Operative techniques in pancreatic trauma—A heuristic approach

Operative techniques in pancreatic trauma—A heuristic approach

Injury, Int. J. Care Injured 44 (2013) 153–155 Contents lists available at SciVerse ScienceDirect Injury journal homepage: www.elsevier.com/locate/i...

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Injury, Int. J. Care Injured 44 (2013) 153–155

Contents lists available at SciVerse ScienceDirect

Injury journal homepage: www.elsevier.com/locate/injury

Technical note

Operative techniques in pancreatic trauma—A heuristic approach Tugba Han Yilmaz a, Thorsten J. Hauer b,c,*, Martin D. Smith c, Elias Degiannis c, Dietrich Doll c,d a

Baskent University, Department of Surgery, Izmir, Turkey Military Hospital Ulm, Department of Surgery, Ulm, Germany c Chris Hani Baragwanath Academic Hospital, Trauma Directorate, University of the Witwatersrand, Johannesburg, South Africa d St. Marienhospital Vechta, Department of Surgery, Vechta, Germany b

A R T I C L E I N F O

Article history: Accepted 23 September 2012

Patients who sustain trauma to the pancreas can in certain cases, if they are physiologically stable, be transferred to a dedicated trauma unit. On the other hand, some of these patients will be physiologically unstable and need to be managed by the locally available surgeon, who may be unfamiliar with the operative management of trauma to the pancreas. The surgeon can, if time is not critical, refer to an operative surgical book and attempt to master this type of surgery. Reading the techniques from an unfamiliar operative textbook is frequently not sufficient to enable performance of the actual operation. It is the small points – the ‘‘tricks of the trade’’ – that make the difference to the ‘‘uninitiated’’: it is the heuristics, the ‘‘rule of the thumb’’ that doctors doing these procedures frequently learn through experience. We describe some of these techniques (heuristics) of the operative management of pancreatic trauma. Suspicion/detection of pancreatic injury The surgeon must be aware that most patients with pancreatic trauma will have concomitant or associated injuries that will themselves require a laparotomy. This is particularly true in cases of penetrating as well as less commonly in blunt trauma. In many cases, the patient is taken to theatre without extensive preoperative workup, due to haemodynamic instability or the presence of an acute abdomen. The surgeon proceeds with a long midline incision as this is the approach providing optimal exposure in pancreatic trauma. The bleeding and the ongoing contamination are controlled, and when the patient is physiologically stable, the surgeon proceeds to the next step, that is to detect the presence of a pancreatic injury. There are certain clues suggesting pancreatic injury: fluid collection in the lesser sac, bile staining of retroperitoneal tissues,

* Corresponding author at: Military Hospital Ulm, Department of Surgery, Oberer Eselsberg 40, 89081 Ulm, Germany. Tel.: +49 731 17101205. E-mail address: [email protected] (T.J. Hauer). 0020–1383/$ – see front matter ß 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.injury.2012.09.020

presence of fat necrosis of the omentum or the retroperitoneum, or a haematoma overlying the pancreas. In penetrating trauma, the surgeon tries to follow the penetrating track for its entire length. The surgeon must remember that the most important factor in the outcome for this patient, is the presence or absence, of a main pancreatic duct (MPD) injury. In the acute situation of pancreatic (especially penetrating trauma), there is no place for the evaluation of the injury by radiology or ERCP. Intraoperative observation is the only method to used to detect ductal damage, based on the intraoperative criteria of main pancreatic duct injury described by Heitsch et al.1 These include, direct visualisation of ductal violation, complete transection of the pancreas, laceration of more than half the diameter of the pancreas, central perforation and severe maceration of the gland. To identify these criteria, the injured area must be fully mobilised, which is the next step that we are going to describe. Mobilisation of the pancreas In the injury to the head of the pancreas, intraoperative evaluation must determine the integrity of the MPD, the presence of a devitalised pancreatic head or duodenum, the extent of duodenal injury, the integrity of the ampulla and bile duct and whether a concomitant vascular injury is present. To achieve this, the surgeon must have good visualisation of the pancreas. In injury to the head of the pancreas the surgeon proceeds to full mobilisation of the head. The surgeon positions themselves to the patient’s left in order to get the transverse colon off the anterior aspect of the duodenum and the head of the pancreas. This is achieved by mobilising the hepatic flexure of the colon. The assistant retracts the colic flexure and the proximal colon caudally and thereby visualising the second part of the duodenum in front. By having an abdominal swab under one’s left hand and applying gentle traction to the duodenal loop the surgeon then divides with his/her scissors the peritoneal attachment along the lateral portion of the second part of the duodenum (Kocher manoeuvre) and inserts the left index finger behind the lateral duodenal ligament which attaches the second part of the duodenum to the Gerota’s fascia. The surgeon then divides this ligament over his/her index finger and continues the line of dissection towards the third portion of the duodenum till the point is reached where the superior mesenteric vein crosses the third part of the duodenum. Special attention must be paid during this manoeuvre as excessive

