Splenic artery as a simple landmark indicating difficulty during laparoscopic distal pancreatectomy

Identifying the preoperative factors predicting the surgical difficulty of robotic distal pancreatectomy

BACKGROUND

Few studies have evaluated the preoperative factors predicting the surgical difficulty of robotic distal pancreatectomy (RDP). This study aims to explore such factors and provide guidance on the selection of suitable patients to aid surgeons lacking extensive experience in RDP.

METHODS

A retrospective study was conducted on consecutive patients who underwent RDP to identify preoperative factors predicting surgical difficulty. High surgical difficulty was defined by both operation time and intraoperative estimated blood loss exceeding their median, or by conversion to laparotomy.

RESULTS

A total of 161 patients were ultimately enrolled, including 51 patients with high levels of surgical difficulty. Multivariate analysis revealed that male sex [OR (95% CI): 4.07 (1.77,9.40), p = 0.001], body mass index (BMI) ≥ 25 kg/m² OR (95% CI): 2.27 (1.03,5.00), p = 0.042], tumors located at the neck of the pancreas [OR (95% CI): 4.15 (1.49,11.56), p = 0.006] and splenic artery type B [OR (95% CI): 3.28 (1.09,9.91), p = 0.035] were independent risk factors for surgical difficulty. Regarding postoperative complications, high surgical difficulty was associated with the risk of overall complications and pancreatic fistula (grade B/C) (49.0% vs. 22.7%, p < 0.001; 39.2% vs. 19.1%, p = 0.006).

CONCLUSION

Male sex, body mass index ≥ 25 kg/m2, tumor located at the neck of the pancreas and splenic artery type B are associated with a high RDP difficulty level. These factors can be used preoperatively to assess the difficulty level of surgery, to help surgeons choose patients suitable for them and ensure surgical safety.

Laparoscopic Radical Antegrade Modular Pancreatosplenectomy with Anterocranial Splenic Artery-First Approach for Left-Sided Resectable Pancreatic Cancer (with Videos)

BACKGROUND

Laparoscopic radical antegrade modular pancreatosplenectomy (Lap-RAMPS) for left-sided pancreatic cancer remains a technically challenging procedure. How to approach the splenic artery in laparoscopic surgery has not been discussed in adequate detail, and the implications of an artery-first approach in left-sided pancreatic cancer remain unclear.

PATIENTS AND METHODS

Forty-five consecutive patients with left-sided resectable pancreatic cancer underwent Lap-RAMPS between July 2018 and September 2020. They were divided according to whether Lap-RAMPS was performed using an anterocranial splenic artery-first (ASF) approach (ASF group, n = 23) or via another approach (non-ASF group, n = 22). Clinical, pathological, and short-term outcomes were reviewed and compared between the groups.

RESULTS

The ASF approach was performed safely in all patients with resectable left-sided pancreatic cancer, and none required conversion to laparotomy. The ASF group had better outcomes in terms of conspicuous bleeding from the spleen during splenic mobilization (P = 0.016) and blood pooling during posterior dissection (P = 0.035). Consequently, blood loss was significantly less and operation time was significantly shorter in the ASF group than in the non-ASF group. There was no significant between-group difference in other short-term outcomes, including mortality, length of hospital stay, or Clavien-Dindo classification.

CONCLUSIONS

The ASF approach was safe when performed for resectable left-sided pancreatic cancer and may help to prevent congestion of the pancreas and lessen intraoperative blood loss.

International Expert Consensus on Precision Anatomy for minimally invasive distal pancreatectomy: PAM-HBP Surgery Project

BACKGROUND

Surgical views with high resolution and magnification have enabled us to recognize the precise anatomical structures that can be used as landmarks during minimally invasive distal pancreatectomy (MIDP). This study aimed to validate the usefulness of anatomy-based approaches for MIDP before and during the Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (February 24, 2021).

