Outcomes of Elective and Emergency Conversion in Minimally Invasive Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma: An International Multicenter Propensity Score-matched Study

Conversion to open surgery in obese patients undergoing minimally invasive distal pancreatectomy: results from a multicenter analysis

BACKGROUND

Although minimally invasive distal pancreatectomy (MIDP) is considered a standard approach it still presents a non-negligible rate of conversion to open that is mainly related to some difficulty factors, as obesity. The aim of this study is to analyze the preoperative factors associated with conversion in obese patients with MIDP.

METHODS

In this multicenter study, all obese patients who underwent MIDP at 18 international expert centers were included. The preoperative factors associated with conversion to open surgery were analyzed.

RESULTS

Out of 436 patients, 91 (20.9%) underwent conversion to open, presenting higher blood loss, longer operative time and similar rate of major complications. Twenty (22%) patients received emergent conversion. At univariate analysis, the type of approach, radiological invasion of adjacent organs, preoperative enlarged lymphnodes and ASA ≥ III were significantly associated with conversion to open. At multivariate analysis, robotic approach showed a significantly lower conversion rate (14.6 % vs 27.3%, OR = 2.380, p = 0.001). ASA ≥ III (OR = 2.391, p = 0.002) and preoperative enlarged lymphnodes (OR = 3.836, p = 0.003) were also independently associated with conversion.

CONCLUSION

Conversion rate is significantly lower in patients undergoing robotic approach. Radiological enlarged lymphnodes and ASA ≥ III are also associated with conversion to open. Conversion is associated with poorer perioperative outcomes, especially in case of intraoperative hemorrhage.

SurgNet: Self-Supervised Pretraining With Semantic Consistency for Vessel and Instrument Segmentation in Surgical Images

Blood vessel and surgical instrument segmentation is a fundamental technique for robot-assisted surgical navigation. Despite the significant progress in natural image segmentation, surgical image-based vessel and instrument segmentation are rarely studied. In this work, we propose a novel self-supervised pretraining method (SurgNet) that can effectively learn representative vessel and instrument features from unlabeled surgical images. As a result, it allows for precise and efficient segmentation of vessels and instruments with only a small amount of labeled data. Specifically, we first construct a region adjacency graph (RAG) based on local semantic consistency in unlabeled surgical images and use it as a self-supervision signal for pseudo-mask segmentation. We then use the pseudo-mask to perform guided masked image modeling (GMIM) to learn representations that integrate structural information of intraoperative objectives more effectively. Our pretrained model, paired with various segmentation methods, can be applied to perform vessel and instrument segmentation accurately using limited labeled data for fine-tuning. We build an Intraoperative Vessel and Instrument Segmentation (IVIS) dataset, comprised of ~3 million unlabeled images and over 4,000 labeled images with manual vessel and instrument annotations to evaluate the effectiveness of our self-supervised pretraining method. We also evaluated the generalizability of our method to similar tasks using two public datasets. The results demonstrate that our approach outperforms the current state-of-the-art (SOTA) self-supervised representation learning methods in various surgical image segmentation tasks.

Association between Unplanned Conversion and Patient Survival after Laparoscopic Liver Resection for Hepatocellular Carcinoma: A Propensity Score Matched Analysis

Unplanned conversion (UPC) is considered to be a predictor of poor postoperative outcomes. However, the effects of UPC on the survival of patients with hepatocellular carcinoma (HCC) remain controversial. The aim of this study is to compare the outcomes between patients who underwent laparoscopic liver resection (LLR) and those who underwent UPC for HCC. Among 1029 patients with HCC who underwent hepatectomy between 2004 and 2021, 251 were eligible for the study. Of 251 patients who underwent hepatectomy for HCC in PS segments, 29 (26.0%) required UPC, and 222 underwent LLR. After 1:5 PSM, 25 patients were selected for the UPC group and 125 for the LLR group. Blood loss, transfusion rate, hospital stay, and postoperative complication were higher in the UPC group. Regarding oncologic outcomes, although the 5-year overall survival rate was similar in both groups (p = 0.544), the recurrence-free survival rate was lower in the UPC group (p < 0.001). UPC was associated with poor short-term as well as inferior long-term outcomes compared with LLR for HCC in PS segments. Therefore, surgeons must carefully select patients and consider early conversion if unexpected bleeding occurs to maintain safety and oncologic outcomes.