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upward traction of the duodenum and pancreas may tear the superior mesenteric vein. In the same way the surgeon mobilises the first and second parts of the duodenum superiorly till the foramen of Winslow is identified or until the lateral aspect of the common bile duct, which does not need to be dissected, is reached. After this mobilisation one should be able to palpate the aorta posteriorly to the pancreas and fully visualise the anterior and posterior aspects of the second and third part of the duodenum, as well as the head and uncinate process of the pancreas. If there is suspicion that the distal pancreas has been injured this should be visualised by opening the lesser sac. The surgeon performs this from the patients right side. It is suggested that the whole lesser sac should be opened up to and including the inferior short gastric vessels. This is achieved by detaching the greater omentum from the transverse colon along the bloodless line. There are times that the greater omentum and the transverse mesocolon are ‘‘stuck’’ together and it is difficult to separate them with this approach without risking damage to the transverse mesocolon and its corresponding vasculature. If the surgeon finds himself or herself in this situation, they should proceed with the following manoeuvre: the surgeon lifts up the stomach by grasping the anterior surface with his/her right hand and breaks the lesser omentum with the fingers of the left hand making sure that one does not damage the vasculature of the lesser curvature of the stomach. Then the surgeons whole left hand is inserted along the back of the stomach, fingers pointing caudally, and by moving the whole palm in a transverse and caudal plane one will easily open the potential left lateral lesser sac space by separating the greater omentum from the transverse mesocolon. Then the surgeon opens the lesser sac by using serially applied artery forceps just outside the vascular arcade along the greater curvature of the stomach. The surgeon should make sure that the opening of the lesser sac is generous, and so should proceed with the division of the greater omentum up to the spleen. If there is suspicion that the injury may involve the distal tail of the pancreas near the hilum of the spleen, the lienosplenic, splenocolic and splenorenal ligaments are incised and the spleen mobilised, by rotating it medially and lifting it upwards towards into the incision but being careful not to damage the short gastric arteries. This will allow inspection of the anterior as well as the posterior aspects of the tail of the pancreas. The same manoeuvre can be used to visualising the body and the tail, but because it requires significant mobilisation of the spleen and the pancreas from the retroperitoneal space, it can lead to significant oozing especially in the coagulopathic patient. An alternative approach to visualising the body of the pancreas is by incising the avascular peritoneal attachment of the transverse mesocolon to the pancreas and exposing the inferior border of the pancreas. This is done by sharp dissection with Metzenbaum scissors. As the peritoneum is divided, two or three millimetres of retroperitoneal fat are seen bulging at the line of division between the lower border of the pancreas and incised mesocolon. There are very few vessels in this space and if they are cut, they can be ignored as they will soon stop bleeding. This incision is extended as far laterally as possible towards the spleen. Then the surgeon should start mobilising the pancreas anteriorly up by inserting the right index and middle finger of the surgeons right hand, facing upwards, in the retroperitoneal space behind the pancreas. The surgeon bluntly dissects the posterior surface of the pancreas from the retroperitoneum using his/her fingers till they reach the superior border of the pancreas. The peritoneum exposed along the superior border of the pancreas is then incised. One must not worry about the veins along the posterior surface of the pancreas in this anatomical area as it is largely avascular and the tissues easily separated. On the other hand the surgeon must always keep in mind that the splenic artery is running at the upper border of the

pancreas, so when he/she divides the peritoneum along the upper border of the pancreas, the artery is not damaged. This will now allow cephalad rotation of the pancreas and inspection of the posterior surface and bimanual palpation. Distal pancreatectomy If the injury is judged to require distal pancreatectomy, the first step should be to ligate the splenic artery and vein to decrease the possibility of extensive bleeding during the resection. Ligation of both vessels about two centimetres to the right of the injury site is performed so that they are not inadvertedly damaged during the transection of the parenchyma. In the same way the surgeon should continue the mobilisation of the pancreas also for two centimetres to the right to the site of the proposed resection line. The surgeon then takes a soft bowel clamp and applies it on the pancreas as proximally as possible and divides the parenchyma with a scalpel (Fig. 1). By intermittently releasing the soft bowel clamp one will identify the superior and inferior pancreatic arteries and overrun them with a 5-0 prolene figure of eight stitch. The bites of the needle are as close as possible to the bleeding vessel, including minimal pancreatic tissue. If it is applied further away from the vessel there is a good possibility that the thin stitch will cut through the parenchyma while applying tension on throwing the knot causing small irritating bleeding. Then the surgeon tries to identify the very small main pancreatic duct. This identification, although difficult, is possible in most cases (Fig. 2). For that reason one should transect the pancreas with a blade, transecting it by electrocautery will make it very difficult to identify the opening of the duct through the cauterised, coagulated pancreatic tissue. However with the modern electrocautery devises this is much less likely and division of the pancreas is possible using electrocautery. The pancreatic duct when identified is closed using a non absorbable 5/0 suture using a figure of eight stitch. Although the different techniques of closure of the pancreatic stump aim at controlling the bleeding as well as a leak from the pancreatic duct by compressing them within the pancreatic tissue, applying figure of eight stitch at the pancreatic duct separately can diminish the risk of fistula formation. The pancreatic stump should be closed by inserting overlapping interrupted mattress sutures of polypropylene or silk. Which is the best way in inserting these mattress sutures? There is a tendency for the surgeon to move the needle holder, while he/she is inserting sutures, from away towards his/her body (in the right handed surgeon, from the right to the left). So in the case of the pancreas the mattress stitch will be inserted from the posterior pancreatic

Fig. 1. Placement of soft bowel clamp on the pancreas (case of pancreatectomy in pancreatic transection after blunt trauma).

