Surgery Today

https://doi.org/10.1007/s00595-021-02280-y

ORIGINAL ARTICLE

Radical antegrade modular pancreatosplenectomy (RAMPS)

versus conventional distal pancreatectomy for left‑sided pancreatic
cancer: findings of a multicenter, retrospective, propensity score
matching study
Hyung Sun Kim1 · Tae Ho Hong2 · Young‑Kyoung You2 · Joon Seong Park1 · Dong Sup Yoon1

Received: 23 October 2020 / Accepted: 15 February 2021

© Springer Nature Singapore Pte Ltd. 2021

Abstract
Purpose Radical antegrade modular pancreatosplenectomy (RAMPS) has been reported to achieve high rates of a negative
margin and resected metastatic lymph nodes. However, many studies have used historical controls and the results remain
controversial. We conducted this study to compare the surgical and long-term outcomes of RAMPS vs. conventional distal
pancreatectomy (DP).
Methods The subjects of this multicenter retrospective study were 106 patients who underwent curative resection for
left-sided pancreatic cancer between 2012 and 2017. Overall survival (OS) and recurrence-free survival (RFS) rates were
compared using Kaplan–Meier estimates.
Results The RAMPS group had more advanced T (T3/T4) and N stages (N1/N2) and a larger tumor size than the conventional
group (T stage, p = 0.04; N stage, p = 0.02; tumor size, p = 0.04). The RAMPS group had more harvested metastatic lymph
nodes (p = 0.02). After propensity-score matching, 37 patients from each group were included in the final analysis. There
was no significant difference in RFS (p = 0.463) or OS (p = 0.383) between the groups. Multivariate analyses revealed the
completion of chemotherapy to be an independent factor for RFS and OS (both p < 0.001).
Conclusions There was no difference in the RFS or OS between RAMPS and conventional DP in this series. RAMPS may
be an option for R0 resection of advanced tumors; however, postoperative chemotherapy has a greater influence than the
surgical procedure on the prognosis of patients with pancreatic cancer.

Keywords Radical antegrade modular pancreatosplenectomy (RAMPS) · Conventional distal pancreatectomy · Left side
pancreatic cancer · Body and tail pancreatic cancer

Introduction

Pancreatic body and tail cancers are aggressive, invading

locally and metastasizing through the lymph nodes [1–3].
* Tae Ho Hong In 2003, Strasberg described a new distal pancreatectomy
gshth@catholic.ac.kr (DP) technique, termed “radical antegrade modular pancrea-
* Joon Seong Park tosplenectomy” (RAMPS), which is oncologically safe with
jspark330@yuhs.ac respect to the dissection planes used to achieve negative mar-
1
gins as well as the extent of lymph node dissection, thereby
Pancreatobiliary Cancer Clinic, Department of Surgery,
improving patient outcomes [4–6]. In RAMPS, the posterior
Gangnam Severance Hospital, Yonsei University
College of Medicine, 20, Eonju‑ro 63‑gil, Gangnam‑gu, plane of dissection continues left from medial, exposing the
Seoul 06229, Republic of Korea left renal vein and clearing Gerota’s fascia off the left kid-
2
Division of Hepato‑Biliary and Pancreas Surgery, ney, or the dissection continues posteriorly to the diaphragm
Department of Surgery, Seoul St. Mary’s Hospital, College using the retroperitoneal muscles as the posterior border [4].
of Medicine, The Catholic University of Korea, 222, The rationale for this approach is to ensure a negative deep
Banpo‑daero, Seocho‑gu, Seoul 06591, Republic of Korea

