral pelvic lymphadenectomy question the benefit of the procedure since only small percentage of patients have lateral LN involvement. The operative time with extended resections is prolonged and morbidity is high. In addition some studies have shown lateral pelvic lymphadenectomy is not necessary in terms of curability for patients with advanced lower rectal cancer who undergo preoperative radiotherapy[ 70 ]. Several other studies reported the outcome with TME to be no different from the data on extended lymphadenectomy.
Hence many surgeons in the Western World, Europe, to some extent in Japan favored the mesorectal excision only. The number of regional LN removed varies with location of the tumor and surgical technique. Considerable anatomical, surgical and physiological importance has been attached to the lateral ligaments of the rectum. Anatomists consider the ligaments as fascial bridge that act as a pathway for nerve fibers, small vessels and lymphatics from and to the rectum[ 28 , 50 ].
Surgeons recognize the ligaments as extraperitoneal thick bundle of dense connective tissue that provide pathway to lymphatic channels and contribute to the support of the rectum and in which the MHA and plexuses are embedded[ 71 , 72 ].
Proper handling of the ligaments during surgery has an important bearing on colonic, anorectal, sexual and urinary function as well as the prevention of local recurrence of the cancer[ 56 , 61 , 73 - 75 ]. To gain access to the depths of the lateral pelvis, full mobilization of the mid-lower rectum requires identification of the lateral rectal ligaments that are then clamped, divided and ligated to avoid intra- and post-operative hemorrhage since the MHA are large and do not respond to electro cautery[ 61 ].
Despite this clear-cut description and straightforward handling of the ligaments, there are many variations and contradictory accounts reported in the literature as to the nature, anatomy, and contents of the lateral rectal ligaments. Thomas Jonnesco[ 29 ] was the first to describe the lateral rectal ligaments as a continuation of the parietal fascia predominantly surrounding the origin of MHA from the IIA.
Goligher et al[ 61 ] described the ligaments, as seen from above, as having a triangular shape with the base on the pelvic sidewall and the apex joining the side of the rectum. Hojo[ 77 ] considered the ligaments as rectal structures that should be removed completely. Heald in original and subsequent articles s [ 30 , 45 ] and Reynolds et al[ 78 ] did not mention the lateral ligaments in their description of TME. Enker[ 75 ] recognized the ligament as an important landmark during autonomic nerve sparing sidewall dissection for rectal cancer.
Takahashi et al[ 14 ] described the ligament as a bundle of dense connective tissue in the pararectal space with variable thickness and length that extends from the peripheral part of the IIA to the sidewall of the midrectum between the peritoneum and levator muscle. The hypogastric nerve fibers reach the center of the ligament where they unite with the PSN as they emerge from the sacral roots and form the inferior hypogastric nerve plexus inside the ligament[ 14 ].
Thus the ligament is divided into a lateral part that contains the MHA and inferior vesicle arteries and the medial part that holds nerve fibers to the rectum together with branches of MHA. In addition to branches of IIA and autonomic nerves, the lateral ligament provides a route for lymph vessels that penetrate the inferior hypogastric plexus and reach LN around the origin of the MHA.
Jones et al[ 34 ] in a study performed on cadavers embalmed in formalin found very insubstantial connective tissue strands and at times no definite connective tissue structure crossing from the pelvic sidewall to the rectum. The strands of fibrous tissue were inconsistent in direction, variable in height above the pelvic floor and often absent all together or present unilaterally.
The branching PSN arose posterior to the origin of the MHA, ran in an anteromedial direction and reached the rectum at a similar height above the pelvic floor as the MHA. Nano et al[ 33 ] in a study on fresh cadavers and embalmed pelves viewed the lateral ligaments as extensions of the lateral aspect of the mesorectum as approximately trapezoid structures with their apex towards the rectum.
The ligaments ran caudally and distally and anchored to the endopelvic fascia. The ligaments contained fatty tissue in communication with mesorectal fat but did not contain any significant vascular structures. When present, in some cases unilaterally, the MHA crossed together with the nervi recti that arose from the inferior hypogastric plexus transverse almost perpendicular to the inferior aspect of the ligament at its distal end before entering the anteromedial aspect of the rectal wall.
The urogenital bundle ran just above the lateral ligament at its insertion of the endopelvic fascia. Sato et al[ 26 ] visualized the ligaments in human as composed of three components, the MHA, middle rectal vein and the pelvic plexus.
When present the artery was long and tortuous and pierced the pelvic plexus. The MHA divided the ligament into medial and lateral segments. The artery entered the rectum mid-way between the superior and inferior branches of the pelvic plexus. The medial segment share a common sheath with the nerves and follow the same course as that of the rectal branches of the pelvic plexus.
