Minimally invasive surgical techniques are becoming more and more important in the treatment of endometriosis. The use of robots for laparoscopic surgery has been introduced abroad in 1997 [6]. Both domestic and foreign experiences have proved that laparoscopic surgery is less invasive, faster recovery, smaller abdominal scar, and lighter postoperative adhesions than open surgery, and has become recognized as the best method for the treatment of endoheterosis [7]. Surgical procedures can be done in all endometriosis, and women with fertility requirements and whose lesions explain their painful symptoms and causes of infertility should undergo conservative surgery. If the surgeon can perform laparoscopic bowel resection and ureteral anastomosis, then there are almost no longer contraindications to laparoscopic treatment of endometriosis. However, open surgery is still appropriate for procedures where laparoscopic skills are not yet proficient, where extensive intestinal adhesions are estimated, where bowel resection is required, or where the procedure is judged to be very complicated. Some studies suggest that those with serum CA125 levels >65 IU/ml may have dense pelvic adhesions, and those with intestinal symptoms and/or masses and suspected deep infiltrative lesions should be prepared for bowel disinfection.
1. Purpose of surgery
That is, to remove ectopic lesions and chocolate cysts, to separate adhesions, and to restore the normal anatomy and physiological state of pelvic organs in order to promote fertility and relieve pain. Removal of the uterus can relieve dysmenorrhea and reduce recurrence for those who have severe dysmenorrhea and also suffer from fibroids or adenomatous famine disease and have no fertility requirements.
2.Commonly used means of removing endometriosis lesions
Scissors can be used directly to remove the endometriosis lesion, and there is usually not much bleeding. Unipolar and bipolar electrocoagulation or thermal coagulation are also often used to directly destroy endoheterotropic lesions. Monopolar electrocoagulation is best performed with needle or hook electrodes, otherwise it is not safe enough due to the large range of thermal damage caused by monopolar electrocoagulation. Bipolar electrocoagulation is more ideal for treating small, superficial ectopic lesions, while thermal coagulation can only destroy superficial lesions. Electrocoagulation is a simple method, but the depth of destruction is not easy to grasp, and the treatment may not be complete when the destruction is shallow, and may damage important organs located below it when the destruction is deep. For safety reasons, monopolar electrocoagulation is contraindicated for ectopic lesions on the surface of the ureter and intestine. Foreign scholars recommend the use of high-energy carbon dioxide laser because of its efficacy and high safety. The CO2 laser does not penetrate water and is best used when water separation is used in conjunction with resection of peritoneal ectopic lesions. Other lasers are generally considered to have high penetrating ability and are not suitable for endoheterotopic surgery. Some authors have used microwave to remove endoheterotopic lesions and found the efficacy satisfactory, pending further experience. In recent years, ultrasonic knife has been reported for the treatment of endoheterosis, and the recent efficacy is satisfactory, but the long-term efficacy needs to be further observed.
3.Recommended methods for removal of endometriosis lesions
(1) Ovarian endometriosis cysts (ectopic cysts)
Ectopic cysts have a recurrence rate of more than 50% with simple aspiration of the intracapsular fluid or partial excision of the cyst wall. Laparoscopic or ultrasound-monitored cyst puncture and aspiration with anhydrous ethanol has been reported both at home and abroad, which is considered less invasive, faster recovery, and less cyst recurrence rate. However, in recent years, the atypical hyperplasia and malignancy of endotopic lesions have attracted attention.Brosens and Puttemansi [8] suggested that before treating ectopic cysts, cyst puncture and aspiration should be performed, the fluid should be sent for cytological examination, the cyst lining should be observed microscopically, biopsies should be taken from suspicious areas and sent for frozen pathological examination, and after the pathology proves to be benign, the lining should be destroyed by small surgical endoscopy using laser or electrocoagulation to a depth of 3-4 mm. The procedure was similar to endometrial removal and no recurrence was seen on ultrasonography and laparoscopic second exploration at follow-up, but the number of cases is small and needs further confirmation. Evidence-based medical data prove that cyst stripping (stripping technique) is clinically superior to cystotomy with internal electrocoagulation and has been recognized as the best surgical method both nationally and internationally [9].
