The development of rectal cancer treatment has always been centered on the two main lines of radical treatment of cancer, prolonging survival, preserving anal function, and improving quality of life. Anus-preserving surgery for low rectal cancer should emphasize both radical cure and function preservation.
The complete resection of the mesorectum and the removal of the 2 cm distal intestinal tube of the cancer meet the requirements of the "golden rule". Under normal circumstances, doctors choose to perform anal preservation surgery without increasing the local recurrence rate.
At present, MRI three-dimensional imaging technology is used in the diagnosis of anal fistulas. Because MRI can distinguish normal tissues, chronic inflammation tissues and muscle tissues, the fistula can be visualized without the use of contrast agents, thereby overcoming the inability to inject contrast agents. Show the shortcomings of fistula.
The ideal treatment of RVF still lacks unified, standardized, and comparative research as a guide.
The failure rate of simple transvaginal repair is high, and it is safer to repair rectovaginal fistula 6 months after the occurrence.
Daniels refers to a fistula with a diameter of <2.5 cm as a small fistula, and a fistula with a diameter of >2.5 cm as a large fistula. The internationally commonly used classification is to divide RVF into simple fistula and complex fistula based on the etiology, size, and location, namely: diameter <2.5 cm, low median fistula, simple fistula caused by trauma or infection; diameter> 2.5 cm, high fistula, complicated fistula caused by inflammatory bowel disease, radiotherapy, tumor and failed multiple repairs.
For those who have failed surgical repair, prolonging a longer period of time will help local tissue edema, sclerosis, and infection disappear. Before surgical repair, it is necessary to control the inflammation of surrounding tissues, eliminate perianal abscess, and evaluate the function of anal sphincter. The success of the operation depends on the removal of the fistula and the replantation of healthy tissue in the rectum and vagina. After rectal cancer, RVF only undergoes bypass stoma, and the spontaneous healing rate is only 41.9% (6/14), and the average healing time is 6 months. In this part of the patients who healed on their own, the cause was all anastomotic leakage and abscesses, while those patients who were injured by the vaginal wall could not benefit from the stoma.
The purpose of tissue flap transplantation is to provide healthy tissue with sufficient blood supply to strengthen the rectovaginal space and promote healing.
Progress in treatment of acquired rectovaginal fistula
Rectovaginal fistula (RVF) is an abnormal passage between the vaginal epithelium and the rectal mucosa. It is an ancient disease. The earliest recorded in the West is in Hippocrates in 430 BC. The record of Chinese fistula first appeared in the "Shan Hai Jing·Zhong Shan Jing": "If the eater does not have carbuncle, it can be a fistula." Patients often complain of vaginal defecation, exhaust, and discharge of pus. Due to the particular complexity of the local anatomy, it not only causes inflammation of the local tissues, but also affects the lives of couples, which is a very harmful disease. RVF can be divided into two categories: congenital and acquired. Congenital is more common in children, often combined with anorectal malformations, surgery requires anal reconstruction in addition to fistula repair. Acquired sex is more common in adults, and fewer people need anal reconstruction. The treatment of RVF has always been the focus of the anorectal department. With the deepening of research, the understanding has been constantly changing.
1.1 Birth injury Birth injury is the first factor leading to RVF. It has been reported that 85% to 92% of RVF is caused by birth injury. The incidence of RVF during vaginal delivery is 0.06% to 0.1% in developed countries, and the rate is even higher in developing countries. Ven katesh et al. investigated 20,500 women who gave birth via vagina, 5% had Ⅲ～Ⅳ degree perineal laceration. Among 1040 patients with degree Ⅳ degree laceration, about 10% of the wounds dehisced again after the first repair, resulting in RVF and anus. incontinence. Wang Jian of the First Affiliated Hospital of Baotou Medical College and others counted 8200 cases of vaginal delivery, 12 cases (0.122%) of third degree perineal laceration, including 6 cases of complete rupture of the anal sphincter, 5 cases of partial rupture, and 1 case of RVF. The main risk factors during delivery are: prolonged second stage of labor, shoulder dystocia, difficulty in delivery with forceps, and episiotomy at the midline. A notable feature of RVF caused by birth injury is that it is often combined with anal sphincter injury, and the proportion of anal incontinence is higher.
