Fistulas after radiation therapy (post-radial fistula)

A particularly serious complication of radiotherapy for malignant tumors of the pelvis is the post-radial fistula, which accounts for about 8% of all urinary fistulas. Fistulas after radiation therapy are formed in 1-5% of patients who underwent radiation therapy.

[1], [2], [3], [4], [5], [6],

Causes of the fistulas after radiotherapy (post-radial fistula)

The frequency of fistula formation increases with repeated courses of radiation therapy. In the etiology of postradiation urological complications, both the involvement of the vaginal and epigastric plexus play a role, as well as the presence of vascular diseases. For example, patients with diabetes mellitus and hypertensive disease develop more severe post-radiation complications. Despite the development of modern equipment for radiotherapy, the number of patients with various postradiation complications, including post-radial genitourinary fistulas, remains significant. Operative intervention also contributes to the violation of trophism of the genito-urinary organs.

So when combined treatment  of cervical cancer, the  risk of formation of urogenital fistulas increases fourfold. Such complications usually occur late in the course of the course of radiation therapy (on average - in two years), as the trophic changes leading to the formation of a fistula. Progress slowly.

However, in the literature there are reports of fistula formation 28 years after the end of radiotherapy and even 38 years after the end of irradiation. Such a long period from the moment of irradiation to the formation of the fistula makes it possible to differentiate the radiation of the urogenital fistula from the primary tumor fistula that occurs immediately after the destruction of the tumor. This indicates the involvement of trophic disorders in the formation of postradiation urogenital fistula.

[7], [8], [9], [10], [11], [12]

Treatment of the fistulas after radiotherapy (post-radial fistula)

Operative correction is carried out after stabilization of the general condition of patients and the acquisition of plastic properties by the tissues in the fistula zone. At the same time, inflammation disappears, necrotic areas are discarded and scars become tender. Post-fistula fistulas operate on average 7 months after the end of radiation therapy or relapse.

Typical methods to close post-radial fistula is difficult, the surgeon must creatively approach the development of the operation. Often patients operate multiple times. Of course, it is increasingly difficult to close the recurrent fistula, since after previous operations scars in the surrounding tissues become extensive and denser, resulting in a deterioration of the blood supply of tissues. Repeated operations result not so much in the restoration of voluntary urination as in the consequent decrease in the capacity of the bladder, which is already reduced in half of the patients.

In order to improve trophism of tissues and replace extensive defects with postradiation fistulas, the basis of most methods is the use of a flap on a leg, cut from uninfected tissues. SR Kovac et al. (2007) believe that fistuloplasty using tissue pads is the main method of surgical treatment of post-  urinary urogenital fistulas. At present, for the closure of postradiation urinary fistulas, many authors recommend using the Martius flap.

In addition, in operative treatment of post-radial fistulas as a liner is used from m. Gracilis, m. Rectus abdominis, peritoneum and omentum.

For the treatment of post-radial vesicovaginal fistulas, it was suggested to use the modification of the Lacko operation. The essence of the proposed technique is that after the widest mobilization of the vaginal and bladder tissues in the fistula region, the edges of the fistula are not excised. On the defect of the wall of the bladder, overlapping seams from synthetic absorbable materials are applied.

If there is a technical possibility, a second row of seams is applied to the paravezic tissues. The sutures on the vaginal defect are superimposed in such a way that the anterior and posterior walls of the vagina are cross-linked below the fistula. That is why the operation was called "high colpkleizis." 174 patients with postoperative vesicovaginal fistulas were operated on this technique. Positive results were achieved in 141 (81%) women.

In separate observations, with a significant decrease in the capacity of the bladder and involving in the process of pelvic ureteral divisions, the restoration of voluntary urination naturally occurs by intestinal grafts. However, if the capacity of the bladder is irretrievably lost or there are extensive defects of the bottom of the bladder and there is no urethra, the question arises about transplanting the ureters into the intestine over the course of or with the supra-localized urine drainage with the formation of the Briquer reservoirs. Mainz-Pouch and their various modifications, which provides normal functional preservation of the kidneys.

Despite the observance of all the rules and principles of surgical interventions, the improvement of surgical techniques and the creation of suture materials with improved properties, the effectiveness of operations in post-radial urogenital fistulas remains low. The frequency of recurrence in different clinics ranges from 15 to 70%. So. In one of the trials of surgical treatment of 182 patients with post-radial puer-vaginal fistulas, random urination was restored in 146 patients (80%). The high frequency of relapses prompts the development and improvement of surgical methods for treating patients with post-urinary urogenital fistulas.