Laparoscopic distal pancreatectomy(LDP) has been recognized as a standard technique for benign or borderline malignant neoplasms. The findings that LDP is associated with lower estimated blood loss, faster recovery than open distal pancreatectomy have increased interest in the procedure[17, 18]. Due to recent technological developments, LDP has been expanded to treat PC by LRAMPS. But the safety and feasibility of LRAMS for PC remains controversial. This study clarified that LRAMPS is technically safe and feasible procedure in well-selected patients with PC in the distal pancreas.
The morbidity rates of LRAMPS reported in literatures varied greatly from 13.3–66.7% (Table 1) [5–11]. PF was the most frequent complication after LRAMPS. The PF rates of LRAMPS varied greatly from 0 to 66.7% (Table 1) [5–11]. Lee et al[6]reported that laparoscopic or robotic RAMPS had comparable rate of morbidity (25% vs. 37.2%, p = 0.412) and PF (grades B and C; 19.2 vs. 35.7%, p = 0.251) in relation to conventional open distal pancreatosplenectomy (DPS). Compared to conventional open DPS, laparoscopic or robotic RAMPS is associated with faster recovery, shorter length of hospital stay(12.3 ± 6.8 vs. 22.4 ± 21.6 days, p = 0.002)[6]. The morbidity rates and PF rates of laparoscopic conventional radical distal pancreatectomy for PC reported in literatures varied greatly from 13.6–52.9%[19].Our series with 10 cases showed a morbidity rate of 50.0%, and the PF rate of 30.0%, similar to what have been reported in the literature[5–11].Even the operation more complicated, the LRAMPS didn't increase the risk of complications but with the advantages related to minimal-access surgery, such as less intraoperative blood loss, faster recovery.
Table 1
Main Published Series of Laparoscopic radical antegrade modular pancreatosplenectomy (Surgical Outcomes)
Author(Year)
|
N
|
Operative
Time
(min)
|
EBL
(ml)
|
Conversion
|
Morbidity
|
Pancreatic Fistula
|
Reoperation
|
Mortality
|
Postoperative hospital stay ( days )
|
Sunagawa et al[5]
(2014)
|
3
|
431.0 A
|
175A
|
0
|
1(33.3%)
|
1(33.3%)
|
0
|
0
|
17.3A
|
Lee et al[6]
(2014)
|
12
|
324.3A
|
445.8A
|
0
|
3 (25%)
|
2 (16.6%)
|
0
|
0
|
12.3A
|
Kim et al[7]
(2017)
|
15
|
219A
|
250A
|
0
|
2(13.3%)
|
0
|
0
|
0
|
6.1A
|
Ome et al[8]
(2017)
|
3
|
358B
|
minimal to 1 ml
|
0
|
1(33.3%)
|
1(33.3%)
|
0
|
0
|
14B
|
Yamamoto et al[9]
(2017)
|
3
|
421B
|
75B
|
0
|
1(33.3%)
|
1(33.3%)
|
0
|
0
|
15B
|
Xu et al[10]
(2018)
|
12
|
250B
|
150B
|
0
|
8(66.7%)
|
8(66.7%)
|
1(8.3%)
|
0
|
9B
|
Kim et al[11]
(2019)
|
1
|
220
|
200
|
0
|
0
|
0
|
0
|
0
|
7
|
This study
|
10
|
235B
|
120B
|
0
|
5(50.0%)
|
3(30.0%)
|
0
|
0
|
14B
|
EBL, estimated blood loss; A = mean; B = median; NA = not available |
RAMPS was designed to increase the rate of R0 resection and lymph node yield for PC in the body or tail[1, 2]. Chun et al [20] performed a systematic literature review that mean lymph node counts of RAMPS was as high as 24, and negative margin rates between 81% and 100%. Tangential margins are reportedly negative in 94% of patients undergoing RAMPS[20]. Studies comparing RAMPS with standard DPS demonstrate significantly higher lymph node counts[21–23]. The lymph node counts of LRAMPS reported in literatures varied greatly from 10.5 to 43 (Table 2) [5–11]. The mean count of retrieved lymph nodes was 18.1 ± 9.5, and 18 patients had malignant-positive lymph nodes[5–11]. Lee et al[6]reported that laparoscopic or robotic RAMPS had comparable number of retrieved lymph nodes (10.5 ± 7.1 vs. 13.8 ± 11.1, p = 0.313) and R0 resection (100% vs. 85.9%, p = 0.381) in relation to conventional open DPS. The lymph nodes harvested and negative surgical margin of laparoscopic conventional radical distal pancreatectomy for PC reported in literatures varied greatly from 9 to 25.9 and 64.1–95.5%,respectively[19]. Our series with 10 cases showed a count of retrieved lymph nodes of 15 (range, 13–21),and the R0 resection rate of 100.0%, similar to what have been reported in the literature[5–11].So whether LRAMPS could achieve better oncological outcomes than laparoscopic conventional DPS or similar oncological outcomes as open RAMPS need more randomized controlled test to confirm.
