What Is: A Morel-Lavallee Lesion?

Anyone who takes care of blunt trauma has seen the Morel-Lavallee lesion (M-L). Here’s an obvious one because it’s acute:

The M-L lesion is essentially a closed degloving injury in which the skin remains intact. The subcutaneous tissue is sheared off of the underlying fascia, and typically blood accumulates in the potential space that is created. This picture shows a less acute lesion; the bruising and ecchymosis on the surface have resolved. Note the collection on the lateral thigh:

These injuries may take a very long time to resolve and may leave some residual deformity. The definitive management has never been very clear: needle drainage vs incision, timing, compression wraps, etc.

The Mayo Clinic reviewed their 8 year experience with 87 of these lesions to try to shed some light on proper management. They treated their patients in four different ways: needle drainage, incision and drainage, compression wraps, and debridement with vacuum drainage devices. Here are the factoids from their study:

  • Motor vehicle crash was the most common etiology for this lesion, which makes sense due to the energy needed to shear the tissues
  • The most common locations were thigh, hip and flank
  • The incidence of pre-existing conditions that might influence outcome (diabetes, obesity, smoking history, use of anticoagulants) did not seem to influence outcomes
  • Lesion location did not change the recurrence rate (even over joints)
  • Aspiration suffered the highest recurrence rate (56%) vs only 15-19% in the other groups
  • Aspiration of more than 50cc of fluid was more common in lesions that recurred (83%) vs those that did not (33%)

Their experience led them to develop the following practice guideline:

Bottom line: The Morel-Lavallee lesion can be challenging to treat. Although this study has limited numbers, it provides enough guidance to suggest a consistent way of managing it. I recommend adopting this algorithm to provide a standard pathway for dealing with it.

Reference: The Mayo Clinic experience with Morel-Lavallee lesions: establishment of a practice management guideline. J Trauma 76(2):493-497, 2014.

Doctor, I Fell On That Knife! Really!?

I’ve had this mechanism of injury described about once a year for my entire career.

“I was just washing the dishes, and I dropped a knife while I was drying it. When I went to pick it up, I lost my balance and tripped over the rug in front of my sink. Then I fell down on the knife, and there you have it”.

What does it really mean?

First, think about physics. Most knives do not land standing straight up. They don’t even land on their side with the blade side up. They land flat with the sharp side perpendicular to anything that might fall on top of it.

Then think about Occam’s razor. You remember, Sir William of Occam back in the 1300’s. He popularized the principle of parsimony in problem solving. What does this mean? If you have more than one possible explanation (or hypothesis) for an event, the simplest one should be selected. Well, the falling down “hypothesis” is way too complicated.

What does it really mean? Your patient either stabbed themself (most common reason), or they are trying to protect the person who really did it (significant other). What to do? Interrogate them, asking the same thing over and over. Ask for exact details. Ask until the story changes. Have other people ask. Sooner or later, you’ll get the answer you were expecting. Then get the appropriate professionals involved to help with the problem (psych, law enforcement, etc).

The January newsletter is now available! Yes, it’s a little late due to my travel schedule. Click the image below or the link at the bottom to download. This month’s topic is Pediatric Trauma. 

In this issue you’ll find articles on:

  • Pediatric ATV injuries
  • DVT in children
  • Identifying sick pediatric trauma patients early
  • Pneumothorax in kids
  • Pediatric pneumomediastinum

Subscribers received the newsletter first on Friday. If you want to subscribe (and download back issues), click here.

Download the newsletter here!

Pancreatic Injury Part 4 – Nonop Management For Kids?

Over the past 30 years or so, we’ve made major advances in managing many injuries without operation. Blunt injuries to liver, spleen, and kidney, along with some penetrating injuries to the liver come to mind. But as we have seen many times in medicine, the pendulum sometimes swings too far.

Hopefully, I’ve impressed upon you how strange and potentially treacherous the pancreas is. In recent years, some centers have dabbled with nonoperative management of the pancreas in children. The belief has been that, since kids heal so much better than adults, maybe the pancreas will be more forgiving in that age group. Unfortunately, the only studies to date have been small, single center work.

But now, a collaborative Pancreatic Injuries In Children Study Group has published results of a multi-institutional retrospective review which will hopefully lay this debate to rest (at least for a while).

Here are the factoids:

  • The study reviewed data from 1195-2012 (18 years!) on patients less than 18 years old. Only grade II or III injuries were selected. Grade was determined by CT, ERCP, MRCP or at operation.
  • Fourteen centers participated, submitting data on 167 patients. These are huge numbers for this uncommon injury!
  • 57 underwent distal pancreatectomy, 95 were managed without operation. The remainder were drained and were studied separately.
  • Diet was resumed significantly more quickly (8 days vs 15 days) in the resection group
  • More endoscopic and interventional procedures were needed due to pseudocyst formation in the nonoperative group (26% vs 2%)
  • Patients with Grade III injuries (distal duct) had fewer complications after resection (33% vs 61%)
  • Hospital stay was significantly shorter in the resection group (13 vs 18 days)

Bottom line: Operative resection of distal pancreatic injury in children is the way to go, just as it is in adults. Persistent attempts to treat without surgery keeps the child in the hospital longer, exposes them to additional invasive procedures, and is fraught with more complications. You may think you’re saving them the pain of major abdominal surgery, but you are just prolonging the torture with endoscopy, IR drainage, repeated blood draws, and starvation.

Related posts:

Reference: Operative vs nonoperative management for blunt pancreatic transection in children: multi-institutional outcomes. J Am Coll Surg 218(2):157-162, 2014.

January Newsletter Released To Subscribers Tonight!

Due to my heavy travel schedule last month, I’ve been slow in getting the January newsletter together. But it’s now ready! The topic is Pediatric Trauma. Articles include:

  • Pediatric ATV injuries
  • DVT in children
  • Identifying sick pediatric trauma patients early
  • Pneumothorax in children
  • Pediatric pneumomediastinum

Anyone on the subscriber list as of 8PM tonight (CST) will receive it by email tonight. I’ll release it to everyone else next Monday via the blog. So sign up for early delivery now by clicking here!

Pick up back issues here!