However, the cyst stripping procedure and technique still need to be improved and perfected. In recent years, both surgeons and fertility specialists are concerned about the effect of cyst debridement on the morphology and function of the ovary and fertility. Many studies have shown that cyst debridement is often associated with loss of normal ovarian tissue and loss of growing follicles during cyst debridement at the ovarian hilum [10-11]. After cyst debridement, ovarian volume is reduced and ovulatory function is temporarily lost [12-13]. Reduced number of eggs retrieved from the affected ovary after ovulation promotion treatment, etc. Of course, in addition to the stripping technique, the damage to the ovary caused by excessive electrocautery should not be ignored. Combined with our years of clinical experience, cyst debridement can be sequentially divided into four steps, including adhesion separation, cyst debridement, proper hemostasis and adhesion prevention.
(1) Adhesion separation The surgery starts with the separation of adhesions, fully exposing the pelvic surgical field and separating the ovary from the rectal sulcus and/or lateral pelvic wall. Ectopic cysts also often have dense adhesions to the uterosacral ligament, and the fibrosis of the lesion even causes the intrinsic ligament of the ovary to adhere to the uterosacral ligament, resulting in posterior retroflexion of the uterus and limitation of movement. Therefore, these adhesions should be sufficiently separated to keep the ovary away from the ureter and medial intestine below the lateral pelvic wall adhesions, which can greatly reduce the chance of damaging them, which is the key to ensure safe and complete debridement of ectopic cysts. Since ectopic cysts almost always rupture when separating the adhesions and can easily cause contamination, especially in large cysts that rupture and contaminate the abdominal cavity, we prefer to first puncture and aspirate and flush the larger ectopic cysts and then proceed to separate the cyst wall from the surrounding adhesions. The ovary is lifted upward by grasping the ovary with forceps to find the interface between the ovary and the broad ligament and the uterosacral ligament adhesions, which are usually easy to identify, and the ovary is separated along this boundary, flushed as it is separated. If it is difficult to identify, the ovary can be separated from the broad ligament by applying force to the ovary with the head of the suction device upward, and the dense adhesions can be cut with scissors if necessary. When separating the adhesions, be careful not to leave the ovarian cortex on the surrounding tissues; otherwise, even after hysterectomy and adnexal resection on both sides, there is still a possibility of residual ovarian syndrome leading to subsequent or even multiple surgeries.
(2) Cyst debridement Nezhat et al. in the United States divided ovarian ectopic cysts into two types [3], and different types of ectopic cysts can be treated with slightly different surgical approaches. Type I ectopic cysts, although small, are difficult to remove completely due to fibrosis and adhesions and can be removed with biopsy forceps, vaporized and cauterized using laser and electrocoagulation after puncture and aspiration or local excision. Type IIA ectopic cysts usually have mild adhesions and are generally easy to remove when the cyst wall is yellow. Type IIB ectopic cysts can be more heavily adherent, but the cyst wall is easily peeled away from the ovarian cortex and interstitium, except for the attachment of ectopic nodes. Type IIC ectopic cysts with dense and extensive adhesions are more difficult to remove.
Accurate finding of the interface between the cyst wall and ovarian tissue is the key to successful debridement. Cyst aspiration and irrigation can be performed by repeated expansion and reduction of the cyst wall to promote separation of the cyst wall from the surrounding ovarian tissue. The cyst wall is then separated from the surrounding ovarian tissue and the correct peeling surface can be easily found by using a suction device and curved forceps to penetrate deep into the cyst rupture to tear it open close to 1/3 to 1/2 of the cyst circumference. Some surgeons prefer to remove some thin layers of ovarian tissue around the incision until they see the correct peeling surface and then do the peeling, although this may result in the loss of more or less normal ovarian tissue. Larger ectopic cysts may require removal of some of the ovarian tissue around the incision at the same time. Some foreign surgeons also inject 5 to 20 ml of Ringer’s solution between the ovarian interstitium and the cyst, and then grasp the base of the cyst wall with a grasping forceps to perform cyst debridement. The cyst is removed by grasping the cyst wall with a toothed grasper and the normal ovary on the outside with another grasper, and the two grasper forces are applied in opposite directions to tear off the cyst wall. Sometimes, rotating the cyst wall in one direction can speed up the peeling process.