Table 2. Main Published Series of Laparoscopic radical antegrade modular pancreatosplenectomy( Pathologic characteristics&Follow-up Data)
Author(Year)
|
N
|
Tumor size
(cm)
|
Count of retrieved
lymph nodes
|
Margin status,
RO(%)
|
Follow-Up
(months)
|
Recurrence
|
Sunagawa et al[5]
(2014)
|
3
|
NA
|
43A
|
NA
|
NA
|
NA
|
Lee et al[6]
(2014)
|
12
|
2.8A
|
10.5A
|
100
|
39B
|
5 (41.7%)
|
Kim et al[7]
(2017)
|
15
|
3.8A
|
18.1B
|
100
|
46B
|
4(26.7%)
|
Ome et al[8]
(2017)
|
3
|
NA
|
NA
|
NA
|
NA
|
NA
|
Yamamoto et al[9]
(2017)
|
3
|
NA
|
37B
|
100
|
NA
|
NA
|
Xu et al[10]
(2018)
|
12
|
3.4B
|
16B
|
100
|
10B
|
2(16.7%)
|
Kim et al[11]
(2019)
|
1
|
2
|
21
|
100
|
NA
|
NA
|
This study
|
10
|
3.5B
|
15B
|
100
|
11B
|
2(20.0%)
|
A = mean;B = median; NA = not available
No study to date has shown improved overall survival between RAMPS and standard DP[21–23]. Abe et al[23] reported that median overall survival rates were not significantly different between patients undergoing RAMPS versus standard DP(47 months vs. 34 months; p = 0.19). In a study of Park et al[22],on univariate analysis ,conventional resection was associated with a worse 5-year overall survival of 12%, compared with 40% after RAMPS (p = 0.014). However, on multivariate analysis, adjuvant chemoradiation and negative margins were the sole factors associated with improved overall survival[22]. Lee et al[6]reported that there were no significant differences in median overall survival between laparoscopic or robotic RAMPS and conventional open DPS within the Yonsei criteria (60.00 vs. 60.72 months, p = 0.616).So whether the patients could benefit the better survival outcomes after LRAMPS need to be further validated based on additional large-volume studies
Potential indications for LRAMPS is still being debated. Generally acceptable potential indications(Yonsei criteria) for patients best suited for LRAMPS were as follows: (1) pancreas-confined tumors; (2) intact fascia layer between the distal pancreas and left adrenal gland and kidney; and (3) tumor located at least 1–2 cm away from the celiac axis[6, 24]. Kang et al[24]and Lee et al[6] considered that it would be wise to limit the LRAMPS procedure to anterior RMAPS alone. The indication proposed by Ome et al[8] for LRAMPS is left-sided PC located ≥ 1 cm away from the origin of the SA without invasion of the SMA, CA, CHA, or PV. Kim et al[7] performed LRAMPS for the left-sided PC that was less than stage T3 without distant metastasis or unable to secure a safety margin from a major vessel, such as the SMA or PV or CA. But from the literature review[5–11],more patients underwent posterior RAMPS even with combined resection of the transverse colon with the safe and effective outcomes. With the technical evolution and clinical experience accumulating, the indication of LRAMPS will be expanded.
There are several approaches in LRAMPS. Sunagawa at al[5]and Ome et al[8] performed a LRAMPS by starting from the resecting the ligament of Treitz and entered the anterior space of the aorta and inferior vena cava. They confirmed that it could be easily to proceed from neck of the pancreas to the level of aorta and easily to avoid causing any damage to the retropancreatic organs, including the left renal vein [5, 8]. Yamamoto et al[9] developed the artery-first approach LRAMPS for left-sided pancreatic cancer. The artery-first approach means that middle segment of the pancreas was initially separated from both the left renal vein and the SMA with the advantage of early detection of no tumor infiltration into the SMA and the early determination of posterior dissection plane[9]. But in most centers, the dissection plane proceeded vertically during LRAMPS, thereby exposing the left side of the CA and SMA down to the level of the aorta after the division of the neck of the pancreas[6, 7, 10]. We also performed LRAMPS in this manner. In our experience, preoperative accuracy assessment of tumor by CT and MRI and fine operation were the key points of the this manner of LRAMPS.
Whether LRAMPS is the ideal approach for the left-sided PC? Only one retrospective control study of LRAMPS compared with conventional open surgery was indexed on Pubmed[6]. No literature of LRAMPS compared with laparoscopic standard distal pancreatectomy was published. Therefore, a randomized controlled test should be performed to test whether the LRAMPS procedure is superior to open RAMPS or standard distal pancreatectomy. But it was difficult to accomplish owing to the infrequent procedure of LRAMPS[3].