Comparative study on gasless laparoscopy using a new device versus conventional laparoscopy for surgical management of postmenopausal patients.

Objective: To compare gasless laparoscopy with conventional laparoscopy for the surgical management of postmenopausal patients.
Methods: The medical records of 80 postmenopausal patients who underwent laparoscopic surgeries between February 2016 and February 2020 were reviewed. Forty patients underwent gasless laparoscopy and 40 patients underwent conventional single-port access (SPA) laparoscopy. The two groups were compared in terms of surgical outcomes.
Results: : Of 80 patients, 42 underwent adnexal surgeries and 38 underwent uterine surgeries such as total hysterectomy or myomectomy. Between the gasless SPA and conventional SPA laparoscopic groups, no significant differences were observed in terms of age, body mass index, parity or history of previous abdominal surgery. The mean retraction setup time from skin incision was 6.8 ± 1.2 min with gasless laparoscopic surgery. There was no significant difference in mean total operation times for the gasless (71.3 ± 31.4 min) and conventional (82.5 ± 36.4 min) groups. There was also no significant difference between the groups in terms of operation type, laparotomy conversion rate or duration of hospitalisation. There were no major complications in either group. Conclusions: Gasless laparoscopy is a safe and feasible alternative to conventional laparoscopy for postmenopausal women.

INTRODUCTION

Laparoscopic surgery is preferred over laparotomy for gynaecologic operations because laparoscopy is minimally invasive and associated with less postoperative pain and shorter recovery periods.[1] Induced pneumoperitoneum using carbon dioxide (CO2) gas is the most widely used method for obtaining a stable laparoscopic surgical field. Impaired cardiopulmonary function associated with CO2 gas can sometimes lead to serious complications during or after surgery. Complications frequently associated with CO2 gas-based laparoscopic surgery mainly result from gas-induced increases in intraperitoneal pressure. Injecting CO2 gas increases the pressure in the abdominal cavity due to the gas, causing the diaphragm to rise towards the lungs. This physiologic change is associated with decreased total lung volume and hypoventilation. CO2 injected into the abdominal cavity is rapidly absorbed into the blood through the peritoneum to maintain equilibrium, and this can lead to hypercarbia, acidosis and increased end-tidal CO2. CO2 gas compresses abdominal vessels, increases systemic vascular resistance and reduces cardiac output.[23] This does not usually cause deleterious effects in healthy patients but can cause serious complications in elderly women with menopause.

Gasless laparoscopy not requiring CO2 gas can overcome these disadvantages. An abdominal wall retraction system is essential to free up surgical space to perform a gasless laparoscopic examination. Various approaches and techniques for securing surgical space have been described. However, gasless laparoscopic surgery has not been widely used. One reason is that there are no effective abdominal retractors that are simple to install. Recently, a new abdominal wall retraction system using a J-shaped retractor was developed to perform gasless laparoscopy.[4] This study aimed to compare gasless laparoscopy using a J-shaped retractor with conventional laparoscopy for the management of menopausal patients with benign gynaecologic conditions.

METHODS

We retrospectively reviewed the medical records of 40 consecutive menopausal patients who underwent gasless laparoscopic surgery at the Catholic Kwandong University, International Saint Mary's Hospital, Incheon, South Korea, between March 2018 and February 2020. For comparison, we identified a control group of 40 age-matched patients who underwent conventional laparoscopy performed by the same group of surgeons between February 2016 and February 2020. We have operated on gasless laparoscopy since 2018. Since 2018, laparoscopic surgeries have been mostly performed by gasless laparoscopy, and some have been conventional laparoscopy. Most of the conventional laparoscopy included in the study was conducted in 2016–2017. Among the women who underwent laparoscopy (gasless or conventional), postmenopausal women were selected. Cases in which menopause was not clear from the medical record were excluded from the study.

The study was reviewed and approved by the institutional review board of International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, Republic of Korea (IS19RISI0043). All surgeries were performed by two laparoscopic surgeons (BW Kim, JH Hwang). Patients suspected to have benign gynaecologic disease, such as myoma or adnexal mass, were included as candidates for laparoscopic surgery after undergoing physical examination and imaging procedures, such as transvaginal ultrasonography, abdominopelvic computed tomography or pelvic magnetic resonance imaging. Patients with malignant diseases, such as endometrial, ovarian and uterine cervical cancer, were excluded. Patients who had undergone prophylactic oophorectomy due to BRCA mutations were included. Postmenopausal women were defined as having no menstrual flow for at least 6 months and experiencing vasomotor symptoms such as hot flushes and night sweats. Women whose amenorrhea period or vasomotor symptom was not clear from the medical record and women without uterus were considered postmenopausal when their follicle-stimulating hormone levels were >30.

