Clinical Usefulness of a Self-Retaining Internal Organ Retractor for Laparoendoscopic Single-Site Adrenalectomy

Abstract

Introduction:

Although laparoendoscopic single-site adrenalectomy (LESS-A) is feasible, it is still considered as a challenging procedure because of technical limitations. Making an optimal retraction is one of major obstacles in LESS-A, and it sometimes requires additional ports or needlescopic devices. Internal organ retractor (IOR) is a novel retraction device that is applied intracorporeally without additional port. In this study, we investigated the clinical usefulness of IOR in LESS-A.

Materials and Methods:

Medical records of 73 consecutive patients who underwent LESS-A from March 2009 to December 2014 were reviewed. Twenty-two patients underwent LESS-A with IOR and 51 patients without IOR.

Results:

Mean age, body mass index, tumor size, operation time, estimated blood loss, and hospital stay were not significantly different between two groups. In IOR group, median number of applied IOR was 2.0 (1.0–3.0) per single operation. Mean time for application and removal was 80.0 and 46.5 seconds for a single IOR, respectively. There were no complications related to the IOR. In without IOR group, there were nine cases that needed needlescopic trocars, six cases that needed 5 mm or larger trocars, and one case that was converted to hand-assisted laparoscopy. However, we did not use any needlescopic instrument or additional trocar in IOR group. There was no case of open conversion in both groups.

Conclusion:

LESS-A could be done effectively and safely using IOR. IOR system maintained optimal retraction throughout the operation. Its application and removal are intuitive and take only a few minutes. We think IOR system is an attractive retraction method in LESS-A.

Introduction

Since it was first reported by Gagner et al. in 1992,¹ conventional laparoscopic adrenalectomy (CL-A) has been considered to be the gold standard treatment for adrenal tumors.² Previous studies well demonstrated clinical benefits of laparoscopic adrenalectomy compared with open adrenalectomy, including less pain, shorter hospital stay, better cosmesis, and lower morbidity.^3–5 Laparoendoscopic single-site surgery (LESS) has become increasingly popular and is accepted as a minimally invasive alternative to conventional laparoscopy in various surgical fields.^6–11 Since laparoendoscopic single-site adrenalectomy (LESS-A) was first introduced by Hirano et al. in 2005,¹² many studies have confirmed its feasibility and superior cosmetic outcomes compared to conventional approaches.^13–15

In minimally invasive adrenal surgery, effective retraction of internal organs is essential to secure a safe surgical field since the adrenal glands are located deep in the retroperitoneal space and are surrounded by large internal organs such as the liver, spleen, and kidney. In CL-A, one or two additional trocars in addition to the three conventional trocars (one camera and two working trocars) are frequently necessary to retract internal organs. In LESS, limited number of working instruments, generally two, can be used simultaneously. Therefore, more technical barriers exist in LESS-A compared with CL-A. To overcome these limitations, the use of additional small trocars, including needlescopic instruments, has been reported.^16,17

In several laparoscopic surgeries, intracorporeal devices for organ retraction have been used successfully.^17–19 In previous reports, we have demonstrated that the internal organ retractor (IOR, Cinch Organ Retractor; Aesculap AG, Tuttlingen, Germany) device is a feasible option in various urological LESS procedures.²⁰ However, there are no comparative data to evaluate the clinical benefits of IOR in LESS. In this study, we investigated the benefits of IOR during LESS-A with regard to operative and safety outcomes.

Materials and Methods

Patients

Seventy-three consecutive patients who underwent LESS-A for an adrenal mass between March 2009 and December 2014 at our institute were included and analyzed retrospectively. Two experienced LESS surgeons, B.C.J. and D.H.H., performed the LESS-A procedures. When effective organ retraction was needed during operation, the surgeon decided the usage of IOR according to his preference. Patients were classified into two groups according to IOR use during the LESS-A procedure. LESS-A was performed with IOR in 22 patients and without IOR in 51 patients. We have performed functional hormonal evaluation in all patients before surgery. After the operation, all patients were administered intravenous (IV) patient-controlled analgesia (PCA) for pain control. The PCA was continued for 2 days following the operation. The PCA consisted of 1500 μg of fentanyl and 100 mL of normal saline. The infusion rate was 1.0 mL/h and was controlled by an infusion pump.