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margin with complete regional lymph node dissection. The dissection continued more laterally from right to left. The
benefits of RAMPS for the resection of pancreatic cancer are area of lymph node dissection was only around the celiac
well documented. Some studies have shown that RAMPS trunk.
is associated with high negative tangential margin rates, RAMPS was performed according to the procedure intro-
more harvested lymph nodes, and better survival rates for duced by Strasberg and Fields. A midline incision was made
pancreatic cancer [7, 8]. Although many studies have been and the pancreas neck was elevated from the PV and SMV.
reported, they used historical controls and the results remain The pancreas neck was transected and the resection margin
controversial. This multicenter retrospective study compares was repaired in the same manner as that in conventional
the surgical outcomes and long-term prognosis of patients DP. The range of medial-to-lateral lymph node dissection
who underwent RAMPS with those who underwent conven- was upward to the diaphragmatic crus, downward to the
tional DP, based on propensity score matching. left renal vein, and to the left lateral part of the aorta on
the posterior side. The dissection continued more laterally
from right to left on Gerota’s fascia and divided the inferior
Methods mesenteric vein. In each case, the surgeon decided the type
of RAMPS, whether anterior or posterior, based on which
Patients approach would optimize the chance of obtaining a nega-
tive tangential margin according to the principles described
The subjects were 106 consecutive patients who underwent by Strasberg et al. A closed suction drain was placed in the
curative surgical resection (R0/R1) for body and tail pancre- pancreas stump and the abdomen was closed in layers [3].
atic cancer at Gangnam Severance Hospital (n = 40) or Seoul
St Mary’s Hospital (n = 66) between 2012 and 2017. None Statistical analysis
of these patients received neoadjuvant treatment. The study
protocol was approved by the Institutional Review Board at All statistical analyses were performed using SPSS software,
Gangnam Severance Hospital, Yonsei University of Korea version 23.0 (SPSS Inc., Chicago, IL, USA). Categorical
(3-2019-0175) and complied with the Declaration of Hel- variables were evaluated using the chi-square or Fisher’s
sinki. Informed consent was obtained from all participants. exact tests. Statistical analysis using propensity-score match-
Major complications were defined as Clavien–Dindo clas- ing was performed by accounting for the covariates that
sification grade III and IV surgical complications [9]. Post- predicted patient prognosis. A 1:1 match was performed
operative pancreatic fistulas were scored using the Interna- according to two related covariates, namely T and N stages,
tional Study Group on Pancreatic Fistula definition [10]. The to generate propensity scores. Overall survival (OS) and
definition of completion of postoperative chemotherapy was recurrence-free survival (RFS) curves were plotted using
the completion of planned chemotherapy or six cycles. Both the Kaplan–Meier method and intergroup differences in sur-
institutions are high-volume centers that perform 10 or more vival time were assessed with the log-rank test. RFS was
pancreatic cancer surgeries a year. The criteria for select- defined as the interval between the date of surgery and the
ing RAMPS or conventional DP in both institutions were date of recurrence or last follow-up. The Cox proportional
decided by the surgeon’s protocols. Generally, conventional hazards regression method was used to calculate independ-
DP was selected when tumor was confined to the pancreas ent prognostic factors. A p value of < 0.05 was considered
parenchyme or to the pancreas tail. In our protocol, abdomi- significant.
nal computed tomography (CT) and blood tests, including
tumor marker testing, were performed every 3 months for the
duration of adjuvant therapy. After adjuvant therapy, tumor Results
marker levels were checked every 3 months and abdomi-
nal CT was performed every 6 months or when the tumor Clinical characteristics of the patients
marker levels were elevated. with pancreatic cancer

Procedures Table 1 shows the clinicopathologic features of the 106

patients who underwent curative resection for left-side
Conventional DP was performed as follows: A midline inci- pancreatic cancer (RAMPS group, n = 53; conventional
sion was made and the lesser sac was accessed through the group, n = 53). The RAMPS procedure in this study con-
gastrocolic ligament to expose the distal anterior pancreas. sisted of anterior RAMPS (n = 15) and posterior RAMPS
First, the pancreas neck was elevated from the confluence of (n = 38). There were significant differences in sex, T stage, N
the superior mesenteric vein (SMV), portal vein (PV), and stage, tumor stage, tumor size, and metastatic lymph nodes
splenic vein and then transected using GIA™ Staplers. The between the groups. The RAMPS group had more aggressive