All patients provided informed consent to undergo conversion to laparotomy if needed. A RUMI system uterine manipulator (CooperSurgical, Trumbull, CT, USA) was used with a balloon tip inserted into the uterine cavity after disinfection and sterile draping. An approximately 2-cm incision was made through the umbilicus, and the umbilical wound was expanded using an Alexis retractor (Applied Medical, Rancho Santa Margarita, CA, USA) [Figure 1a]. For gasless laparoscopy, abdominal wall retraction was performed with the newly developed J-shaped retractor. The J-shaped retractor was designed for attachment to the Thompson surgical retractors used in the obstetrics and gynaecology department of International St. Mary's Hospital. The Thompson retractor was mounted on the surgical table with an angled arm that fits in the joint of a rail clamp [Figure 1b], and two J-shaped retractors were secured to the angled arm with articulation [Figure 1c and d]. The J-shaped retractor was manually lifted and tightened to secure the working area [Figure 1e]. An abdominal suspension suture was not used for all patients. Pre-operative preparation measures and the detailed gasless single-port access (SPA) laparoscopy procedure using J-shaped and Thompson retractors have been reported previously.[456] SPA laparoscopic surgery was performed in all cases. An additional 5-mm trocar was used for patients with severe pelvic adhesions and obese patients.

Figure 1

Set up of J-shaped retractor (a) After a vertical incision of the skin through the umbilicus, the umbilical wound including the entire thickness of the abdominal wall was expanded using an Alexis retractor. (b) A Thompson surgical retractor was applied. The Thompson retractor was mounted on the surgical table with an angled arm that fits in the joint of a rail clamp. (c) One J-shaped retractor was secured to the angled arm with articulation. A J-shaped retractor was designed for attachment to the Thompson surgical retractor. Then, a 5-mm 30° rigid laparoscope was inserted into the pelvic cavity via the umbilical incision to exclude the presence of adhesions. (d) Abdominal wall retraction was performed with two J-shaped retractors for gasless laparoscopy. While the operator lifted the J-shaped retractor manually, the assistant adjusted the clamp of the angled arm connected to the Thompson retractor. (e) The J-shaped retractor was manually lifted and tightened to secure the working area

The demographic and physical characteristics of the patients were documented preoperatively. The data included age, height, body mass index (BMI), parity and history of previous abdominal surgery. Total operative time, estimated blood loss and type of surgery were recorded. The setup time for abdominal wall retraction was also recorded for the gasless procedures. Setup time included the time from the umbilical incision to the construction of the pathway into the abdominal cavity, application of the wound retractor and the setting up of the Thompson surgical retractor and J-shaped retractor. We evaluated the complications of laparoscopic surgeries The laparotomy conversion rate and specific surgical findings, such as severe pelvic adhesions, were also evaluated.

The data were entered into Microsoft Excel and analysed using SPSS Statistics for Windows, version 22 (IBM Corp., Armonk, NY, USA). The mean values ± standard deviations or median with a range of normally distributed data for the two groups were compared using Student's t-test. For skewed data, the median values (maximum, minimum) of two groups were compared using the Mann–Whitney U-test. Nominal variables were analysed using the χ2 test or Fisher's exact test. A P < 0.05 was considered statistically significant.

RESULTS

During the study period, 40 women underwent gasless laparoscopy, and 40 women underwent conventional laparoscopy. Table 1 shows the indications for surgery and the surgical procedures used in the two groups. Leiomyoma and adenomyosis were the most common reason for total laparoscopic hysterectomy (74.3%; 26 out of 35). Three women underwent myomectomy because they wanted to preserve the uterus. Cystadenoma (serous or mucinous) was the most common reason for adnexal surgery (35.7%; 15 out of 42 cases), followed by paratubal cyst (21.4%; 9 out of 42 cases). The most common type of adnexal surgery was bilateral salpingo-oophorectomy (66.7%; 28 out of 42 cases), followed by unilateral salpingo-oophorectomy (23.8%, 10 out of 42 cases).