Nationwide analysis of unplanned conversion during minimally invasive distal pancreatectomy for pancreatic adenocarcinoma

BACKGROUND

Utilization of minimally-invasive distal pancreatectomy (MIDP) for pancreatic adenocarcinoma has increased. While unplanned conversion to an open procedure during MIDP is associated with inferior short-term outcomes, the long-term consequences of conversion have not been adequately examined.

METHODS

Patients with pancreatic adenocarcinoma undergoing MIDP were selected from the National Cancer Database (2010-2015) and subdivided based on the occurrence of unplanned conversion. Post-operative outcomes and overall survival (OS) were examined. Conversion was additionally compared to a matched group of planned open resections.

RESULTS

Among 592 patients undergoing attempted MIDP, unplanned conversion occurred in 23.1%. Despite increased 90-day mortality among patients experiencing conversion, there was no difference in median OS between groups (25.0 vs 27.8 months, p = 0.095). For patients undergoing conversion, post-operative outcomes and long-term survival were similar when compared to a propensity-matched group of patients undergoing planned open resection. On multivariable analysis, treatment at an academic facility (OR 0.63) and a robotic approach (OR 0.50) were both significantly associated with completed MIDP.

CONCLUSION

Despite inferior post-operative outcomes compared to successful MIDP, unplanned conversion did not result in significantly reduced long term survival. MIDP can be attempted selectively but treatment at experienced centers via a robotic approach should be considered.

Practical implications of tumor proximity to landmark vessels in minimally invasive radical antegrade modular pancreatosplenectomy

Careful preoperative planning is key in minimally invasive radical antegrade modular pancreatosplenectomy (MI-RAMPS). This retrospective study aims to show the practical implications of computed tomography distance between the right margin of the tumor and either the left margin of the spleno-mesenteric confluence (d-SMC) or the gastroduodenal artery (d-GDA). Between January 2011 and June 2022, 48 minimally invasive RAMPS were performed for either pancreatic cancer or malignant intraductal mucinous papillary neoplasms. Two procedures were converted to open surgery (4.3%). Mean tumor size was 31.1 ± 14.7 mm. Mean d-SMC was 21.5 ± 18.5 mm. Mean d-GDA was 41.2 ± 23.2 mm. A vein resection was performed in 10 patients (20.8%) and the pancreatic neck could not be divided by an endoscopic stapler in 19 operations (43.1%). In patients requiring a vein resection, mean d-SMC was 10 mm (1.5-15.5) compared to 18 mm (10-37) in those without vein resection (p = 0.01). The cut-off of d-SMC to perform a vein resection was 17 mm (AUC 0.75). Mean d-GDA was 26 mm (19-39) mm when an endoscopic stapler could not be used to divide the pancreas, and 46 mm (30-65) when the neck of the pancreas was stapled (p = 0.01). The cut-off of d-GDA to safely pass an endoscopic stapler behind the neck of the pancreas was 43 mm (AUC 0.75). Computed tomography d-SMC and d-GDA are key measurements when planning for MI-RAMPS.

Safety and Feasibility of Laparoscopic Right or Extended Right Hemi Hepatectomy Following Modulation of the Future Liver Remnant in Patients with Colorectal Liver Metastases: A Systematic Review

