Introduction
Neoplasms located in the neck of pancreas pose a challenge to pancreatic surgeons. In general, tumors in this location are resected by distal pancreatectomy (DP) [
1]. However, DP removes a significant amount of normal pancreatic parenchyma and may cause endocrine and exocrine insufficiency [
2‐
4]. Central pancreatectomy (CP) has been proposed as an alternative to DP for benign or low-grade malignant tumors in the neck of the pancreas because it spares normal pancreatic tissue and potentially preserves the function [
5]. In addition, CP was also applied to treat metastatic lesions to the pancreas [
6,
7]. Central pancreatectomy, also known as middle pancreatectomy or medial pancreatectomy, was first performed by Dagradi and Serio [
8] in patients with oncological indication in 1982. Since then, an increasing number of cases have been reported. Some systematic reviews and meta-analyses [
9‐
11] showed that CP could decrease the risk of exocrine failure and impairment of endocrine function than DP, although it was associated with a slightly higher postoperative morbidity.
In recent years, data in favor of limited resections for pancreatic tumors have been accumulating. Enucleation has been reported to be alternative procedure to radical pancreatectomy [
12‐
14] and patients treated by pylorus-preserving pancreaticoduodenectomy (PPPD) could achieve similar long-term survival as patients undergoing pancreaticoduodenectomy (PD) [
15]. However, there is concern that CP is not an adequate oncological procedure for pancreatic ductal adenocarcinoma (PDAC) [
16,
17]. Studies regarding CP for PDAC are quite limited. With the advancement of radiology, more early-stage PDAC are detected. In this context, there is a need to study the role of CP in the treatment of small PDAC.
Therefore, this case–control study was performed to analyze operative morbidity, mortality, and, more importantly, survival outcomes to evaluate the real effect, safety, and feasibility of CP in PDAC.
Discussion
There is a trend of limited resections for pancreatic tumors without compromising the oncologic principles. For instance, solitary benign or low-grade malignant pancreatic tumors can be resected by enucleation [
12‐
14]. A Cochrane meta-analysis [
15] suggested no relevant difference in mortality, morbidity, and survival between PPPD and PD. In general, CP has the following potential advantages [
23]: (1) parenchyma preserving to reduce endocrine and exocrine insufficiency even with a slightly higher morbidity rate; (2) spleen preserving.
One of the major concerns of CP is its high operative morbidity rate, particularly POPF. As Table
4 presents, we summarized recent studies on CP. The table indicated that the CP group had a slightly higher postoperative morbidity but better preservation of pancreatic function than the DP group. The overall morbidity of the CP group ranges from 28 to 72%. Overall POPF ranges from 7 to 63% with clinically significant (grade B + C) POPF ranging from 16 to 44%. Such a large range of POPF rate may be attributed to different assessments and definitions of POPF. Operative mortality is also low and many studies have reported zero mortality. In this study, the overall morbidity of the CP group was 56%. The overall POPF was 56%, yet the grade B + C POPF accounted for 33%, which was consistent with the reported findings. Fortunately, no postoperative deaths occurred in the series. From the viewpoint of short-term results, these data reflected that CP was a safe procedure with morbidity and mortality consistent with other reported findings.
