The TRIANGLE operation for pancreatic head and body cancers: early postoperative outcomes

TRIANGLE operation, combined with adequate adjuvant chemotherapy, can improve the prognosis of pancreatic head cancer: A retrospective study

BACKGROUND

The TRIANGLE operation involves the removal of all tissues within the triangle bounded by the portal vein-superior mesenteric vein, celiac axis-common hepatic artery, and superior mesenteric artery to improve patient prognosis. Although previously promising in patients with locally advanced pancreatic ductal adenocarcinoma (PDAC), data are limited regarding the long-term oncological outcomes of the TRIANGLE operation among resectable PDAC patients undergoing pancreaticoduodenectomy (PD).

AIM

To evaluate the safety of the TRIANGLE operation during PD and the prognosis in patients with resectable PDAC.

METHODS

This retrospective cohort study included patients who underwent PD for pancreatic head cancer between January 2017 and April 2023, with or without the TRIANGLE operation. Patients were divided into the PDTRIANGLE and PDnon-TRIANGLE groups. Surgical and survival outcomes were compared between the two groups. Adequate adjuvant chemotherapy was defined as adjuvant chemotherapy ≥ 6 months.

RESULTS

The PDTRIANGLE and PDnon-TRIANGLE groups included 52 and 55 patients, respectively. There were no significant differences in the baseline characteristics or perioperative indexes between the two groups. Furthermore, the recurrence rate was lower in the PDTRIANGLE group than in the PDnon-TRIANGLE group (48.1% vs 81.8%, P < 0.001), and the local recurrence rate of PDAC decreased from 37.8% to 16.0%. Multivariate Cox regression analysis revealed that PDTRIANGLE (HR = 0.424; 95%CI: 0.256-0.702; P = 0.001), adequate adjuvant chemotherapy ≥ 6 months (HR = 0.370; 95%CI: 0.222-0.618; P < 0.001) and margin status (HR = 2.255; 95%CI: 1.252-4.064; P = 0.007) were found to be independent factors for the recurrence rate.

CONCLUSION

The TRIANGLE operation is safe for PDAC patients undergoing PD. Moreover, it reduces the local recurrence rate of PDAC and may improve survival in patients who receive adequate adjuvant chemotherapy.

Short-term Outcomes of Robotic Versus Open Pancreatoduodenectomy: Propensity Score-matched Analysis

OBJECTIVE

The goal of the current study was to investigate the perioperative outcomes of robotic pancreaticoduodenectomy (RPD) and open pancreaticoduodenectomy (OPD) in a high-volume center.

BACKGROUND

Despite RPDs prospective advantages over OPD, current evidence comparing the 2 has been limited and has prompted further investigation. The aim of this study was to compare both approaches while including the learning curve phase for RPD.

METHODS

A 1:1 propensity score-matched analysis of a prospective database of RPD with OPD (2017-2022) at a high-volume center was performed. The main outcomes were overall- and pancreas-specific complications.

RESULTS

Of 375 patients who underwent PD (OPD n=276; RPD n=99), 180 were included in propensity score-matched analysis (90 per group). RPD was associated with less blood loss [500 (300-800) vs 750 (400-1000) mL; P =0.006] and more patients without a complication (50% vs 19%; P <0.001). Operative time was longer [453 (408-529) vs 306 (247-362) min; P <0.001]; in patients with ductal adenocarcinoma, fewer lymph nodes were harvested [24 (18-27) vs 33 (27-39); P <0.001] with RPD versus OPD. There were no significant differences for major complications (38% vs 47%; P =0.291), reoperation rate (14% vs 10%; P =0.495), postoperative pancreatic fistula (21% vs 23%; P =0.858), and patients with the textbook outcome (62% vs 55%; P =0.452).

CONCLUSIONS

Including the learning phase, RPD can be safely implemented in high-volume settings and shows potential for improved perioperative outcomes versus OPD. Pancreas-specific morbidity was unaffected by the robotic approach. Randomized trials with specifically trained pancreatic surgeons and expanded indications for the robotic approach are needed.

Comparison of prognosis and postoperative morbidities between standard pancreaticoduodenectomy and the TRIANGLE technique for resectable pancreatic ductal adenocarcinoma

BACKGROUND

Radical surgery combined with systemic chemotherapy offers the possibility of long-term survival or even cure for patients with pancreatic ductal adenocarcinoma (PDAC), although tumor recurrence, especially locally, still inhibits the treatment efficacy. The TRIANGLE technique was introduced as an extended dissection procedure to improve the R0 resection rate of borderline resectable or locally advanced PDAC. However, there was a lack of studies concerning postoperative complications and long-term outcomes of this procedure on patients with resectable PDAC.