Background: Major hepatectomies after future liver remnant (FLR) modulation are technically demanding procedures, especially when performed as minimally invasive surgery. The aim of this systematic review is to assess current evidence regarding the safety and feasibility of laparoscopic right or extended right hemihepatectomies after FLR modulation. Materials and Methods: The Medline, PubMed, Cochrane Library, and Embase databases were searched for studies involving laparoscopic right or extended right hemihepatectomies after FLR modulation, from their inception to December 2021. Two reviewers independently selected eligible articles and assessed their quality using the Newcastle-Ottawa Quality Assessment Scale (NOS). Baseline characteristics and outcomes were extracted from the included studies and summarized. Results: Six studies were included. In these studies, the median length of stay after the second stage ranged from 4.5 to 15.5 days and postoperative complication rates between 4.5% and 42.8%. Overall, 7.4% of patients developed liver failure, and 90-day mortality occurred in 3.2% of patients. The R0 resection rate was 93.5%. Only one study reported long-term outcomes, describing comparable 3-year overall survival rates following laparoscopic and open surgery (80% versus 54%, P = .154). Conclusions: The current evidence is scarce, but it suggests that in experienced centers, laparoscopic right or extended right hemihepatectomy, following FLR modulation, is a safe and feasible procedure.

Robot-Assisted Versus Laparoscopic Distal Pancreatectomy in Patients with Resectable Pancreatic Cancer: An International, Retrospective, Cohort Study

BACKGROUND

Robot-assisted distal pancreatectomy (RDP) is increasingly used as an alternative to laparoscopic distal pancreatectomy (LDP) in patients with resectable pancreatic cancer but comparative multicenter studies confirming the safety and efficacy of RDP are lacking.

METHODS

An international, multicenter, retrospective, cohort study, including consecutive patients undergoing RDP and LDP for resectable pancreatic cancer in 33 experienced centers from 11 countries (2010-2019). The primary outcome was R0-resection. Secondary outcomes included lymph node yield, major complications, conversion rate, and overall survival.

RESULTS

In total, 542 patients after minimally invasive distal pancreatectomy were included: 103 RDP (19%) and 439 LDP (81%). The R0-resection rate was comparable (75.7% RDP vs. 69.3% LDP, p = 0.404). RDP was associated with longer operative time (290 vs. 240 min, p < 0.001), more vascular resections (7.6% vs. 2.7%, p = 0.030), lower conversion rate (4.9% vs. 17.3%, p = 0.001), more major complications (26.2% vs. 16.3%, p = 0.019), improved lymph node yield (18 vs. 16, p = 0.021), and longer hospital stay (10 vs. 8 days, p = 0.001). The 90-day mortality (1.9% vs. 0.7%, p = 0.268) and overall survival (median 28 vs. 31 months, p = 0.599) did not differ significantly between RDP and LDP, respectively.

CONCLUSIONS

In selected patients with resectable pancreatic cancer, RDP and LDP provide a comparable R0-resection rate and overall survival in experienced centers. Although the lymph node yield and conversion rate appeared favorable after RDP, LDP was associated with shorter operating time, less major complications, and shorter hospital stay. The specific benefits associated with each approach should be confirmed by multicenter, randomized trials.

Tips and tricks for robotic pancreatoduodenectomy with superior mesenteric/portal vein resection and reconstruction

BACKGROUND

Open pancreatoduodenectomy with vein resection (OPD-VR) is now standard of care in patients who responded to neoadjuvant therapies. Feasibility of robotic pancreatoduodenectomy (RPD) with vein resection (RPD-VR) was shown, but no study provided a detailed description of the technical challenges associated with this formidable operation. Herein, we describe the trips and tricks for technically successful RPD-VR.

METHODS

The vascular techniques used in RPD-VR were borrowed from OPD-VR, as well as from our experience with robotic transplantation of both kidney and pancreas. Vein resection was classified into 4 types according to the international study group of pancreatic surgery. Each type of vein resection was described in detail and shown in a video.

RESULTS

Between October 2008 and November 2021, a total of 783 pancreatoduodenectomies were performed, including 233 OPDs-VR (29.7%). RPD was performed in 256 patients (32.6%), and RPDs-VR in 36 patients (4.5% of all pancreatoduodenectomies; 15.4% of all pancreatoduodenectomies with vein resection; 14.0% of all RPDs). In RPD-VR vein resections were: 4 type 1 (11.1%), 10 type 2 (27.8%), 12 type 3 (33.3%) and 10 type 4 (27.8%). Vascular patches used in type 2 resections were made of peritoneum (n = 8), greater saphenous vein (n = 1), and deceased donor aorta (n = 1). Interposition grafts used in type 4 resections were internal left jugular vein (n = 8), venous graft from deceased donor (n = 1) and spiral saphenous vein graft (n = 1). There was one conversion to open surgery (2.8%). Ninety-day mortality was 8.3%. There was one (2.8%) partial vein thrombosis, treated with heparin infusion.