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Table 1  Clinical characteristics RAMPS (n = 53) Conventional DP (n = 53) p value

of the 106 patients with
Mean ± SD or N (%)
pancreatic cancer
Age 66.32 ± 8.97 64.96 ± 10.39 0.47
Sex
Male 19 (35.8%) 29 (54.7%) 0.05
Female 34 (64.2%) 24 (45.3%)
T stage, 8th
T1 6 (11.3%) 12 (22.6%) 0.04
T2 22 (41.5%) 28 (52.8%)
T3 22 (41.5%) 13 (24.5%)
T4 3 (5.7%) 0 (0%)
N stage, 8th
N0 22 (41.5%) 31 (58.5%) 0.02
N1 16 (30.2%) 18 (34%)
N2 15 (28.3%) 4 (7.5%)
Stage, 8th
IA 3 (5.7%) 12 (22.6%) 0.005
IB 10 (18.9%) 14 (26.4%)
IIA 8 (15.1%) 5 (9.4%)
IIB 15 (28.3%) 18 (34%)
III 17 (32.1%) 4 (7.5%)
Tumor size
cm 4.24 ± 1.94 3.44 ± 2.11 0.04
Harvested Lymph node 15.81 ± 10.256 13.36 ± 9.831 0.21
Metastatic Lymph node 2.08 ± 2.663 1.08 ± 1.90 0.02
Perineural invasion
Positive 42 (51.9%) 39 (73.6%) 0.41
Negative 10 (41.7%) 14 (26.4%)
Unknown 1 (100%) 0 (0%)
Lymphovascular invasion
Positive 26 (49.1%) 17 (32.1%) 0.07
Negative 27 (50.9%) 36 (67.9%)
Differentiation
Well-Mod 47 (88.7%) 46 (86.8%) > 0.99
Poorly-Undiff 5 (9.4%) 5 (9.4%)
Unknown 1 (1.9%) 2 (3.8%)
POPF
No + Grade A 46 (86.8%) 50 (94.3%) 0.18
Grade B + C (clinically relevant 7 (13.2%) 3 (5.7%)
POPF)
Clavien dindo classification
No 45 (84.9%) 50 (94.3%) 0.14
I–II 4 (7.5%) 0 (0%)
III–IV 4 (7.5%) 3 (5.7%)
Length of hospital stay
Days 13.85 ± 6.359 14.66 ± 13.515 0.69
SMV-PV resection
Yes 4 (7.5%) 2 (3.8%) 0.40
No 49 (92.5%) 51 (96.2%)
Other organ resection
Yes 10 (18.9%) 6 (31.6%) 0.33
No 43 (81.1%) 13 (68.4%)

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Table 1  (continued)
RAMPS (n = 53) Conventional DP (n = 53) p value
Mean ± SD or N (%)

Estimated blood loss

Ml 518.87 ± 510.726 626.47 ± 558.956 0.30
Operation time
Min 262.75 ± 107.515 261.55 ± 99.392 0.95

RAMPS radical antegrade modular pancreatosplenectomy, Conventional DP conventional distal pancrea-

tectomy, POPF postoperative pancreatic fistula, SMV superior mesenteric vein, PV portal vein

