Posterior pelvic organ resection with preservation of anus via double midline approach through vesicovaginal space and presacral space Wang Gangcheng, Department of General Surgery, Henan Cancer Hospital Wang Gangcheng, Department of General Surgery, Henan Cancer Hospital 1. The indications are: 1). Tumor invasion of cervix uterus and rectum. (2). The lower edge of the tumor is more than 6.0 cm from the anus, and the resection content is the whole uterus and part of the rectum, preserving the anus. Vaginal palpation: all patients had tumors more than 6 cm from the external vaginal opening, normal anterior vaginal wall, invasion of the posterior vaginal wall, and poor mucosal mobility. Rectal palpation: the lower edge of the tumor was palpable more than 6 cm from the dentate line, and the tumor was fixed with poor mobility. Pelvic CT suggests that there is no metastasis to distant organs, and the tumor has not invaded the pelvic wall and sacrum.2. Surgical methods: (1) Take the amputation position, and after successful anesthesia, perform rectal palpation or rectovaginal bimanual diagnosis again, to find out the distance of the tumor from the dentate line of the anus and the vaginal orifice, to judge the scope of rectovaginal resection, and to find out the relationship of the tumor with the anterior wall of the vagina and cervix, so as to further determine whether the tumor has invaded the triangle of the bladder. If the tumor invades and infiltrates the anterior vaginal wall and is closer to the vaginal opening, the bladder triangle may be invaded, and only posterior pelvic organ resection is performed, which fails to achieve the goal of tumor eradication. (2) Sacral median approach to free rectum pre-sacral space: after open abdominal exploration, decide to perform posterior pelvic organ resection, free and open the peritoneum on both sides of the sigmoid colon and rectum, break the rectal mesenteric blood vessels, at least 10cm from the tumor to break the rectum with a cutting closure device (the tumor, such as rectal cancer, should be dissected from the root of inferior mesenteric artery, and the whole rectal mesentery should be resected), lift the distal end of the rectum to expose the pre-sacral space, and sharply separate the rectum along the mid-sacral line. The gap between the visceral peritoneum and the mural peritoneum is freed to the point of pre-resection of the lower edge of the tumor. (3) Free the vesicovaginal septum by a median approach to the vesicovaginal space. Break both sides of the uterine garden ligament and part of the broad ligament to the cervical paracervical tissue, lift up the bilateral uterine garden ligament, lift up the uterine uterus, open the vesico-uterine peritoneum, and free along the vesico-vaginal hiatus up to the preexcision point at the lower edge of the tumor. (4) The anterior and posterior vaginal walls were severed, and the paracervical tissues and ureters were separated in a retrograde and inverted fashion. Along the vesicovaginal space will be pushed to the posterior wall of the bladder to the vaginal pre-excision point, the posterior wall of the bladder will be cautiously pulled apart, the lower edge of the tumor at least 2cm break the anterior and posterior walls of the vagina, will be broken through the vagina of the uterus, the rectum and the tumor as a whole lifted upward, the paracervical tissues and uterine arteries on both sides of the laxity of the state by the stretch, the physiological and anatomical walk of the lower end of the ureter not only completely exposed fully, the ureter and the uterus because of the stretching of the uterine body with a certain distance, break the bilateral The uterine arteries and parietal tissues of the uterus are separated to protect the ureter on both sides. (5) Free the lateral rectal ligament, break the rectal intestinal tube. After vaginal dissection and paracervical tissue freeing, the whole pre-excision specimen is pulled up, the lateral rectal ligament is sharply separated, and the lower edge of the tumor is severed from the rectum by at least 2 cm.3. Discuss the bottleneck of the overall resection of the posterior pelvic organs. Ureteral injury is a common complication of pelvic tumor surgery [1-2]. Most of the medical ureteral injuries originate from the extrusion of pelvic tumors on the ureter, and the tissue adhesions lead to local anatomical structure changes, resulting in inconspicuous exposure of the ureter [3-5]. The ureteric uterine artery crossing and the transiliac external vascular segment are the vulnerable sites of ureteral injury [7]. Therefore, the uterine cervicorectal space is infiltrated by the tumor, resulting in the uterus and rectum can not be separated and resected separately, due to tumor extrusion, local adhesion bilateral ureter and uterine artery crossings, the paracervical tissues at the trans-iliac external vessels and the lateral ligament of the rectum are not easy to be exposed, both the obstetrician-gynecologists and the general surgeons, due to the anatomical structure of the changes in the resection procedures, are often worried about the resection process to injure the ureter or the Pelvic wall blood vessels, in order to be able to achieve the R0 resection effect, many operators are always careful when dealing with the ureter and parauterine tissues, as if walking on thin ice. They may even be over-conservative for fear of injuring the ureter or pelvic wall vessels, resulting in unclean margins of the paracervical tissues and lateral rectal ligaments. The author utilized the vesicovaginal space and