CONCLUSIONS

We have reported 36 technically successful RPDs-VR. We hope that the tips and tricks provided herein can contribute to safer implementation of RPD-VR. Based on our experience, and according to data from the literature, we strongly advise that RPD-VR is performed by expert surgeons at high volume centers.

The effect of minimally invasive or open radical antegrade modular pancreatosplenectomy on pancreatic cancer: A multicenter randomized clinical trial protocol

Background

Radical antegrade modular pancreatosplenectomy (RAMPS) has been proven to improve R0 resection and lymph harvest in treating patients with distal pancreatic cancer. The development of minimally invasive surgery has advantages in postoperative recovery. Therefore, minimally invasive (MI-) RAMPS may combine the advantages of both benefits to improve survival. Nevertheless, evidence to validate the safety and efficacy of MI-RAMPS is limited.

Method/Design

The MIRROR trial will be the first multicenter prospective randomized clinical trial to investigate the outcome of MI-RAMPS. The hypothesis is that MI-RAMPS is superior in postoperative recovery. The primary outcome is the length of postoperative stay. Based on the hypothesis and primary outcome, the sample size is 250 patients (125 participants in each group). The trial will investigate factors related to surgical safety, short-term outcome, pathological assessment, and survival as secondary outcomes.

Conclusion

This study will offer a relatively higher level of evidence to further illustrate the accessibility and benefits of MI-RAMPS for the treatment of distal pancreatic cancer.

Clinical Trial Registration

Clinicaltrials.gov, NCT03770559.

What Is the Current Role and What Are the Prospects of the Robotic Approach in Liver Surgery?

Simple Summary

Robotic liver surgery is being applied with increasing frequency. Comparable, and in specific settings superior, perioperative outcomes compared to laparoscopic liver surgery have been reported. In its current form, the most commonly mentioned advantage of robotic surgery is improved dexterity. Important obstacles to its wider implementation in daily clinical practice are the associated costs, technical difficulties, and a scarce amount of evidence. Robotic liver surgery will likely continue to evolve in parallel with technological developments that enhance the robots’ abilities.

Abstract

In parallel with the historical development of minimally invasive surgery, the laparoscopic and robotic approaches are now frequently utilized to perform major abdominal surgical procedures. Nevertheless, the role of the robotic approach in liver surgery is still controversial, and a standardized, safe technique has not been defined yet. This review aims to summarize the currently available evidence and prospects of robotic liver surgery. Minimally invasive liver surgery has been extensively associated with benefits, in terms of less blood loss, and lower complication rates, including liver-specific complications such as clinically relevant bile leakage and post hepatectomy liver failure, when compared to open liver surgery. Furthermore, comparable R0 resection rates to open liver surgery have been reported, thus, demonstrating the safety and oncological efficiency of the minimally invasive approach. However, whether robotic liver surgery has merits over laparoscopic liver surgery is still a matter of debate. In the current literature, robotic liver surgery has mainly been associated with non-inferior outcomes compared to laparoscopy, although it is suggested that the robotic approach has a shorter learning curve, lower conversion rates, and less intraoperative blood loss. Robotic surgical systems offer a more realistic image with integrated 3D systems. In addition, the improved dexterity offered by robotic surgical systems can lead to improved intra and postoperative outcomes. In the future, integrated and improved haptic feedback mechanisms, artificial intelligence, and the introduction of more liver-specific dissectors will likely be implemented, further enhancing the robots’ abilities.

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

PURPOSE

Recent studies have reported worse outcomes of converted laparoscopic distal pancreatectomy (CLDP) with respect to total laparoscopic (TLDP) and open (ODP). The aim of the study was to evaluate the impact of conversion on patient outcome and on total cost.

