With the extensive multidisciplinary and comprehensive treatment of rectal cancer, thelocal recurrence rate of rectal cancer has decreased to less than 10% [1, 2]. Locally recurrent recta cancer (LRRC) refers to foci that appear in the pelvis and perineum region with the same pathologic type as the primary tumor after radical surgery for rectal cancer, excluding the accompanying other distant transitions, such as liver, lungs and bones. The common sites of local recurrence are mainly the anastomosis, perineum, soft tissues in the pelvis and adjacent organs or structures. Due to the heterogeneity of the patient population, different clinical manifestations, and different sites of recurrent tumor tissue invasion, there is a lack of standardized diagnostic and therapeutic procedures for the diagnosis, treatment strategies, and surgical methods of LRRC. In recent years, studies at home and abroad have shown that the treatment of local recurrence in patients with rectal cancer should be individualized and based on a multidisciplinary team to carry out diagnosis and treatment [3], and radical surgical resection for local recurrence (R0 resection) is still the best choice for successful treatment of local recurrence [4].
Close follow-up after radical rectal cancer treatment is an important means to diagnose recurrence as early as possible, and regular tumor marker tests, imaging examinations and physical examinations are more important for patients with recurrence and no symptoms. In this case, the patient underwent radiotherapy and chemotherapy after radical treatment for rectal cancer, during which no obvious abnormalities were found in the tumor marker or CT. In February 2023, pelvic MRI suggested that a ring-shaped reinforced nodular shadow of approximately 1.0 cm in transverse diameter was observed in the posterior part of the vagina, and there was no obvious diffusion limitation. In August 2023, pelvic MRI suggested that a ring-shaped reinforced nodular shadow of approximately 1.5 cm in transverse diameter was observed in the posterior part of the vagina, and there was diffusion limitation. In November, the patient presented with irregular vaginal fluid symptoms. Perfect MRI suggested that the posterior wall of the vaginal ring-shaped strengthened mass was significantly larger than before, the border was irregular and lobulated, and burrs were observed. Additionally, metastatic tumors are likely when combined with the history.
Secondary malignant tumors of the vagina can be confined to the vagina or not and can originate from the recurrence of primary malignant tumors of the vagina or from recurrent vaginal metastases of malignant tumors of other organs. Tumors originating from pelvic organs are mainly metastasized by implantation, direct infiltration, the lymphatic tract and hematogenous metastasis, while tumors originating from other sites are mainly metastasized by hematogenous metastasis. The rectum has no plasma membrane below the peritoneal reflex, and the tumor can easily infiltrate into the surrounding tissues after infiltrating the intestinal wall. It is generally believed that middle and low rectal cancers are more invasive. The patient in this case had moderately differentiated cancer of the lower rectum, the cancer tissue invaded the plasma layer, and a cancerous embolus in the vasculature and nerve invasion could be seen.
For patients who experience recurrence and metastasis after radical surgery for rectal cancer, MRI and PET- CT are recommended for understanding the systemic condition and lesion site. Pelvic MRI can accurately show the extent of tumor invasion and determine the relationship between the tumor and adjacent structures [5]. PET-CT is better than Computed tomography (CT) and MRI for identifying tissue fibrosis and tumor recurrence, is a guide for the evaluation of local recurrence, and can also be used to evaluate distant metastasis [6]. Histopathological findings confirm that homology with previous tumor pathology is the gold standard for the diagnosis of recurrence, and biopsy is recommended to obtain histopathological evidence if possible [7]. Therefore, after the patient in this case presented with localized vaginal symptoms, pelvic MRI, PET-CT and histopathological examination of the biopsy of the posterior vaginal wall were perfected, suggesting that the shadow of the ring- enhanced mass in the posterior vaginal wall had increased significantly compared with that of the previous mass, and biopsy of the posterior vaginal wall suggested that adenocarcinoma was present.
In patients with localized recurrence after comprehensive treatment for rectal cancer, several studies have shown that radical resection (R0 resection) is an independent factor influencing survival in patients with localized recurrence [3, 8, 9]. As the only curative treatment for patients with localized recurrence of rectal cancer, radical resection is important for potentially curable patients. Direct surgical resection is recommended for patients with a history of pelvic radiotherapy for isolated tumors without distant metastases and locally resectable tumors [10]. Based on the relevant examination results, a multidisciplinary team discussion was held to assess the R0 surgical resectability and surgical risk, determine the surgical access, choose the surgical procedure and the scope of resection, and adequately plan the surgery to minimize the occurrence of postoperative complications. If the boundary of the lesion is unclear, the infiltration range is wide, it is difficult to resect cleanly by surgery, or the patient has absolute contraindications to radical surgery (such as severe cardiopulmonary dysfunction unable to tolerate surgery, bilateral sciatic nerves invaded by the tumor, external iliac blood vessels involved, pelvic wall invasion, etc.) [11], in those cases, surgery should not be performed blindly, and preoperative combined radiotherapy and chemotherapy should be performed so as to strive for the chance of surgery.