AIM

To compare the prognosis and postoperative morbidities between standard pancreaticoduodenectomy (PD) and the TRIANGLE technique for resectable PDAC.

METHODS

Patients with resectable PDAC eligible for PD from our hospital between June 2018 and December 2021 were enrolled in this retrospective cohort study. All the patients were divided into PDstandard and PDTRIANGLE groups according to the surgical procedure. Baseline characteristics, surgical data, and postoperative morbidities were recorded. All of the patients were followed up, and the date and location of tumor recurrence, and death were recorded. The Kaplan-Meier method and log-rank test were used for the survival analysis.

RESULTS

There were 93 patients included in the study and 37 underwent the TRIANGLE technique. Duration of operation was longer in the PDTRIANGLE group compared with the PDstandard group [440 (410-480) min vs 320 (265-427) min] (P = 0.001). Intraoperative blood loss [700 (500-1200) mL vs 500 (300-800) mL] (P = 0.009) and blood transfusion [975 (0-1250) mL vs 400 (0-800) mL] (P = 0.009) were higher in the PDTRIANGLE group. There was a higher incidence of surgical site infection (43.2% vs 12.5%) (P = 0.001) and postoperative diarrhea (54.1% vs 12.5%) (P = 0.001) in the PDTRIANGLE group. The rates of R0 resection and local recurrence, overall survival, and disease-free survival did not differ significantly between the two groups.

CONCLUSION

The TRIANGLE technique is safe, with acceptable postoperative morbidities compared with standardized PD, but it does not improve prognosis for patients with resectable PDAC.

Extended lymphadenectomy based on the TRIANGLE for pancreatic head cancer: a single-center experience

BACKGROUND

This study was to compare the safety and efficacy of different lymphadenectomy methods in patients with pancreatic head cancer undergoing pancreaticoduodenectomy (PD).

MATERIAL AND METHODS

A total of 150 patients were included in this study. Patients were divided into Group A (n = 79), Group B (n = 44), and Group C (n = 27) according to the different lymphadenectomy methods. The clinical endpoint was time to progression (TTP) and overall survival (OS). Postoperative complications of different lymphadenectomy methods were compared respectively. TTP and OS of the three groups were compared by Kaplan-Meier curves.

RESULTS

There were no significant differences between the three groups in operative time (P = 0.300), death in the hospital (P = 0.253), postoperative hemorrhage (P = 0.863), postoperative pancreatic fistula (POPF) B/C (P = 0.306), bile leakage (P = 0.215), intestinal fistula (P = 0.177), lymphatic leakage (P = 0.267), delayed gastric emptying [(DGE) (P = 0.283)], ICU stay (P = 0.506), and postoperative hospital stay [(PHS) (P = 0.810)]. Median TTP in Groups B and C was significantly longer than in Group A (log-rank test, A vs B: P = 0.0005, A vs C: P = 0.0001). Median OS between the three groups has no statistical difference (P = 0.1546).

CONCLUSIONS

Extended lymphadenectomy methods based on the TRIANGLE do not increase perioperative complications significantly and can effectively delay tumor progression in patients with pancreatic head cancer.

Radiological classification of the Heidelberg triangle and its application in laparoscopic pancreaticoduodenectomy for malignancies

BACKGROUND

The TRIANGLE operation benefits patients with pancreatic cancer; however, the Heidelberg triangle, where the operation occurs, contains vessels that can impact safety, especially in laparoscopic pancreaticoduodenectomy (LPD) with the TRIANGLE operation. This study aimed to identify Heidelberg triangle vessel types and their implications in pancreaticoduodenectomy (PD).

METHODS

Retrospective collection of radiographic data was performed from January 2017 to April 2023. Three-dimensional (3D) CT reconstructions were performed on patients. Vascular types in the Heidelberg triangle were classified based on named vessels crossing its interior. The impact of these types on surgical outcomes and complications in PD with the TRIANGLE operation was assessed.

RESULTS

Preoperative CT reconstruction was conducted on 184 pancreatic surgery patients. The findings revealed 99 patients (53.8%) with the type I Heidelberg triangle, lacking named vessels crossing the interior. Type II (n = 85, 46.2%), with named vessels crossing the interior, was identified. Among reconstructed patients who underwent PD with the TRIANGLE operation (n = 103), they were categorized as type I (n = 57) or type II (n = 46). The results showed that LPD patients with type II had significantly higher median intraoperative blood loss (300 mL vs. 200 mL, P = 0.030) and mean examined lymph nodes (17.2 ± 7.6 vs. 13.4 ± 5.2, P = 0.019) compared to those with type I. No significant differences were found in operative time or postoperative complications.

