Improved Hysteroscopic Resection of Endometrial Polyps Using 6-Fr Micro-Scissors and Forceps

Summary

The novel technique presented here employs a combination of 6-Fr micro-scissors and forceps for hysteroscopic treatment of endometrial polyps, demonstrating encouraging outcomes for infertile patients afflicted with this condition.

Abstract

Endometrial polyps commonly contribute to female infertility, and hysteroscopic resection is the established surgical approach for their treatment. Numerous resection methods are available, with the most used and cost-effective options being cold resection employing micro-scissors or hot resection using an electric loop. However, both methods involve sharp resection, posing a challenge in achieving complete polyp removal while avoiding damage to the uterine endometrium. To address this issue, this study proposes an innovative approach: the combined use of the 6 Fr micro-scissors and forceps under hysteroscopy. The method entails utilizing 6 Fr micro-scissors to initially remove large polyps, followed by using 6 Fr micro-forceps to extract the remaining polyp tissue expeditiously and bluntly near the basal layer of the endometrium. This approach not only prevents surgical damage to the basal layer of the endometrium but also mitigates the risk of residual polyps resulting from incomplete resection. This method is particularly suitable for women with fertility requirements, offering additional considerations for the selection of treatment options for endometrial polyp resection.

Introduction

Endometrial polyps are abnormal tissue growths in the uterine lining with significant implications for fertility and reproductive health¹. The estimated incidence rate of endometrial polyps is approximately 35% among patients with infertility², though this figure may vary. These polyps can disrupt embryo implantation by inducing structural deformities in the uterine cavity and impacting the endometrium's ability to support implantation^3,4,5,6. While hysteroscopic surgery is a common procedure for removing endometrial polyps, it is not without risks, with uterine perforation being the primary complication, particularly during the removal of multiple polyps⁷. Hysteroscopy with resectoscopes and classic mechanical resection with scissors and/or graspers remain standard for evaluating and treating the pathology of the cervical canal and endometrial cavity⁸. The application of electric energy during the procedure can result in endometrial damage, especially in cases involving anatomical variations such as a unicornuate uterus⁹. Mechanical technology such as morcellators and scissors are less painful than electrical devices when eliminating structural lesions in the office¹⁰.

In response to these challenges, a novel approach is proposed involving the combined use of micro-scissors and forceps during hysteroscopy. This technique aims to minimize the risk of injury to the endometrium, particularly the basal layer while ensuring the complete excision of polyps to enhance fertility outcomes for women. The technique is easy to learn and requires two doctors to perform the operation. Doctors with experience in hysteroscopy are capable of executing this procedure. It is a new and unique technique that eliminates thermal damage in a very common gynecologic indication.

Overall, this innovative approach presents a safer and more precise method for eliminating endometrial polyps, particularly in women with fertility concerns, offering a valuable alternative to traditional hysteroscopic procedures and potentially enhancing outcomes for patients requiring treatment for endometrial polyps.

Protocol

This prospective observational study, involving outpatient hysteroscopy surgery patients, was conducted from March to December 2023. It was approved by the hospital's ethics committee of Shanghai JiAi Genetics & IVF Institute (ethics file number: JIAI E2020-09). All participants provided informed consent prior to inclusion in the study.

1. Patient selection and preparation

1. Patient eligibility
   1. Inclusion criteria: include patients with primary or secondary infertility, aged 18-45, with at least one transvaginal ultrasound suggesting uneven endometrial thickening or suspicion of endometrial polyps.
   2. Exclusion criteria: exclude individuals aged below 18 or above 45 years, those with severe internal medical comorbidities, unstable hemodynamics, acute pelvic inflammatory diseases, untreated infections, body temperature exceeding 37.5 °C on the day of surgery, pregnant women, individuals with suspected endometrial or cervical cancer, uncontrolled hyperthyroidism, uterine enlargement with uterine cavity exceeding 12 cm, and those unwilling to provide informed consent.
2. Preoperative patient preparation
   1. Perform a thorough assessment covering tests for hepatitis B, hepatitis C, human immunodeficiency virus (HIV), and syphilis, alongside evaluations such as an electrocardiogram, liver and kidney function tests, blood coagulation function analysis, complete blood count, vaginal discharge examination, and preoperative transvaginal ultrasound.
   2. Schedule surgery within 10 days following the cessation of menstrual bleeding. Prepare the following surgical instruments: a speculum, Hegar dilators, sponge holder, cervical forceps, sterilized gauze, probes, and curettes, as illustrated in Figure 1A.