These ligaments were closer to the coccyx than the promontory of the sacrum. Components of the ligaments were loose connective tissue containing multiple small nerves.
The paraproctium houses the rectal nerves and middle rectal vessels when present. The lateral rectal ligaments vary from insubstantial connective tissue strands to no definite connective tissue structure crossing from the pelvic sidewall to the rectum.
Hence the ligaments can be divided with diathermy. The nervi erigentes lie in and under the endopelvic fascia and are close to the lateral margin of the ligament and together with the MHA do not run below them. The ligaments contain mesorectal fat and must be divided close to the pelvic wall to ensure optimal oncologic clearance.
Leaving behind remnants of the ligaments implies inadequate adequate lateral clearance of the mesorectum[ 45 ]. Traction on the rectum may tent the endopelvic fascia with its enclosed nerves and puts the nerve at jeopardy during division of the ligament[ 22 ]. Separating the rectum from the anterior urogenital structures is a layer of tissue that is an important anatomical structure to the colorectal and urology surgeons for oncologic and functional reasons, particularly in males.
There is controversy as to origin, morphology, function and anatomical relationship to the fascia propria and urogenital structures and whether it can be identified during surgery and the precise plan of anterior rectal dissection for rectal cancer.
Earlier studies have suggested that the septum is formed either as a result of incomplete partition between the rectum and urogenital organs or represents peritoneal fusion or condensation of loose areolar tissue after peritoneal fusion[ 80 - 82 ].
Aigner et al[ 83 ] on the other hand noted that local condensation of collagenous fibers is present between the rectum and urogenital organs from the beginning of fetal development and subsequent increase in dense collagen fibers and longitudinal smooth muscle cells produced the anatomical partition.
The fascia widened laterally and became continuous with the perirectal fascia posteriorly and the lateral pelvic fascia between the levator ani and prostate anteriorly. The fascia splits into a number of laminae laterally[ 16 , 19 - 21 ]. The septum forms an anatomical incomplete partition between the middle and posterior compartments in the female and the anterior and posterior compartments in the male that is completed by the perineal body distally[ 83 ].
Immediately anterior to the lateral borders of the fascia, the parasympathetic cavernous nerves run to supply the corpora and govern erectile function and are in jeopardy during deep anterior dissection of the rectum and are jeopardy[ 85 ]. Histologically, the rectogenital septum is predominantly made of connective tissue and contains smooth muscle fibers and sensory neurons[ 18 , 20 , 27 , 79 , 80 , 83 ].
The connective tissue consists mainly of dense collagenous fibers and few course elastic fibers derived from mesenchymal condensation[ 27 , 80 , 83 ]. Similar muscle fibers are also noted within the anal sphincter musculature[ 83 ]. The smooth muscle fibers in the ventral rectal wall give origin to the longitudinal muscle of the anal canal and also bend caudally to traverse the rectogenital septum terminating in the perineal body that is a dense connective tissue that separates the urogenital hiatus from the anal hiatus.
The longitudinal smooth muscle fibers are accompanied by small nerve bundles attached to the connective tissue of the perineal body. Neurovascular bundles coming from the autonomic inferior hypogastic plexus intermingle with the lateral margin of the septum and cross the midline between the septum and the rectum[ 83 ]. The precise function of the rectogenital septum is not clear but there is evidence to suggest an important role in urinary and fecal continence. In one study, intrinsic innervation was confirmed by the presence of parasympathetic nerves innervating the septum and sensory neurons present within the septum was demonstrated[ 83 ].
Neurovascular bundles coming from the autonomic inferior hypogastric plexus intermingled with the lateral margin of the septum and crossed the midline between the septum and the rectum.
The rectogenital septum and its smooth muscle component share the same innervation as the longitudinal muscle layer of the rectum. The longitudinal muscle fibers in the septum terminate in the perineal body and act as anchors and when the muscle contracts it results foreshortening and opening of the anal canal[ 83 ]. To mobilize the midrectum, anterior dissection is performed to separate the anterior wall of the rectum from the urogenital structures.
From the surgical point, there is controversy as to the appearance of the septum and whether it can be identified during surgery and plane of dissection during proctectomy. Many surgeons believe the fascia is more closely applied to the prostate gland and seminal vesicles than the rectum[ 28 , 86 ]. Others describe the fascia as more closely adherent to the rectum than the prostate[ 87 ]. The operative appearance of the fascia varies considerably from a fragile translucent layer to a tough leathery dense membrane but overall it is more obvious and substantial than fascia propria which is a thin membrane enveloping the mesorectum[ 28 , 87 ].