CONCLUSION

The presence of named vessels crossing the interior of the Heidelberg triangle was associated with increased intraoperative bleeding during LPD combined with the TRIANGLE operation. Therefore, targeted preoperative planning is required before the operation, thus improving the safety of the TRIANGLE operation in minimally invasive surgery.

Cost-effectiveness of open pancreaticoduodenectomy with or without Heidelberg TRIANGLE operation for pancreatic cancer in China

OBJECTIVE

Pancreatic cancer is a digestive malignancy with dismal prognosis. The advent of Heidelberg TRIANGLE dissection technique brings a turning point to improve the chance of survival. Our study aimed to evaluated the cost-effectiveness of open pancreaticoduodenectomy (OPD) versus OPD combined with TRIANGLE operation (OPD-TRIANGLE) for patients with pancreatic cancer from the perspective of healthcare system in China.

METHODS

Two hundred forty-six patients with pancreatic cancer who underwent OPD or OPD-TRIANGLE from January to September 2022 were enrolled in this study. We performed a decision tree model to assess clinical and economic implications of different surgical strategies. Estimation of health utilities was based on published literature, while costs were acquired from the hospitals, clinical expert consultations, and other local charge. The incremental cost-effectiveness ratio (ICER) was regarded as the primary outcome. Uncertainty of the findings was addressed via sensitivity analyses and scenario analyses.

RESULTS

The results indicated that OPD-TRIANGLE group yielded additional 0.0402 QALYs at an incremental cost of US$1501.83 compared with OPD group, and the corresponding ICER was US$37,358.96 per QALY. The probabilities of OPD-TRIANGLE as the prior option were 52.8% at the WTP threshold of 60,000 US$/QALY. The main factors lined with costs incorporating total medical costs and operation-related costs. With 5-20% price reduction of OPD-TRIANGLE, the outcomes were also economically attractive.

CONCLUSION

The findings of this population-based study suggested that OPD-TRIANGLE was likely to be cost-effective for patients with pancreatic cancer when compared against OPD. Further in-depth studies should be conducted to provide more comprehensive evidence.

The Presence of an Aberrant Right Hepatic Artery Did Not Influence Surgical and Oncological Outcomes After Pancreaticoduodenectomy: A Comprehensive Systematic Review and Meta-Analysis

BACKGROUND

The presence of an aberrant right hepatic artery (a-RHA) could influence the oncological and postoperative results after pancreaticoduodenectomy (PD).

METHODS

A systematic review and metanalysis were conducted, including all comparative studies having patients who underwent PD without (na-RHA) or with a-RHA. The results were reported as risk ratios (RRs), mean differences (MDs), or hazard ratios (HRs) with 95% confidence intervals (95 CI). The random effects model was used to calculate the effect sizes. The endpoints were distinguished as critical and important. Critical endpoints were: R1 resection, overall survival (OS), morbidity, mortality, and biliary fistula (BL). Important endpoints were: postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), post pancreatectomy hemorrhage (PPH), length of stay (LOS), and operative time (OT).

RESULTS

Considering the R1 rate no significant differences were observed between the two groups (RR 1.06; 0.89 to 1.27). The two groups have a similar OS (HR 0.95; 0.85 to 1.06). Postoperative morbidity and mortality were similar between the two groups, with a RR of 0.97 (0.88 to 1.06) and 0.81 (0.54 to 1.20), respectively. The biliary fistula rate was similar between the two groups (RR of 1.09; 0.72 to 1.66). No differences were observed for non-critical endpoints.

CONCLUSION

The presence of a-RHA does not affect negatively the short-term and long-term clinical outcomes of PD.

Conventional partial pancreatoduodenectomy versus an extended pancreatoduodenectomy (triangle operation) for pancreatic head cancers-study protocol for the randomised controlled TRIANGLE trial

BACKGROUND

Pancreatic ductal carcinoma (PDAC) is the fourth most frequent cause of cancer-related death in the Western world, and its incidence is rising. In patients that undergo curative resection, local recurrence (LR) is frequent. A recently described surgical technique of extended pancreatoduodenectomy (PD) termed the TRIANGLE operation has been proposed as a promising approach to reduce LR and improve disease-free survival in PDAC patients.