Regarding baseline characteristics, we compared patient age, gender, body mass index (BMI), abdominal surgery history, American Society of Anesthesiologists (ASA) score, adrenal tumor laterality, and character of the tumor. For intraoperative and postoperative parameters, we measured operation time, IOR application and retrieval time, size and pathology of the tumor, surgical conversion rate, estimated blood loss (EBL), hospital stay, time to oral intake, and visual analog scale (VAS) pain score on postoperative days 1, 2, and 3. To assess postoperative pain, we used a VAS from 0 (no pain) to 10 (worst possible pain). Intraoperative and postoperative complications were classified according to the Satava classification²¹ and the modified Clavien-Dindo classification.²² We defined operation time as the time from the initial skin incision to the time at which wound repair was initiated. Any usage of additional ports, including needlescopic trocar, is defined as conversion. Conventional laparoscopy was defined as the usage of additional trocar that is 5 mm or bigger. We measured the time consumed for IOR application and removal. We defined the IOR application time as the time at which the applicator was introduced into the abdominal space until the IOR was completely anchored to the abdominal wall. Removal time was defined as the time from introduction of the remover into the abdominal space to the expulsion of the IOR through the laparoscopic port.

Operative technique

Preparation and positioning for the LESS-A procedure were similar to those in a previous report.²³ Briefly, patients were placed in a 70° semilateral decubitus position. An ∼2.5-cm vertical incision was made at the umbilicus, through which either a commercial multichannel trocar, Lap Single (Sejong Medical, Paju, Korea), or a homemade multichannel trocar was inserted as previously described.²⁴ LESS-A was conducted using similar procedures to those in CL-A. In brief, for right adrenalectomy, the right triangular ligament was divided, and the liver was retracted. The right-sided vena cava was dissected to expose the adrenal gland.²⁵ For left adrenalectomy, mobilization of the splenic flexure of the colon and exposure of the lateral border of the spleen were performed.²⁶ After exposure of the adrenal gland, LigaSure (Covidien, Mansfield, MA) was used to ligate feeding vessels and laparoscopic clips or Hem-o-lok (Weck Surgical Instruments; Teleflex Medical, Durham, NC) was used to ligate the central vein of the adrenal gland.

In the IOR group, the IOR was applied using techniques described previously.²⁰ In brief, the IOR consists of a reusable atraumatic clip, a disposable silicone ring, and an anchoring hook. After the clip was attached, the anchoring hook was fixed to the abdominal wall, avoiding blood vessels. Two or more IORs were applied using the same technique. For right adrenalectomy, the atraumatic clip was applied to the visceral peritoneum below the liver, and the metal hook was anchored to the abdominal wall to elevate the liver. For left adrenalectomy, the atraumatic clip was applied to the splenorenal ligament after dissecting the lateral border of the spleen (after incising the visceral peritoneum lateral to the spleen). Then, the metal hook was anchored to the right abdominal wall.

Statistical analyses

All statistical analyses were performed using SPSS version 20.0 (SPSS, Inc., Chicago, IL). Numerical data with a normal distribution were expressed as group mean with standard deviation, and these data were compared using Student's t-test. Numerical data with a non-normal distribution were expressed as group median with range and were compared using Mann–Whitney U test. Pearson's Chi-square test was used to compare categorical data. Statistical significance was defined as P < .05.

Results

The mean patient age was 46 years, and all patients were followed up for a median of three months (range 1.0–69.0 months) after adrenalectomy. Age, BMI, gender, abdominal surgery history, laterality, ASA score, and tumor features were not different between patients in the IOR and non-IOR groups (Table 1). In the IOR group, the median time for IOR application was 80.0 seconds (range 42.0–128.0 seconds), and the median retrieval time was 46.5 seconds (range 23.0–149.0). There were no differences in operation time, tumor size, pathology, EBL, or hospital stay between the IOR and non-IOR groups (Table 2). However, the total conversion rate was significantly higher in the non-IOR group compared to the IOR group (0% versus 23.5%, respectively, P = .003). Among the 51 patients in the non-IOR group, 16 patients underwent conversion. Specifically, additional needlescopic trocars were used in 9 patients, conventional laparoscopy was required in 6 patients, and hand-assisted laparoscopy was needed in 1 patient. Notably, conversion to an open procedure was not required in either group.