Table 1

Surgical procedure and indication

Variables	Gasless laparoscopy (n=40)	Conventional laparoscopy (n=40)
Uterine surgery, n (%)	18 (45.0%)	20 (50%)
TLH or TLH plus adnexal surgery	17 (42.5%)	18 (45.0%)
Myomectomy	1 (2.5%)	2 (5.0%)
Surgical indication, n (%)
Leiomyoma	11 (27.5%)	11 (27.5%)
Adenomyosis	3 (7.5%)	4 (10.0%)
Endometrial hyperplasia	0	3 (7.5%)
Mucinous cystadenoma	2 (5.0%)	1 (2.5%)
Serous cystadenoma	1 (2.5%)	0
Cervical carcinoma in situ	1 (2.5%)	1 (2.5%)
Adnexal surgery only, n (%)	22 (55.0%)	20 (50.0%)
BSO	13 (32.5%)	15 (37.5%)
USO	6 (15.0%)	4 (10%)
Ovarian cystectomy	1 (2.5%)	1 (2.5%)
Bilateral salpingectomy	2 (5.0%)	0
Surgical indication, n (%)
Cystadenoma (serous or mucinous)	7 (17.5%)	8 (20.0%)
Paratubal cyst	4 (10.0%)	5 (12.5%)
Mature cystic teratoma	3 (7.5%)	3 (7.5%)
Tubo-ovarian abscess	2 (5.0%)	3 (7.5%)
Endometrioma	1 (2.5%)	1 (2.5%)
Hydrosalpinx	3 (7.5%)	0
Granulosa cell tumor	1 (2.5%)	0
BRCA mutation	1 (2.5%)	0

*TLH; total laparoscopic hysterectomy, BSO; Bilateral salpingo-oophorectomy, USO; Unilateral salpingo-oophorectomy

Table 2 shows the demographic characteristics of patients who underwent benign gynaecologic surgery in the two groups. The overall mean age was 55.5 ± 8.5 years. There were no statistically significant differences between the two groups with regard to age, parity, or history of abdominal surgery. The mean of BMI was 23.2 ± 2.5 kg/m2 in gasless group and 24.7 ± 4.2 kg/m2 in the conventional group (P = 0.067).

Table 2

Demographics of menopausal patients undergoing laparoscopy

Variables	Gasless laparoscopy (n=40)	Conventional laparoscopy (n=40)	P
Age (year)	53.5 [49.0-87.7]	52.0 [48.0-85.6]	0.350b
Height (cm)	155.6±5.3	154.4±5.3	0.327a
Body weight (kg)	56.4±9.3	54.5±7.9	0.332a
Body mass index (kg/m2)	23.2±2.5	24.7±4.2	0.067a
Parity (Number)	2.3±1.1	2.1±1.1	0.791a
Patients with previous pelvic surgery (Number)	23	18	0.263c

*Variables are given as mean±SD or median with range; History of each specific surgery was calculated in duplicate. P value of continuous variables was obtained from aStudent’ t test or bMann-Whitney U test. P value of nominal variables was obtained from cχ2 test

Surgical outcomes are shown in Table 3. Eight patients (20%) in the gasless group underwent surgery with combined spinal and epidural anaesthesia. There were ten patients with specific surgical findings, such as moderate or severe pelvic adhesions (gasless group, n = 4, vs. conventional group, n = 6). In the gasless group, the mean setup time from umbilical skin incision to abdominal wall retraction was 6.8 ± 1.2 min. The mean total operation times were 71.3 ± 31.4 min and 82.5 ± 36.4 min in the gasless and conventional groups, respectively (P = 0.143). The estimated blood loss was higher in the conventional group (100.8 ± 97.7 ml) than in the gasless group (157.3 ± 124.5 ml) (P = 0.027). There were no conversions to laparotomy in the gasless groups. In the conventional group, two patients (5.0%) underwent conversion to laparotomy because of severe pelvic adhesions caused by tubo-ovarian abscess formation. No serious urologic or intestinal complications or vessel injuries were noted in either group. There were no cases of retraction-site abdominal wall injury in the gasless group.