2. Surgical preparation

1. Pre-operative preparation
   1. Gather comprehensive medical history records encompassing the patient's age, obstetric and menstrual history, underlying medical conditions, history of uterine and abdominal procedures, and pertinent clinical symptoms such as irregular vaginal bleeding. Additionally, document uterine size, position (anteverted or retroverted), endometrial thickness, endometrial echo, and the presence of other uterine diseases such as uterine fibroids or adenomyosis through transvaginal ultrasound examinations during the follicular phase preceding the surgery.
   2. Determine the surgical risks to the patient and obtain their signed informed consent. Furthermore, prior to the surgical procedure, evaluate the patient's anesthesia risks, obtain their signed informed consent, and allow the patient to choose between local anesthesia and no anesthesia based on their individual condition.
2. Operation field
   1. Ask the surgical team to be positioned as follows: the surgeon is situated at the foot of the patient, the first assistant stands to the right of the surgeon, the anesthesiologist is located on the left side at the head end of the patient, and the scrub nurse is positioned on the left side of the patient (refer to Figure 1B).
   2. Position the endoscopic equipment on the right side at the foot of the patient, place the anesthesia equipment on the right side at the head end of the patient, and situate the monitoring equipment at the head end of the patient. Place the patient in the lithotomy position, with the lower legs secured by bandages on both sides to ensure immobilization during the procedure.
3. Disinfection
   1. Perform disinfection according to the principle of disinfecting from top to bottom and inside to outside. Use iodine gauze to disinfect the external genitalia, labia, perineum, inner thighs, and perianal skin three times. Perform iodine gauze disinfection of the vagina 3 times. Complete the surgical draping with sterile surgical drapes.

3. Surgical procedure

1. Perform the following tasks as per the personnel's specialization: the anesthesiologist establishes peripheral venous access; the primary surgical assistant is responsible for assembling the hysteroscope lens, cleaning the lens, adjusting focus, and setting the white balance.
   NOTE: All surgeries are performed using a 5.2-mm-diameter hysteroscope by the same experienced hysteroscopic surgeon.
2. Set the hysteroscope pressure at 100 mmHg, with a flow rate of 300 mL/min. Use 0.9% saline solution as the distension media. Evacuate gas from the uterine cavity using the hysteroscope. Use cervical forceps to grasp the lower right lip of the cervix and carry out iodine disinfection again for the vagina, fornix, and cervix.
3. Introduce the hysteroscope into the uterine cavity through the cervical canal. In case of encountering difficulties, retract the hysteroscope and use a measuring probe with a scale to evaluate the uterine cavity's positioning and depth. Then, pull the cervical clamp to flatten the overly curved uterus to facilitate the hysteroscope to enter the uterine cavity.
4. Perform cervical dilation using Hegar dilators ranging from No. 3.5 to No. 5.5. Administer Phloroglucinol (80 mg intravenous injection) to relax the cervical smooth muscle if required.
5. Keep detailed records during hysteroscopy surgeries upon introducing the hysteroscope into the uterine cavity, documenting the presence or absence of endometrial polyps, along with their location, size, morphology (pedunculated or broad-based), and any other notable endometrial conditions.
6. Polyp removal
   1. For patients with a single uterine polyp, perform the following steps.
      1. Carry out individual removal using micro-forceps. Use the blunt end of the micro-forceps to pinpoint the basal layer of the endometrium (refer to Figure 2A). An anatomical gap exists between the endometrial polyp and the basal layer (as illustrated in Figure 2B); place the forceps here to grasp the basal portion of the endometrial polyp.
      2. Swiftly withdraw the micro-forceps to ensure complete separation of the polyp base from the endometrial base (as depicted in Figure 2C). Carry out the procedure incrementally until the polyp is entirely excised. Collect the excised polyp tissue for pathological examination. The typical pre- and post-operative images are shown in Figure 3A, B.
   2. For patients with multiple endometrial polyps, perform the following steps.
      1. In patients presenting with multiple endometrial polyps causing obstructive effects during surgery, employ micro-scissors initially to excise most of the polyps (refer to Figure 2D). This strategy is intended to increase the surgical space and enhance visibility within the operative field. Following this, remove any remaining polyp bases utilizing step 3.6.1.
         NOTE: Special caution should be exercised when using micro-scissors to avoid cutting too deeply during the procedure to prevent injury to the basal layer of the endometrium.
      2. Start the sequence for polyp excision with the posterior uterine wall, followed by the uterine lateral wall and corners, and then the anterior uterine wall. This surgical order is designed to optimize the clarity of the surgical field.
      3. Once the complete excision of all polyp bases is confirmed, withdraw the hysteroscope and use a small curette or sponge forceps to ensure complete removal of the polyp tissue. The typical pre- and post-operative images are shown in Figure 3C-E.
         NOTE: To minimize the heightened risk of infection associated with repeated hysteroscope insertions, it is generally advisable not to conduct further hysteroscopic exploration after the tissue removal.
7. Following the retrieval of all surgical instruments, clean the cervix and vagina by iodine disinfection.