It should be noted that it is not uncommon to have multiple ectopic cysts in a single ovary (we have removed 5 and 6 ectopic cysts of varying sizes from the right and left ovaries of a patient with recurrent endometriosis). Unless the ectopic cysts are small and located at one end of the ovary, the ovary becomes a depressed disc after cyst debridement, and the possibility of small ectopic cysts should be alerted to any marked thickening or protrusion of the tissue.
According to Nezhat’s staging of ectopic cysts, most ectopic cysts are secondary; therefore, after complete removal of the cyst wall, the ectopic nodules surrounding the cyst should be sought and destroyed i.e. their primary lesions should be destroyed. In our experience, ectopic lesions are mostly located on the uterosacral ligament with adhesions to the cyst, and purple-blue nodules or miniature ectopic cysts are often found close to the intrinsic ovarian ligament [14], which we usually treat by excision or electrocautery.
Recently, Muzii et al [10] in Italy performed a more detailed pathological examination of 59 patients with a total of 70 chocolate cysts >3 cm and found that ectopic endometrial tissue could be seen on the cyst wall of chocolate cysts, covering an average of 60% (10%-98% ) of the luminal area, with an average thickness of 1.4±0.6mm and an average depth of ectopic endometrial invasion of the cyst wall of The average depth of ectopic endothelial invasion was 0.6±0.4 mm (0.1-2.0 mm). Although different from that reported by Nezhat, who considered that there are not so called two or three different types of ectopic cysts, this result, however, is more supportive to perform cyst debridement.
If only one ovary is diseased with very severe adhesions and symptoms are limited to the affected side and the contralateral ovary is normal, tubo-ovariectomy on the affected side may also be considered. After removal of the affected ovary, the risk of recurrence of ectopic disease is significantly reduced and fertility may also be improved because only the healthy ovary is ovulating.
(3) Proper hemostasis The cyst is peeled and then hemostatic if there is little bleeding. If there is significant bleeding, the bleeding can be stopped while peeling, and bipolar electrocoagulation is preferable. After rinsing the trauma, electrocoagulate only the active bleeding point and try not to blindly electrocoagulate the entire ovarian trauma.
Electrocoagulation of bleeding near the ovarian gate should be moderate, and suture can be used to stop bleeding when electrocoagulation is not easy to stop bleeding so as not to affect the ovarian blood supply.
(4) Prevention of adhesions According to animal experiments and clinical experience, trauma to the ovary does not need to be sutured [15]. Continuous cautery of the interior of the wound for 1 to 2 seconds with a low-energy laser or mono- or bipolar electrocoagulation will cause the ovarian cortex to curl inward and shrink the wound, but excessive cautery should be avoided. For larger ovarian defects after cyst debridement of 5 cm or more in diameter, 1 stitch can also be placed within the ovarian mesenchyme to buttress the incision margins, with the thread knot tied within the ovary and not penetrating the cortex or exposing the ovarian surface to minimize adhesion formation. Continuous internal sutures with 2/0 Dexon sutures have also been reported. However, suturing with ovarian exposed sutures is time-consuming and prone to adhesions. We customarily spray bioprotein gel or sodium hyaluronate on the larger ovarian trauma and adhesion stripping surface, and leave dexamethasone 10 mg intraperitoneally after surgery to prevent adhesions. It has also been reported that the ovary was temporarily suspended on the anterior abdominal wall after surgery and then placed back on the ovary 5-7 days after the healing of the adhesions in the ovarian fossa, which was thought to help prevent adhesions between the ovary and the surrounding area.
(2) Endoheteropathy lesions
(1) Superficial peritoneal lesions Electrocoagulation, vaporization or excision are used when they are small, and serial vaporization or excision is required when they are more than 5 mm. Serial cautery can destroy the lesion from superficial to deep until normal non-pigmented tissue is seen.