METHODS

Patients requiring a conversion (CLDP) were compared with both TLDP and ODP patients. The relevant patient- and tumour-related variables were collected for each patient. Both intra and postoperative data were extracted. Propensity score matching (PSM) analysis was carried out to equate the groups compared.

RESULTS

Two hundred and five patients underwent DP, 105 (51.2%) ODPs, 81 (39.5%) TLDPs, and 19 (9.3%) CLDPs. After PSM, 19 CLDPs, 38 TLDPs, and 38 ODPs were compared. Patients who underwent CLDP showed a significantly longer operative time (P < 0.001), and an increase in blood loss (P = 0.032) and total cost (P = 0.034) with respect to TLDP, and a significantly longer operative time (P < 0.001), less frequent postoperative morbidity (P = 0.050), and a higher readmission rate (P = 0.035) with respect to ODP.

CONCLUSION

Total laparoscopic pancreatectomy was superior regarding operative findings and total costs with respect to CLDP; ODP showed a higher postoperative morbidity rate and a lower readmission rate with respect to CLDP. However, the reasons for the readmission of patients who underwent CLDP were mainly related to postoperative pancreatic fistula (POPF) grade B which is usually due to pancreas texture. Thus, the majority of distal pancreatectomies can be started using a minimally invasive approach, performing an early conversion if necessary.

Minimally invasive distal pancreatectomy: Chronologic changes in the trends and clinical outcomes through a 15-year, single-center experience with 2212 patients

BACKGROUND

We identified the chronologic changes in the clinical outcomes of minimally invasive distal pancreatectomy (MIDP) for left-sided pancreatic tumors in a single high-volume center over a period of 15 years.

METHODS

Between 2005 and 2019, 2212 patients underwent planned MIDP. Chronologic changes were analyzed according to 5-year intervals (P1, P2, P3). Furthermore, we assessed the prognostic factors of open conversion and postoperative complications.

RESULTS

MIDP has steadily increased during the last 15 years when compared to open distal pancreatectomy, from 10.8% to 84.9%. Also, MIDP for pancreatic ductal adenocarcinoma (PDAC) has been steadily increasing from 5.6% to 68.4%. According to the 5-year intervals, lengths of hospital stay decreased, but age and American Society of Anesthesiologists (ASA) ≥3 increased; conversely, the rates of Clavien-Dindo classification ≥grade 3 (9.5%) and postoperative pancreatic fistula (39.7%) showed no differences. The 90-day mortality and open conversion rates were 0.2% and 3.5%, respectively. Multivariate logistic regression analysis revealed malignancy and extended pancreatectomy were risk factors for open conversion. Furthermore, the poor prognostic factors for severe complications were malignancy, extended pancreatectomy, and ASA ≥3.

CONCLUSION

MIDP has become a popular procedure not only for benign cases but also for malignant ones. However, well-organized training, experience and skill are necessary, especially for poor-performance patients and extensively malignant conditions.

Adverse Impact of Intraoperative Conversion on the Postoperative Course Following Laparoscopic Pancreaticoduodenectomy

PURPOSE

The aim of the current study was to evaluate the adverse clinical impact of intraoperative conversion during laparoscopic pancreaticoduodenectomy (LPD).

MATERIALS AND METHODS

The medical records of patients who underwent pancreaticoduodenectomy (PD) were retrospectively reviewed. Perioperative clinical variables were compared between patients who underwent converted PD (cPD) and initially planned open PD (OPD) to investigate the clinical impact and predictive factors of intraoperative conversion during LPD.

RESULTS

A total of 171 patients were included. Among them, 31 patients (19.3%) were found to have intraoperative conversion during LPD. Failure of progression due to severe adhesion (12 patients, 7%) and major vessel invasion (7 patients, 4%) were the two most frequent reasons for conversion. On multivariate analysis, age [Exp(β)=1.044, p=0.044] and pancreatic texture [Expa(β)=2.431, p=0.039) were found to be independent factors for predicting intraoperative conversion during LPD. In comparative analysis with the OPD group, the cPD group had a longer operation time (516.8 min vs. 449.9 min, p=0.001), higher rate of postoperative hemorrhage (12.1% vs. 0.85%, p=0.008), higher reoperation rate (9.1% vs. 0%, p=0.01), and higher cost (21886.4 USD vs. 17168.9 USD, p=0.018).

