Converted laparoscopic distal pancreatectomy: is there an impact on patient outcome and total cost?

A single tertiary referral centre retrospective cohort study based on a prospectively maintained database, of patients undergoing distal pancreatectomy (DP) for body-tail pancreatic neoplasms from January 2005 to January 2021 was carried out. The study was approved by the Ethical Committee of S. Orsola-Malpighi Hospital with code PANBO 064/2017/ U/Oss; patient informed consent was obtained from all participants included in the study. The patients who underwent DP were divided into three groups: ODP, TLDP, and CLDP. Patients requiring a conversion (CLDP) were compared with both TLDP and ODP patients. A comparison between TLDP and ODP was not carried out. For each patient, the following relevant variables were collected: (1) patient-related (gender, age, comorbidities, American Society of Anesthesiologists (ASA) score, body mass index (BMI), previous abdominal surgery, and extended procedures) and (2) tumour-related (tumour size, tumour site, and malignancy). The malignant tumours included pancreatic ductal adenocarcinomas (PDACs); the non-malignant tumours included intraductal papillary mucinous neoplasms (IPMNs), mucinous and serous cystadenomas, and pancreatic neuroendocrine tumours (pNETs). The intra- and postoperative data (operative time, blood loss, 90-day mortality, postoperative morbidity, severe postoperative morbidity, CR-POPF, postoperative pancreatic fistula grade C, PPH, DGE, reoperation rate, readmission rate, length of hospital stay, and the total cost of the procedures) were also extracted.

When the authors indicated that the tumour was in the body of the pancreas, it signified that it was located between the left border of the portal vein and the left border of the aorta; when the authors indicated that the tumour was located in the pancreatic tail, it signified that it was distal to the left border of the aorta. A left distal pancreatectomy was defined as the transection of the pancreas on the left border of the portal vein; a subtotal distal pancreatectomy was defined as the transection of the pancreas on the right border of the portal vein. In a subtotal distal pancreatectomy, the resection line was at the level of the portal vein, requiring a tunnelling procedure, while in a left pancreatectomy, the tunnelling procedure was not required. The pancreatic transection was always performed using a stapler. An extended procedure was defined as a surgical resection involving other neighbouring organs in addition to the pancreas. A converted laparoscopic distal pancreatectomy was defined as any resection which was attempted as laparoscopic, but required conversion thereafter with any laparotomy or hand assistance for reasons other than trocar placement or specimen extraction [11]. A total laparoscopic distal pancreatectomy was considered to be a successfully completed laparoscopic distal pancreatectomy. Operative time was defined as the interval from the incision to the suturing of the skin. Poor visualisation of the tumour meant that the tumour was not clearly identified, even if an intraoperative ultrasound was performed. Postoperative mortality was defined as the number of deaths occurring during hospitalisation or within 90 days after surgery. Postoperative morbidity included all complications following surgery up to the day of discharge according to the Clavien-Dindo classification [12]. Major complications were classified as Clavien-Dindo > 2 [13]. A postoperative pancreatic fistula (POPF) was defined according to the 2016 definition proposed by the International Study Group of Pancreatic Fistula (ISGPF) [14]. Post-pancreatectomy haemorrhage was defined as intra-abdominal or intestinal bleeding according to the criteria of the International Study Group of Pancreatic Surgery (ISGPS) [15]. Delayed gastric emptying was defined according the criteria of the ISGPS [16]. Reoperation was defined as any surgical procedure performed in the first 30 postoperative days or before discharge from the hospital. Length of hospital stay (LOS) was calculated as the interval from the day of surgery to the date of discharge. The total cost of the surgical procedures was calculated in Euros and included pre-, intra-, and postoperative costs for the reference year 2019. The initial purchase expense of the laparoscopic system was excluded. Preoperative costs regarded the hospitalisation costs; intraoperative costs included operative theatre cost/hour and device costs; and postoperative costs included the hospitalisation costs, postoperative imaging studies, nutritional support, surgical reoperation or interventional postoperative procedures, intensive care unit admission expenses, and readmission costs.

