Invasive Therapy Surgery

Surgical therapy is the principal modality used for treatment of rectal cancer with curative intent. Yet it is only one of many modalities used in palliative therapy. Although many options are available for the palliation of cancer of the intra-abdominal colon, such as abdominal colectomy, segmental resection, internal bypass, or fecal diversions, surgical palliation of rectal cancer is technically more difficult and options are more limited. This is due to the anatomic restrictions of the pelvis and the fact that there is more commonly fixation of the tumor to major structures like the iliac vessels, prostate, bladder, or nerve roots. Operative palliative therapy is indicated in patients that are able to tolerate surgery and with the intent of providing relief or improvement of symptoms while maintaining normal function. Indications include bowel obstruction, perforation of the rectum, formation of rectal fistulas to the vagina, bladder or prostate, bleeding, pain, and local obstructions of the urinary system. Surgical resection should be avoided in patients with extensive pelvic disease. This includes patients with invasion of the pelvic sidewall or of the sacrum above S2, bilateral ureteral obstruction, lymphedema, and encasement of major vascular structures, extensive nodal disease and distant metastases. Surgery is also not a good modality in most patients with a life expectancy < 3 to 6 months. Surgical options include tumor resection and fecal diversion by way of a colostomy. The best option is dictated by the clinical scenario with the intent of minimizing morbidity while obtaining optimal quality of life.

Colostomy

Fecal diversion is most often achieved by creating a sigmoid colostomy. This is probably the most common surgical therapy for palliation of unresectable rectal cancer. Formation of such a colostomy used to require a limited open laparotomy. However, now palliative stomas are commonly created laparoscopically to minimize the impact on the patient's quality of life. Whether laparoscopic creation of such colostomies is superior to the open method is still unproven. In most cases, an end colostomy with mucus fistula is preferred to a loop colostomy because it results in complete fecal diversion and avoids stoma recession, which would make stoma management more difficult. A transverse colostomy is a lesser alternative but can be used in patients who require an operation with minimal negative physiologic impact. In patients with mid and low rectal cancers, colostomies are increasingly being replaced with endoscopic stenting and by conventional transanal debulk-ing (eg, by transanal endoscopic excision). These procedures can be carried out with less morbidity compared to transabdominal palliative procedures. However, formal randomized studies comparing colostomies with other invasive treatment options are scant.

Resections

In patients with an incurable condition but technically resectable local disease, an anterior resection with primary anastomosis can be considered if the distal rectal remnant is > 4 cm. Ultralow anterior resections with coloanal anastomoses require temporary colostomies. They often lead to temporary continence problems after colostomy takedown that can persist for a few weeks or months. These operations are not a good option for palliation. An extended low Hartmann operation leaving a minimal distal rectal stump is an excellent alternative if the patient is willing to accept a permanent colostomy because it completely eliminates the risk of anastomotic leakage. Also, if the patient has received previous pelvic irradiation or has poor anal sphincter function, a colostomy would be the preferred surgical palliative therapy. However, if the tumor involves the low rectum or the sphincter complex, an abdominal-peritoneal resection is optimal. A pelvic exenteration is rarely performed for rectal cancer because of an associated high morbidity, which in turn negatively affects the patient's quality of life. However, limited involvement of the vagina or the uterus is not a contraindication and many surgeons will include a posterior vaginectomy or hysterectomy as part of the procedure if necessary. In contrast, few surgeons will extend their resection to include the bladder or prostate.

Rectal Stenting

Self-expanding metal stents are becoming a more widely accepted alternative to surgical palliation in patients with incurable rectal cancer that have extensive locoregional or metastatic disease, comorbidities precluding surgery, or recurrent disease after resection. Successful palliation with stenting has been achieved in approximately 90% of patients while avoiding a colostomy. These stents provide good long term resolution of obstruction that exceeds 1

year in some studies and have acceptable complication rates. Migration of stents is the most common issue and rates have been reported as < 15% (Fernandez et al, 1999; Baron, 2001). Migration rates appear to be higher with covered stents, which have been successfully used in palliation of rectovaginal or rectovesical fistulas resulting from the rectal cancer. Patients with stents placed too distally may experience tenesmus, rectal pain, and fecal incontinence. Stent occlusion resulting from tumor ingrowth can be treated with argon beam coagulation, laser, or restenting. The relationship of stents and radiotherapy and chemotherapy has not been clearly defined. However, a few patients with stents have been reported to have undergone successful subsequent radiation therapy. There is a separate chapter on intestinal and colonic strictures (see Chapter 85, "Intestinal and Colonic Strictures").

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

Get My Free Ebook


Post a comment