4. Postoperative procedures

1. Following the surgical procedure, thoroughly document all observations and surgical interventions performed. After this, submit the specimens for pathological evaluation.
2. Carry out postoperative monitoring for 1 h to assess the patient's condition. In the absence of any complications, discharge patients without the need for additional medication.
   NOTE: The surgery process does not require any electronic devices and only requires the use of micro-scissors and micro-forceps. If electronic devices are used during surgery, it will be documented as a failure of the surgical procedure. All surgical complications should be documented, and postoperative pathological reports should also be recorded.

5. Statistical analysis

1. For quantitative data, use descriptive statistics such as mean, standard deviation, median, and confidence interval; for qualitative data, use frequency and percentage for description.

Results

A total of 114 patients suspected of having endometrial polyps based on transvaginal ultrasound findings participated in this study (Figure 4). All patients underwent hysteroscopy, with 15 patients diagnosed without endometrial polyps. The remaining 99 patients underwent endometrial polyp resection using the hysteroscopy technique. Among these 99 patients, aged between 26 and 44 years (Table 1), the average parity was 0.54 ± 0.78, and the median diameter of endometrial polyps was 12 mm (range 4-22 mm). In this research, the most common types of polyps were anterior and posterior wall polyps, accounting for 67.67% and 69.69%, respectively.

A telephone follow-up was conducted on 99 patients (Table 2), with a follow-up period of 3-9 months post-operation. Out of these, 11 patients were not reachable for the follow-up, leaving 88 patients who were successfully followed up. Among them, one patient received treatment for atypical endometrial hyperplasia, one patient underwent artificial insemination without successful conception, and four patients attempted natural conception. Out of the four, two were progressing with successful pregnancies, one had an early miscarriage, and one had an unsuccessful attempt. A total of 49 patients underwent embryo transfer, with 36 achieving clinical pregnancies, resulting in a clinical pregnancy rate of 73.46%. Out of these, 33 patients are currently pregnant, while 3 experienced miscarriages. Additionally, 33 patients are in preparation for embryo transfer.

In summary, the surgical approach has proven to be safe and reliable with no postoperative complications. The clinical pregnancy rate following surgery exceeds that of most reproductive centers, indicating the effectiveness of the surgical technique in endometrial protection, especially for patients with infertility.

Figure 1: Diagram of preoperative preparation. (A) The preparation of surgical instruments. (B) The schematic of the operating room layout. Please click here to view a larger version of this figure.

Figure 2: Diagram illustrating the hysteroscopic surgical procedure for endometrial polyps. (A) The blunt end of the forceps was used to locate the basal layer of the endometrium. (B) The gap between polyp and endometrial base. (C) The endometrial polyp was completely removed. (D) Micro-scissors were used to excise most of the polyps. Please click here to view a larger version of this figure.

Figure 3: Endometrial polyps pre- and post-operative images. (A) Preoperative photo of single anterior wall endometrial polyp. (B) Post-operation image of single anterior wall endometrial polyp, which was completely excised. (C) Preoperative photo of multiple endometrial polyps. (D) Post-operation image of anterior wall endometrial polyps, which were completely excised. (E) Post-operation image of posterior wall endometrial polyps, which were completely excised. Please click here to view a larger version of this figure.

Figure 4: Flow diagram of the study screening and selection process. We enrolled a total of 114 patients, of whom 15 had no polyps found during hysteroscopy, and 99 had endometrial polyps diagnosed by hysteroscopy and were treated with the method outlined here. Please click here to view a larger version of this figure.

		Intrauterine polyp (n=99)
Age Median [Range]		33 [26-44]
Gravida Mean±Std.		0.54±0.78
Polyp sizeusing hysteroscopy (mm), Median [Range]		12 [4-22]
Polyp origin location within the uterus n (%)	Ant. Wall	67 (67.67%)
	Post. Wall	69 (69.69%)
	Fundus	2 (0.02%)
	Left/Right wall	20 (20.2%)
Surgical duration (min), Mean±Std.		13.48±3.74

Table 1: Demographics of all endometrial polyp patients and findings of hysteroscopy. The table describes some information on patients, including age, gravidity, size, and location of the polyps.

