Clinical Pancreatology for Practising Gastroenterologists and Surgeons. Группа авторов
be assessed 72 hours after placement of the first drain to assess whether a second is required [14]. Similarly, there is no clear consensus on the timing of drainage placement, but most studies recommend the second and third weeks from onset of symptoms, before WON [19]. Questions have been raised about the usefulness of the drain in the early stages of the disease and whether it can prevent later complications such as pancreas fistula or bleeding. In this regard, an ongoing randomized clinical trial (POINTER) is being carried out to determine whether immediate drainage is more effective than postponing intervention [20].
The secondary goal of this strategy is to chart a path for use as a guide when locating the anatomical space to be drained, which is the preliminary step for further procedures, should the conservative treatment fail (see following chapters) [21].
Sinus Tract Endoscopy
Sinus tract endoscopy is a special variant of percutaneous treatment and forms part of the “step‐up” approach. This technique was first described by Carter et al. [22], who hypothesized that complications and multiorgan failure could be reduced by minimizing the massive inflammatory “hit” of open pancreatic necrosectomy. In fact, sinus tract endoscopy was described as a procedure that followed open necrosectomy in order to preclude further reoperations, although the initial indication was extended to the primary management of retroperitoneal peripancreatic sepsis, as patients developed fewer organ dysfunctions and postsurgical recovery was faster.
This approach would be ideal for treating laterally placed WON (i.e. at more than 1–2 cm from the stomach and duodenal wall [23]), whereas it is not appropriate for necrotic collections in and around the pancreatic head, which are more suitable for transmural drainage (see next section).
The procedure takes place under general anesthesia and fluoroscopic guidance with the patient in the right lateral decubitus position, using the previous drain as the point of entry. The drain tract is dilated by a 30‐Fr balloon to allow the insertion of Amplatz dilators and sheaths (Figure 15.1a).
A 5‐mm working channel nephroscope (Figure 15.1b) is normally employed to clean the residual cavity [24]. Abundant normal saline serum together with a grasper and a Dormia basket can be used to evacuate the abundant, fluffy, cloud‐like pus and loose necrotic material. A 32‐Fr Nelaton drain is reintroduced along the sinus track to permit subsequent postoperative cleaning. The drainage tube is kept in place until the output is less than 10 ml/day and is then withdrawn, the main advantage being that necrotic tissue can be removed as many times as necessary without the need for formal reoperation. Antibiotics are usually administered while the drain is in place.
Endoscopic (Endoluminal) Approach
The endoscopic approach is a less invasive approach consisting of extracting the necrosis by natural orifices and has now become a promising option for the management of IPN patients. The technique was initially defined in 1996 by Baron et al. [25] and since then the results reported on different series in the literature show that mortality has been reduced to 5.6% with an overall complication rate of 28%. More recently, a randomized controlled trial comparing the endoscopic and surgical approaches revealed significantly fewer complications and rate of pancreatic fistula in the endoscopic arm [24]. As with all other techniques, serious specific complications have been reported, such as bleeding, perforation of the abdominal cavity, and peritonitis [18]. Although the endoscopic approach via the duodenum has been described, in practice the transgastric route is usually preferred as it can also be used to assess the integrity of the duct and has the further advantage of providing a diagnostic and therapeutic option for associated pancreatic and biliary pathologies.
The endoscopic approach is normally performed under general anesthesia but can also be carried out under sedation with midazolam and fentanyl. The post‐inflammatory pancreatic necrosis behind the posterior stomach wall is located and punctured. With successive balloon dilatations, a window of up to 2 cm in length is obtained for direct lavage, through which a gastroscope is passed to enable manipulation of the necrosis with forceps. Optionally, additional transgastric pigtails may also be inserted to facilitate drainage and ensure the reproducibility of the procedure [26].
Figure 15.1 (a, b) Amplatz and dilatators used to dilate the drainage tract and facilitate nephroscope insertion. (c) The previous drain is used as a guide to introduce the wire under fluoroscopic guidance. (d) Necrotic tissue and debris are extracted with the Dormia basket under direct visualization.
Source: courtesy of Patricia Sánchez‐Velázquez.
One of the technique’s drawbacks is that at least three procedures are usually required due to the small size of the window in the gastric wall and the poor capacity of the devices used to grasp the necrosis. Also, since it is quite a complex operation, it is performed at only a few centers, including tertiary referral centers, and is heavily reliant on the endoscopist’s experience. Although the published results seem to be satisfactory and mortality is very low, up to 40% of patients require additional placement of percutaneous drains to eliminate new areas of necrosis or collections, and between 20 and 28% require further surgical treatment. However, it has the great advantage of being less invasive and of providing further endoscopic therapy options. Moreover, the pancreatic juice drains directly into the gastric/duodenal lumen, so the rate of pancreatic fistula is reduced to less than 10%, as has been shown by the only randomized controlled trial published on this topic [27].
Retroperitoneal Approach
With the rise of minimally invasive techniques, retroperitoneal pancreatic necrosectomy has become more widespread than open necrosectomy and the transperitoneal laparoscopic approach. Ideally, it should be applied to pancreatic or peripancreatic necrosis in the left pancreas, lesser sac, and left paracolic gutter (Figure 15.2a,b).
The technique was initially described in 1998 by Gambiez et al. [28], was later defined by Horvath et al. [29] as video‐assisted retroperitoneal debridement (VARD), and then popularized by van Santvoort et al. [14]. This approach is accepted as a secondary therapeutic procedure after failure of percutaneous drainage, which indeed is crucial for reaching the pancreatic lodge. It should be noted that the purpose of this procedure is to facilitate percutaneous drainage rather than to completely evacuate necrotic fluid from the cavity. The surgeon will find it easier to locate the necrosis within the cavity if a second anterior or caudal drain has been placed, although this is not essential.
The patient is placed in a modified lateral decubitus position (Figure 15.2c). The entire abdomen and flank are prepared and draped within the sterile field to allow adequate access to the retroperitoneum. A small incision is performed below the 12th rib following the previously inserted drainage. The pancreatic cell is reached via the left retroperitoneal access without opening the peritoneum, passing behind the splenic flexure of the colon and spleen. This dissection is performed bluntly under digital control. Once lodged in the pancreatic area, a laparoscopic camera is inserted through the small incision to view the area. Care must be taken to avoid injuring the blood vessels, so that adherent or necrotic tissue that cannot be freed easily should be left in place. The necrotic tissue is grasped and removed by suction and forceps. At the end of the procedure a large drain should be inserted to allow postoperative washes (Figure