Necrotizing pancreatitis can be the inciting event leading to multisystem organ dysfunction. Over the past several years, there have been many attempts to quantify the severity of disease processes. Early scores such as Ranson’s criteria were an attempt to predict clinical outcomes based on the severity of acute pancreatitis. Although historically significant, it is no longer routinely utilized. Newer scores such as the multiple organ dysfunction score [MODS] or the sequential failure assessment score (SOFA) have been developed to evaluate organ dysfunction in the intensive care units. The RAC adopted the modified Marshall score for their definition of organ failure [13] (Table 10.2).

Although previously routinely recommended to detect bacteria, percutaneous fine needle aspiration is no longer considered a mandatory requirement. Instead, clinical signs such as worsening or persistent fever or the presence of gas in peri-pancreatic collections are considered accurate predictors of infected necrosis in most patients [14].

Given the aggressive fluid resuscitation required for these patients, the acute care surgeon should always be concerned about the development of abdominal compartment syndrome. The clinical sequelae of this potentially fatal complication include abdominal distention, sustained elevated intra-abdominal pressure (greater than 25 mmHg measured by bladder pressure), decreased urine output, and increasing respiratory insufficiency. Paracentesis may be considered in the early stages to help with drainage of ascites that could be contributing to increased abdominal pressure. Should the concern for abdominal compartment syndrome persist, the definitive management is surgical decompression. A wound VAC is then placed for temporary abdominal closure [21].

Clinical judgment should be used when considering pursuing pancreatic necrosectomy concomitant with abdominal decompression for compartment syndrome. It is advisable to delay surgical necrosectomy until pancreatic collections have become walled off to help delineate between viable and non-viable tissue [22, 23]. However, depending on the degree of necrosis, delayed operative management, despite wishful thinking, may not be possible. In this case, the patient can be expected to become sicker after exploration and debridement. All necrotic material should be debrided. Wide drainage of the pancreas including drains placed in the lesser sac, above the pancreatic bed, and below the level of the transverse mesocolon is encouraged [24].

The Step-Up Approach is another option for management of necrotizing pancreatitis [25, 26]. This approach utilizes a percutaneously placed drain [12 Fr] drain with assistance of interventional radiology through the left retroperitoneum. Proper positioning of this initial drain cannot be overstated, and the surgical team should have direct input into the exact location planned by interventional radiology (Fig. 10.1). A poorly placed drain will make it difficult to perform the video-assisted retroperitoneal debridement (VARDS) and potentially increase the chance of injury [27]. After placement of the initial drain, the patient is observed for clinical improvement as evidenced by drop in fever, WBC, and improvement of other physiologic parameters as well as resolution of fluid collections and inflammatory foci seen on CT scan. If no improvement is seen over the next 72 hours, upsizing of the drain should be considered. If this fails, the patient should proceed to VARDS [28–34] (Fig. 10.2).

Surgery is preferably postponed until at least 4 weeks from the onset of the disease [24]. This is considered essential as it allows for peri-pancreatic collections to sufficiently demarcate and the wall to mature, thus optimizing conditions for debridement. The VARDS technique we use is similar to that described by van Santvoort et al. The patient is placed in supine position with the left side elevated 30° to 40°. A subcostal incision approximately 5 cm in length is placed in the left flank at the mid-axillary line, close to the exit point of the percutaneous drain.

With the help of CT images and by using the in situ percutaneous drain as a guide into the peri-pancreatic collection, the fascia is dissected and the retroperitoneum is entered. The cavity is cleared of purulent material using a standard suction device. The first necrosis encountered is carefully removed with the use of long grasping forceps. Loose necrotic material is removed while periodic irrigation and continuous suction are performed to enhance vision as the percutaneous drain is followed as a road map deeper into the cavity (Fig. 10.3). When debridement can no longer be performed under direct vision, a single extra-long laparoscopic port is placed into the incision and a 0° videoscope is introduced. At this stage, CO₂ gas (10 L/min) can be infused through the percutaneous drain, still in position, to inflate the cavity, thereby facilitating inspection. Under videoscopic assistance, further debridement of retained necrotic tissue is performed with laparoscopic forceps. Complete necrosectomy is not the ultimate aim of this procedure. Only loosely adherent pieces of necrosis are removed, thereby keeping the risk of tearing underlying blood vessels to a minimum. Overly aggressive necrosectomy of un-demarcated, necrotic tissue will increase the chance of injury and bleeding. The main complications of VARDS remain hemorrhage and colonic perforation. Significant retroperitoneal bleeding has a reported incidence of as high as 16–20 %. In the case of extensive bleeding, packing of the retroperitoneal cavity should be performed, either as definite treatment or as a bridge to laparotomy or angiographic coiling in the situation of persistent hemorrhage. When the bulk of necrosis is removed, the cavity is irrigated with saline until the fluid becomes clear. The percutaneous drain is removed, and two large-bore single-lumen drains are positioned in the cavity extending through the edges of the incision. Multiple large-bore drains are placed to allow for postoperative lavage. The fascia and skin are closed, and the drains are sutured to the skin. Continuous postoperative lavage is performed with 10 L of normal saline or dialysis fluid per 24 hours until the effluent is clear. One week after the procedure repeat CT is performed to evaluate resolution [35–38].