tumor features and metastatic lymph nodes (2.08 ± 2.663 vs Prognostic impact of clinicopathologic
1.08 ± 1.90, p = 0.02) than the conventional group, but there features on pancreatic cancer in the propensity
were no significant differences in intraoperative and postop- score‑matched cohort
erative outcomes; namely, complications, length of hospital
stay, blood loss, and operation time, between the groups. In the propensity score-matched analysis, there were no
significant differences in T and N stages between groups
Postoperative recurrence patterns (Table 3). The propensity score-matched cohort com-
prised 74 patients: 37 in the RAMPS group and 37 in
Recurrence and R0 resection rates were not significantly dif- the conventional group. After propensity-score match-
ferent between the groups (p = 0.20, p = 0.37), but the recur- ing, univariate analysis revealed node stage, tumor stage,
rence patterns differed significantly between the groups. The and completion of chemotherapy as independent factors
conventional group had more local recurrence at the initial for poor RFS. On multivariate analyses, completion of
diagnosis of recurrence than the RAMPS group (32.3% vs chemotherapy was identified as an independent factor
5.4%, p = 0.004; Table 2). The regimen of postoperative for poor RFS (p < 0.001) (Table 4). After propensity-
chemotherapy included gemcitabine (50%, n = 54) and a score matching, univariate analysis revealed T stage, N
5-FU based regimen (32%, n = 34). We defined the absence stage, tumor stage, cell differentiation, and completion
of cancer cells in the margin (retroperitoneal margin, supe- of chemotherapy as independent factors for poor OS. On
rior mesenteric vein groove) as R0 resection. multivariate analysis, cell differentiation and completion
of chemotherapy were identified as independent factors for
poor OS (p < 0.001; Table 5). Before propensity matching
the mean levels of CA19-9 were 1504.25 [3.45–40350]
in RAMPS and 190.84 [0.8–1728.6] in conventional DP.

Table 2  Postoperative RAMPS (n = 53) Conventional DP (n = 53) p value

recurrence patterns
Recurrence rate
Recurrence 37 (69.8%) 31 (58.5%) 0.20
No recur 12 (22.6%) 20 (37.7%)
Unknown 4 (7.5%) 2 (3.8%)
R0/1 rate
R0 37 (69.8%) 41 (77.4%) 0.37
R1 16 (30.2%) 12 (22.6%)
Chemotherapy completion rate
Completion 26/43 (60.5%) 42/48 (87.5%) 0.003
No completion 17/43 (39.5%) 6/48 (12.5%)
Recurrence pattern
Local recurrence only 2/37 (5.4%) 10/31 (32.3%) 0.004
Local and distant recurrence 35/37 (94.6%) 21/31 (67.7%)

RAMPS radical antegrade modular pancreatosplenectomy, Conventional DP Conventional distal pancrea-

tectomy

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Table 3  Clinical characteristics RAMPS (n = 37) Conventional DP (n = 37) p value

of the 106 patients with
pancreatic cancer in the Mean ± SD or N (%)
propensity matched cohort
Age 67.27 ± 9.29 64.30 ± 10.79 0.209
Sex
Male 13 (35.1%) 21 (56.8%) 0.062
Female 24 (64.9%) 16 (43.2%)
T stage, 8th
T1 3 (8.1%) 3 (8.1%) > 0.99
T2 21 (56.8%) 21 (56.8%)
T3 13 (35.1%) 13 (35.1%)
N stage, 8th
N0 18 (48.6%) 18 (48.6%) > 0.99
N1 15 (40.5%) 15 (40.5%)
N2 4 (10.8%) 4 (10.8%)
Stage, 8th
IA 3 (8.1%) 3 (8.1%) > 0.99
IB 10 (27%) 10 (27%)
IIA 5 (13.5%) 5 (13.5%)
IIB 15 (40.5%) 15 (40.5%)
III 4 (10.8%) 4 (10.8%)
Tumor size
cm 3.79 ± 1.43 3.95 ± 2.27 0.209
Harvested lymph nodes 12.3 ± 8.38 13.27 ± 10.21 0.656
Metastatic lymph nodes 1.35 ± 2.03 1.38 ± 2.13 0.956
Perineural invasion
Positive 30 (83.3%) 28 (75.7%) 0.418
Negative 6 (16.7%) 9 (24.3%)
Lymphovascular invasion
Positive 17 (45.9%) 15 (40.5%) 0.639
Negative 20 (54.1%) 22 (59.5%)
Differentiation
Well-Mod 33 (89.2%) 32 (86.5%) > 0.99
Poorly-Undiff 3 (8.1%) 3 (8.1%)
Unknown 1 (2.7%) 2 (5.4%)
POPF
No + Grade A 31 (83.8%) 36 (97.3%) 0.054
Grade B + C (clinically relevant POPF) 6 (16.2%) 1 (2.7%)
Clavien dindo classification
No 31 (83.8%) 36 (97.3%) 0.169
I-II 3 (8.1%) 0 (0%)
III-IV 3 (8.1%) 1 (2.7%)
Length of hospital stay
days 13.11 ± 4.91 15.92 ± 15.98 0.312
SMV-PV resection
Yes 3 (8.1%) 2 (5.4%) > 0.99
No 34 (91.9%) 35 (94.6%)
Other organ resection
Yes 6 (16.2%) 5 (29.4%) 0.293
No 31 (83.8%) 12 (70.6%)
Blood loss
ml 458.11 ± 426.20 684.29 ± 619.85 0.078

