**4. Indications for vascular resection**

Extended surgical approaches, such as vascular and multivisceral resections, have become commonly performed in PDAC due to the improvement of surgical technique and intensive care, as well as the exact complications management [18].

Combined portal vein resection with pancreatectomy should be considered in order to achieve clear resection margins on the basis of preoperative imaging in cases suspectable of invasion of the portal vein rather than making the decision purely on operative findings. All patients should undergo contrast‐enhanced tomography (CT) as routine preoperative work up. The development of multislice multidetector computed axial tomography allows imaging of the whole pancreas in peak contrast intensification. Additionally, the information from the CT may be processed for acquiring of three‐dimensional images and visualization of different view planes. Spiral computed axial tomography with i.v. contrast and technique for thin sections may accurately assess the relations of tumor formation with low density to the celiac trunk, superior mesenteric artery, and superior mesenteric‐portal vein confluence. Magnetic resonance imaging (MRI), endoscopic ultrasound scans (EUS), and laparoscopy should be performed on an individual patient basis depending on the multidisciplinary team (MDT) discussion. MRI is usually recommended when there is a suspicion of liver metastases present.

According to Ishikawa et al. and Nakao and coworker, the indications are limited to uni‐ lateral (<180°) segmental vascular involvement [19, 20]. Attention was especially paid to the exclusion of the cases with deep retroperitoneal invasion, defined by the absence of intact connective tissue between the tumor and the right lateral side of the superior mes‐ enteric artery. Isolated arterial involvement is not accepted as an absolute contraindication. Endoscopic ultrasonography (EUS) at this stage is more reliable regarding detection of inva‐ sion in the porto‐mesenteric system and is a standard procedure in the specialized medical centers. Tumors with simultaneous involvement of several blood vessels or massive retro‐ peritoneal invasion are treated as resectable only in the case of sensitivity to neoadjuvant chemotherapy.

**3. Rationale in vascular resections**

head of the pancreas, despite of the growing evidence.

**4. Indications for vascular resection**

care, as well as the exact complications management [18].

Surgeons have gradually pushed the boundaries in surgical resection thanks to the advance‐ ments in oncology and critical care. Unfortunately, PDVR has not yet been generally accepted and applied as surgical management of patients with locally advanced adenocarcinoma of the

Pancreatic carcinoma is characterized with high biological activity and early involvement of retroperitoneal tissue, lymph nodes, and peripancreatic blood vessels. Vascular involvement is frequently combined with invasion in neural plexus so clear resection margin could not be achieved. Vascular resections especially arterial ones add an additional level of complexity to the usually difficult pancreatic surgery without clear impact on the long‐term survival

Extended surgical approaches, such as vascular and multivisceral resections, have become commonly performed in PDAC due to the improvement of surgical technique and intensive

Combined portal vein resection with pancreatectomy should be considered in order to achieve clear resection margins on the basis of preoperative imaging in cases suspectable of invasion of the portal vein rather than making the decision purely on operative findings. All patients should undergo contrast‐enhanced tomography (CT) as routine preoperative work up. The development of multislice multidetector computed axial tomography allows imaging of the whole pancreas in peak contrast intensification. Additionally, the information from the CT may be processed for acquiring of three‐dimensional images and visualization of different view planes. Spiral computed axial tomography with i.v. contrast and technique for thin sections may accurately assess the relations of tumor formation with low density to the celiac trunk, superior mesenteric artery, and superior mesenteric‐portal vein confluence. Magnetic resonance imaging (MRI), endoscopic ultrasound scans (EUS), and laparoscopy should be performed on an individual patient basis depending on the multidisciplinary team (MDT) discussion. MRI is usually recommended when there is a suspicion of liver metastases

According to Ishikawa et al. and Nakao and coworker, the indications are limited to uni‐ lateral (<180°) segmental vascular involvement [19, 20]. Attention was especially paid to the exclusion of the cases with deep retroperitoneal invasion, defined by the absence of intact connective tissue between the tumor and the right lateral side of the superior mes‐ enteric artery. Isolated arterial involvement is not accepted as an absolute contraindication. Endoscopic ultrasonography (EUS) at this stage is more reliable regarding detection of inva‐ sion in the porto‐mesenteric system and is a standard procedure in the specialized medical

**3.1. Pro**

198 Challenges in Pancreatic Pathology

**3.2. Cons**

rates.

present.

Preoperative evaluation of resectability should be based on a computed tomography (CT) scan with a pancreas‐specific protocol, for example, a "hydropancreas" CT, according to these recommendations. Three grades of resectability can be defined for localized PDAC— "resectable," "borderline resectable," and "unresectable" [21]. A tumor is defined as resectable when no vascular attachment (no distortion of the venous structures and clearly preserved fat planes toward the arteries) is present. The resectability is accepted as borderline when distortion/narrowing/occlusion of the mesentericoportal veins with a technical possibility of reconstruction on the proximal and distal margin of the veins or a semicircumferential abut‐ ment (≤180°) of the superior mesenteric artery (SMA) or an attachment at the hepatic artery without the celiac axis is diagnosed—see below. The locally advanced, surgically unresect‐ able tumors are defined as those with infiltration of celiac trunk and/or superior mesenteric artery or as tumors involving the superior mesenteric vein, portal vein, or their confluence. The term "encasement" indicates that the tumor is undistinguishable from the blood vessel for more than 180° of the circumference of the latter. A tumor is defined as unresectable when it presents with the presence of distant metastases, greater than 180° SMA encasement, any celiac abutment, unreconstructible SMV/portal vein, aortic/IVC invasion or encasement, or metastases to lymph nodes beyond the field of resection.

Despite the development of pancreatic imaging, distinguishing between the resectable (stage I and II) and locally advanced (stage III) disease may be difficult and these cases are named with the term "borderline resectability." Vascular resections are usually required in cases often described as with "borderline resectable" findings.

The definition of borderline resectable carcinoma according to an expert consensus statement from 2009 [22] includes short SMV/PV involvement with free proximal and distal venous seg‐ ments, permitting secure reconstruction and SMA < 180° or short hepatic artery involvement with intact truncus coeliacus. The difference from the M. D. Anderson Group classification is in considering tumors, encasing or abutting (depending on the degree of tumor‐vessel inter‐ face) the SMV/PV borderline but not resectable [23].


**Table 1.** CT criteria for borderline resectable pancreatic cancer.

The TVI‐classification of Tran Cao et al. [24] considers the radiographic tumor‐vein circumfer‐ ential interface and its value as a predictive factor for concomitant vessel resection.

A consensus statement standardizing the definition of the term "borderline resectability" in accordance with the guidelines of the National Comprehensive Cancer Network (NCCN) as well as the definition of extended resections published by the International Study Group for Pancreatic Surgery (ISGPS) (**Table 1**) [21–23].

The approach should be different when borderline findings in venous and arterial vessel involvement are diagnosed. No neoadjuvant treatment is recommended in venous borderline resectability. Upfront surgery should be performed and, if the intraoperative finding matches the presumed borderline situation as defined above, completed as an en bloc tumor removal with venous replacement [21]. In contrast, palliative treatment should be regarded as the stan‐ dard of care when suspected arterial borderline resectability is intraoperatively confirmed as a true arterial involvement. Stratification and recognition of the patients with borderline findings who do not benefit from extended resections could be done with the neoadjuvant treatment. Patients with a clear tumor progression under neoadjuvant treatment should be excluded from secondary exploration.

Vascular resection must be performed only upon carefully selected patients with data for presence of resectable tumors or tumors with borderline resectability from the preoperative computed axial tomography.
