الفهرس 
Anatomy of the RectumOnly 14 pages are availabe for public view
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Abstract
Rectal cancer is the fourth most frequently diagnosed cancer in United States and has the second highest cancer-related mortality rate after lung cancer. Cancer of the colon is equally frequent in men and women while rectal cancer occurs 20-50% more frequently in men. Incidence of colorectal cancer increased with increasing socioeconomic status.
Diets high in meat and fat and low in fruit and vegetables are associated with an increased risk of rectal cancer.
A number of groups have an increased risk of developing colorectal cancer. At highest risk are those with either of the dominantly inherited conditions familial adenomatous polyposis (FAP) and hereditary non polyposis colorectal cancer (HNPCC).
The most of rectal cancers arise in adenomatous polyps and that their ablation arrests the development of cancer at that site. Other groups at moderately increased risk include those with long-standing ulcerative colitis or Crohn’s disease.
Prevention of progress to invasive rectal cancer is actually prevented by early detection and removal of adenomatous polyps. Because of the slow growth period, regular screening tests can detect rectal cancer in its earliest phase, before any symptoms have occurred several approaches are available for the detection of rectal neoplasia, including physical examination, digital rectal examination, fecal occult blood testing (FOBT), standard sigmoidoscopy, fiber optic sigmoidoscopy, full colonoscopy, single and double Contrast barium enema. When cancer becomes invasive other methods of evaluation include endorectal ultrasound (ERUS) to determine the depth of penetration and identify locoregional nodal metastases.
Computed tomography (CT) scan can evaluate metastatic disease. Magnetic resonance imaging (MRI) of the abdomen and pelvis to determine the depth of penetration and the potential for achieving negative circumferential (radial) margins as well as to identify locoregional nodal metastases and distant metastatic disease.
Surgical treatment techniques and outcome depending on the histopathological staging which is carried on resection specimens is to obtain an estimate of prognosis, in rectal cancer the Dukes system, the Jass system and TNM system.
Surgical management of rectal cancer patients have rapidly changed over the last two decades in order to improve the outcome. A lot of methods have been introduced including radiation therapy, chemotherapy, and the total mesorectal excision. In addition function-preserving techniques have been also developing to preserve anal function by performing low anterior resection inested of Abdomino-Perineal resection this is supported by developing of auto sutures and double stapling techniques.
Laparoscopy has improved the surgical treatment of various diseases due to its limited surgical trauma and has developed as an interesting therapeutic alternative for open colorectal surgery. Laparoscopic management of colorectal diseases, it is important to standardize the preoperative and the postoperative care plans, so that optimal results can be obtained. Also appropriate patient choice and differences in surgical techniques or surgeon’s skills may account for the great variability in outcome.
Laparoscopic-assisted colectomy) LAC (for Colon cancer has been shown to be safe, with equivalent long-term survival rates to conventional open colectomy and better short-term patient outcomes. It tends to require more operating theatre time and disposable equipment. ) LAC (for colon cancer appears to be cost-effective relative to open colectomy. Expected future reductions in operating times, conversion rates and postoperative stays will further improve cost-effectiveness.
In rectal cancer, technical difficulty as well as doubt on oncological clearance had once limited sphincter preservation to carcinomas located at the recto sigmoid junction or in the upper rectum. Progress in technology and skills, however, has finally led to the controversial extension of minimally invasive tech¬niques to distal rectal cancer with sphincter preservation. The majority of the comparative studies found similar local recurrence rates for laparoscopic and open rectal cancer excision. The long procedure time of certain laparoscopic rectal cancer operations is of interest.
Generally laparoscopic management of colorectal diseases has a lot of advantages including decreased postoperative pain, early discharge from the hospital, less duration of postoperative ileus, less postoperative adhesions, less morbidity, less wound infection, less intraoperative blood loss, and improved cosmoses. Significant improvement of pulmonary function and the faster postoperative recovery of pulmonary complications compared with conventional surgery consider one of the important advantages.
Longer operating time, Conversion rates and economic cost are considered the only disadvantages of laparoscopic management of colorectal diseases, but conversion rates vary widely between studies depending on patient selection, and which phase of the learning curve.
Modern cancer management is a team effort involving experts in surgery, chemotherapy, radiotherapy, and palliative care.
Locally recurrent rectal cancer is a challenging and debilitating problem. It manifests in large variety of ways, and treatments need to be tailored to each individual.
Patients with complete obstruction tend to be acutely ill, with advanced disease. Because preoperative placement of an expandable metal colorectal stent permits clinical stabilization with preoperative decompression and cleansing, a one-stage operation can then be performed and colostomy avoided. The stent is removed en bloc at the time of resection of the primary tumor, after serving as a bridge to surgery. If the patient is a poor candidate for surgical resection because of underlying illness or has unresectable or widely metastatic disease discovered by imaging studies, the stent can remain in place for palliation.