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Table 3  (continued) RAMPS (n = 37) Conventional DP (n = 37) p value

Mean ± SD or N (%)

Operation time
min 269.84 ± 121.58 265 ± 108.70 0.859
Recurrence rate
Recurrence 27 (73%) 23 (62.2%) 0.577
No recur 9 (24.3%) 12 (32.4%)
Unknown 1 (2.7%) 2 (5.4%)
R0/1 rate
R0 27 (73%) 26 (72.2%) 0.943
R1 10 (27%) 10 (27.8%)
Chemotherapy completion rate
Completion 20 (66.7%) 27 (84.4%) 0.104
No completion 10 (33.3%) 5 (15.6%)
Recurrence pattern
Local recurrence only 2 (7.4%) 7 (30.4%) 0.062
Local and distant recurrence 25 (92.6%) 16 (69.6%)

POPF postoperative pancreatic fistula, SMV superior mesenteric vein, PV portal vein, RAMPS radical ante-
grade modular pancreatosplenectomy, Conventional DP conventional distal pancreatectomy

After propensity matching, the mean levels of CA19-9 Lymph node invasion and positive margin status are
were 249.30 [3.45–2207] in the RAMPS group and 212.76 major predictors of recurrence and survival for patients
[0.8–1728.6] in the conventional DP group. undergoing surgery for pancreatic cancer [11–21]. A clear
The main regimens of chemotherapy were gemcitabine- advantage of RAMPS over conventional DP is a large num-
and 5-FU based. We analyzed the survival rate (RFS, OS) in ber of harvested lymph nodes and higher R0 resection rate
the two groups, but found no significant difference between [4–6]. In 2017, a meta-analysis by Cao et al. revealed that
the groups in the propensity matching cohort. RAMPS was correlated with higher R0 resection rates and
more successful harvesting of more lymph nodes than the
standard procedure. However, no significant difference was
RFS and OS after RAMPS vs. conventional DP found between the procedures with respect to RFS, OS, or
in the propensity‑score matched cohort disease-free survival [22]. In this study, the number of har-
vested lymph nodes and the number of metastatic lymph
After propensity-score matching, the 3-year RFS rate was nodes were higher in the RAMPS group, but there was no
19.9% (median RFS, 9.9 months; range 2.8–17.1 months) in significant difference in R0 resection rates between the
the RAMPS group and 27.5% (median RFS, 10.4 months; groups because conventional DP was analogous to RAMPS
range 7.3–13.5 months) in the conventional group. The (right to left dissection after pancreatic neck resection).
5-year OS rate was 14.2% (median OS, 27.5 months; range Many studies have compared these two surgical proce-
13.7–41.3 months) in the RAMPS group and 29.9% (median dures by using historical controls; however, discrepancy
OS, 25.5 months; range 17.1–33.8 months) in the conven- between historical and concurrent controls led to a biased
tional group. There was no significant difference in RFS or assessment of control response, thereby resulting in a biased
OS between the groups (p = 0.46, p = 0.38) (Figs. 1, 2). assessment of the effectiveness of RAMPS. These discrep-
ancies can be caused by improvements in clinical care
from those practiced at the time of the historical trials [23].
Discussion Notably, the present multicenter study evaluated recent data
within the same period, retrospectively, thus comparing the
This study found no significant difference in DFS or OS two surgical methods more objectively. Before propensity-
between RAMPS and conventional DP. Moreover, our find- score matching, the more advanced T and N stages were
ings support the consensus that in pancreatic cancer treat- distributed in the RAMPS group. Because these stages
ment, postoperative chemotherapy is more important than were important factors affecting survival, T and N stages
the surgical procedure for prognosis. were used as covariates in the propensity-score matching
analysis. A propensity-score matched cohort analysis was