1.2 Inflammatory bowel disease Inflammatory bowel disease (Crohn) often causes complex anal fistulas, which is generally considered to be the second cause of RVF in the United States. The pathological feature of Crohn's disease is a full-wall inflammatory disease that penetrates all layers of the intestinal wall. The ulcer of the diseased intestinal segment penetrates the surrounding tissues and organs and easily forms internal and external fistulas. Ulcerative colitis mainly involves the mucosa and submucosa, so anal fistulas are rarely formed. In St. Mark Hospital, about 10% of women with Crohn's disease develop RVF. Searching the literature of the Chinese full-text journal database in the past five years, there are fewer reports of Crohn's disease causing RVF in China. Liu Qingsen from Beijing 301 Hospital and others compared the clinical characteristics of 85 patients with Crohn's disease in China and 68 patients in the United States. There were only 2 cases of rectal involvement in patients in 301 Hospital, and no perianal invasion. In the United States, 42 of the 68 cases involved the rectum, 25 cases involved the perianal, and up to 35 cases had a perianal fistula or RVF. Differences in clinical characteristics may reflect differences between races, but still need the support of large sample statistics.
1.3 Surgical injuries Surgical injuries often lead to high RVF, and more often occur during the anterior resection of middle and low rectal cancer. Total hysterectomy, transvaginal partial rectal resection, and rectal protrusion repair can also cause RVF. Nakagoe et al. reported that in a group of 140 patients with low rectal cancer before resection, 2.9% developed RVF. Domestic Chen Zhen reported 68 cases of double stapling anus preservation surgery for low rectal cancer. Anastomotic leakage occurred in 6 cases (9%) and RVF occurred in 1 case. It can be expected that with the promotion of comprehensive treatment plans, an increase in anus preservation surgery, and the high frequency use of double stapling, RVF will increase.
1.4 Radiotherapy RVF is a common disease in the large intestine injury related to radiotherapy. When the total amount of radiation exceeds 5000 cGy, the incidence of gastrointestinal injury increases significantly, and it usually occurs within six months to two years of radiotherapy. Radiotherapy is most common in cervical cancer. It can also occasionally be seen in radiotherapy for cancer of the anal canal, rectum and bladder. It has been reported that in the early stage of radiotherapy, proctitis and ulcers, 1/3 develop into anal fistula. Shao Bingfeng and others reported 26 cases of radioactive RVF, all of which were caused by cervical cancer radiotherapy. It is worth noting that RVF can also be caused by tumor recurrence, which requires a biopsy of the fistula to exclude it.
1.5 Infection After an abscess occurs in the vaginal rectal space, it can compress and penetrate the back wall of the vagina. Infection of the anastomotic stoma before rectal cancer resection, perirectal abscess, and diverticulitis can all lead to RVF. Other rare infections such as: pelvic tuberculosis, venereal lymphogranuloma, schistosomiasis, and vestibular cysts can also cause RVF.
1.6 Others Injection treatment of internal hemorrhoids with sclerosing agent can also cause RVF. Ju Yingdong reported 7 cases of RVF caused by Xiaozhiling injection. In addition, Fang Yonghong reported two cases of RVF complicated by severe coma. It is speculated that the cause may be caused by long-term compression of the intestinal tube by induration of stool. In addition, glycerin enema, tumor invasion, metal foreign body, anal fistula hanging thread, and sexual life have been reported.
There are many classification methods, usually according to the cause, location, and size of the fistula. According to the position of the fistula on the rectovaginal side, it can be divided into low, medium and high positions. Table 1 Classification of RVF location According to the size of the fistula, Daniels refers to a fistula with a diameter of <2.5 cm as a small fistula, and a fistula with a diameter of >2.5 cm as a large fistula.
