Chapter 30 – Urological Trauma




Abstract






  • Both kidneys have similar muscular surroundings. Posteriorly, the diaphragm covers the upper third of each kidney. Medially, the lower two-thirds of the kidney lie against the psoas muscle, and laterally, the quadratus lumborum.
  • The right kidney borders the duodenum medially. Its lower pole lies behind the hepatic flexure of the colon.
  • The left kidney is bordered superiorly by the tail of the pancreas, the spleen superolaterally, and the splenic flexure of the colon inferiorly.
  • The Gerota’s fascia encloses the kidney and is an effective barrier for containing blood or a urine leak.
  • The renal artery and vein travel from the aorta and IVC just below the SMA at the level of the second lumbar vertebra. The vein lies anterior to the artery. The renal pelvis and ureter are located posterior to the vessels.
  • The right renal artery takes off from the aorta with a downward slope under the IVC into the right kidney. The left renal artery courses directly off the aorta into the left kidney. Each renal artery branches into five segmental arteries as it approaches the kidney.
  • The right renal vein is typically 2–4 cm in length, does not receive any branches, and enters into the lateral edge of the IVC. Ligation of the vein causes hemorrhagic infarction of the kidney because of the lack of collaterals.
  • The left renal vein is typically 6–10 cm in length, passes posterior to the SMA and anterior to the aorta. The left renal vein receives branches from the left adrenal vein superiorly, lumbar veins posteriorly, and the left gonadal vein inferiorly. This allows for ligation of the left renal vein close to the IVC.





Chapter 30 Urological Trauma


Leo R. Doumanian , Charles D. Best , Jessica A. Keeley , and Stephen Varga



Surgical Anatomy



Kidney




  • Both kidneys have similar muscular surroundings. Posteriorly, the diaphragm covers the upper third of each kidney. Medially, the lower two-thirds of the kidney lie against the psoas muscle, and laterally, the quadratus lumborum.



  • The right kidney borders the duodenum medially. Its lower pole lies behind the hepatic flexure of the colon.



  • The left kidney is bordered superiorly by the tail of the pancreas, the spleen superolaterally, and the splenic flexure of the colon inferiorly.



  • The Gerota’s fascia encloses the kidney and is an effective barrier for containing blood or a urine leak.



  • The renal artery and vein travel from the aorta and IVC just below the SMA at the level of the second lumbar vertebra. The vein lies anterior to the artery. The renal pelvis and ureter are located posterior to the vessels.



  • The right renal artery takes off from the aorta with a downward slope under the IVC into the right kidney. The left renal artery courses directly off the aorta into the left kidney. Each renal artery branches into five segmental arteries as it approaches the kidney.



  • The right renal vein is typically 2–4 cm in length, does not receive any branches, and enters into the lateral edge of the IVC. Ligation of the vein causes hemorrhagic infarction of the kidney because of the lack of collaterals.



  • The left renal vein is typically 6–10 cm in length, passes posterior to the SMA and anterior to the aorta. The left renal vein receives branches from the left adrenal vein superiorly, lumbar veins posteriorly, and the left gonadal vein inferiorly. This allows for ligation of the left renal vein close to the IVC.





Figure 30.1 Anatomy of the kidneys and ureters and their relationship with the major vessels. Note the right renal artery coursing under the inferior vena cava. Also, note the different drainages of the right and left gonadal veins. The ureters cross over the bifurcation of the common iliac arteries (circle). SMA, superior mesenteric artery.





Figure 30.2 The distal ureter crosses over the bifurcation of the common iliac artery.



Ureter




  • The ureter courses posterior to the renal artery and travels along the anterior edge of the psoas muscle.



  • The gonadal vessels cross anterior to the ureter.



  • It crosses over the bifurcation of the common iliac artery.



Bladder




  • The superior surface of the bladder is covered by the peritoneum. Posteriorly, the peritoneum passes to the level of the seminal vesicles (in males) and meets the peritoneum on the anterior rectum.



  • The bladder neck rests approximately 3–4 cm behind the midpoint of the symphysis pubis.



  • The bladder neck and ureteral orifices form a triangular structure known as the bladder plate or trigone. The ureteral orifices are located at the right and left apex of the trigone. The ureteral orifices are in close proximity to the bladder neck.



Kidney Injuries



General Principles




  • In hemodynamically stable patients, the vast majority of blunt and a significant proportion of penetrating renal injuries can be managed nonoperatively. Gerota’s fascia effectively contains bleeding and urine leaks. CT scan evaluation is important in assessing the severity and location of the injury. Delayed CT scan allows the evaluation of the collecting system and proximal ureter.