presacral space double midline approach to decompose the relationship between the tumor and the ureter and paracervical tissues relatively easily. Mechanism of double midline approach to the vesicovaginal space and presacral space double midline approach. (1). Characteristics of posterior pelvic tissues and organs. ①. The rectal bowel below the peritoneal reflex is stretchable. When the ligaments surrounding the bowel below the peritoneal reflex are free, the bowel can be stretched at least 3 to 4 cm. ②. The vagina and cervix have restricted stretchability. The vagina and cervix are diametrically opposed to the rectal tissue properties and do not have stretching properties; instead, the tumor as a whole cannot be lifted because of the pulling down of the vagina. ③. The tortuous and floppy nature of the parauterine tissues and rectal ligaments. Para-uterine soft tissues, uterine arteries, and the soft tissues of the lateral rectal ligaments are relatively floppy and have some stretchability. ④. Relative fixity of bilateral ureteral position. The ureters and uterine arteries are in a crisscross state. The position of the ureter remains essentially unchanged when the paramedian tissue and uterine arteries are stretched. (2). The previous hysterectomy procedure of dissecting the paracervical tissues and uterine arteries first and then the vaginal wall has been changed. After pushing the bladder wall to the normal vaginal tissue along the vesicovaginal space, the method is to dissect the anterior and posterior vaginal walls first instead of the paracervical tissues and uterine arteries, and the whole posterior pelvic organs and tumors are uprooted from the pelvis like a big tree that has broken off its main roots after dissecting the anterior and posterior vaginal walls first. At the same time, the paracervical tissues, uterine arteries, and lateral rectal ligaments were stretched, and the relationship between the bilateral ureters and uterine arteries, as well as the relationship between the tumor and the pelvic wall, were clearly revealed. The relationship of the ureters, uterine arteries, and tumor to the pelvic wall is easily addressed. Advantages of double midline approach to the vesicovaginal space and presacral space Double midline approach. (1). Shortened operative time. The bottleneck in the overall resection of the posterior pelvic organs is the management of the ureter and para-uterine tissues, which can shorten the operative time by a significant amount if this area can be easily managed. In the present case of 26 patients, the median operative time for posterior pelvic organ resection utilizing this method was 120 min; (2). Avoiding injury to the ureter. After lifting the posterior pelvic organs and tissues using this method, the gap between the ureter and the uterine artery and tumor widened significantly, reducing the chance of injury to the ureter. There was no damage to the ureter in 26 patients in this group, and 3 cases were placed with ureteral stent tubes because of the proximity of the ureteral tumor, and the ureter was free and bare for a longer period of time for fear of ischemic necrosis. (3). Reduced chance of positive parietal tissue margins. In this case, 26 patients had negative lateral pelvic wall tissue margins and vaginorectal margins. (4). It is in line with the principle of tumor-free operation, which is beneficial to the patient’s prognosis. This method avoids the situation of dismembering the posterior pelvic organs and resecting them separately, which reduces the chance of tumor dissemination and metastasis, and, theoretically, is beneficial to the patient’s prognosis. All the cases in this group were resected for the tumor as a whole, but 26 patients were patients with different categories of tumors, and the number of sample cases was small, so the prognosis of the patients could not be given for control comparison. Clinical data show that complete resection of solid tumors such as rectal tumors, ovarian tumors, mesenchymal tumors and other solid tumors combined with multiple organs is the key to prolonging life [8-11]. (5). Simplified surgical procedure. The method is easy to understand, simple to operate, and easy to promote the application. Double midline approach to the vesicovaginal space and presacral space Double midline approach requires attention. (1). The vesicovaginal space must be adequately separated to avoid injury to the posterior bladder wall. (2). The vaginal margin and the rectal margin may not be in the same section due to the degree of tumor invasion, so pay attention to the distance of the margin from the tumor. In conclusion, for female patients with pelvic malignant tumors, if the tumor is located in the vaginorectal space, the lower edge of the tumor is more than 6.0 cm from the anus, and the patient has the desire to preserve the anus, the transvesical vaginal space and pre-sacral space double midline approach can be used to resect the tumor as a whole, which not only avoids the decomposition of the tumor by resecting the whole uterus and the rectum separately, which is prone to lead to the risk of tumor implantation and dissemination, but also, more importantly, the method is more concise and simpler in dealing with the ureters More importantly, this approach is more concise in dealing with the ureter and parauterine tissues, which reduces the difficulty of surgery. Special cases: the bladder is compressed and displaced by the tumor, the uterus is encircled by the tumor, and the rectum is invaded by the tumor. The tumor, bladder, uterus and rectum are fused and fixed.