Table 4
Characteristics of recent studies on CP (n ≥ 30)
| 2002 | 53/− | 41/− | 30/− | NA | 2/− | 6/− | 8/− |
| 2003 | 32/21 | 62/29 | 50/14 | NA | 0/0 | 10/15.8 | 6.2/4.8 |
| 2006 | 40/40 | 27.5/25 | 7.5/10 | NA | 2.5/0 | 15/42 | 46/41 |
| 2007 | 100/45 | 58/46.7 | 44/29 | 17/13 | 0/0 | 4/38 | 5/15.6 |
| 2008 | 50/− | 38/− | 8/− | NA | 0/− | 0/− | NA |
| 2008 | 34/− | 47.1/− | 29.4/− | 11.8/− | NA | 5/− | NA |
| 2010 | 50/50 | 42/40 | 24/20 | 18/14 | 0/0 | 14/46 | 0/0 |
| 2013 | 36/26 | NA | 42/31 | 17/− | 0/0 | 2.8/21.7 | 8.3/8.7 |
| 2014 | 100/− | 72/− | 63/− | 44/− | 3/− | 7/− | 6/− |
| 2017 | 35/165 | 74/55 | 51/40 | 23/27 | 0/0 | NA | NA |
| 2013 | 359/480 | 47.1/29.4 | 30.8/14.3 | NA | 0.9/0 | 5.5/23.6 | 11.9/19.1 |
| 2016 | 586/− | 50.3/− | 34.1/− | NA | 0.7/− | 3.2/− | 6.5/− |
| 2018 | 539/869 | 51/26 | 35/21 | NA | 0.5/0.1 | 4/31 | 5/13 |
In this case–control study, demographic features, CA19-9 and tumor TNM staging, N staging, lymph nodes resected, and differentiation were well matched in the two groups, except the greatest tumor diameter and T staging. Although the DP group had larger tumors, which could result in some bias, the two groups were generally comparable in TNM staging. Hence, it is practicable to compare the prognosis of the two groups. The findings of the present study demonstrated no significant difference in operative time, blood loss, and blood transfusion. Although the CP group had higher overall morbidity, overall POPF, and grade B + C POPF rate, the difference was not statistically significant. Moreover, no difference was found in the DGE, chyle leak, hemorrhage, abdominal collections, pulmonary complications, postoperative hospital stay, readmission, reoperation, and R0 resection rate. Several reasons might be responsible for our result. First, a statistically significant difference was difficult to obtain due to the limited number of CP cases (n = 9). Second, most of the published studies focused on CP resecting benign or low-grade malignant tumors, and these tumors were usually in the soft pancreas, which is a known risk factor for pancreatic fistula. In the present series, all patients were diagnosed with PDAC and the parenchyma of the pancreas with PDAC was often hard.
The main benefit of CP is the preservation of endocrine and exocrine functions because it spares more pancreatic parenchyma than DP. However, limited tissue resection and inadequate lymph node dissection may be potentially noncurative for patients with PDAC [
16,
17]. Thus, CP is not considered an oncologically appropriate procedure for PDAC. As a matter of fact, very few studies reported treatment of PDAC using CP, especially for early-stage PDAC, let alone high-quality evidence of evidence-based medicine, such as prospective studies or randomized controlled trials.
Given that CP was a limited resection, R0 resection should be guaranteed by performing an intraoperative frozen-section biopsy to obtain sound oncologic safety. The DP group had a higher trend of R0 rate compared with the CP group. Due to the dissatisfactory widespread of intraoperative frozen-section biopsy before and relatively smaller tumors of the CP group, it was more likely for the surgeons to misjudge that sufficient resection had been made, resulting in significantly higher positive margin in the CP group. The rate of adjuvant chemotherapy was reported to be different [
32‐
34], varying from 29 to 78%. In this study, the rate of adjuvant chemotherapy was 45% in the CP group and 67% in the DP group. In our study, tumors in the CP group were confined to pancreatic parenchyma with no infiltration to the pancreatic capsule. The findings of this study indicated that for small PDAC (greatest tumor diameter ≤ 2 cm) confined to pancreatic parenchyma in the neck of the pancreas, patients undergoing CP could obtain similar long-term survival as patients treated using DP (20.4 months for CP vs 19.4 months for DP,
P = 0.842).
This was the first series to evaluate the safety and feasibility of the CP procedure for PDAC. This retrospective study had some limitations. First, data on adjuvant chemotherapy were incomplete. Their impact on survival was not included in the statistical analysis. Second, the size of patient cohort limited the statistical analysis between the CP and DP groups.
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