  • If no preoperative imaging is available and the patient is undergoing exploratory laparotomy, it is important to assess by palpation the presence and size of the contralateral kidney.



  • Intraoperatively, in a hemodynamically stable patient, in the absence of active bleeding or expanding hematoma or injury to the hilar vessels, Gerota’s fascia should not be opened, as it increases the probability of nephrectomy.



  • Nephrectomy should be reserved for life-threatening hemorrhage or renal injuries that are beyond repair, approximately in 10% of renal injuries.



  • If time allows, proximal vascular pedicle control should be considered before kidney exploration in order to reduce the need for nephrectomy.



Patient Positioning




  • The patient is placed in the standard trauma laparotomy position, supine with both arms abducted at 90° to allow access to the extremities.



Incision




  • Standard midline trauma laparotomy incision. A Bookwalter or other fixed abdominal retractor facilitates the exposure.



Kidney Exposure




  • Proximal vascular control, before opening the Gerota’s fascia, may be considered in stable patients if a kidney-preserving operation is planned. This approach increases the chances of kidney salvage.



  • In unstable patients or those undergoing a planned nephrectomy, a direct approach through Gerota’s fascia without prior vascular control is faster and preferable.



Proximal Renal Vascular Control




  • Proximal control of both the left and right renal vessels can be obtained directly through a single incision of the retroperitoneum over the abdominal aorta.




    • The transverse colon is retracted anteriorly and superiorly towards the patient’s chest. The small intestine is wrapped in a moist towel and retracted superiorly and to the right to expose the ligament of Treitz, the root of the mesentery, and the underlying great vessels.



    • An incision is made in the posterior peritoneum, over the aorta, just above the inferior mesenteric vein. The dissection continues superiorly along the aorta until the left renal vein is identified crossing over anteriorly. A vessel loop is placed around the vein for retraction. Once the left renal vein is mobilized and retraced, dissect out the left renal artery, which is located posterior to the renal vein.





      Figure 30.3 Dissection in the posterior peritoneum lateral to the aorta and just above the inferior mesenteric vein and continuing superiorly along the aorta will identify the left renal vein crossing the aorta anteriorly. The left renal artery is located posterior to the vein.





  • After vascular control has been achieved, a medial visceral rotation is performed by mobilizing the left colon along the white line of Toldt and reflecting the colon medially. The kidney is then exposed by making an anterior vertical incision in Gerota’s fascia.


    Figure 30.4



    (a) Incision of the white line of Toldt and mobilization and medial rotation of the left colon exposes the left kidney.





    (b) Exposure of the left kidney and the hilum after medial rotation of the left colon (artery in red, vein in blue, and ureter in yellow loop).





    (c) Exposure of the left kidney and the hilum after medial rotation of the left colon. Note the left renal vein crossing over the aorta. IMV, inferior mesenteric vein; IVC, inferior vena cava.




    • The right renal vessels can be exposed through the same posterior peritoneal incision described above. The right renal artery originates from the right side of the aorta and courses under the inferior vena cava and behind the renal vein.



    • As described above, the left renal vein is mobilized and retracted as it crosses over the aorta. The right renal artery, which is located posterior to the vein and to the right of the aorta, is identified.



    • Finally, identify the right renal vein traveling to the inferior vena cava and control with a vessel loop.



    • After vascular control has been achieved, perform a right medial visceral rotation, mobilizing the right colon by incising the white line of Toldt and reflecting it medially.



    • Explore the right kidney by making an anterior vertical incision in Gerota’s fascia. Completely expose the kidney, mobilizing it and lifting it anteriorly into the wound.



Figure 30.5



(a) Exposure of the right renal vessels through a midline retroperitoneal dissection. The left renal vein is identified as it crosses over the aorta and is retracted to expose the underlying right renal artery (red loop).





(b) Exposure of the right kidney and the hilum after medial rotation of the right colon. Note the renal vein anteriorly, the artery posteriorly, and the ureter inferiorly.



Direct Kidney Exposure without Prior Vascular Control




  • This is a common approach to the kidney and the preferred approach in patients with hemodynamic instability or unsalvageable renal injuries.



  • A medial visceral rotation is performed by mobilizing the left or right colon after incising the white line of Toldt.



  • Gerota’s fascia is opened with an anterior vertical incision and the kidney is exposed and delivered anteriorly.



  • The blood supply and ureter can then be controlled.

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Sep 4, 2020 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 30 – Urological Trauma
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