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the transected pancreas. In this case a thick stitch is used (usually stitches with high tensile strength like 0, 1, 2 which are also thicker). This helps the surgeon in two ways: firstly the needle is longer, so that the surgeon includes in his/her bite the whole cut surface of the pancreas, and secondly, as the stitch is thicker, there is less chance of cutting through the parenchyma – ‘‘like a hot wire through swiss cheese’’. The distal pancreas should be removed together with the spleen. If the patient is physiologically stable (usually in isolated pancreatic injuries), an attempt can be made to preserve the spleen. This means additional time to dissect small perforating vessels originating from splenic vasculature on the posterior pancreas surface. As a rule we do not attempt splenic preservation when we are performing distal pancreatectomy for trauma in adults. Fig. 2. Main pancreatic duct (arrow).

Fig. 3. Direction of mattress suture from anterior to posterior and from posterior to anterior.

surface to the anterior, and then from the anterior to the posterior. Consequently the stitch will be knotted on the posterior surface of the pancreas. As the normal pancreatic tissue is very soft it is important when the surgeon puts tension on the knot, to do it in such a way that it compresses the occluded pancreatic tissue but does not cut through it. This can be better achieved when the knot is in front, so that more controlled tension is applied with the two index fingers. Therefore the mattress stitch is inserted ‘‘backhanded’’ (remember the surgeon is standing on patient’s right side) starting from the anterior surface to the posterior, and back from the posterior to the anterior (Fig. 3). The first knot – the one that counts – should be straight and double, so that appropriate tension can be applied and it does not give way while ‘‘relaxing’’ it on throwing the second knot. Resection of the body of the pancreas can also be achieved with the linear stapler, but a 4.5–4.8 mm TA or GIA stapler (green) must be used. In our hands, handsewing of the pancreatic stump has achieved better results, but this is not reflected in the literature.2 If the pancreas is very swollen, as happens frequently in patients with blunt transection of the body of the pancreas especially when there is a delayed presentation – a stapler should not be used. The clips are too small to include the whole width of

Pancreaticoduodenectomy in trauma This procedure is rarely performed for traumatic injuries to the pancreas head. It should only be done if the mechanism of injury results in a complete or near complete transection of the head of the pancreas. A few principles: pancreaticoduodenectomy should be performed as a two-stage procedure. After the initial damage control operation and achievement of haemostasis, the stomach, the duodenum, and the head of pancreas are resected and the common bile duct externally drained or ligated. We prefer ligation as after 48 h, when the patient is stable and the anastomoses are completed at reoperation, it will be easier to anastomose the dilated common bile duct to the small bowel. It can dilate up to 5 mm when ligated for 48 h. A side to side hepaticojejunostomy is then performed. It is useful to remember that there are two main differences between performing a pancreaticoduodenectomy in the clinical setting of trauma and that of cancer. Firstly, in trauma surgery it is not necessary to remove the uncinate process. This simplifies the procedure, as the surgeon can operate away from the superior mesenteric vein and superior mesenteric artery. Second, the gallbladder is not removed in a trauma case, as it can be used for biliary-enteric reconstruction, in the presence of a delicate common bile duct.3 This is however not routinely recommended. It is advisable that if a surgeon who is not experienced in doing pancreaticoduodenectomies finds himself doing a proximal pancreatic resection in the middle of the night, one should ask the hepatobiliarypancreatic surgeons to deal with the reconstruction within the next 48 h. It is wise to avoid doing anastomoses with a normal, soft pancreas by yourself. They are more experiencened, will have better results, and if they have complications, they are the best people to deal with them! Conflict of interest The authors hereby declare that there is no conflict of interest. References 1. Heitsch RC, Knutson CO, Fulton RL, Jones CE. Delineation of critical factors in the treatment of pancreatic trauma. Surgery 1976;80:523–9. 2. Degiannis E, Glapa M, Loukogeorgakis SP, Smith MD. Management of pancreatic trauma. Injury International Journal of Care Injured 2008;39:21–9. 3. Smith MD, Degiannis E. Penetrating trauma to the pancreas. In: Velmahos GC, Degiannis E, Doll D, editors. Penetrating trauma – a practical guide on operative technique and peri-operative management. Berlin, Heidelberg: Springer-Verlag; 2012.