Heald et al[ 30 ] noted the fascia on the anterior surface of the mesorectum with a distinct plane separating this shiny fascia and the seminal vesicles. Thus during TME dissection takes the surgeon anterior to the fascia and thus resecting the fascia. Northover[ 89 ] and Bisset et al[ 27 ] on the other hand described dissection anterior to the fascia cranially then breaching it distally by dividing it transversely 1 cm below the base of the prostate in the male and opposite the vault of the vagina in the female to dissect posterior to it caudally.
Others have maintained that excision of the fascia depends on location of the tumor in the rectum[ 59 , 64 , 84 ]. For anterior and circumferential tumors in which the anterior margin is threatened, it is often taken with the specimen to gain maximal margin control[ 18 ].
In these cases the dissection is considered extramesorectal resulting in excision of the fascia[ 18 , 84 ]. In cases where the anterior circumferential margin is not threatened resection that does not jeopardize erectile dysfunction must be employed. To these cases the caudal portion of the ventral rectal wall including the septum must be left undissected[ 83 ].
Staying anterior to the septum behind the bladder and then posterior to it more caudally will prevent injury to the cavernous nerves and in consequence prevent erectile dysfunction[ 28 , 86 ].
In the female the peritoneum is incised in the pouch of Douglas. The parasympathetic cavernous nerves run anteriorly, in close proximity to the lateral borders of the fascia to supply the corpora and govern erectile function[ 90 ]. These nerves are in jeopardy during deep anterior dissection of the rectum[ 85 ].
When disrupted during dissection of the distal aspect of ventral wall of the rectum during restorative proctectomy, the anchoring mechanism of the septum is interfered with and incontinence may result[ 90 ]. On the other hand when the caudal portion of the ventral rectal wall including the septum are left undisturbed during sphincter preserving procedure potency and continence are preserved[ 90 ].
Parasympathetic innervation to the proximal colon down to the transverse colon runs via the vagus nerve and sympathetic innervation via postganglionic fibers from the paravertebral sympathetic chain. The left colon and rectum receive sympathetic innervation from the preaortic plexus and presaral nerves and retrograde parasympathetic innervation from neural efferents running through the lateral ligaments. The sympathetic nerves arise from the thoracolumbar center TL2. Preganglionic fibers synapse in the pre-aortic plexus and postganglionic fibers follow the branches of the IMA and SHA to the left colon and upper rectum.
The presacral nerves formed by fusion of aortic plexus and lumbar splanchnic nerves form the superior hypogastric plexus that gives rise to the right and left hypogastric nerves that innervate the lower rectum.
The hypogastric nerves run between the presacral fascia and fascia propria and send nerves to the pelvic plexus also termed inferior hypogastric plexus [ 65 ]. The retroperitoneal fascia covers the lumbar sympathetic nerves and superior hypogastric plexus and the plexus is situated directly in the visceral fascia above the bifurcation of the aorta[ 65 ]. The hypogastric nerves separate from the plexus and descend caudad and laterally passing for a short distance through the visceral endopelvic fascia.
The right and left hypogastric nerves run distally about 1 cm lateral to the midline and cm medial to the ureters[ 27 ]. Thereafter the hypogastric nerve fibers are situated close to the visceral endopelvic fascia[ 14 ]. The parasympathetic nerves are formed largely by visceral efferent preganglionic fibers that arise from sacral nerves mainly S3-S4, at times S2 and contain sensory nerves PSN [ 26 , 71 ].
The PSN are identified as two bundles on either side that emerge from the sacral roots, travel over the piriformis muscle covered by the endopelvic fascia[ 26 , 65 ]. The largest branch is S3 that runs caudal to the middle rectal artery and vein. The PSN pass laterally, forward and upwards and join the parietal pelvic fascia and the pelvic plexus within it very close to the anterolateral aspect of the lower rectum and the upper lateral wall of the vagina or posterolateral aspect of the prostate[ 16 , 65 ].
The inferior pelvic plexus is a complex network of sympathetic and parasympathetic nerves, located between the internal iliac vessels and the rectum on the pelvic sidewall amid the parietal pelvic fascia well outside the fascia propria of the rectum and is divides the MHA into a lateral and medial segments[ 16 , 26 - 28 , 91 ].
It is the center of autonomic innervation of the pelvic visceral. Branches from the inferior pelvic plexus diverge in fanlike pattern and innervate the urinary bladder, distal ureters, seminal vesicles, prostate, membranous urethra, corpora cavernosa, uterus and vagina, rectum and the perineal body[ 16 , 26 , 65 , 71 ].
The nerve to the rectum diverge directly from the plexus into the rectal wall T-junctions and the remaining nervous network form the neurovascular bundles[ 16 ]. The nerves to the rectum arise from the pelvic plexus as a 1 cm long band course towards the rectum accompanied by small vessels along fascial fibers lateral ligaments and reach the rectal wall 6 cm above the anus or similar height above pelvic floor as the MHA[ 25 , 34 ].
