Tag Archives: kidney

Abstracts, Solid organ

Best Of AAST 2022 #6: The “Missed” Splenic Pseudoaneurysm

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Like so many things in trauma, there are two camps when it comes to repeat CT scan after solid organ injury: the believers vs the non-believers. In my experience, a minority of US trauma centers incorporate this repeat CT study in their practice guidelines. 

Yet the question keeps coming up in the literature. Earlier this year, I reviewed a paper from the University of Cincinnati from a group of believers. I was not very kind, and you can read the review here. The biggest problem with most believer papers is that they cite very old literature that overstates the incidence of delayed hemorrhage. They then use this to justify an extra CT scan to find more of these “dangerous” pseudoaneurysms. Unfortunately, those old papers are just not very good and many overstate the problem.

So let’s look at this year’s abstract from the LAC+USC group. They open by stating that the natural history is unclear but that “risk for spontaneous rupture and exsanguination exist.” The authors sought to further define the utility of using a delayed CT angiogram (dCTA) in diagnosing and triggering intervention after high-grade blunt solid organ injury.

They performed a retrospective study of all patients arriving at their Level I center over a nearly five year period with a Grade 3 or higher injury to liver, spleen, or kidney. They excluded the young, patients transferred in, early deaths, and patients who underwent immediate operation on their spleen or kidney. The primary outcome was intervention triggered by the dCTA.

Here are the factoids:

  • A total of 349 patients with 395 high grade solid organ injuries were analyzed (42% liver, 30% spleen, 28% kidney)
  • Median injury grade for each organ was 3
  • Initial management was “typically” nonoperative or angioembolization (liver 83%, spleen 95%, kidney 89%)
  • Delayed CT angiogram was typically performed on day 4 and identified a lesion in 16 spleen, 10 liver, and 6 renal injuries
  • The dCTA prompted an intervention in 12 spleen, 8 liver, and 5 kidney injuries

The authors conclude that delayed CTA identified a significant number of vascular lesions requiring endovascular or surgical intervention. They recommend further examination and consideration of universal screening to avoid missing these pesky pseudoaneurysms.

Bottom line: Once again, we have a paper that conflates finding a pseudoaneurysm with the need to get rid of it. Granted, I was always taught that pseudoaneurysms (in adults) found on initial CT required an intervention. In the old days of “delayed splenic rupture” a pseudoaneurysm was the likely culprit. 

But the majority of centers do not go looking for pseudoaneurysms days later. And there are precious few patients coming back with delayed hemorrhage after discharge. So what gives?

Could it be that there is a difference between a “fresh” pseudoaneurysm and a “delayed” one? Perhaps the fresh ones portend a real risk of bleeding, but delayed ones are just a normal part of the healing process and rarely bleed? We just don’t know for sure.

This paper shows that if you look for a delayed pseudoaneurysm you will find them. And at this center, if you find them you will be compelled to angioembolize or even operate on them. Yet we really don’t know if that is necessary. It certainly adds to length of stay and hospital charges.

My take is that we desperately need a broad tally of patients discharged with a liver or spleen injury who return within a few weeks for bleeding complications. I would exclude kidneys because they act so differently. And I would not look at all returns because most liver injury readmissions are for bile problems. Just focus on readmissions for bleeding. Once we see what the real incidence is, we can decide whether these pseudoaneurysms are a problem significant enough to pursue with delayed scans, etc.

Here are my questions for the authors and presenter:

  1. What is your assessment of the incidence of delayed rupture and exsanguination? Have you read through the old papers in detail to assure yourselves that they are actually correct?
  2. Do you hold patients in the hospital for their delayed CT angiogram? The studies were typically performed on days 3-7. Do you really keep your solid organ injured patients in the hospital that long? At our center, a grade 3 injury could be discharged home in two days!
  3. How do you decide to take a patient to interventional radiology or the OR after the delayed CT? Is it an unwritten rule? It seemed like most, but not all, had some type of intervention. A (very) few had the lesion but nothing was done. Please explain the difference.

This is an interesting paper just because of the intuitive leap it makes from pseudoaneurysm to intervention. I’m anticipating your presentation so I can hear all the details.

Reference: PSEUDOANEURYSMS AFTER HIGH GRADE BLUNT SOLID ORGAN INJURY AND THE UTILITY OF DELAYED CT ANGIOGRAPHY. Plenary paper #34, AAST 2022.

Abdomen, Complications

Consequences Of Embolizing Renal Injuries

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In my last post, I noted that nonoperative management is the norm for dealing with high grade renal injuries. One of the possible options, angioembolization, was relatively infrequently used at only 6% of the time.

For management of other organs like the spleen, there are several angioembolization options. Depending on the type and severity of injury, selective (partial) or nonselective (main splenic artery) embolization can be carried out. For the liver, only selective embolization can be used. But what about the kidney? 

Are there consequences of nonselective renal embolization? Or should we always strive for selective control? The urology group of the University of Tennessee – Knoxville published a series of papers on their experience using embolization in patients with the most severe injuries (Grade 5). They retrospectively examined just over 3 years of admissions with this injury. Numbers were very small (6 men, 3 women).

But they also published a second paper, extending the review dates to capture one more male patient. And they followed this group for 1.5 to 5 years (mean 2.5 years) to determine if any delayed complications surfaced.