In addition, the internationally commonly used classification is to combine the cause, size, and location to divide RVF into simple fistulas and complex fistulas, namely: diameter <2.5 cm, low-media fistula, simple fistula caused by trauma or infection Fistula; diameter>2.5 cm, high fistula, caused by inflammatory bowel disease, radiotherapy, tumor, and multiple repair failures are complex fistulas.
In recent years, the promotion of laparoscopy has broken the boundaries of the above classification. Some scholars believe that those high fistulas that are relatively small and can be repaired under laparoscopic surgery can also be regarded as "simple".
The main purpose of the assessment is to determine the location of the fistula and the condition of the surrounding tissues.
3.1 Medical history collection The common symptoms of RVF are vaginal defecation and gas. Diarrhea, blood in the stool, sticky stools, and abdominal pain usually reflect the underlying cause of the fistula. During the medical history collection process, the focus should be on the history of childbirth, inflammatory bowel disease, pelvic and lower gastrointestinal surgery, history of radiotherapy, and whether there is fecal incontinence.
3.2 Physical examination The physical examination pays attention to the thickness of the perineal body and whether there are scars, and the digital rectal examination touches the sinus tract, lumps, fluctuating uplifts, and estimates the tension of the anal sphincter. When necessary, probes, speculum, and proctoscope can be used to assist in diagnosis. Clinically highly suspected, but the above measures are ineffective, you can try the following methods: ①The patient takes the lithotomy position, infuse the vagina with warm water, ventilate the rectum with a rectaloscope, and observe whether there are bubbles from the vagina side. ②Pour methylene blue into the rectum and insert cotton gauze into the vagina. After 10-20 minutes, observe whether the cotton gauze is stained.
3.3 Imaging examinations include transrectal ultrasound, vaginography, barium enema, CT, MRI, etc. Among them, ultrasound is the most commonly used. The fistula appears to be hypoechoic or anechoic in ultrasound, so hydrogen peroxide injection can enhance the ability of ultrasound to accurately locate complex fistulas. Recently, MRI has also been used for the evaluation of anal fistula. Some scholars believe that MRI is superior to other examinations in the clinical classification of RVF and the diagnosis of perianal abscess.
3.4 Local tissue evaluation The necessary examinations are often different due to different causes. RVF caused by birth injuries should be done by ultrasound or anal pressure measurement to detect the anal sphincter. For patients secondary to radiotherapy, a biopsy is required if necessary to rule out tumor recurrence. The health of the anorectal mucosa can be completed by barium enema and colonoscopy.
4 RVF treatment
4.1 Principles of treatment Small fistulas with a diameter of less than 2.5 cm may heal spontaneously, and surgery can be considered after conservative treatment for 6 to 12 weeks. For fistulas caused by birth injuries, some authors suggest to delay the operation for 3 to 6 months. For those who have failed multiple surgical repairs, prolonging a longer period of time will help the local tissue edema, hardening, and infection disappear. Before surgical repair, it is necessary to control the inflammation of surrounding tissues, eliminate perianal abscess, and evaluate the function of anal sphincter. The success of the operation depends on the removal of the fistula and the replantation of healthy tissue in the rectum and vagina.
4.2 Non-surgical treatment and diversion stoma
4.2.1 Conservative treatment includes local care (bath and local washing), abscess drainage, low-residue diet, oral broad-spectrum antibiotics for 10 to 14 days, parenteral nutrition, etc. In addition, loperamide hydrochloride can be used to extend the passage time of fecal intestines. Recently, it has been reported that the use of infliximab to treat RVF caused by Crohn's disease can close the fistula in a short time and prolong the duration of fistula healing. Although most RVF still requires surgical treatment, medical treatment can relieve symptoms, improve local tissue conditions, and create the best conditions for surgery.