Table 1.

Baseline Characteristics of Patients Who Underwent Laparoendoscopic Single-Site Adrenalectomy With or Without an Internal Organ Retractor Device

	Total (n = 73)	With IOR (n = 22)	Without IOR (n = 51)	P
Age (years)	45.6 ± 13.8	48.1 ± 16.1	44.6 ± 12.7	.319^a
Body mass index (kg/m²)	24.2 ± 3.0	25.0 ± 2.9	23.9 ± 3.0	.143^a
Gender				.200^b
Male	28 (38.4%)	11 (50.0%)	17 (33.3%)
Female	45 (61.6%)	11 (50.0%)	34 (66.7%)
Previous abdominal surgery	11 (15.1%)	5 (22.7%)	6 (11.8%)	.289^b
Laterality				.204^b
Left	39 (53.4%)	9 (40.9%)	30 (58.8%)
Right	34 (46.6%)	13 (59.1%)	21 (41.2%)
ASA score				.154^b
1	22 (30.1%)	5 (22.7%)	17 (33.3%)
2	46 (63.0%)	17 (77.3%)	29 (56.9%)
3	5 (6.8%)	0 (0%)	5 (9.8%)
Tumor feature				.205^b
Cystic	15 (20.5%)	2 (9.1%)	13 (25.5%)
Solid	58 (79.5%)	20 (90.9%)	38 (74.5%)

Values indicate mean ± SD or n (%).

Student's t-test.

Chi-square test.

ASA, American Society of Anesthesiologists; IOR, internal organ retractor.

Table 2.

Operative Outcomes in Patients Who Underwent Laparoendoscopic Single-Site Adrenalectomy With or Without an Internal Organ Retractor Device

	With IOR (n = 22)	Without IOR (n = 51)	P
Operation time (minutes)	86.0 (35.0–150)	67.0 (25.0–195.0)	.056^a
No. of IORs used	2.0 (1.0–3.0)
IOR application time (seconds)	80.0 (42.0–128.0)
IOR retrieval time (seconds)	46.5 (23.0–149.0)
Tumor size on pathology (cm)	3.1 (1.5–8.0)	3.0 (1.0–8.0)	.523^a
Pathology			.381^b
Cortical adenoma	10 (45.5%)	19 (37.3%)
Pheochromocytoma	2 (9.1%)	10 (19.6%)
Benign cyst	2 (9.1%)	8 (15.7%)
Neurogenic tumor	2 (9.1%)	5 (9.8%)
Cortical hyperplasia	2 (9.1%)	3 (5.9%)
Metastatic renal cell carcinoma	2 (9.1%)	0 (0%)
Cortical carcinoma	1 (4.5%)	0 (0%)
Others	1 (4.5%)	6 (11.8%)
Conversion	0	16 (23.5%)	.003 ^b
Additional trocar (2 mm)	0	9 (17.6%)
Conventional laparoscopy	0	6 (11.8%)
Hand-assisted laparoscopy	0	1 (2.0%)
Open	0	0
Estimated blood loss (mL)	100 (20.0–200.0)	100 (20.0–2700.0)	.592^a
Hospital stay (day)	6.0 (4.0–10.0)	5.0 (3.0–15.0)	.441^a
Resumption of oral intake (day)	1.0 (1.0–2.0)	2.0 (1.0–5.0)	.009 ^a
VAS pain score
POD 1	3.0 (0–5.0)	4.0 (2.0–7.0)	.001 ^a
POD 2	2.5 (0–4.4)	3.0 (0–6.5)	.004 ^a
POD 3	2.0 (0–3.0)	2.5 (0–5.0)	.011 ^a

Values indicate median (range) or n (%). Bold values indicate significant results; P < 0.05.

Mann–Whitney U test.

Chi-square test.

IOR, internal organ retractor; POD, postoperative day; VAS, visual analog scale.

Postoperatively, the time to resumption of oral intake was shorter in the IOR group compared to the non-IOR group (1.0 day versus 2.0 days, respectively, P = .009). In addition, pain severity during the first 3 postoperative days was also significantly lower in the IOR group compared to the non-IOR group (P = .001, .004, and .011 on POD 1, 2, and 3, respectively). Regarding intraoperative complications, there were more grade II complications in the non-IOR group than the IOR group (4.5% versus 17.6%, respectively); however, the difference was not statistically significant. There was no difference in postoperative complication rate between groups (Table 3), and there were also no complications associated with IOR application or retrieval.