Damage to the pelvic nerves results in sexual and urinary dysfunction[ 92 ]. ANP may be total where major components of the pelvic nerves are identified and preserved or partial where one or more component is sacrificed unilaterally or bilaterally[ 65 ]. During TME, the superior hypogastric plexus and nerves, PSN and the pelvic plexus are encountered and adequate mobilization of the mesorectum can be achieved while preserving these nerves. The rectum is the final straight portion of the large intestine in humans and some other mammals , and the gut in others.
The adult human rectum is about 12 centimetres 4. It terminates at the level of the anorectal ring the level of the puborectalis sling or the dentate line , again depending upon which definition is used. The word rectum comes from the Latin rectum intestinum , meaning straight intestine. The rectum is a part of the lower gastrointestinal tract. The rectum is a continuation of the sigmoid colon , and connects to the anus.
The rectum follows the shape of the sacrum and ends in an expanded section called the rectal ampulla , where feces are stored before their release via the anal canal. An ampulla is a cavity, or the dilated end of a duct, shaped like a Roman ampulla. Unlike other portions of the colon, the rectum does not have distinct taeniae coli.
The rectum connects with the sigmoid colon at the level of S3 , and connects with the anal canal as it passes through the pelvic floor muscles. Supports of the rectum include: The rectum acts as a temporary storage site for feces. As the rectal walls expand due to the materials filling it from within, stretch receptors from the nervous system located in the rectal walls stimulate the desire to defecate.
If the urge is not acted upon, the material in the rectum is often returned to the colon where more water is absorbed from the feces.
If defecation is delayed for a prolonged period, constipation and hardened feces results. When the rectum becomes full if the internal and external sphincters are relaxed the increase in intrarectal pressure forces the walls of the anal canal apart, allowing the fecal matter to enter the canal.
The rectum shortens as material is forced into the anal canal. Although peristalsis in the colon delivers material to the rectum, laxatives such as bisacodyl or senna that induce peristalsis in the large bowel do not appear to initiate peristalsis in the rectum. They induce a sensation of rectal fullness and contraction that frequently leads to defecation, but without the distinct waves of activity characteristic of peristalsis.
For the diagnosis of certain ailments, a rectal exam may be done. These include faecal impaction , prostatic cancer and benign prostatic hypertrophy in men, faecal incontinence , and internal haemorrhoids. A colonoscopy or sigmoidoscopy are forms of endoscopy that use a guided camera to view the rectum.
These may have the ability to take biopsies if needed, and may be used to diagnose diseases such as cancer. Body temperature can also be taken in the rectum. A mercury thermometer should be inserted for 3 to 5 minutes; a digital thermometer should remain inserted until it beeps. Endoscopy is a procedure in which the gastro-intestinal tract GI tract is viewed through a lighted, flexible tube with a camera at the end endoscope.
Small samples of tissues cells biopsy can also be collected and sent for testing. Your doctor will spray your throat with a local anesthetic or give you a sedative to help you relax. Most patients consider the test only slightly uncomfortable, and many patients fall asleep during the procedure.
You will be observed closely until most of the effects of the medication have worn off. Your throat might be a little sore, and you might feel temporarily bloated due to the air introduced into your stomach during the test.
You will be able to eat after you leave unless your doctor instructs you otherwise. Your doctor generally can tell you your test results on the day of the procedure; however, the results of some tests might take several days. You should arrange for someone to accompany you home because the sedatives may affect your judgment and reflexes for the rest of the day.
Colonoscopy is well-tolerated and rarely causes much pain. You might feel pressure, bloating or cramping during the procedure. You will likely receive a sedative to help you relax and better tolerate any discomfort. You will lie on your side or back while your doctor slowly advances a flexible tube colonoscope through your large intestine to examine the lining. The whole procedure itself usually takes 45 to 60 minutes, although you should plan on two to three hours for waiting, preparation and recovery.
How to Use Rectal Suppositories Properly
Rectal prolapse occurs when the rectum turns itself inside out and comes out through the anus. Pain and discomfort felt deep within the lower abdomen; Blood and mucus from the anus; The feeling of Back to top This involves inserting slender instruments through a number of small incisions in the abdomen. 7 Lie on your side with your lower leg straightened out and your upper leg bent forward toward (If not inserted past this sphincter, the suppository may pop out.) . Surgery is usually the main treatment for rectal cancer, although radiation Some stage I rectal cancers and most stage II or III cancers in the upper part of the with the colon) can be removed by low anterior resection (LAR).