4.2.2 Fibrin glue Because the RVF fistula is short, it is difficult to attach biological glue, and the treatment effect is not ideal. However, the operation is extremely simple, does not damage the anal sphincter, does not affect subsequent treatment, and has the potential to close the fistula, so it can still be tried.
4.2.3 Fecal diversion For those with poor general conditions who cannot tolerate repair surgery, advanced tumors, and severe RVF symptoms, simple fecal diversion can effectively relieve symptoms and improve quality of life. It can also be considered for radiotherapy, RVF caused by Crohn's disease, and those who have failed multiple repairs. The study by Kosugi et al. showed that RVF after rectal cancer only undergoes bypass stoma, and the spontaneous healing rate is only 41.9% (6/14), and the average healing time is 6 months. In this part of the patients who healed on their own, the cause was all anastomotic leakage and abscesses, while those patients who were injured by the vaginal wall could not benefit from the stoma.
4.3 Surgical treatment
4.3.1 Principles of preoperative preparation and repair The patient is given mechanical bowel preparation and preventive antibiotics before surgery. The principle of repair is to fully free the tissue, remove the fistula, carefully stop bleeding to prevent hematoma, and suture layer by layer without tension to ensure adequate blood supply. Insufficient blood supply can transplant skin flaps or omental flaps.
4.3.2 Surgical methods and choices There are many surgical methods for RVF, and the choice of surgical method depends on the location of the fistula, the size of the fistula, the experience of the physician, the condition of the anal sphincter, and the previous operation. The surgical methods are classified into advancement flap surgery, advancement sleeve flap, transvaginal flip fistula suture, layered suture of fistula resection, transvaginal push flap surgery, transperineal sphincteroplasty (Sphincteroplasty), transperineal rectal wall advancement flap (sliding anterior rectal wall advancement flap/Noble Mengert Fish procedure), transperineal fistula resection, perineoproctotomy. Tissue transplantation includes Martius skin flap (subcutaneous fat pad of the labia majora), gracilis, omentum, gluteus maximus, sartorius, and rectus abdominis; transabdominal surgery includes low anterior resection, colon-anal anastomosis, transabdominal perineum Combined resection, fecal diversion (fecal diversion), Onlay patch anastomosis.
22.214.171.124 Low-position simple fistula and anal sphincter injury can choose perineal rectal fistula incision, anal sphincteroplasty, transperineal rectal flap operation. The main point of perineal rectal fistula incision is to convert RVF to degree IV perineal laceration, and then suture layer by layer. The main point of anal sphincteroplasty is to make an incision through the perineum and suture the two ends of the external anal sphincter. Patients without anal sphincter injury can choose transperineal fistula resection. The advantage is that while the perineal body makes a curved incision approach, the levator ani muscle can be pulled and sutured to separate the front wall of the rectum and the back wall of the vagina, reducing the risk of recurrence.
At present, more doctors with low RVF tend to choose transanal rectal valve surgery. This procedure was first proposed by Noble in 1902. This method is simple to operate, does not damage the anal sphincter, and can close the high-pressure area of the fistula to prevent intestinal bacterial contamination. It has become the most popular method for RVF repair. The surgical success rate reported in the literature varies greatly, ranging from 29% to 100% . Whether combined with sphincteroplasty, number of operations, whether anal fistula recurrence or fecal incontinence is used to investigate the effect of surgery will bring differences to the statistical results. The main advantages are: ① No need to cut the vagina, less pain and quick healing. ②It is not necessary to cut all the sphincter to avoid anal incontinence. ③Avoid keyhole deformities. In China, Shao Wanjin et al. reported 11 cases of sliding flap repair, of which 7 cases underwent rectal sliding flap operation and 4 cases underwent transanal sliding flap. After an average follow-up of 30.5 months, only 1 case recurred.
In addition, it can also be used as a rectal push flap through the perineum. The advantage is that it can repair the external anal sphincter and reconstruct the perineal body. It is suitable for complete perineal tear and low RVF. Transvaginal flap surgery has also been reported. Because Crohn's disease invades the rectal wall but does not affect the vaginal wall, it has an advantage in repairing RVF caused by Crohn's disease.