Statistical analyses were carried out using the Statistical Package for the Social Science (SPSS, Chicago, IL), version 13 on a personal computer. All the categorical variables were described as frequencies and percentages, while the continuous variables were reported as means with standard deviation. Comparison of the groups was carried out using the Fischer’s exact test, Student’s t test, and Pearson chi square test. Two-tailed P values less than 0.05 were considered statistically significant. The propensity score matching analysis used relevant variables with the aim of equating the complexity of the surgical cases. The relevant variables were patient-related (gender, age, comorbidities, ASA score, BMI, previous abdominal surgery) and tumour-related (tumour size, tumour site, and malignancy). Two propensity score matching comparisons were carried out: CLDP versus TLDP and CLDP versus ODP. A matched group of patients was created with a 1:2 ratio in both the PSM analyses. The PSM method is closest to the neighbourhood method having a caliper width of 0.20. Standardised mean difference (SMD) was used to assess the balance of the clinical backgrounds between the two groups. An SMD < 0.2 indicated very small differences between the means (this implied that optimal balance regarding a variable was generally achieved), an SMD between 0.2 and 0.8 indicated medium differences (this implied that fairly sufficient balance regarding a variable was generally achieved), and SMD > 0.8 indicated considerable differences (this implied that poor balance regarding a variable was generally achieved).

Two hundred and five patients underwent DP for body-tail pancreatic tumours from January 2005 to January 2021: 105 (51.2%) ODPs, 81 (39.5%) TLDPs, and 19 (9.3%) CLDPs. The reasons for conversion to an open procedure were the following: tumour close to major vessels (7 cases, 36.8%), oncological concerns (4 cases, 21.1%), bleeding (4 cases, 21.1%), adhesions (2 cases, 10.5%), and poor visualisation of the tumour (2 cases, 10.5%). It should be pointed out that the conversion was due to the proximity of the tumour to major vessels (< 1 cm), even if it was always detected preoperatively by abdominal CT scan. The comparison regarding the relevant variables of CLDP versus TLDP and CLDP versus ODP is summarised in Table 1. The patients undergoing CLDP had a significantly higher BMI and more frequent comorbidities with respect to TLDP (28.4–6.2- versus 25.6–4.2 kg/m²; P = 0.017 and 16, 84.2% versus 45, 55.6%; P = 0.035, respectively). Open distal pancreatectomy was preferred in patients who had undergone previous abdominal surgery and in those who had tumours located in the neck-body of the pancreas (71 (67.6%) versus 8 (42.1%); P = 0.041 and 89 (84.2%) versus 10 (52.6%); P = 0.003, respectively). The comparisons regarding operative findings, postoperative outcomes, and total costs are summarised in Table 2. The patients who underwent CLDP had a significantly longer operative time (314 ± 72 versus 235 ± 69 min; P < 0.001), more frequent postoperative morbidity (12 (63.2%) versus 40 (49.4%); P = 0.009), CR-POPF rates (11 (57.9%) versus 18 (22.2%); P = 0.004), and increased costs (19,760 ± 7504 versus 14,989 ± 4670 Euros; P = 0.014) with respect to TLDP. Converted laparoscopic distal pancreatectomy had a significantly longer operative time (314 ± 72 versus 260 ± 74 min; P = 0.006), less frequent postoperative morbidity (12 (63.8%) versus 94 (89.5%); P = 0.009), higher readmission rates (5 (26.3%) versus 8 (7.6%); P = 0.029), and increased costs (19,760 ± 7504 versus 19,092 ± 7256 Euros; P < 0.001) with respect to ODP.

Using propensity score matching, three groups of patients were created with a 1:2 ratio, and well-balanced groups of 19 CLDPs, 38 TLDPs and 38 ODPs were compared. The samples compared were similar, and no differences were observed in the relevant variables. The SMD was always between 0.2 and 0.8, indicating a fairly sufficient balance of the groups (Table 3).

Operative findings, postoperative outcomes, and total cost after the propensity score matching analysis of CLDP versus TLDP and CLDP versus ODP are reported in Table 4. Propensity-matched patients who underwent CLDP had a significantly longer operative time (315 ± 72 versus 238 ± 68 min; P < 0.001), increased blood loss (161 ± 92 versus 108 ± 57 ml; P = 0.032), and total costs (19,760 ± 7506 versus 16,044 ± 5242 Euros; P = 0.034) with respect to TLDP. Propensity-matched patients undergoing CLDP had a significantly longer operative time (315 ± 72 versus 239 ± 61 min; P < 0.001), less frequent postoperative morbidity (12 (63.8%) versus 31 (81.6%); P = 0.050), and higher readmission rates (5 (26.3%) versus 2 (5.3%); P = 0.035) with respect to ODP. The reasons for readmission of the patients who underwent CLDP were the following: POPF grade B (treated with computed tomography (CT)-guided drainage) (3 cases); pleural effusion (medical treatment) (1 case), and nausea and vomiting (medical treatment) (1 case).