What is transanal minimally invasive surgery (TAMIS)?
Also known as transanal endoscopic microsurgery, transanal minimally invasive surgery (TAMIS) is a procedure that allows local resection of polyps or tumors that, due to their size, cannot be removed by colonoscopy. This innovative technique avoids resorting to more radical surgeries that entail greater risks, incisions and a slower recovery for the patient.
Why is it performed?
This procedure is designed for those cases in which the size of polyps or tumors are too large, so large that it is not possible to remove them by colonoscopy. Minimally invasive transanal surgery is a very useful treatment in patients with cancers in early local stages, polyps by endoscopy and other lesions.
It is currently a very precise surgical procedure and the least aggressive. However, transanal resection without the use of TAMIS still has its place and is also a good and effective method, especially for very low early lesions and in selected cases.
What does it consist of?
Transanal minimally invasive surgery (TAMIS) presents fewer risks than conventional surgery, precisely because there are no incisions, and also the loss of blood, if it occurs, is slight (the same as in local resection without TAMIS). All this speeds up the recovery process.
The main advantages of this procedure are speed, safety and minimization of the risks to which the patient is subjected. Specialists usually resort to minimally invasive transanal surgery in those cases in which it is more complicated to use conventional methodology, either because the patient has a narrow pelvis or suffers from obesity.
Preparation for minimally invasive transanal surgery (TAMIS)
Before undergoing the procedure, a preoperative evaluation is necessary to alert patients in particular situations to preventive measures. Also, a bowel preparation (ensuring that the rectum remains unoccupied) and partial cleansing of the rectum are necessary.
There are different techniques to achieve this, but the method to be used is at the surgeon’s discretion. For example, the lithotomy position speeds up the preparation time in the operating room and is the most commonly used by most anesthesiologists. Alternative positions can also be used, such as the sevillian knife or lateral decubitus for those cases in which the lesion is located on the anterior or lateral aspect, respectively.
Regarding possible complications, it should be taken into account that difficulties similar to those of the classic transanal approach may arise during surgery, but less frequent. Some of them are:
- Hemorrhage.
- Perforation of adjacent viscera.
- Accidental opening of the bottom of the pouch of Douglas.
Care after the operation
It is considered a low risk intervention and of short hospitalization, since most patients are discharged after the first 24-48 hours after surgery. Regarding the diet, it is advisable that during the first days the patient should be subjected to an initial diet based on liquids, although he/she will be able to progress without restrictions as tolerated. Also, if a full-thickness resection was performed or there was an intraperitoneal entry, antibiotics may be administered beyond the preoperative prophylaxis.
After the procedure, some complications may occur, although they are rare. Some of them are:
- Hemorrhage.
- Rectovaginal, rectourethral and rectovesical fistula.
- Stenosis.
- Incontinence.
- Genitourinary functional disorders and persistent pain.
- Severe pelvic sepsis.
- Fournier’s gangrene.
As for the follow-up, it is normally performed two and six weeks after the operation. During the same, the specialist will perform a clinical examination to assess healing by means of digital rectal examination and rigid rectoscopy.