Newer Developments in Colon and Rectal Surgery
- Endosonography of the Anal Canal in the Evaluation of Fecal Incontinence
- Preoperative Radiotherapy for Rectal Cancer
- Colonic Reservoir (Colon J-Pouch) Reconstruction after Rectal Cancer Surgery
- Total Mesorectal Excision (TME) in the Operative Treatment of Rectal Cancer
- New PPH Surgical Procedure for Hemorrhoids
- New Artificial Sphincter for Incontinent Patients
- New Doppler Guided Hemorrhoidal Artery Ligation & Mucopexy Treatment for Hemorrhoids
Endoluminal sonography of the rectum has been utilized in the last ten years as an adjunct modality in the evaluation and staging of rectal cancer. With experience, it became evident that excellent imaging of the individual muscles of the anal canal and pelvic floor can be achieved. Surgeons skilled in the evaluation of fecal incontinence realize the physical examination with digital rectal examination is often equivocal in the ability to identify a sphincter defect. Disruption or thinning of the sphincter mechanism is however readily appreciated with this quick and painless examination.
Endoanal sonography relies on an image is created by a rotating piezoelectric crystal transducer probe which is placed into the anal canal. The crystal both sends and receives ultrasound (10 MHz) frequency waves, with different tissues (i.e. smooth muscle, fat, mucosa, bone) allowing different degrees of reflection and transmission according to their intrinsic acoustic density. A real time ultrasound image is generated based upon the reflected waves received by the rotating transducer probe.
The accuracy of the endoanal ultrasound examination is quite surprising. It correlates very well with structural findings noted at surgical exploration. The exam permits detailed investigation of the internal and external sphincter for areas of thinning or disruption, as well as other structures of the pelvic floor such as puborectalis muscle, urethral sphincter, vagina, and outlines of the bony pelvis. The examination has proven to be quite accurate in the evaluation of obstetrical injury to the sphincter, and can reliably identify sphincter injuries amenable to surgical correction. Endoanal sonography has now emerged as the procedure of choice to evaluate anal sphincter anatomy and continuity during the evaluation of fecal incontinence.
Sphincter saving surgery is increasingly common in the treatment of cancers of the low and middle rectum. These operations can be performed with the same prospects for cure as removal of the rectum and colostomy as long as lateral and lower margins are free of disease. Postoperative radiotherapy is commonly recommended for rectal cancers if the circular muscle coat is breached by tumor or lymph nodes are involved. Postoperative radiotherapy after bowel resection and anastomosis can however affect functional results. Patients often complain of rectal urgency, incontinence, and soiling that leads to some degree of impaired social life. Small bowel radiation injury is also common when postoperative radiotherapy is used since small bowel adhesions to the pelvic structures fix the small bowel in place (maximizing damage).
Preoperative radiotherapy offers obvious advantages, since the majority of the irradiated bowel is removed at surgery and nonirradiated bowel is delivered into the pelvis for anastomosis. The nonirradiated bowel maintains near normal compliance, and when combined with a colonic reservoir J-pouch (see below) can decrease urgency and stool frequency to a substantial degree. Preoperative radiotherapy also has potential to downstage rectal tumors and make sphincter saving surgery possible. In addition, small bowel radiation injury is minimized since surgical adhesions do not fix the small bowel in place.
In the past, preoperative radiotherapy was only offered at research institutions, since radiation oncology physicians were reluctant to give radiotherapy treatment prior to accurate staging, which generally required surgical resection and pathologic analysis. In addition, there was only weak scientific evidence that preoperative radiotherapy prolonged survival. The recent Swedish Rectal Cancer Trial (1997) demonstrates statistically significant reduction in local cancer failure rates and an improvement in overall survival by using high-dose preoperative radiotherapy. Our ability to accurately stage these rectal cancers prior to treatment has improved as well; imaging studies with endorectal ultrasound, CT, and MRI scans give excellent anatomic information about the depth of tumor penetration and lymph node involvement. Because of vastly improved functional results, improved tumor resectability, and diminished long term sequelae, we embrace the philosophy of preoperative radiotherapy for middle and low rectal cancers.