Follow-up Details	Number of Patients	Outcome
Total Patients for Follow-Up	99
Patients Not Reachable	11
Patients Successfully Followed Up	88
Treatment for Atypical Endometrial Hyperplasia	1	Received treatment
Artificial Insemination	1	Unsuccessful
Natural Conception Attempts	4
Successful Pregnancies	2	Progressing successfully
Early Miscarriage	1
Unsuccessful Attempt	1
Embryo Transfer Attempts	49
Clinical Pregnancies	36	Clinical pregnancy rate: 73.46%
Currently Pregnant	33
Miscarriages	3
Patients Preparing for Embryo Transfer	33
Recurrence of endometrial polyps	0

Table 2: Description of postoperative telephone follow-up outcomes. This table summarizes the follow-up data for the 99 patients, including those who received various treatments and their pregnancy outcomes.

Discussion

Our research presents a novel surgical technique for removing endometrial polyps without cutting or causing electrical damage to the uterine endometrium, which is especially beneficial for women with fertility concerns. Sharon et al. introduced a similar technique using a non-electric loop for polyp excision¹¹, demonstrating its efficacy and safety. However, the traditional resectoscope has a larger diameter¹², necessitating cervical dilation and potentially increasing the risk of cervical dysfunction. In contrast, the hysteroscope we utilize has a smaller diameter, essentially eliminating the need for cervical dilation. Most patients in this study underwent the procedure under intravenous anesthesia, while a few cases were performed without anesthesia. Patients in these cases report very mild discomfort, rendering it suitable for outpatient hysteroscopic surgery.

A key feature of the technique is conducting the surgery in the anatomical space between the basal layer of the uterine endometrium and the endometrial polyps (Figure 2B), ensuring complete polyp excision and decreasing the recurrence rate. Existing literature reports postoperative recurrence rates of 5.6%-31.4% for uterine endometrial polyps^13,14, yet we did not observe any recurrences in the 3-9 months following the surgery (Table 2). This signifies a notable reduction in the recurrence rate with this technique. Another crucial aspect is the predominant utilization of micro-forceps during the procedure, essential for safeguarding the basal layer of the endometrium and fertility, particularly for women with infertility. The surgical approach has shown no complications, and the clinical pregnancy rate after transplantation reaches as high as 73.46%, affirming the safety and efficacy of the technique. It is hypothesized that minimizing thermal damage and preserving endometrial integrity are key factors in improving patients' fertility¹⁵.

Prior literature^16,17 has described various methods for cold knife excision of endometrial polyps involving the use of scissors or a morcellator. Micro-scissor operations demand rigorous training to prevent residual tissue and deep harm to the basal layer of the endometrium. The morcellating system consists of a 9 mm sheath¹⁸, which necessitates cervical dilation, incurring additional costs and potential complications. In contrast, this procedure is straightforward and easy to master; micro-scissors are employed exclusively for removing large polyps, preventing harm to the basal layer of the endometrium, and offering a cost-effective option for outpatient hysteroscopy. We recognize the limitations of our report, including the lack of a comparison group, which limits the generalizability of the results. We are currently gathering data on long-term issues, including pregnancy outcomes. Nonetheless, further studies are required to establish the long-term efficacy.

In conclusion, the present surgical technique is safe, effective, and easy to learn, which is particularly suitable for infertile women due to the avoidance of potential damage to the endometrium caused by electrocoagulation. Future research should focus on prospective randomized controlled trials to validate these findings further. Such studies should compare this method with traditional electrocautery-based techniques to assess not only fertility outcomes but also long-term endometrial health and patient quality of life.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Grasping Forceps	ShenDa	X5164B
Hysteroscope Lens	ShenDa	J0122A
Hysteroscopic Infusion Set	ShenDa	T7511
IMAGE 1 S CONNECT	KARL STORZ	TC200
IMAGE1 HD	KARL STORZ	H3-Z
IMAGE1 S H3-LINK	KARL STORZ	TC300
Monitor	NDS surgical imaging, LLC	N-90X0568-G
Optical Cable	ShenDa	U8724
Scissors	ShenDa	X5261A
Sealing Cap	ShenDa	T7303
Uterine Balloon Dilator	ShenDa	U9522 DG-1
XENON NOVA 300	KARL STORZ	201340 20