Exposure and Management of Retroperitoneal Injuries 

The retroperitoneum is one of the most challenging areas of the abdomen.  There are three anatomical zones which define the retroperitoneum.  Each of these zones has a specific number of organs which are at risk for injuries.  It is essential that the surgeon is familiar with the anatomy of this area and has a well thought out plan for the management of each injury to a particular organ or vascular structure. 

Zone I of the Retroperitoneum 

This includes the central medial superior aspect of the retroperitoneum.  The central medial zone extends from the diaphragm to distal to the bifurcation of the aorta and the inferior vena cava.  A number of important vascular structures are contained in Zone I.  They include the celiac trunk, the superior mesenteric artery, the inferior mesenteric artery, the renal pedicle vessels, the aorta, and the vena cava.  The pancreas and the second, third, and fourth portions of the duodenum also are found in Zone I.  The critical management decision is that any penetrating injury in this area requires mandatory exploration.  The area should be thoroughly inspected and any hematoma needs to be carefully identified to determine what particular vascular structure has been injured. 

Zone II of the Retroperitoneum 

Zone II includes the lateral aspects of the superior abdomen.  The kidney, adrenal glands, the ureter, and the hilum of the vascular pedicle of the kidney reside in this area.  In a penetrating injury to Zone II, it is appropriate to explore the area to identify which vascular structure or organ has been injured.  In blunt injuries to the area, it is not necessary to explore the retroperitoneum.  If the hematoma is expanding or pulsating or if there is extravasation of urine, the appropriate management strategy is to identify the injury with radiographic images to determine renal function and if there is a need for operative exploration.  If the abdomen is being explored for another reason and the surgeon identifies a hematoma in the retroperitoneum from a blunt force, it is important to identify the size of the hematoma at the beginning of the exploration.  If the hematoma is neither expanding nor pulsating, it should be left alone.  On the other hand, if at the end of the exploration, the hematoma has expanded, then in all likelihood is from an arterial injury and needs to be further explored.  If there is extravasation of urine, the kidney needs to be carefully evaluated for function and an injury to the collecting system.  A careful inspection for penetrating injury either from a laceration from the rib or a direct penetration should be performed.  The injured collecting system is then repaired and a drain is placed close to the kidney.  Drainage from the injured collecting system will prevent a perinephric urinoma.  With a patent ureter, this drainage will usually resolve spontaneously. 

Zone III is the Pelvic Retroperitoneum 

This zone is only explored if there is a penetrating injury usually a transpelvic gunshot wound which may have involved the vascular structures, the ureter, and the colon.  It is critical to explore these areas and be sure there is no colonic injury and that the ureter is intact.  In blunt injuries to the pelvis, with a retroperitoneal hematoma, the appropriate management is to apply an external fixation device.  This can be a sheet which is place around the buttock and tied anteriorly to restore the bony pelvic skeleton to its normal configuration.  There are external binders which are available and external fixation devices which effectively restore the pelvic anatomy.  These devices compress the pelvic hematoma.  Seventy percent of pelvic bleeding is from pelvic veins.  Restoring the pelvis to its normal configuration cause the hematoma to compress the veins and stop venous bleeding.  If the patient continues to be hemodynamically unstable, an arteriogram with selective embolization of the bleeding vessel coming from the internal iliac artery should be performed. 

Exposure 

In order to identify and control bleeding in Zone I, a number of maneuvers have been described.  The left medial visceral rotation moves the kidney, the spleen, and the pancreas from its posterior position to the midline.  This allows the surgeon to identify the celiac trunk and the superior mesenteric artery.  In the case of severe hemorrhage, a vascular clamp can be placed at the takeoff of these vessels and allows for proximal control of the vessel at the aorta without entering the hematoma.  Once the vessel has been controlled proximally, careful dissection can be carried out to identify and repair the bleeding site.  The modified left medial rotation allows the kidney to remain in its position and rotates the spleen and pancreas to the midline.  This gives excellent exposure to the celiac trunk and the mesenteric artery.

Exposure of the vena cave, the gonadal vessels, and the posterior aspect of the head of the pancreas is accomplished by an extended Kocher maneuver.  The second and third portions of the duodenum are dissected medially and the posterior aspect of the head of the pancreas and the distal biliary pancreatic tree are then inspected.  Any bile staining in this area represents an injury to the hepatobiliary complex.  The dissection is carried medially until the medial aspect of the aorta is identified.  This exposure gives excellent visualization of the infrahepatic vena cava.  In order to gain full exposure of the entire vena cava down to the bifurcation, the Cattel-Braasch maneuver or the right-sided medial visceral rotation is carried out.  The white line of Toldt is dissected and the cecum, the ascending colon, and the base of the small bowel mesentery is dissected and placed in the left upper quadrant.  This provides excellent exposure of the bifurcation of the aorta and vena cava.  It also allows for full exposure of the right ureter and the kidney. 

Injuries to the Kidney 

A penetrating injury to the kidney can either involve the parenchyma or it can extend deep into the collecting system.  It is essential to gain vascular control of the bleeding kidney.  There are two methods to achieve this.  The first is to deliver the kidney out of Gerotaños fascia and apply digital pressure to the bleeding area.  This area is then inspected to determine the extent of the injury.  A small injury can be managed with a pledgeted repair.  However, if the injury extends deep into the collecting system, central control of the renal pedicle with either silastic loops or a vascular clamp is the best method.  The collecting system is then identified and repaired with absorbable sutures.  The renal parenchyma is then also repaired in a similar fashion.  At the end of the procedure, the wound is inspected for urostasis and hemostasis.  A drain is then placed posteriorly and brought out through a lateral stab wound.

Ureter 

Injuries to the ureter are unusual.  A laceration of the proximal ureter is identified and the determination is made as to whether this is a partial or complete laceration.  It is important not to skeletonize the ureter as this puts the blood supply in jeopardy.  If it is a partial laceration, the wound is then closed with interrupted absorbable sutures over a stent.  If the laceration is complete, it is wise to spatulate the ends of the ureter so that a stricture does not occur.  The repair is then drained and the drain is brought out through a lateral stab wound.  When the ureter is healed at 7 to 10 days, the ureteric stent is removed transurethrally.

In summary, the retroperitoneum is a difficult and challenging area.  It is essential to have a sound knowledge of the anatomy to fully understand the methods to gain control of the injuries in the area and to have a clear understanding of the types of operative procedures which should be employed. 

Selected Reading

Advanced Trauma Operative Management: Surgical Strategies for Penetrating Trauma. Textbook. Eds. LM Jacobs, RI Gross, SS Luk. Chapter One. Trauma Laparotomy. Pp. 1-26.