METHODS

Twenty-five international MIDP experts developed clinical questions regarding surgical anatomy and approaches for MIDP. Studies identified via a comprehensive literature search were classified using Scottish Intercollegiate Guidelines Network methodology. Online Delphi voting was conducted after experts had drafted the recommendations, with the goal of obtaining >75% consensus. Experts discussed the revised recommendations in front of the validation committee and an international audience of 384 attendees. Finalized recommendations were made after a second round of online Delphi voting.

RESULTS

Four clinical questions were addressed, resulting in 10 recommendations. All recommendations reached at least a 75% consensus among experts.

CONCLUSIONS

The expert consensus on precision anatomy for MIDP has been presented as a set of recommendations based on available evidence and expert opinions. These recommendations should guide experts and trainees in performing safe MIDP and foster its appropriate dissemination worldwide.

Laparoscopic distal pancreatectomy in a patient with aberrant splenic artery originating from the superior mesenteric artery: A case report

RATIONALE

Splenic artery originating from the superior mesenteric artery is extremely rare. Because of this, its significance in laparoscopic distal pancreatectomy has never been reported. Here, we present the first case of laparoscopic distal pancreatectomy in a patient with a splenic artery arising from the superior mesenteric artery.

PATIENT CONCERNS

A 46-year-old Japanese woman with type 2 diabetes mellitus presented with worsening glycemic control. Abdominal ultrasonography revealed a pancreatic tail mass.

DIAGNOSES

The patient was diagnosed with pancreatic neuroendocrine tumor by endoscopic ultrasound-guided fine needle aspiration. Preoperative computed tomography showed that the splenic artery with branches of dorsal pancreatic artery originated from the superior mesenteric artery.

INTERVENTIONS

The patient underwent laparoscopic distal pancreatectomy. Prior to pancreatectomy, the splenic artery and its dorsal pancreatic branches were clamped using the superior and inferior approaches, respectively, to avoid bleeding and congestion.

OUTCOMES

The postoperative course was uneventful.

LESSONS

Preoperative evaluation of anatomical variants and development of strategies are important to avoid intraoperative complications in pancreatic surgery. Our results revealed that laparoscopic distal pancreatectomy can be performed safely by strategic approach even in a patient with a rare aberrant splenic artery.

Evaluation of relationship between splenic artery and pancreatic parenchyma using three-dimensional computed tomography for laparoscopic distal pancreatectomy

AIM

Isolating the root of the splenic artery (SPA) is a challenging procedure in laparoscopic distal pancreatectomy (LDP). We investigated the usefulness of evaluation of the relationship between the SPA and pancreatic parenchyma using three-dimensional computed tomography (3D-CT).

METHODS

In total, 104 patients were evaluated. The relationship between the SPA and pancreatic parenchyma was classified into two types: buried and non-buried. Video clips of 50 patients who underwent LDP requiring isolation of the SPA root were reviewed to determine whether the classification is related to difficulty of LDP.

RESULTS

Of the 50 assessed patients who underwent LDP, the relationship between the SPA and pancreatic parenchyma was the buried type in 30 (60.0%) and non-buried type in 20 (40.0%). The buried type was associated with a significantly longer median operative time than the non-buried type (285.0 vs. 235.5 min, respectively; P < 0.01). The median time required to isolate the SPA in the buried type (25.8 min; range, 4.0-101 min) was significantly longer than that in the non-buried type (7.0 min; range, 1.0-27.0 min) (P < 0.001).

CONCLUSION

Preoperative 3D-CT around the pancreas is practical for predicting the difficulty of SPA isolation and determining the safety of the procedure.

Surgical approaches for minimally invasive distal pancreatectomy: A systematic review

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP) was initially performed for benign tumors, but recently its indications have steadily broadened to encompass other conditions including pancreatic malignancies. Thorough anatomical knowledge is mandatory for precise surgery in the era of minimally invasive surgery. However, expert consensus regarding anatomical landmarks to facilitate the safe performance of MIDP is still lacking.