Table 3.

Intraoperative and Postoperative Complications in Patients Who Underwent Laparoendoscopic Single-Site Adrenalectomy With or Without an Internal Organ Retractor Device

	Total (n = 73)	With IOR (n = 22)	Without IOR (n = 51)	P
Intraoperative complications^a	10 (13.7%)	1 (4.5%)	9 (17.6%)	.135^b
Grade II
Liver injury	4 (5.4%)	1 (4.5%)	3 (5.8%)
Spleen injury	0 (0%)	0 (0%)	0 (0%)
IVC injury	3 (4.1%)	0	3 (5.8%)
Renal vein injury	1 (1.4%)	0	1 (2.0%)
Bowel injury	1 (1.4%)	0	1 (2.0%)
Diaphragm injury	1 (1.4%)	0	1 (2.0%)
Postoperative complications^c	13 (17.8%)	6 (27.2%)	7 (13.8%)	.165^b
Grade I
Diarrhea	5 (6.8%)	3 (13.7%)	2 (3.9%)
Headache	3 (4.1%)	1 (4.5%)	2 (3.9%)
Abnormal liver enzyme (AST/ALT)	2 (2.7%)	1 (4.5%)	1 (2.0%)
Fever	1 (1.4%)	0	1 (2.0%)
Voiding difficulty	1 (1.4%)	1 (4.5%)	0
Grade IIIb
Wound dehiscence	1 (1.4%)	0	1 (2.0%)

Values indicate n (%).

According to the Satava classification.

Chi-square test.

According to the modified Clavien-Dindo classification.

ALT, alanine aminotransferase; AST, aspartate aminotransferase; IOR, internal organ retractor; IVC, inferior vena-cava.

To investigate risk factors of conversion during LESS-A, preoperative factors were evaluated. The percentage of right side adrenalectomies was significantly higher in the group of patients requiring conversion compared to the nonconversion group (81.2% versus 36.8%, respectively, P = .002). In addition, IOR usage rate was also significantly different between the two groups (38.6% versus 0%, P = .003) (Table 4).

Table 4.

Characteristics of Patients According to the Need for Conversion During Laparoendoscopic Single-Site Adrenalectomy

	No conversion (n = 57)	Conversion (n = 16)	P
Age (years)	45.8 ± 14.2	44.9 ± 12.4	.822^a
Body mass index (kg/m²)	24.2 ± 3.1	24.4 ± 2.7	.751^a
Gender			.508^b
Male	23 (40.4%)	5 (31.2%)
Female	34 (59.6%)	11 (68.8%)
Previous abdominal surgery	9 (15.8%)	2 (12.5%)	.745^b
Laterality			.002 ^b
Left	36 (63.2%)	3 (18.8%)
Right	21 (36.8%)	13 (81.2%)
ASA score			.077^b
1	19 (33.3%)	3 (18.8%)
2	36 (63.2%)	10 (62.5%)
3	2 (3.5%)	3 (18.8%)
Presence of a cystic component	11 (33.3%)	3 (18.8%)	.618^b
IOR usage	22 (38.6%)	0 (0%)	.003 ^b

Values indicate mean ± SD or n (%). Bold values indicate significant results; P < 0.05.

Student's t-test.

Chi-square test.

ASA, American Society of Anesthesiologists; IOR, internal organ retractor.

Discussion

In many cases requiring adrenalectomy, the size of the adrenal mass is relatively small, and large skin incision is not needed to retrieve these specimens. Therefore, minimally invasive approaches are thought to be suitable for these adrenalectomies. To facilitate safe and effective operations during LESS-A, we applied IOR and compared the surgical outcomes between the IOR group and the non-IOR group. According to previous IOR study, the benefits of this approach include its reproducible technique, reusable clips, easy intraoperative repositioning, and easy maneuverability.¹⁷ In addition to these inherent advantages of the device, we found other favorable surgical outcomes to be associated with IOR use.