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Table 4  Univariate analysis (a) and multivariate analysis (b) of the relationship between recurrence-free survival and clinicopathologic variables
by Cox regression hazard model in the propensity matched cohort
(a) Univariate analysis
HR 95%CI p value

Age
> 65 0.638
< 65 0.872 0.493–1.542
Sex
M 0.899
F 0.963 0.542–1.712
T stage, 8th
T1 1
T2 2.358 0.716–7.770 0.159
T3 2.585 0.748–8.940 0.133
N stage, 8th
N0 1
N1 1.817 0.999–3.303 0.05
N2 1.380 0.471–4.044 0.557
Stage, 8th
IA 1
IB 1.731 0.482–6.219 0.4
IIA 2.411 0.597–9.743 0.217
IIB 3.083 0.921–10.323 0.068
III 2.325 0.519–10.409 0.270
Perineural invasion
Negative 1 0.728
Positive 1.138 0.550–2.355
Lymphovascular invasion
Negative 1 0.604
Positive 1.163 0.658–2.055
Differentiation
Well-Mod 1 0.175
Poorly-Undiff 1.910 0.750–4.864
R0/R1 resection
R0 1 0.097
R1 1.673 0.911–3.073
Operation type
Conventional DP 1 0.464
RAMPS 1.236 0.701–2.181
Chemotherapy completion
No 1 < 0.001
Yes 0.264 0.128–0.545
Regimen of chemotherapy
5-FU 1 0.088
Gemcitabine 1.735 0.921–3.265
(b) Multivariate analysis
HR 95% CI p value

Age
> 65
< 65

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Table 4  (continued)
(b) Multivariate analysis
HR 95% CI p value

Sex
M
F
T stage,8th
T1
T2
T3
N stage, 8th
N0
N1
N2
Stage, 8th
IA 1
IB 0.960 0.193–4.761 0.960
IIA 2.272 0.378–13.670 0.370
IIB 3.695 0.862–15.836 0.078
III 3.419 0.610–19.178 0.162
Perineural invasion
Negative
Positive
Lymphovascular invasion
Negative
Positive
Differentiation
Well-Mod
Poorly-Undiff
R0/R1 resection
R0
R1
Operation type
Conventional DP
RAMPS
Chemotherapy completion
No 1 < 0.001
Yes 0.142 0.056–0.361
Regimen of chemotherapy
5-FU
Gemcitabine

RAMPS Radical antegrade modular pancreatosplenectomy, Conventional DP Conventional distal pancreatectomy, RFS Recurrence-free survival

also performed to compare RAMPS and conventional DP, adjuvant chemotherapy has increased survival significantly
which revealed that only completion of chemotherapy was and is indispensable for patients with pancreatic cancer.
a significant independent factor for RFS and OS. The surgi- The complication rate of Clavien–Dindo classifications
cal procedures did not differ significantly in this regard. Our grade III and IV in our study was higher in the RAMPS
results confirmed that completion of chemotherapy was the group than in the conventional DP group. Poor physical sta-
most significant factor for the prognosis of left-side PDAC, tus, such as malnutrition related to a high complication rate
in accordance with previous studies [24–30]. Postoperative in the RAMPS group probably affected the completion rate

