UROGENITAL TRAUMA

Renal gunshot wounds: clinical management and outcome
Voelzke BB, McAninch JW
Department of Urology, University of California San Francisco at San Francisco General Hospital, San Francisco, California 94114, USA
J Trauma. 2009; 66: 593-600; discussion 600-1

• Background: To analyze our experience with renal gunshot wounds (GSW).
• Methods: We analyzed our prospective trauma database for patients with renal GSW.
• Results: Two hundred one patients (206 renal units) with renal GSW were collected from our database. Preoperative imaging (1-shot intravenous pyelogram, dedicated intravenous pyelogram, or computed tomography) was performed in 68.7% (n = 140). Gross or microscopic (>5 red blood cell/high power field) hematuria was present in 88.7%. Injury to other organs was present in 96.5% (194 of 201), with >1 organ involved in 74.6% (other than kidney). The liver was the most commonly injured organ. Using the American Association for the Surgery of Trauma grading system, there were 46 grade 1 (G1), 21 G2, 62 G3, 51 G4, and 26 G5 injuries. The trend to observe without renal exploration has not changed significantly during the past three decades (1978-1989 = 32.8%, 1990-1999 = 39%, 2000-2007 = 30.4%). Ninety-five renal units (excluding nephrectomy) underwent repair with associated small or large bowel injuries without any known complications, including 14 patients with mesh used during renal repair. The renal salvage rate was 85.4% (n = 176 of 206) with two delayed nephrectomy procedures for persistent bleeding after initial repair. The total number of nephrectomy procedures was 30 of 206 renal units. Postoperative imaging was obtained in 32.8% (55 of 201) patients, and there were no known cases of postinjury hypertension. Overall survival was 90.6% (182 of 201), with 2 intraoperative and 17 postoperative deaths. There were no postoperative infections related to renal reconstruction. Isolation of renal vessels was obtained in all patients before opening Gerota’s fascia with no deaths secondary to urologic intervention.
• Conclusion: Selective observation and various operative techniques can yield high renal salvage rates approximating 85% after GSW.
  
  
• Editorial Comment
  The above two articles on gunshot wounds to the kidney and the other on haemostatic agents are both very timely and raise many controversies and unanswered questions. Although the authors hold on to the dogma of a one-shot IVP before any renal exploration, I have generally found little utility it its use. In our hands, the IVP is usually a “fuzzy-gram” and adds little to the decision making. While Morey et al published some value in the IVP in helping to grade the renal injury, as to high or low grade, we have not had such luck. In our trauma center, if the patient is stable enough to undergo imaging, we take the patient to the CT scanner and get an accurate read as to the grade of renal and associated injuries. If the patient is so unstable that no imaging can be done and needs to be rushed to the OR, this patient is typically a “damage control” patient where fancy and time consuming renal reconstructions are a disservice to the patient. It is our feeling that a damage control patient with a kidney injury needs to be observed, temporized by packing or the like, or undergo a quick nephrectomy. In such an unstable patient, a one-shot IVP will not help you or allow you to change your intra-operative decision making. Furthermore, an easy way to assess contralateral kidney function is to place a vessel loop to occlude the ipsilateral injured kidney ureter, give indigo, and look for blue in the Foley. Blue indicates at least a partially functional contralateral kidney. The notion that we should do a one-shot IVP on all patients to prevent taking out a solitary kidney that has a 0.1% incidence makes no sense to me. While we are in the tissue preservation business, and would like to preserve every kidney, kidney repair should not be at the expense of compromising patient recovery and survival from the associated injuries. While the urology community has been slow to accept the above statements, there is mounting evidence from the general surgical and trauma literature that one shot IVPs and getting primary vascular control are dogma, and have little value in the contemporary setting.
  I also have problems with the dogma of primary, proximal vascular control of the renal hilum before opening Gerota’s fascia. By definition a GSW to the kidney has penetrated Gerota’s so it is an uncontained hematoma and Gerota’s is open already. In general, if the kidney injury is significant, Grade 3-5, the hematoma has already done the kidney mobilization and dissection – so getting the kidney to the midline to place a vascular clamp on the hilum typically can be done very quickly and easily. Primary, proximal control has value for a zone 1 hematoma where there is a potential injury to the great vessels. Here getting proximal and distal control has great value to prevent exsanguination. However, if the injury is just to the renal parenchyma, I really don’t understand the need for proximal control - especially in every patient. Furthermore, while the SF General group reports that it takes only 10 minutes to get proximal control, in my own experience it typically takes more like 20 plus minutes, especially on the right. So, in the unstable and potential damage control patient I feel we do the patient a disservice is delaying kidney repair for 20 or more minutes. They also report that they only clamp the renal artery 12% of the time – that suggests to me that they are over grading the renal injuries. In our experience, true grade 4 and 5 renal injuries are usually aggressively bleeding from the kidney, and clamping the hilum expedites and facilitates renal repair. As long as the warm ischemia time is < 30 minutes, I see no reason not to clamp the artery. Furthermore, the use of adjunctive hemostatic agents, such as Floseal and the use of Nu-knit make sense to me and can expedite vascular control. Such agents should not substitute for renal parenchymal suturing, but be an adjunct, expect perhaps in the very unstable damage control patient where packing the kidney and applying agents can preclude the need for a damage control nephrectomy.
  The last comment I have is why we should treat low grade GSW to the kidney any differently then a blunt renal injury, if the kidney grade for grade injury is the same. Clearly high grade GSW have a high degree of blast injury and delayed necrosis and need to be more aggressively explored and repaired. However, for low velocity GSW and no clear intra-abdominal injury, I feel in this day and age of excellent interventional radiology imaging and the readily available use of selective angio-embolization in most trauma centers, that conservative management of isolated penetrating injuries, even grade 3 and 4 are very under utilized. Arguably, the rate of pseudoaneurysms and AV fistulas can approach 25% in conservatively managed high grade penetrating injuries – but an unnecessary abdominal exploration can be avoided – in so doing expediting morbidity and recovery time.

Dr. Steven B. Brandes
Associate Professor, Division of Urologic Surgery
Washington University in St. Louis
St. Louis, Missouri, USA
E-mail: brandess@wudosis.wustl.edu