Superficial ectopic implant lesions on the ureter can be treated with water separation techniques [15]. For example, 20-30 ml of lactated Ringer’s solution is injected subperitoneally in the lateral pelvic wall to lift the peritoneum and create a water cushion. A small 0.5-cm-long incision is made on the surface of the bulge. The suction tip is inserted into the incision and lactated Ringer’s fluid is injected into the retroperitoneum under pressure along the ureteral course. The fluid is allowed to penetrate around the ureter and push the ureter backward so that laser resection or vaporization of the superficial peritoneum in that area can be done. Once the water pad is ready, vaporization or excision can be done with a CO2 laser or any other cutting instrument. If the lesion is large, a circumferential incision can be made around the peripheral edge of the lesion. The peritoneum is lifted with a non-invasive forceps and torn off using excisional instruments and suction probes. If the ectopic lesion has buried itself in the peritoneum and formed a scar in the subperitoneal connective tissue, water will enter beneath the lesion during water separation, often loosening the scar tissue, and this will assist in safe removal of the lesion. Bladder endometriosis can also be treated with water separation and vaporization or excision if the lesion is superficial. Frequent flushing with water during surgery removes the carbon crusts to see the depth of vaporization or resection and to ensure that the lesion does not involve the muscular and mucosal layers of the bladder.
(2) Deeply infiltrating endometriosis (DIE) includes deep ectopic lesions (depth 5 mm) in the uterosacral ligament, rectovaginal septum, posterior vaginal vault and posterior cervix, ureter and rectum. symptoms are closely related to these deep ectopic lesions and to a lesser extent to chocolate cysts [16-17]. Therefore, cyst debridement alone is clearly not a complete treatment. In fact, laparoscopic surgery or laparoscopically assisted transvaginal resection is also feasible for these lesions.Donnez et al [18] found by histological examination of lesions in 500 patients with endorectal vaginal septal ectopia that the rectovaginal septal lesions were composed of smooth muscle and endometrial glands and interstitium, similar to uterine adenomyosis. Moreover, the estrogen and progesterone receptor content was different from that of the endometrium, suggesting that they receive a different regulatory mechanism than the in situ endometrium. Therefore, the authors concluded that rectovaginal septal endometriosis differs from peritoneal and ovarian endometriosis in that it originates from residual Mullerian ducts and should be treated as a separate disease. Of course, there are different opinions on this point of view.
The disappearance of the utero-rectal sulcus indicates deep endoheterosis and dense adhesions in the rectovaginal septum, as well as anatomic abnormalities in the local area including the intestinal canal, vaginal vault, posterior cervix, ureter and great vessels. Endoheterosis rarely penetrates the rectocolonic mucosa, and in most cases, lesions do not necessarily require bowel resection even if they invade the rectum and the rectovaginal septum. Although the management of intestinal endometriosis is controversial, the majority opinion is that if the lesion invades the intestinal mucosa and causes bleeding, pain or obstruction, intestinal resection and anastomosis should be performed; otherwise, partial resection of the lesion, like shaving operation, should be performed with minimal damage to the intestinal canal.
For surgery of lesions in the rectal recess and vagina, in order to better identify the anatomical relationships and tissue demarcation, the patient can be examined rectally or/and vaginally with an assistant standing between the patient’s legs and lifting a rigid curved uterine device upward with one hand. If the ovaries interfere with the field of view they can be temporarily sutured to the anterolateral abdominal wall, and after seeing the normal anatomy, a dilute fluid containing vasopressin (12u dissolved in 50 ml saline) is injected into the lateral rectal fossa with a puncture needle, then the peritoneal adhesions are separated with CO2 laser and scissors, and the pelvic floor fascia is opened to free the rectum and enter the rectovaginal space. At this point, the lesion can be continued under the microscope, or the posterior vaginal vault can be incised under the microscope before turning to transvaginal surgery to remove the lesion. In case of intraoperative bleeding from gross vessels, bipolar electrocoagulation, vascular clips or sutures can be used to stop the bleeding. If the lesion is found to reach the intestinal mucosa after resection, the intestinal wall should be reinforced with interrupted 3/0 or 4/0 PSD sutures. In case of extensive rectal lesions, sigmoidoscopy can be performed at the same time to guide the surgeon and exclude the possibility of intestinal perforation. Before the end of the procedure, a flushing solution is injected into the utero-rectal sink, and then air is instilled into the rectum, and the utero-rectal sink is observed microscopically; if air bubbles are seen to indicate intestinal perforation, repair or bowel resection anastomosis is required. Harry Reich in the United States prefers to use a rectal loop cutting anastomosis to repair small breaches, which is simple to perform and reliable, but more costly.