METHODS

The TRIANGLE trial is a multicentre confirmatory randomised controlled superiority trial with two parallel study groups. A total of 270 patients with suspected or histologically confirmed pancreatic head cancer scheduled for PD will be included in the trial and randomly assigned to the intervention group (extended PD defined as Inoue level 3 dissection along the superior mesenteric and celiac artery as well as removal of all soft tissue in the so-called triangle between the celiac artery, the SMA and the mesenterico-portal axis) or the control group (conventional PD with lymphadenectomy and removal of soft tissue according to current guidelines). The primary endpoint of the trial will be the disease-free survival of patients. Other perioperative outcomes as well as oncological parameters and patient-reported outcomes will be analysed as secondary outcomes.

DISCUSSION

Despite multimodal treatment, LR remains high and disease-free survival is limited following PD for PDAC. The TRIANGLE operation could address these shortcomings of conventional PD as indicated in several retrospective studies. However, this technique could be associated with more adverse events for patients including intractable diarrhoea. The TRIANGLE trial will close the evidence gap as well as offer a risk-benefit assessment of this more radical approach to PD.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00030576 (UTN U1111-1243-4412) 19th December 2022.

Current Approaches for the Curative-Intent Surgical Treatment of Pancreatic Ductal Adenocarcinoma

Radical resection is the only curative treatment for pancreatic cancer. However, only up to 20% of patients are considered eligible for surgical resection at the time of diagnosis. Although upfront surgery followed by adjuvant chemotherapy has become the gold standard of treatment for resectable pancreatic cancer there are numerous ongoing trials aiming to compare the clinical outcomes of various surgical strategies (e.g., upfront surgery or neoadjuvant treatment with subsequent resection). Neoadjuvant treatment followed by surgery is considered the best approach in borderline resectable pancreatic tumors. Individuals with locally advanced disease are now candidates for palliative chemo- or chemoradiotherapy; however, some patients may become eligible for resection during the course of such treatment. When metastases are found, the cancer is qualified as unresectable. It is possible to perform radical pancreatic resection with metastasectomy in selected cases of oligometastatic disease. The role of multi-visceral resection, which involves reconstruction of major mesenteric veins, is well known. Nonetheless, there are some controversies in terms of arterial resection and reconstruction. Researchers are also trying to introduce personalized treatments. The careful, preliminary selection of patients eligible for surgery and other therapies should be based on tumor biology, among other factors. Such selection may play a key role in improving survival rates in patients with pancreatic cancer.

Neoadjuvant therapy for pancreatic cancer

Patients with localized pancreatic ductal adenocarcinoma (PDAC) are best treated with surgical resection of the primary tumour and systemic chemotherapy, which provides considerably longer overall survival (OS) durations than either modality alone. Regardless, most patients will have disease relapse owing to micrometastatic disease. Although currently a matter of some debate, considerable research interest has been focused on the role of neoadjuvant therapy for all forms of resectable PDAC. Whilst adjuvant combination chemotherapy remains the standard of care for patients with resectable PDAC, neoadjuvant chemotherapy seems to improve OS without necessarily increasing the resection rate in those with borderline-resectable disease. Furthermore, around 20% of patients with unresectable non-metastatic PDAC might undergo resection following 4-6 months of induction combination chemotherapy with or without radiotherapy, even in the absence of a clear radiological response, leading to improved OS outcomes in this group. Distinct molecular and biological responses to different types of therapies need to be better understood in order to enable the optimal sequencing of specific treatment modalities to further improve OS. In this Review, we describe current treatment strategies for the various clinical stages of PDAC and discuss developments that are likely to determine the optimal sequence of multimodality therapies by integrating the fundamental clinical and molecular features of the cancer.

Tissue clearing and 3D reconstruction of digitized, serially sectioned slides provide novel insights into pancreatic cancer

Pancreatic cancer is currently the third leading cause of cancer death in the United States. The clinical hallmarks of this disease include abdominal pain that radiates to the back, the presence of a hypoenhancing intrapancreatic lesion on imaging, and widespread liver metastases. Technologies such as tissue clearing and three-dimensional (3D) reconstruction of digitized serially sectioned hematoxylin and eosin-stained slides can be used to visualize large (up to 2- to 3-centimeter cube) tissues at cellular resolution. When applied to human pancreatic cancers, these 3D visualization techniques have provided novel insights into the basis of a number of the clinical characteristics of this disease. Here, we describe the clinical features of pancreatic cancer, review techniques for clearing and the 3D reconstruction of digitized microscope slides, and provide examples that illustrate how 3D visualization of human pancreatic cancer at the microscopic level has revealed features not apparent in 2D microscopy and, in so doing, has closed the gap between bench and bedside. Compared with animal models and 2D microscopy, studies of human tissues in 3D can reveal the difference between what can happen and what does happen in human cancers.

