**7. Technical advances**

Many of the advances that are discussed above are system‐based and involve the perioperative period of patient care. These have had a tremendous impact on patient outcomes in the treatment of PDAC. But of all the modalities involved, surgery remains the only treatment with the potential for cure in patients with localized pancreatic cancer. Significant improve‐ ments in preoperative evaluation and postoperative care have reduced the perioperative morbidity and mortality associated with pancreatectomy. As previously discussed, mortality after PD has dropped significantly and there have also been improvements in long‐term survival rates. In addition to these changes, surgical technique itself is progressing and evolving.

In an evidence‐based systematic review, Wright and Zureikat identified four key elements that have allowed minimally invasive pancreatic surgery to gain momentum: safety, oncologic efficacy, cost, and reproducibility. Even though the evidence available is not the result of randomized controlled trials but instead on case series matched with cohorts undergoing open procedures, morbidity and mortality have been shown to be comparable between minimally invasive (MI) and open techniques. This applies for both PD and DP and encompasses all modalities of MI techniques: laparoscopy, robotic‐assisted surgery, and their institutional variations.

The main concern with the adoption of MI techniques for the treatment of PDAC is undoubt‐ edly oncologic efficacy. A study by Kendrick et al. favored MI technique by demonstrating fewer delays to initiation of adjuvant chemotherapy after laparoscopic PD with similar oncologic survival when compared to that in open procedure. Another study using the National Cancer Data Base demonstrated no difference in oncologic outcomes between laparoscopic and open PD [36]. In the setting of DP cases, Lee and colleagues (reference below) showed similar oncologic outcomes and high rates of R0 resection between open and laparo‐ scopic DP. The mean number of lymph nodes evaluated in the aforementioned series was higher with open DP (15.4) when compared with the minimally invasive techniques (10.4 with laparoscopy and 12 with robotic approach). However, there was no statistically significant difference in the number of positive lymph nodes evaluated. Although the retrospective design of these studies introduces the possibility of selection bias in terms of patient selection, surgeon preference/experience, and preoperative patient and oncologic characteristics, the available evidence so far demonstrates that laparoscopic and robotic approaches to pancreatectomy do not adversely affect oncologic outcomes and add benefits such as decreased EBL and LOS [37– 39]. However, it is important to note that the sources of most of the available literature are high‐ volume centers, which introduces a potential source of bias and reinforces the importance of patient evaluation and treatment at high‐volume centers with multidisciplinary teams.

the study also illustrated a fourfold increase in mortality (3–12%) [35]. This raises skepticism toward findings in the previous literature and supports advocating caution against eliminating the use of drains altogether. However, per ERAS recommendations, early removal of the drain

These strategies provide a unified protocol for perioperative management of the PD procedure that could likely prove beneficial to centers through reducing postoperative complication rates, time of recovery and hospital length of stay [28, 32]. Ultimately, it is the summation of these factors that contribute to the improvement in the postoperative outcomes of pancreatic cancer patients. While the aforementioned concepts and strategies prove significant for the manage‐ ment of the acute surgical patient, the overall management strategy for a pancreatic cancer

Many of the advances that are discussed above are system‐based and involve the perioperative period of patient care. These have had a tremendous impact on patient outcomes in the treatment of PDAC. But of all the modalities involved, surgery remains the only treatment with the potential for cure in patients with localized pancreatic cancer. Significant improve‐ ments in preoperative evaluation and postoperative care have reduced the perioperative morbidity and mortality associated with pancreatectomy. As previously discussed, mortality after PD has dropped significantly and there have also been improvements in long‐term survival rates. In addition to these changes, surgical technique itself is progressing and

In an evidence‐based systematic review, Wright and Zureikat identified four key elements that have allowed minimally invasive pancreatic surgery to gain momentum: safety, oncologic efficacy, cost, and reproducibility. Even though the evidence available is not the result of randomized controlled trials but instead on case series matched with cohorts undergoing open procedures, morbidity and mortality have been shown to be comparable between minimally invasive (MI) and open techniques. This applies for both PD and DP and encompasses all modalities of MI techniques: laparoscopy, robotic‐assisted surgery, and their institutional

The main concern with the adoption of MI techniques for the treatment of PDAC is undoubt‐ edly oncologic efficacy. A study by Kendrick et al. favored MI technique by demonstrating fewer delays to initiation of adjuvant chemotherapy after laparoscopic PD with similar oncologic survival when compared to that in open procedure. Another study using the National Cancer Data Base demonstrated no difference in oncologic outcomes between laparoscopic and open PD [36]. In the setting of DP cases, Lee and colleagues (reference below) showed similar oncologic outcomes and high rates of R0 resection between open and laparo‐ scopic DP. The mean number of lymph nodes evaluated in the aforementioned series was higher with open DP (15.4) when compared with the minimally invasive techniques (10.4 with laparoscopy and 12 with robotic approach). However, there was no statistically significant

is associated with fewer and reduced rate of complications [28, 35].

patient has substantially changed [23, 25, 28, 32].

**7. Technical advances**

170 Challenges in Pancreatic Pathology

evolving.

variations.

Cost is one of the limitations of MI pancreatectomy, particularly the robotic technique. However, some authors have shown the robotic technique to be cost effective when the reduction in length of stay is taken into consideration [40, 41]. Additionally, the robotic technical skills are potentially easier to acquire when compared to laparoscopic technique. This is secondary to the advantages provided by stereotactic vision, robotic simulators, and training consoles. The learning curve defined as 80 cases for a reduction in operative time may shorten with time since the operative steps and training techniques have recently become betterdefined [42].

Another noteworthy technical advancement is the incorporation of vascular resection (VR) with PD. Tseng et al. described five types of venous resection and reconstruction involving the superior mesenteric vein (SMV), portal vein (PV), or superior mesenteric‐portal venous (SMPV) confluence. These are tangential resection with saphenous vein patch (V1), segmental resection with splenic vein ligation and primary anastomosis (V2) or with interposition graft (V3), segmental resection without splenic vein ligation and primary anastomosis (V4) or with interposition graft (V5). In their single institution series, Tseng and colleagues demonstrated that properly selected patients with PDAC of the head of the pancreas undergoing VR had a median survival of approximately two years. There was no statistical difference between survival of patients undergoing standard PD and those undergoing PD and VR (*p* = 0.177) [43].

Adequate patient selection for PD with VR has been possible by technological advances in computer tomography and by a multidisciplinary approach involving surgeons and radiol‐ ogists. While several single center studies [44–46] have demonstrated PD with VR to be safe, a retrospective cohort analysis of the National Surgical Quality Improvement Program database demonstrated increased postoperative morbidity and mortality with the inclusion of venous resection [47]. This difference can be attributed to publication bias since most of the previously published single center studies have been from high‐volume centers. Based on this, PD with VR in carefully selected patients at high‐volume institutions opens up the possibility of survival comparable to that of patients undergoing standard PD, even in the setting of an increased frequency of R1 resections in patients that require VR [43].

Not only has surgical technique evolved but also, operative standards of care have been improved. It is known that lymph node metastasis is a poor prognostic factor for PDAC of the pancreatic head. The retrieval of an adequate number of lymph nodes or total lymph nodes examined (TNLE) is a measure of quality of care. Not only does it lead to optimal locoregional control but also, it is of upmost importance for pathological staging. Current NCCN guidelines recommend that at least 11 lymph nodes are retrieved and examined. Gleisner and colleagues showed an association between TNLE and overall survival, but the association was not uniform through time at their institution. Standards of care improved. We have found that less than 12 lymph nodes are inadequate lymphadenectomy [48].