Due to the complexity of the pelvic anatomy and the destruction of the normal anatomical structure by the first surgery or radiotherapy, the traditional transabdominal or transabdominal perineal combined approach is difficult to perform, and the unclear surgical field, anatomical structure disorder, local adhesions, tumor infiltration, and roughness of the operation can increase the difficulty of the surgery, the intraoperative damage to the neighboring organs in the urinary tract, the risk of bleeding, and the difficulty of precise hemostasis. Therefore, improving surgical access, ensuring the curative nature of surgery as much as possible, shortening the operation time, and reducing the occurrence of complications have become the core of treatment.
Adequate exposure of the surgical field is a prerequisite for ensuring complete resection of tumor tissue and avoiding pelvic organ damage, so the patient in this case underwent a longitudinal incision via the sacral prone position. The patient was placed in the prone position, the incision was made parallel to the gluteal sulcus, 2 cm lateral to it, or via the gluteal sulcus, and the incision was prolonged under the buttocks if necessary. The skin and subcutaneous tissues are incised, the gluteus maximus muscle and part of the anal retinaculum muscle are dissected at the attachment of the spine below the 4th sacral vertebra, and the branches of the inferior gluteal artery, the inferior gluteal nerve, and the branches of the subanal (rectal) and perineal nerves are cut off in this area. Intraoperative care is required to protect the urinary tract. The tip of the tailbone was dissected, and the fascia of the inferior border of the gluteus maximus muscle and the inferior gluteal cutaneous nerve were incised on both sides. The gluteal muscles are pulled back to the sides to expose the tumor tissue, the coccyx or part of the sacrum (sacrum below sacral 3) is resected if necessary to expose the operative field, and the tumor is resected 3 cm from the outer edge of the tumor under finger guidance. Reconstruction of the operative area is required to fill the presacral defect, promote surgical wound repair, and prevent surgical complications. Intraoperative flaps can be designed by selecting bilateral gluteus maximus muscles, with paired “kite” flaps on both sides, preserving the superior gluteal artery, and embedding them to cover the trauma completely. The use of muscle flaps for reconstruction results in better vascularization and reconstruction [12]. The use of a muscle flap for reconstruction results in better vascularization and reconstruction.
A longitudinal incision via the sacrum in the prone position reduces tissue damage, decreases the degree of organ function destruction, and in case of intraoperative bleeding, a good view also facilitates hemostasis. If the incision is too tight to be sutured, then a flap graft with a tipped flap can be used to fill the incision with a free part of the gluteus maximus flap, and the skin can be sutured. In addition, the prone longitudinal incision approach is also suitable for patients with presacral cysts whose upper pole is lower than the level of the 4th sacral vertebra, cysts that are biased on the sacral side, and presacral cysts whose lower pole is closely related to the tip of the coccyx and the anorectal ring [13]. In this case, the patient underwent complete resection of the tumor tissue through this approach, and postoperative recovery of the incision was possible.
Complete resection of locally recurrent tumor tissue is central to improving patients’ quality of life and prolonging survival. There is a lack of large-sample clinical randomized controlled studies on the prognostic impact of adjuvant therapy on the local recurrence of rectal cancer. Whether to administer adjuvant therapy after surgery needs to be discussed by a multidisciplinary team in conjunction with postoperative pathological and histochemical results and imaging findings. Currently, radical surgical options for local recurrence of rectal cancer are still undergoing continuous exploration to ensure radical surgical resection while minimizing complications and improving patients’ quality of life. For patients with local recurrence involving the vagina after comprehensive treatment of rectal cancer, if the possibility of radical resection is evaluated after discussion by a multidisciplinary team, in addition to the traditional transabdominal or combined transabdominal-perineal approach, the longitudinal incision approach through the prone position of the sacrum is also an option, which can successfully resect the tumor in a complete manner, reduce the difficulty of the operation, and prolong the patient’s survival period. This surgical approach does not require special medical equipment, and clinicians need to fully understand the anatomical structure, which makes it easy to promote its application.