Feasibility of "cold" triangle robotic pancreatoduodenectomy

BACKGROUND

Triangle pancreatoduodenectomy adds to the conventional procedure the en bloc removal of the retroperitoneal lympho-neural tissue included in the triangular area bounded by the common hepatic artery (CHA), the superior mesenteric artery (SMA), and the superior mesenteric vein/portal vein. We herein aim to show the feasibility of "cold" triangle robotic pancreaticoduodenectomy (C-Tr-RPD) for pancreatic cancer (PDAC).

METHODS

Cold dissection corresponds to sharp arterial divestment performed using only the tips of robotic scissors. After division of the gastroduodenal artery, triangle dissection begins by lateral-to-medial divestment of the CHA and anterior-to-posterior clearance of the right side of the celiac trunk. Next, after a wide Kocher maneuver, the origin of the SMA, and the celiac trunk are identified. After mobilization of the first jejunal loop and attached mesentery, the SMA is identified at the level of the first jejunal vein and is divested along the right margin working in a distal-to-proximal direction. Vein resection and reconstruction can be performed as required. C-Tr-RPD was considered feasible if triangle dissection was successfully completed without conversion to open surgery or need to use energy devices. Postoperative complications and pathology results are presented in detail.

RESULTS

One hundred twenty-seven consecutive C-Tr-RPDs were successfully performed. There were three conversions to open surgery (2.3%), because of pneumoperitoneum intolerance (n = 2) and difficult digestive reconstruction. Thirty-four patients (26.7%) required associated vascular procedures. No pseudoaneurysm of the gastroduodenal artery was observed. Twenty-eight patients (22.0%) developed severe postoperative complications (≥ grade III). Overall 90-day mortality was 7.1%, declining to 2.3% after completion of the learning curve. The median number of examined lymph nodes was 42 (33-51). The rate of R1 resection (7 margins < 1 mm) was 44.1%.

CONCLUSION

C-Tr-RPD is feasible, carries a risk of surgical complications commensurate to the magnitude of the procedure, and improves staging of PDAC.

Safety and efficacy of TRIANGLE operation applied in pancreatic surgery: a protocol of the systematic review and meta-analysis

BACKGROUND

Pancreatic surgery is regarded as the only curative treatment for pancreatic cancer (PC). As the neoadjuvant therapy is applied widely nowadays, the proportion of patients with PC undergoing surgery also with locally advanced tumour findings has increased accordingly. Especially in these situations, a radical resection of all tumour tissues is challenging. A novel surgical strategy has been introduced recently to achieve this aim, namely the TRIANGLE operation which comprises the radical resection of all nerve and lymphatic tissue between coeliac artery, superior mesenteric artery and mesenteric-portal axis without including extended lymphadenectomy outside this area. Due to currently published studies, Triangle Operation is a safe and feasible procedure. However, this has not been systematically analysed to date. This systematic review and meta-analysis aim to evaluate surgical and postoperative outcomes of Triangle Operation in pancreatic surgery.

METHODS AND ANALYSIS

Pubmed, Web of Science and Cochrane Central Register of Controlled Trials in the Cochrane Library will be searched from inception until 31 December 2022. This study will include all articles comparing Triangle Operation versus non-Triangle Operation in pancreatic surgery to assess outcomes. The primary endpoints will be R0 resection rate and 1-year overall survival. The secondary endpoints will be delayed gastric emptying, postoperative pancreatic fistula, post pancreatectomy haemorrhages and reoperation incidence, overall complications, mortality and 3-year overall survival. The study selection, study quality assessment, data extraction and critical appraisal will be carried out by two reviewers. Inter-reviewer disagreements will be evaluated by discussion with a third reviewer. Besides, a subgroup analysis will be conducted focused on robotic surgery, laparoscopic surgery and open surgery in detail. Additionally, the Grading of Recommendations, Assessment, Development and Evaluations framework will be performed to evaluate the strength of evidence.

ETHICS AND DISSEMINATION

This systematic review and meta-analysis will not require ethical approval. Results will be published in a peer-reviewed scientific journal.

PROSPERO REGISTRATION NUMBER

CRD42021234721.