CONCLUSION

Intraoperative conversion during LPD can have an adverse clinical impact on the postoperative course following LPD. Appropriate patients selection and improvement of surgical techniques will be crucial for unnecessary intraoperative conversion and safe LPD.

Assessment of difficulty in laparoscopic distal pancreatectomy: A modification of the Japanese difficulty scoring system - A single-center high-volume experience

Background

The Japanese difficulty scoring system (DSS) was developed to assess the difficulty of laparoscopic distal pancreatectomy (LDP). The study aimed to validate a modified DSS (mDSS) in a European high‐volume center.

Methods

Patients' clinical data underwent LDP for benign and malignant pancreatic lesion between September 2013 and February 2020 were reviewed. Expert laparoscopic surgeons performed the procedures. The mDSS consisted of seven variables, such as type of operation, malignancy, neoadjuvant therapy, pancreatic resection line, tumor close to major vessels, tumor extension to peripancreatic tissue, and left‐sided portal hypertension and/or splenomegaly. According to the difficulty level and previous score, the mDSS was subdivided into three classes: low, intermediate, and high. Surrogates of case complexity (operative time, intraoperative blood loss and blood transfusion requirements, conversion rate) were used to validate the new scoring system.

Results

The study population included 140 LDP. Ninety‐five (68%), 35 (25%) and 10 (7%) patients belonged to low, intermediate, and high difficulty groups. The mDSS identified the complexity of the surgical case of the series for all the surrogates of complexity considered, namely conversion rate (P = .004), operative time (P = .033) and intraoperative blood loss (P = .009). No differences were recorded in the postoperative outcomes (P > .05).

Conclusion

The mDSS for LDP better stratified the pancreatic procedures according to their complexity. The new scoring system may allow an appropriate preoperative evaluation of surgical difficulty, facilitating LDP's training program. Future prospective studies are needed to validate the mDSS.

Robotic versus laparoscopic distal pancreatectomy: multicentre analysis

BACKGROUND

The role of minimally invasive distal pancreatectomy is still unclear, and whether robotic distal pancreatectomy (RDP) offers benefits over laparoscopic distal pancreatectomy (LDP) is unknown because large multicentre studies are lacking. This study compared perioperative outcomes between RDP and LDP.

METHODS

A multicentre international propensity score-matched study included patients who underwent RDP or LDP for any indication in 21 European centres from six countries that performed at least 15 distal pancreatectomies annually (January 2011 to June 2019). Propensity score matching was based on preoperative characteristics in a 1 : 1 ratio. The primary outcome was the major morbidity rate (Clavien-Dindo grade IIIa or above).

RESULTS

A total of 1551 patients (407 RDP and 1144 LDP) were included in the study. Some 402 patients who had RDP were matched with 402 who underwent LDP. After matching, there was no difference between RDP and LDP groups in rates of major morbidity (14.2 versus 16.5 per cent respectively; P = 0.378), postoperative pancreatic fistula grade B/C (24.6 versus 26.5 per cent; P = 0.543) or 90-day mortality (0.5 versus 1.3 per cent; P = 0.268). RDP was associated with a longer duration of surgery than LDP (median 285 (i.q.r. 225-350) versus 240 (195-300) min respectively; P < 0.001), lower conversion rate (6.7 versus 15.2 per cent; P < 0.001), higher spleen preservation rate (81.4 versus 62.9 per cent; P = 0.001), longer hospital stay (median 8.5 (i.q.r. 7-12) versus 7 (6-10) days; P < 0.001) and lower readmission rate (11.0 versus 18.2 per cent; P = 0.004).

CONCLUSION

The major morbidity rate was comparable between RDP and LDP. RDP was associated with improved rates of conversion, spleen preservation and readmission, to the detriment of longer duration of surgery and hospital stay.