The functional outcome of patients after anterior resection of the rectosigmoid is often less than optimal. Patients may complain of urgency, incontinence, and stool soiling which can greatly impact social life. Some authors refer to this diminished function as the “anterior resection syndrome.” Why this affects some more than others is not clearly understood, but we know that reservoir function of the bowel decreases as the level of the anastomosis moves more distally. Some patients with resection of the middle and low rectum who require postoperative radiotherapy often have even worse functional outcome due to chronic radiation injury to the bowel.
Creating a new rectum (neorectum) from a section of descending colon folded and attached laterally to itself in a “J” shape, and then attaching this to the upper anal canal has been recently shown to improve functional outcome of patients over conventional straight end to end anastomosis. Patients have improved compliance of the neorectum, diminished frequency of stools and diminished urgency and soiling. With the additional suture lines in the pouch construction, usually a temporary diverting stoma (ileostomy) is required. Activation of the pouch follows after confirmation of satisfactory healing (generally 6-8 weeks). We have been offering this form of reconstruction since 1997, and believe it is a significant advance in the treatment of rectal cancer.
The technique of Total Mesorectal Excision (or Complete Circumferential Mesorectal Excision) is not new. It was described in the early 1980s. Over the last two decades an important shift in the operative technique of rectal cancer resection has been toward TME as evidence mounts that the oncologic results are superior. Conventional surgical techniques of rectal resection, where blunt tissue dissection occurs along unidentifiable tissue planes has given way to sharp dissection along identifiable planes. TME removes the entire rectum along with its entire surrounding mesentery(mesorectum), its surrounding fascia (visceral fascia) and uninvolved circumferential margins.
Rectal resection with TME has been reported to increase five-year rectal cancer survival rates as well as decrease local rectal cancer recurrence rates. Initially TME was thought to increase leak rates of anastomoses deep in the pelvis, but recent studies suggest equivalent leak rates after conventional rectal resection and rectal resection with TME. Since fascial planes are followed and pelvic autonomic nerves spared, compromise of sexual and bladder function is less with TME than conventional techniques. Because of superior oncologic results, we believe the technique of TME should be routinely employed when dealing with middle or lower third rectal cancer.
PPH is a technique developed in the early ’90’s that reduces the prolapse of hemorrhoidal tissue by excising a band of the prolapsed anal mucosa membrane with the use of a circular stapling device. In PPH, the prolapsed tissue is pulled into a device that allows the excess tissue to be removed while the remaining hemorrhoidal tissue is stapled. This restores the hemorrhoidal tissue back to its original anatomical position.
- Faster procedure
- Less postoperative pain
- Faster return to “normal” activities
Dr. Young was the first Surgeon in our area to begin performing the PPH Procedure.
The Acticon* Neosphincter is used in men and women to treat severe fecal incontinence. It is a small, fluid-filled prosthesis that is completely implanted within the body. It is designed to mimic the natural function of the anal sphincter muscle, giving the patient control over bowel movements. Some 13 centers in the U.S. and a number of international sites were selected to study the device in the fall of 1999.
Dr. Baker was selected for a training program on the AMS Acticon Neosphincter. Dr. Baker performed the first Acticon Neosphincter Implant in Tennessee in 2000. For more information, visit www.visitAMS.com.
Doppler Guided Hemorrhoidal Artery Ligation and Mucopexy is a newer hemorrhoid treatment that does not involve excision of tissue. In 1995, a Japanese surgeon, Kasumasa Morinaga developed this new treatment method which identified the Hemorrhoidal arteries using a specialized Doppler Ultrasound probe mounted within an anoscope. He noted that there were usually six arteries identified instead of the classical three arteries taught in training programs. His anoscope modification allowed accurate suture ligation of the Hemorrhoidal arteries- usually reducing swelling, bleeding and protrusion of tissue. Many surgeons were skeptical of early reports of success, although the popularity of this technique has spread across Europe over the last 15 years, and more recently into the US. Results of treatment continue to be impressive, with studies citing upwards of 90% patients with complete resolution of symptoms. Long term results are not known since the technique is still novel.
Most patients have mild pain or fullness for 2-4 days after the procedure. Most patients can return to work in 3-5 days. Complication rates are very low and similar to other hemorrhoid treatment techniques.