METHODS

A systematic literature search was performed using keywords to identify articles regarding the vascular anatomy and surgical approaches/techniques for MIDP.

RESULTS

All of the systematic reviews revealed that MIDP was not associated with an increase in postoperative complications. Moreover, most showed that MIDP resulted in less blood loss than open surgery. Regarding surgical approaches for MIDP, a standardized stepwise procedure improved surgical outcomes, including blood loss, operative time, and major complications. There are two approaches to the splenic vessels, superior and inferior; however, no study has ever directly compared them with respect to clinical outcomes. The morphology of the splenic artery affects the difficulty of approaching the artery's root. To select an appropriate dissecting layer when performing posterior resection, thorough knowledge of the anatomy of the fascia, left renal vein/artery, and left adrenal gland is needed.

CONCLUSIONS

In MIDP, a standardized approach and precise knowledge of anatomy facilitates safe surgery and has the advantage of a shorter learning curve. Anatomical features and landmarks are particularly important in cases of radical MIDP and splenic vessel preserving MIDP.

Precision vascular anatomy for minimally invasive distal pancreatectomy: A systematic review

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP) is increasingly performed worldwide; however, the surgical anatomy required to safely perform MIDP has not yet been fully considered. This review evaluated the literature concerning peripancreatic vascular anatomy, which is considered important to conduct safe MIDP.

METHODS

A database search of PubMed and Ichushi (Japanese) was conducted. Qualified studies investigating the anatomical variations of peripancreatic vessels related to MIDP were evaluated using SIGN methodology.

RESULTS

Of 701 articles yielded by our search strategy, 76 articles were assessed in this systematic review. The important vascular anatomy required to recognize MIDP included the pancreatic parenchymal coverage on the root and the running course of the splenic artery, branching patterns of the splenic artery, confluence positions of the left gastric vein and the inferior mesenteric vein, forms of pancreatic veins including the centro-inferior pancreatic vein, characteristics of the left renal vein, and collateral routes perfusing the spleen following Warshaw's technique. Very few articles evaluating the relationship between the anatomical variations and surgical outcomes of MIDP were found.

CONCLUSIONS

The precise knowledge of peripancreatic vessels is important to adequately complete MIDP. More detailed anatomic analyses and descriptions will benefit surgeons and their patients who are facing these operations.

Morphometric analysis of the splenic artery using contrast-enhanced computed tomography (CT)

PURPOSE

To evaluate the morphology and course of the splenic artery, which might impact the surgical implantation of systems that stimulate the nerves surrounding the splenic artery. Experimental studies indicate that these nerves play an important part in immune modulation, and might be a potential target in the treatment of autoimmune diseases.

METHODS

This retrospective cohort study made use of contrast-enhanced CT images from 40 male and 40 female patients (age 30-69) that underwent a CT examination of the aorta, kidneys or pancreas. Anatomic features were described including total splenic artery length, calibers, tortuosity, the presence of arterial loops and the branching pattern of the splenic artery.

RESULTS

No age-gender-related differences could be found related to tortuosity or branching pattern. The length of splenic artery in contact with pancreatic tissue decreased with increasing age, but was not different between genders. Artery diameters were wider in male compared to female subjects. Loops of variable directions, that represent a part of the artery that curls out of the pancreatic tissue, were identified in each age-gender category and were present in nearly all subjects (86%).

CONCLUSION

This study suggests that although some anatomic features of the splenic artery are subject to factors as age and gender, the tortuosity of the splenic artery is not age dependent. Most subjects had one or multiple loops, which can serve as a target for neuromodulatory devices. Future studies should investigate whether splenic nerve stimulation is safe and feasible.

Vascular anatomy of the splenic flexure, focusing on the accessory middle colic artery and vein

AIM

Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV).

METHOD

Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas - below the pancreas or to the dorsal side of the pancreas.

RESULTS

The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients.

CONCLUSION

The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left-sided hemicolectomy.