Table 3

Surgical Outcomes

Variables	Gasless laparoscopy (n=40)	Conventional laparoscopy (n=40)	P
Operation Time [minute: mean±SD]	71.3±31.4	82.5±36.4	0.143a
Estimated Blood loss [ml: mean±SD]	100.8±97.7	157.3±124.5	0.027a
From incision to setup time [minute: mean±SD]	6.8±1.2	NA
Laparotomy conversion, Number (%)	0	2 (5.0%)	0.494b
Type of anesthesia, Number (%)
General anesthesia	32 (80.0%)	40 (100%)	0.005b
Combined spinal and epidural anesthesia	8 (20.0%)	0	0.005b
Specific surgical finding, Number (%)
Moderate or severe pelvic adhesion	4 (10.0%)	6 (15.0%)	0.737b
Hospital stay (day: mean±SD)	5.2±1.2	5.5±1.4	0.313a
Major complicationsc	None	None	NA

*Variables are given as mean±SD or number (%). P value were obtained from aStudent’s t test, or bFisher exact test. CMajor complications include urologic, bowel and vessel injuries, NA: non-applicable

DISCUSSION

Laparoscopic surgery is currently accepted as a feasible and effective way to treat benign gynaecologic diseases, such as leiomyoma, adenomyosis and adnexal masses. Conventionally, pneumoperitoneum using CO2 gas and the Trendelenburg position were required to maintain visibility in the operative field. However, laparoscopy using CO2 gas has some disadvantages. It adversely affects cardiopulmonary function as well as haemodynamic, metabolic and neurologic systems due to the associated high intraperitoneal pressure.[789] The increased intra-abdominal pressure caused by pneumoperitoneum in addition to the Trendelenburg position exacerbates several pathophysiologic changes, such as decreased total lung volume, hypercapnia, decreased cardiac output and increased systemic vascular resistance, increased dead space and ventilation-perfusion mismatch. These pathophysiologic changes can cause serious complications in menopausal women. Such patients are usually subject to cardiovascular disease because oestrogen withdrawal has detrimental effects on cardiopulmonary function and metabolism. Pulmonary changes caused by aging, such as decreased alveolar elasticity, reduced chest wall compliance and increased residual volume, reduce total lung compliance. Conventional laparoscopic surgery using CO2 gas can also affect kidney function.[10] Progressive impairment of the physiological glomerular filtration rate and renal blood flow with aging can predispose menopausal patients to post-operative renal insufficiency.[11]

These disadvantages can be overcome using gasless laparoscopy, which has been shown to have no effect on cardiac function.[12] Pawlowicz et al. reported that gasless laparoscopy has advantages over conventional laparoscopy, particularly in reducing cardiovascular complications among postmenopausal women, and it should be recommended to high-risk patients with poor cardiopulmonary reserve or with contraindications for general anaesthesia.[13] Laparoscopy using CO2 gas is also associated with postoperative shoulder pain[14] and post-operative nausea and vomiting.[15] When the intra-abdominal pressure is increased by the insufflation of CO2 gas, the diaphragm expands and stimulates the diaphragm nerve, which can cause shoulder pain. Since laparoscopic surgery in the gynaecologic field is performed in the Trendelenburg position, the diaphragm stimulation by CO2 gas and the resulting shoulder pain may be more severe. Pneumoperitoneum using CO2 gas can excite the afferent vagus nerve and the vomiting centre by stimulating intestinal mechanoreceptors and chemoreceptors. Nausea and vomiting after laparoscopic surgery using CO2 gas may be more prominent in the elderly. Rarely, extraperitoneal leakage of CO2 can cause subcutaneous emphysema, pneumomediastinum and pneumothorax.

Regional anaesthesia, including spinal, epidural and combined spinal-epidural anaesthesia, can be used in laparotomy for patients with poor cardiopulmonary function because regional anaesthesia prevents the deterioration of the respiratory system. Regional anaesthesia is also advantageous over general anaesthesia in terms of overall safety, shorter postoperative stay, less emesis, less postoperative pain and absence of airway manipulation.[16] However, there are limited reports in the literature about the implementation of laparoscopic gynaecologic surgery under regional anaesthesia.[1718] The Trendelenburg position and the use of CO2 gas are the two major factors that make the application of regional anaesthesia challenging in laparoscopic surgery. If gasless laparoscopy is used instead of conventional laparoscopy, regional anaesthesia can be safely applied for postmenopausal women with poor cardiopulmonary function. In this study, eight cases (20.0%) in the gasless SPA laparoscopy group were performed under combined spinal and epidural anaesthesia.

