The lowest position for anal preservation surgery

When a person suffers from severe rectal tumors, surgical intervention will be performed, among which anal preservation surgery is a surgical method for rectal tumors. However, there is much discussion about anal preservation surgery in clinical medicine in China, because it is a surgical method that is not very mature and it is easy to leave sequelae to the patient's body. For patients who need anal preservation surgery, what is the lowest position during the anal preservation surgery?

Anal preserving surgery is simple and labor-saving. With the help of a stapler, anal preserving surgery is easy to complete, and both the doctor and the patient are happy after the operation.

In reality, many patients with low rectal cancer have undergone anal preservation surgery, but many patients have also experienced anastomotic tumor recurrence within 1-2 years. However, they are basically unable to undergo a secondary radical resection, and the effects of adjuvant radiotherapy and chemotherapy are not ideal. As a result, they can only have a palliative fistula to provide a way for defecation. The creation of a fistula alone does not have much impact on the quality of life. Instead, the continued growth of the unresectable tumor causes bleeding, swelling and pain, and compression of the nerves and urethra, leading to cancer pain and difficulty urinating. These are the pain after recurrence.

Therefore, we, the colleagues in gastrointestinal surgery, must strictly grasp the indications for anal preservation surgery for rectal cancer, and strongly recommend that patients who are not suitable for anal preservation surgery give up the idea of ​​anal preservation surgery, rather than complying with the patient's wishes or actively inducing the patient to undergo anal preservation surgery. We must always put tumor eradication and life first in the first place in tumor surgery. We should make extending the patient's survival time as long as possible our ultimate goal.

Indications for anal preservation surgery

Today, anal preservation surgery is no longer a problem of surgical technique, but a problem of different understandings of it. This is especially true since the application of staplers and double-staple technology. Many colleagues believe that anal preservation surgery has become the preferred treatment for low rectal cancer, and abdominoperineal resection (Miles surgery) has become the last option for treating low rectal cancer. As a result, the proportion of anal preservation surgery in my country has increased significantly, allowing some patients to avoid the pain of artificial anus after surgery and improve their quality of life. But the other side of the problem is that some surgeons blindly perform anal preservation surgery without strictly grasping the indications, which not only fails to improve the quality of life, but also affects the survival period. An ideal anal preservation surgery should have good defecation and bowel control functions without affecting the survival period, so that it can be said to truly improve the quality of life. To ensure survival, surgery must be performed according to the principle of radical cure. A standard radical surgery should be: sufficient primary lesions must be removed, and a certain length of normal intestinal tract above and below the primary lesion should also be removed; the connective tissue around the rectum (mesorectum) should be completely removed according to the TME principle; and the superior and lateral lymph nodes should also be completely removed. Only when these conditions are met, and different anal preservation surgeries are selected according to different cases, will the survival period not be affected.

There are many clinical pathological factors that should be considered during anal preservation surgery, but the most important reference factor is the distance between the lower edge of the tumor and the anal verge. Anatomy shows that the average distance between the anal verge and the dentate line is 2.5 cm, and 0.5 cm above the dentate line is the upper edge of the levator ani muscle. Therefore, in order to ensure the integrity of the levator ani muscle, at least 3 cm of the anal canal and rectum should be preserved after tumor removal. If 3 cm of normal intestinal tract at the lower edge of the tumor is removed (it can be limited to 2 cm in early cases), then the lower edge of the tumor must be at least 6 cm away from the anal verge for anal preservation surgery to be performed. Only in this way can the postoperative function be guaranteed; otherwise, the result will be counterproductive and there will be no quality of life. The author has performed surgical treatment on 8 patients who reluctantly underwent anal preservation surgery in other hospitals (with extremely poor postoperative function and no local recurrence) but who strongly requested to undergo Miles surgery within 2 years. Patients feel satisfied after the operation, which in turn guarantees the quality of life to a certain extent. According to the author's experience, anal-preserving surgery must be performed with caution in patients with mucinous adenocarcinoma. Most of this pathological type have extremely strong infiltration ability, with a long reverse infiltration distance and easy to infiltrate the surrounding mesentery. Therefore, we advocate that the lower incision end should reach 5cm and the excision of the surrounding tissue should be more thorough. In addition, we have observed the pathological characteristics, treatment and prognosis of rectal cancer in young people.

The clinical misdiagnosis time is long, the disease stage is often late when seeking medical treatment, the macroscopic type is mostly narrowing type, the microscopic type is mostly poorly differentiated adenocarcinoma and mucinous adenocarcinoma, the lymph node metastasis rate is high, and the survival rate is low. Based on these characteristics, we advocate that anal preservation surgery must be performed with caution. If anal preservation surgery is suitable, we advocate that the minimum lower resection margin should be 5 cm, and earlier cases should be selected. Therefore, for young patients with mucinous adenocarcinoma, the distance between the lower edge of the tumor and the anal verge should be more than 8-9 cm before anal preservation surgery can be performed.