It is not necessary to reperitoneate the rough surface of the rectal or utero-rectal trap, as several reports have concluded that reperitoneation is unnecessary and promotes adhesion formation. Nezhat et al [19] performed such procedures in 185 women, of whom 80 had complete closure of the hystero-rectal recess, 175 patients were discharged 24 hours postoperatively after successful laparoscopic surgery, 9 had bowel perforation, and 1 had partial mesenteric resection 2-4 days postoperatively. The duration of surgery ranged from 55 to 245 minutes. 174 of the 185 cases were followed up for 1-5 years after surgery, with moderate to complete pain relief in 162 cases (93%). 13 cases (8%) required a second surgery, 4 cases required 3 surgeries, and 12 cases (7%) had persistent or worsening pain after surgery.
In recent years, there has been interest in nerve-preserving complete excision of the ectopic lesion (nerve-sparing complete excision), which may reduce bladder retention and dry stools associated with nerve injury, but requires a high level of skill on the part of the surgeon.
It must be emphasized that inexperienced laparoscopists, or gynecologists unfamiliar with bowel and urinary tract surgery, should not attempt to remove deep infiltrating ectopic lesions or reconstruct utero-rectal traps, as major complications may be inevitable. Most of our gynecologists lack surgical experience and are afraid or unwilling to do these surgeries however, burning, ectopic nodules in these areas are often less effective if they are not removed, so the surgical treatment of endorectal diaphragmatic ectopia has become an urgent problem in front of gynecologists, and it is believed that joint surgery between gynecologists and intestinal surgeons is the direction of future development.
4.Restore pelvic anatomy and relieve pain
In addition to reconstructing the uterine rectal sink, once the lesion is cleared and the adnexal adhesions are separated, the anatomical relationship between the ovary and the ipsilateral fallopian tube should be carefully observed to correct any anatomical distortion caused by adhesions, more so for those with fertility requirements. The fallopian tube tract often adheres to the ovarian cortex along the abdomen, and these adhesions usually cover a significant portion of the ovarian cortex and may interfere with the release of oocytes during ovulation. Not only that, but the fallopian tubes are often stacked together, limiting their ability to pick up eggs. When releasing adhesions to the fallopian tube umbilicus, the anatomy is clearer when the adhesions are released underwater than when the adhesions are released under the pneumoperitoneum alone. The lactated Ringer’s solution is first instilled into the pelvis to make the membrane-like adhesions of the tubal umbilicus float and disperse in the clear liquid, with the lighter umbilicus floating on top and separated from the normal tissue. When the tubal umbilicus floats from the folds at the end of the umbilicus, the adhesions are grasped with small forceps, and the adhesions can be released non-invasively using microscissors, usually without bleeding and without damaging the normal tissue. In patients with infertility, a methylene blue tubal lavage test is performed, and in cases of posterior uterus, uterine suspension and in cases of severe dysmenorrhea, anterior sacral neurectomy are also feasible. In recent years, laparoscopy uterine nerve removal (LUNA) has been advocated.
ablation (LUNA), which is to remove the 2-3 cm long and 1 cm deep uterosacral ligament starting from the root of the uterosacral ligament 0.5 cm, is a simple and easy procedure, but care should be taken not to damage the ureter. Although some evidence-based medical data suggest that LUNA is ineffective in relieving dysmenorrhea caused by endometriosis [20], we believe that if there is an obvious endometriosis lesion in the uterosacral ligament, we should still strive for complete removal of the lesion there, and actually do LUNA at the same time.
Conservative surgery, although rarely curative, improves the patient’s chances of fertility and provides temporary pain relief, and Adamson and Pasta [21] performed a meta-analysis of the literature and found that surgical treatment was better than pharmacological treatment for endometriosis I-II with infertility, and that laparoscopic surgery improved fertility in infertile patients. Approximately 25% of patients require reoperation after conservative surgery due to recurrence of endoheterosis or progression of residual (micro) lesions. The recurrence rate is directly related to the extent of the lesion and to the postoperative pregnancy, with only 10% of postoperative pregnancies requiring reoperation.