Prediction of the Probability of Malignancy in Mucinous Cystic Neoplasm of the Pancreas With Ovarian-Type Stroma: A Nationwide Multicenter Study in Japan

OBJECTIVE

The aim of the study was to develop a formula for predicting the probability of malignancy of mucinous cystic neoplasm (MCN) of the pancreas with ovarian-type stroma.

METHODS

A total of 364 patients were enrolled. A total score was calculated as the sum of the approximate integers of the odds ratios of the predictive factors identified by multivariate analysis. The relationship between the total score and pathological results was assessed.

RESULTS

A total of 321 patients had benign MCN and 43 had malignant MCN. Five possible predictive factors were analyzed: 56 years or older, high serum carcinoembryonic antigen level, high carbohydrate antigen 19-9 level, tumor size of 51 mm or greater, and the presence of mural nodules. The total score was significantly higher in patients with malignant MCN (median, 24; range, 0-37) compared with benign MCN (median, 5; range, 0-33; P < 0.001). Receiver operating characteristic curve analysis demonstrated that the area under the curve was 0.86, and the sensitivity and specificity of the total score for discriminating malignant MCNs were 72% and 83%, respectively, using a cut-off value of 22.

CONCLUSIONS

The current simple formula can predict the malignancy of MCN and may thus contribute to the adequate management of patients with MCN.

A multicenter prospective registration study on laparoscopic pancreatectomy in Japan: report on the assessment of 1,429 patients

BACKGROUND

Prospective studies are needed to understand the safety and feasibility of laparoscopic pancreatectomy. The aim of the present study was to describe laparoscopic pancreatectomy currently undertaken in Japan, using a prospective registration system.

METHODS

Patient characteristics and planned operations were registered preoperatively, and then the performed operation and outcomes were reported using an online system. Collected data were also compared between institutions based on their level of experience. This study was registered with UMIN000022836.

RESULTS

Available data were obtained from 1,429 patients at 100 Japanese institutions, including 1,197 laparoscopic distal pancreatectomies (LDPs) and 232 laparoscopic pancreatoduodenectomies (LPDs). The rates of completion for planned operations were 92% for LDP and 91% for LPD. Postoperative complication rates after LDP and LPD were 17% and 30%, and 90-day mortality rates were 0.3% and 0.4%, respectively. Shorter operation time, less blood loss, and lower incidence of pancreatic fistula were observed in institutions experienced in LDP. A higher rate of pure laparoscopic procedure and shorter operation time were noted in institutions experienced with LPD.

CONCLUSION

LDPs and LPDs are performed safely in Japan, especially in experienced institutions. Our data could support the next challenges in the field of laparoscopic pancreatectomy.

Difficulty scoring system in laparoscopic distal pancreatectomy

BACKGROUND

Several factors affect the level of difficulty of laparoscopic distal pancreatectomy (LDP). The purpose of this study was to develop a difficulty scoring (DS) system to quantify the degree of difficulty in LDP.

METHODS

We collected clinical data for 80 patients who underwent LDP. A 10-level difficulty index was developed and subcategorized into a three-level difficulty index; 1-3 as low, 4-6 as intermediate, and 7-10 as high index. The automatic linear modeling (LINEAR) statistical tool was used to identify factors that significantly increase level of difficulty in LDP.

RESULTS

The operator's 10-level DS concordance between the 10-level DS by the reviewers, LINEAR index DS, and clinical index DS systems were analyzed, and the weighted Cohen's kappa statistic were at 0.869, 0.729, and 0.648, respectively, showing good to excellent inter-rater agreement. We identified five factors significantly affecting level of difficulty in LDP; type of operation, resection line, proximity of tumor to major vessel, tumor extension to peripancreatic tissue, and left-sided portal hypertension/splenomegaly.

CONCLUSIONS

This novel DS for LDP adequately quantified the degree of difficulty, and can be useful for selecting patients for LDP, in conjunction with fitness for surgery and prognosis.