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Table 5  Univariate analysis (a) and multivariate analysis (b) of the relationship between overall survival (OS) and clinicopathologic variables by
Cox regression hazard model in the propensity matched cohort
(a) Univariate analysis
HR 95%CI p value

Age
> 65 1 0.603
< 65 0.859 0.485–1.523
Sex
M 1 0.605
F 0.858 0.479–1.535
T stage, 8th
T1 1
T2 8.359 1.130–61.821 0.038
T3 10.339 1.370–78.050 0.024
N stage, 8th
N0 1
N1 3.138 1.627–6.054 0.001
N2 2.381 0.930–6.100 0.071
Stage, 8th
IA 1
IB 5.759 0.738–44.919 0.095
IIA 53,835 0.649–52.481 0.116
IIB 14.095 1.879–107.753 0.010
III 10.659 1.276–89.055 0.029
Perineural invasion
Negative 1 0.140
Positive 1.910 0.809–4.508
Lymphovascular invasion
Negative 1 0.830–2.660 0.182
Positive 1.486
Differentiation
Well-Mod 1 0.047
Poorly-Undiff 2.600 1.012–6.676
R0/R1 resection
R0 1 0.135
R1 1.617 0.861–3.040
Operation type
Conventional DP 1 0.384
RAMPS 1.294 0.724–2.314
Chemotherapy completion
No 1 0.002
Yes 0.342 0.173–0.677
Regimen of chemotherapy
5-FU 1 0.098
Gemcitabine 1.701 0.907–3.190
(b) Multivariate analysis
HR 95%CI p value

Age
> 65
< 65

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Table 5  (continued)
(b) Multivariate analysis
HR 95%CI p value

Sex
M
F
T stage, 8th
T1
T2
T3
N stage, 8th
N0
N1
N2
Stage,8th
IA 1
IB 1.978 0.241–16.240 0.526
IIA 4.739 0.492–45.663 0.178
IIB 7.341 0.959–56.164 0.055
III 6.510 0.712–59.567 0.097
Perineural invasion
Negative
Positive
Lymphovascular invasion
Negative
Positive
Differentiation
Well-Mod 1 0.027
Poorly-Undiff 3.121 1.141–8.538
R0/R1 resection
R0
R1
Operation type
Conventional DP
RAMPS
Chemotherapy completion
No 1 < 0.001
Yes 0.211 0.096–0.465
Regimen of chemotherapy
5-FU
Gemcitabine

RAMPS Radical antegrade modular pancreatosplenectomy, Conventional DP Conventional distal pancreatectomy, OS Overall survival

of postoperative adjuvant therapy; however, as this was a This study has some limitations. First, although it was a
retrospective analysis, we do not know the exact correlation. multicenter study, it included data of patients from only two
In our original collected data, there were 5 cases of bor- institutions and cannot reflect an analysis of the entire popu-
derline resectable PDAC (BR-PDAC) and 101 cases of lation of patients with pancreatic cancer. Second, because
resectable PDAC. However, after propensity matching, there there were no clear indications for when to perform RAMPS
were 3 cases of BR-PDAC and 71 cases of resectable PDAC. or conventional DP, the potentially differing indications
In the case of BR-PDAC, it was difficult to perform a sub- between the two hospitals may have introduced selection
group analysis because the number of cases was too small. bias. Although we performed propensity score matching

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indicated for advanced tumors, defined as large tumors that

are more likely to have a positive posterior margin.

Author contributions Study design: THH, JSP. Data collection: THH,

HSK. Data analysis: HSK. Original draft: HSK. Review and editing:
Y-KY, DSY, THH, JSP.

Funding Our research did not receive funding.

Declarations

Conflict of interest We have no competing interests to declare.

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