Essential updates 2018/2019: Current topics in the surgical treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant. While cancers in other organs have shown clear improvements in 5-year survival, the 5-year survival rate of pancreatic cancer is approximately 10%. Early relapse and metastasis are not uncommon, making it difficult to achieve an acceptable prognosis even after complete surgical resection of the pancreas. Studies have been performed on various treatments to improve the prognosis of PDAC, and multidisciplinary approaches including non-surgical treatments have led to gradual improvement. In the present literature review, we have described the significance of anatomical and biological resectability criteria, the concept of R0 resection in surgical treatment, the feasibility of minimally invasive surgery, the remarkable development of perioperative chemotherapy, the effectiveness of conversion surgery for unresectable PDAC, and ongoing challenges in PDAC treatment. We also provide an essential update on these subjects by focusing on recent trends and topics.

Risk factors and outcomes of conversion in minimally invasive distal pancreatectomy: a systematic review

Purpose

The reported conversion rates for minimally invasive distal pancreatectomy (MIDP) range widely from 2 to 38%. The identification of risk factors for conversion may help surgeons during preoperative planning and patient counseling. Moreover, the impact of conversion on outcomes of MIDP is unknown.

Methods

A systematic review was conducted as part of the 2019 Miami International Evidence-Based Guidelines on Minimally Invasive Pancreas Resection (IG-MIPR). The PubMed, Cochrane, and Embase databases were searched for studies concerning conversion to open surgery in MIDP.

Results

Of the 828 studies screened, eight met the eligibility criteria, resulting in a combined dataset including 2592 patients after MIDP. The overall conversion rate was 17.1% (range 13.0–32.7%) with heterogeneity between studies associated with the definition of conversion adopted. Only one study divided conversion into elective and emergency conversion. The main indications for conversion were vascular involvement (23.7%), concern for oncological radicality (21.9%), and bleeding (18.9%). The reported risk factors for conversion included a malignancy as an indication for surgery, the proximity of the tumor to vascular structures in preoperative imaging, higher BMI or visceral fat, and multi-organ resection or extended resection. Contrasting results were seen in terms of blood loss and length of stay in comparing converted MIDP and completed MIDP patients.

Conclusion

The identified risk factors for conversion from this study can be used for patient selection and counseling. Surgeon experience should be considered when contemplating MIDP for a complex patient. Future studies should divide conversion into elective and emergency conversion.

The Usefulness of a Preoperative Nomogram for Predicting the Probability of Conversion from Laparoscopic to Open Distal Pancreatectomy: A Single-Center Experience

Background

Laparoscopic distal pancreatectomy (LDP) represents a challenging procedure with a high conversion rate. A nomogram is a simple statistical predictive tool which is superior to risk groups. The aim of this study was to develop and validate a preoperative nomogram for predicting the probability of conversion from laparoscopic to open distal pancreatectomy.

Methods

This is a retrospective study of 100 consecutive patients who underwent LDP. For each patient demographic, pre-intra- and postoperative data were collected. Univariate and multivariate analyses were carried out to identify the factors significantly influencing the conversion rate. The effect of each factor was weighted using the beta coefficient (β), and a nomogram was built. Finally, a logistic regression between the score and the conversion rate was carried out to calibrate the nomogram.

Results

The conversion rate was 19.0%. At multivariate analysis, female (β =  − 1.8 ± 0.9; P = 0.047) and tail location of the tumor (β =  − 2.1 ± 1.1; P = 0.050) were significantly related to a low probability of conversion. Body mass index (BMI) (β = 0.2 ± 0.1; P = 0.011) and subtotal pancreatectomy (β = 2.4 ± 0.9; P = 0.006) were factors independently related to a high probability of conversion. The nomogram constructed had a minimum value of 4 and a maximum value of 18 points. The probability of conversion increased significantly starting from a minimum score of 6 points (P = 0.029; conversion probability 14.4%; 95%CI, 1.5–27.3%) up to 16 (P = 0.048; 27.8%; 95%CI, 0.2–48.7%).

Conclusion

The nomogram proposed could serve as an effective preoperative tool capable of assessing the probability of conversion, allowing to take reliable decisions regarding indications and adequate stepwise training program of LDP.