The use of gasless laparoscopy is not widespread despite its many merits. One of the reasons may be that the instrument for abdominal wall retraction to secure operative space is not commercially available and standardised. Recently, we developed a new instrument for intraabdominal wall retraction and reported the safety of gasless laparoscopy using J-shaped and Thompson retractors.[456] This instrument is J-shaped and designed to separate the entire thickness of the abdominal wall from the intraabdominal organs. It is simple and easy to set up. It can be connected and clamped to the Thompson retractor, which is commonly used in surgery. Potential complications of abdominal wall retraction include abdominal wall trauma and injury. The skin is significantly affected by the ageing process and the oestrogen deficiency caused by menopause.[1920] Postmenopausal women have dry skin with deficient elasticity due to atrophy of dermal collagen and alterations of elastic fibers, which are fragile and susceptible to trauma.[21] Therefore, these changes should be considered when constructing an abdominal wall retraction system for gasless laparoscopy in postmenopausal women. The inelastic and atrophic skin of postmenopausal women is highly extensible, which might be beneficial for securing surgical space through abdominal wall retraction. However, care must be taken not to apply excessive tension to the abdominal wall, and abdominal wall retraction should be minimised if there is no difficulty in performing the surgery. In this study, there were no patients with abdominal injuries after gasless laparoscopy using the J-shaped and Thompson retractors. No long-term side effects or complications were not observed in either group.

In this study, we performed gasless laparoscopy on 40 menopausal women with benign gynaecologic disease using an abdominal wall retraction system featuring a J-shaped retractor. We demonstrated that surgical outcomes are similar to those in conventional CO2 laparoscopy. Estimated blood loss was higher in the conventional group than in the gasless group (P = 0.027). In the gasless group, convenient suturing using an extracorporeal suture technique, continuous intraoperative suction without abdominal wall collapse, and the free movement of the laparoscopic instrument without trocar insertion might help minimise blood loss. Since patients undergoing laparoscopic surgery often have anemia, the lower estimated blood loss during surgery can be an advantage of gasless laparoscopy. In menopausal patients with the benign gynaecologic disease, gasless laparoscopy appeared to be a safe and effective alternative to conventional laparoscopy, with the advantage of avoiding the potentially negative effects of CO2 gas.

Our study had several limitations. The study was performed at a single centre and a retrospective study, which is a major limitation because it was susceptible to selection bias. The mean BMI of the patients who underwent gasless laparoscopy was 23.2 kg/m2, and most of them corresponded to the standard BMI. We performed conventional laparoscopic surgery in four out of five obese women with a BMI of more than 30, although there was no significant difference in BMI between the gasless laparoscopic and conventional laparoscopic groups (P = 0.067). The surgical field of view is particularly problematic in obese patients. The feasibility of gasless laparoscopy in obese patients with a BMI of more than 30 is questionable. When comparing the weight of the uterus in 35 patients who underwent hysterectomy (17 in the gasless group and 18 in the conventional group), the mean weights of the uterus were 228.3 ± 142.3 g and 357.1 ± 201.1 g, respectively (P = 0.172). Although this difference was not statistically significant, we cannot rule out the surgeon preference for conventional laparoscopy for patients with larger uteruses. Gasless laparoscopy may be difficult to perform even in patients with severe adhesions. However, even in these cases, gasless laparoscopy can be considered first because it can be easily converted to conventional laparoscopy.

This study is a comparison of technical feasibility and surgical outcomes. When patients had a history of the cardio-pulmonary disease, cardiology and pulmonology consultation were performed preoperatively in both groups. However, we did not compare the incidence of cardio-pulmonary disease in both groups. No analysis has been made on how much gasless laparoscopic surgery can help prevent cardiopulmonary complications in postmenopausal women. In the future, randomised controlled studies investigating the physiologic advantages of gasless laparoscopy for postmenopausal women are required to verify our findings and evaluate the effect of cardiopulmonary function and complications.

CONCLUSION

In menopausal patients with the benign gynaecologic disease, gasless laparoscopy appeared to be a safe and effective alternative to conventional laparoscopy, with the advantage of avoiding the potentially negative effects of CO2 gas.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.