Resectable

– Absence of extrapancreatic disease, no evidence of direct tumor extension to the Superior mesenteric artery (SMA) or celiac axis (presence of fat plane between the tumor and these vessels), patent Superior mesenteric, and Portal vein (SMPV).

Borderline resectable (Potentially resectable)

– Absence of extrapancreatic disease, SMA encasement < 180 degree, SMV/portal impingement, short segment SMV occlusion, celiac encasement < 180 degree (tail), abutment/ encasement of hepatic artery.

Locally advanced/unresectable

– Absence of extrapancreatic disease, SMA encasement > 180 degree, un-reconstru-ctable SMV/ portal vein occlusion; any celiac abutment (head) or celiac encasement > 180 degree (body/tail), aortic invasion or encasement, lymph node metastases beyond ?eld of resection.

Metastatic

The aim of pancreaticoduodenectomy is R0 resection. Adequate surgery includes negative margins (CBD, pancreatic duct and especially retropancreatic margin). Minimum of 12-15 lymphnodes should be removed. R1 resection following PD is associated with inferior survival although it is better compared to patients who did not undergo surgery. Thus aim of PD should be an R0 resection. 

Mesentericoportal venous resection

 There are two main rationales for vein resection (VnR) of the portal vein (PV), superior mesenteric vein (SMV), or superior mesenteric-portal vein confluence (SMPV) as part of pancreatic cancer resection. First, VnR is performed in order to achieve a negative resection margin because the tumor invades the vessel or inflammatory adhesions around the tumor preclude adequate separation from the vein. Second, VnR is performed to achieve the benefits of an “extended pancreatectomy” via clearance of second-order lymph nodes and surrounding connective tissue6. Initially venous involvement was considered a sign of unresectablity. However, it is no longer considered so. It has been associated with higher incidence of intraoperative blood loss and operating time. However, overall morbidity and mortality are similar compared to PD.  Studies have shown that the fact that vascular resection is required means that the tumor itself is large in size and is a poor prognostic factor. But in select cases especially borderline tumors vascular resection may be required to achieve R0 margin as their survival is definitely better than those who are not operated.    

Arterial resection and reconstruction (SMA) is rarely performed for PD. It is associated with higher morbidity, mortality and no benefit in survival. Thus most authors do not recommend arterial resection. 

The primary methods for vascular resection and reconstruction are as follows. 

1. Partial wedge resection of the vascular wall, which is suitable for cases with a range of invaded blood vessels less than 1/3 of the circumference and with less severe invasion. After resection, suture and repair of the defective blood vessel wall with sutures or an artificial patch is used to repair the gap. 

2. Venous end-to-end anastomosis, which is suitable for cases with a range of invaded blood vessels greater than 1/3 of the circumference and less than 5 cm. After resection of the invaded part, the two ends of the blood vessel are directly connected. 

3. Artificial vascular graft. If the invaded blood vessel is longer than 5 cm, connecting the two ends directly after resecting the invaded part can be difficult; Grafts can be used for reconstruction. Various grafts used are- internal jugular vein, internal iliac vein or artificial grafts.

SMA first approach

Another major advancement in pancreatic cancer is the use of SMA first approach. It is now established that SMV- PV resection for achieving a negative margin is well accepted. But resecting SMA is associated with higher morbidity without benefit. CT is 95% sensitive in detecting the vessel involvement preoperatively. But its sensitivity falls in the setting of neoadjuvant chemotherapy especially for border line tumors. Thus it is this category of borderline tumors, where artery first approach is best suited.  The artery-first approach has come to mean that the artery is given primary place in determining resectability, and trial dissection is directed towards the early determination of whether there is arterial involvement before committing an irreversible step in the operation. 

Minimally invasive PD

Laparoscopic approaches are routinely used for a variety of procedures in general surgery and various surgical specialties including surgical oncology. Pancreaticoduodenectomy (PD) poses a particular challenge. During this procedure, there is extensive retroperitoneal dissection around anatomically complex and hazardous structures, and a prolonged reconstruction that includes 3 technically demanding anastomoses. Hybrid PD has also been used in which mini laparotomy is done to do the anastomosis once the specimen is removed laparoscopically. In a recent meta analysis to be published in January 2104, showed that MIS was associated with reduction in intraoperative blood loss, higher lymph node retrieval and shorter hospital stay. But post operative complications were comparable. There was a 10% incidence of conversion with main cause being uncontrollable intraoperative bleeding. The authors opined that the most common cause of morbidity following PD is anastomotic leak and since leak rate is not associated with open or MIS, morbidity is not significantly lower following MIS PD. On the other hand, late wound complications (eg, incisional hernias) have been identified as a source of delayed morbidity after pancreatic resection; however, the morbidity associated with an incisional hernia must be interpreted in the context of pancreatic malignancy.Show Less

Salvage pancreatectomy

Soft pancreas such that a subsequent pancreatoenterostomy is likely to leak 

One of the most important complications following TP is pancreatogenic diabetes in as high as 25% patients. TP patients have been thought to be more vulnerable to severe hypoglycemic episodes, tend to be resistant to ketosis. These patients have lower requirements of insulin but the therapeutic window is narrowed thus resulting in frequent episodes of hypoglycaemia following insulin administration. The combined use of glargine with supplemental short-acting insulins such as insulin lispro or insulin aspart at mealtimes helps to prevent postprandial hypoglycemia after intestinal carbohydrate absorption has been completed. Most patients are able to achieve adequate glycemic control using these insulin preparations. However, continuous subcutaneous insulin infusion pumps have also been used to simplify dosing for patients. Current clinical work in patients with type I diabetes suggests that glucagon rescue injections can help prevent late postprandial hypoglycaemia. Finally, islet cell transplantation is being used in patients with chronic pancreatitis following TP to prevent endocrine complications.

Pancreatic body and tail tumors

Ductal adenocarcinoma of the body and tail of the pancreas usually remain asymptomatic until late in the course of disease. Thus, patients are very likely to present with advanced disease or  sometimes metastasis, excluding the possibility of surgical resection with a curative intent. The only chance of cure for these patients is complete resection of the tumor with a clear margin and regional lymph node clearance. Strasberg et al. have reported that the conventional distal  pancreatosplenectomy (DPS) using the left-to-right approach does not take into consideration the lymph node drainage of the pancreas body and tail, and that it is associated with a high rate of retropancreatic margin positivity. It was in this regard that the Strasberg group proposed a right-to-left approach named radical antegrade modular pancreatosplenectomy (RAMPS). The procedure is performed as follows: the neck of the pancreas and splenic vessels are divided, followed by lymph node and perineural plexus dissection from the celiac axis downward to the SMA. Then, the dissection is continued laterally anterior (anterior RAMPS) or posterior (posterior RAMPS) to the left adrenal gland. 

GI & HPB MALIGNANCIES Show Less