Simple fistula incision is rarely used because unnecessary incision of the vagina and sphincter often leads to fecal incontinence.
126.96.36.199 Median simple fistula Fistula resection through the vagina or anus is a simple and effective method, and the rectal valve can also be used.
188.8.131.52 High RVF often requires open surgery and laparoscopic surgery. The open surgery methods include low anterior resection, combined transperitoneal resection, colon-anal anastomosis, fecal diversion, and Onlay patch anastomosis. Onlay patch anastomosis was first described by Bricker et al. The basic procedure is: free the rectosigmoid colon to expose the fistula and remove the surrounding tissues of the fistula. The sigmoid colon was cut horizontally, the proximal opening was transabdominal stoma, and the distal opening was anastomosed with the exposed fistula. When the imaging showed that the RVF had healed completely, the fistula was returned by the second operation, and the rectosigmoid ring was anastomosed end-to-side. It is suitable for RVF caused by radiotherapy, especially those patients with large fistula and radiation proctitis. The advantage is that there is no need to free the back of the colon and no need to enter the presacral space. The main disadvantage is that the diseased intestine is indwelled.
At present, laparoscopic repair of RVF is not yet mature, and there are few cases of RVF independently completed by endoscopy reported in the literature. Kumaran et al. reported a case of RVF after hysterectomy: the fistula of the rectum and vagina were sutured separately under the endoscope, and the omentum was sutured between the two. Later, Palanivelu.C and others also made two similar reports. This technology is relatively strict in the selection of patients and has high technical requirements for the surgeon.
184.108.40.206 The complicated RVF caused by radiotherapy and Crohn's disease can consider rectal cuff flap and tissue flap transplantation. The rectal cuff flap was first reported by Hull and Fazio. Four of the five RVF patients healed, and the remaining one underwent colorectal resection and ileostomy. Sleeve sliding flap surgery is a better choice for patients who can only consider fecal diversion and patients with anal stenosis.
The purpose of tissue flap transplantation is to provide healthy tissue with sufficient blood supply to strengthen the rectovaginal space and promote healing. For mid-low fistulas, commonly used tissue flaps include the levator ani muscle, Martius flap, gluteal muscle flap, gracilis and so on. High fistula usually fills the omentum or folds the rectus abdominis after transabdominal repair. The most commonly used procedure in anorectal department is Martius flap transfer. The procedure was first described by Martius in 1928 and was originally used to repair bladder rectal fistulas. It can also be used to repair ileal pouch-vaginal fistulas caused by radiotherapy, major birth injuries, multiple failed operations, and restorative colorectal resection. It can be used as a first-line treatment for radiotherapy of anal fistula. Cui Long in China reported 7 cases. It is believed that the transperineal autologous tissue flap transfer and internal isolation technique is safe and effective for the treatment of recurrent rectovaginal (urethral) fistula, with fast healing and low recurrence, and it is worthy of promotion and application.
220.127.116.11 Others In recent years, there have been reports of the use of SurgisisTM mesh (biocompatible mesh tissue) placed between the vagina and rectum in a new surgical method to repair recurrent RVF. In addition, there are reports of a new method of using Surgisis AFPTM anal fistula plug to treat anal fistula. The biocompatible tissue is extracted from porcine collagen to fill the internal opening of the anal fistula. The short-term effect is better than that of bio-glue. The above two methods are rarely reported, and further research is needed for their efficacy.
In short, the ideal treatment of RVF is affected by many factors, such as the etiology, location, surgical skills of the surgeon, the presence or absence of anal sphincter injury and fecal incontinence. Although there are many clinical reports, there is still a lack of unified, standardized, and comparative research as a guide. Considering the diversity of etiology and the complexity of anatomical structure, it will be very difficult to improve the quality of research. Further research is needed to choose the best treatment for different patients.