Here are the factoids:

  • Seven patients underwent full, nonselective embolization, and the other three had “super selective” embolization
  • All patients had control of bleeding without surgical intervention
  • Followup CT imaging showed no persistent extravasation or expanding hematoma
  • No patient developed complications, such as a retroperitoneal abscess, prolonged fever, or hypertension while in the hospital or during short-term followup
  • Most patients showed a very small increase in serum creatinine (mean 0.04), but one patient increased from 1.1 to 1.7
  • On longer term followup, one patient, age 51, developed hypertension 10 months after his injury. It is not possible to determine whether he was one of the 20% of older adults who develop hypertension, or whether it was due to the procedure. it was well-controlled with a single antihypertensive med.
  • None developed altered renal function, stones, chronic pain, fistula, or pseudoaneurysm

Bottom line: Obviously, the data is very limited with only 10 patients. However, it is very interesting to note that the majority of these patients underwent nonselective embolization of the renal artery without any adverse event. The one case of hypertension occurred with nonselective embolization, although I have seen several case reports where this occurs with selective embolization as well.

It is now well-accepted that high-grade renal injury can and should be managed nonoperatively if the patient’s hemodynamic status is reasonable. I recommend a trip to interventional radiology if the patient has active extravasation or a high-grade (Grade 4 or 5) injury, as these patients are at risk for loss of the entire kidney otherwise. Selective embolization can be attempted first, but don’t be shy to take out the entire organ if need be. 

References: 

  • Percutaneous embolization for the management of Grade 5 renal trauma in hemodynamically unstable patients: initial experience. J Urology 181:1737-1741, 2008.
  • Intermediate-term follow-up of patients treated with percutaneous embolization for Grade 5 blunt renal trauma. J Trauma 69(2):468-470, 2010.
Abdomen

Contemporary Management Of Renal Injuries

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A synopsis of contemporary management of renal injury was presented at the annual meeting of the American Association for the Surgery of Trauma last year. The Genito-Urinary Trauma Study Group (GUTS [groan!]) prospectively collected data on high-grade (grades 3-5) renal injuries from 14 Level I trauma centers over a 14 year period.

Here are some factoids from the article:

  • Expectant management (nonoperative or minimally invasive angio/stenting/drainage) was the norm, with 80% of these high-grade injuries dealt with in this manner
  • Only 6% of patients undergoing minimally invasive treatment underwent angioembolization
  • As expected, the higher the grade, the more likely the kidney would be removed (Grade 4 = 15%, Grade 5 = 62%)
  • Once operative management was performed, the nephrectomy rate escalated to 67%
  • Nephrectomy was more common in patients with penetrating trauma (60%)

Bottom line: Nonoperative management of renal injuries has long been the norm. This more recent review confirms it. Once the abdomen is opened, the chance of losing the entire kidney skyrockets. Expectant management (repeat exam and labs) is very common, and very successful. 

Angiography is an important adjunct, but was not used very commonly in this study. Perhaps the surgeons were concerned about complications from embolizing part or all of the kidney? I’ll discuss the consequences of this in my next post.

Reference: Contemporary management of high-grade renal trauma: Results from the American Association for the Surgery of Trauma Genitourinary Trauma study. J Trauma 84(3):418-425, 2018.

General

Evaluation of Hematuria in Blunt Trauma

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Hematuria ranges from microscopic to gross. Microscopic means blood that can only be seen with a microscope, and gross means visible to the naked eye. In trauma, we only care about gross hematuria, which ranges from the faintest of pink to the deepest red.

In trauma, gross hematuria is a result of an injury to kidney, ureter or bladder. Blunt injury to the ureter is so rare it’s reportable, so you can pretty much forget that one unless the mechanism is extreme. So you really just need to focus on kidney and bladder.

Any victim of blunt trauma that presents with visible hematuria needs to be evaluated by CT of the abdomen and pelvis with an added CT cystogram. Standard CT technique is done without a urinary catheter, or with the catheter clamped. Only 50% of bladder injuries show up with this technique.

CT cystogram is an add-on to the standard CT, and consists of the administration of contrast into the bladder which is then kept under pressure while the scan is done. Delayed slices through the pelvis after the bladder is depressurized and emptied is routine. Nearly 100% of bladder injuries are detected using this technique.

If the CT shows a renal laceration or hematoma, the patient should be admitted and managed according to your solid organ injury protocol. Kidney injuries fare better that livers and spleens, and only rarely require surgery. If no kidney or bladder injury is seen, the default diagnosis of a renal contusion is the culprit. No treatment is needed, and the patient can be discharged if no other injuries are present. The blood will clear over a few days, but may disappear and reappear a few times in the process. The patient can followup with their primary care physician in a week or two.

General

AAST 2011: Acute Kidney Injury From IV Contrast

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Yesterday, I wrote about using acute kidney injury (AKI) as a predictor for multiple organ failure. But what about kidney failure that we may inadvertently create through the use of IV contrast during CT scan evaluation? Contrast is generally safe for use in the general trauma population, but is known to cause renal problems in high risk groups like the elderly and critically ill.

Investigators at UCSD retrospectively reviewed ICU patients who had no history of pre-existing renal disease. A total of 570 eligible patients were identified, and 170 (30%) developed AKI. Being old (age>=75) or severely injured (ISS>=25) was a predictor of AKI, but IV contrast was not. Even during subgroup analysis, the addition of contrast to the elderly or severely injured patient population did not predict AKI.

Bottom line: This limited study shows that IV contrast exposure may be considered safe, even in the elderly and severely injured. However, I still recommend that all risks and benefits be thoroughly weighed in every patient, and that scans that have little diagnostic and therapeutic benefit be avoided.

Reference: Is contrast exposure safe among the highest risk trauma patients? AAST 2011 Annual Meeting, Paper 69.