Compared to the non-IOR group, the IOR group showed a significantly lower conversion rate (0% versus 23.5%, P = .003). When we analyzed this low conversion rate, right-sided laterality (P = .002) and low IOR usage rate (P = .003) were significantly different between the conversion and no-conversion groups. Regarding laterality, we encountered several technical and anatomical difficulties during right-sided adrenalectomy. Because the right adrenal gland is located deep and posterior to the vena cava and liver, the liver can cover and hide the adrenal gland. To secure a clear surgical field, liver retraction is an essential procedure. Thus, right-sided laterality could increase the need of usage of additional trocars. Many feasibility studies were performed mainly for left adrenalectomies. Vidal et al.²⁷ studied only those patients who underwent left-sided LESS-A; in another study by Wang et al.,²⁸ the rate of left-sided LESS-A was 92.3%. According to a study by Hirasawa et al.,¹³ an additional 3-mm trocar was routinely inserted for liver retraction in right-sided LESS-A. In our series, the percentage of right-sided adrenalectomies was comparable to left-sided cases (46.6% versus 53.4%, P = .204) (Table 1). The use of IORs allows right-sided LESS-A to be performed without difficulty. Despite the use of IORs, intraoperative and postoperative complication rates were not different between the groups in the current study (P = .135 and P = .165, respectively). Notably, during LESS-A, there were no IOR-associated complications such as intra-abdominal organ injury caused by the anchoring hook. Our results indicate that LESS-A using IOR can be performed safely.

Although all patients received IV PCA for pain control postoperatively, there were significant differences in postoperative pain between the IOR and non-IOR groups. When comparing pain score outcomes between CL-A and LESS-A, there are still controversies. For example, a study by Inoue et al. compared pain scales between CL-A and needlescopic-assisted LESS-A and showed no significant differences.¹⁶ On the contrary, Wang et al.²⁸ performed a meta-analysis between CL-A and LESS-A and showed LESS-A to result in significantly lower levels of postoperative pain than did CL-A. Furthermore, in our study, we found postoperative VAS pain score to be significantly lower in the IOR group compared to the non-IOR group in LESS-A. Some suggested reasons for this lower pain score in LESS than conventional laparoscopy include the smaller size and number of incisions required. In our study, the non-IOR group showed a higher conversion rate and need for additional trocars and incisions compared to the IOR group. These can be reasons of lower postoperative pain in the IOR group. Besides size and number of incision, type of instrumentation might be associated with the postoperative pain. When a retraction device is used for a heavy internal organ through a trocar, it can produce high suppression force on the incision site which might be responsible for some of the operative wound pain. Specifically, the IOR was used for counter retraction of the intra-abdominal organs. The IOR retraction force is lower than the suppression force by laparoscopic instrumentations and so it could result in reduced organ and tissue damage and less postoperative pain.

When we considered using IORs first, we were concerned about prolonged operation times and more technical difficulties. In our study, the operation time in the IOR group was slightly longer than that in the non-IOR group, but the difference was not significant. In this study, the median IOR application time was 80 seconds, and the retrieval time was 46.5 seconds. Approximately 5 minutes were required to place median two IORs. We think the application and retrieval times did not significantly increase the total operation time. Another consideration in this study was safe placement and removal of the IORs, during which intra-abdominal organs and vessels can be damaged. To prevent this complication, we kept the tip of the hook pointing in the direction opposite to the direction of IOR travel. We fixed the anchoring hook between the jaws of the clip during IOR insertion through a trocar, and we used a needle holder to grasp the hook during IOR retrieval through a trocar.²⁰ Using these techniques, there was no IOR-associated complications.

One limitation of our study is its retrospective study design. Thus, inherent limitations due to this retrospective nature are inevitable. However, as far as we know, this is the first comparative study to demonstrate the clinical merits of IOR use in LESS-A. Another limitation is that the number of patients in the IOR group was small. Nonetheless, we were able to demonstrate the beneficial role of IOR in reduction in conversion rate and decrease in postoperative pain.

Conclusion

The IOR system maintained optimal retraction throughout the operation. Compared to the non-IOR group, the IOR group showed significantly lower conversion rate and postoperative pain score. The rates of intraoperative and postoperative complications were not significantly different between groups. Thus, we suggest that the IOR system is an attractive retraction technique for use in LESS-A.

Funding

This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (grant no.: HI14C3229).

Footnotes

Disclosure Statement

No competing financial interests exist.

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