Tag Archives: diaphragm

5 Guidelines For Diaphragmatic Injury

Today’s post is another review of some of the practice guidelines published by the Eastern Association for the Surgery of Trauma (EAST).  This one covers the evaluation and management of diaphragmatic injury.

Diaphragm injury is a troublesome one to diagnose. It is essentially an elliptical sheet of muscle that is doubly-curved, so it does not lend itself well to diagnosis by axial imaging. Addition of sagittal and coronal reconstructions to a thoraco-abdominal CT has been helpful, but still has a far from perfect diagnostic record.

From an evaluation standpoint, there are several possibilities:

  • Observation – not generally recommended. It is usually combined with imaging such as chest x-ray to see if interval changes occur that would indicate the injury.
  • Chest x-ray – this is not often diagnostic, but when herniation of abdominal contents is obvious the patient most assuredly has an operative problem.
  • Thoraco-abdominal CT scan – this technology keeps getting better, especially with thinner cuts and different planes of reconstruction. Sometimes even subtle injuries can be detected. But this exam is still imperfect.
  • Laparoscopy or thoracoscopy – this technique yields excellent accuracy when the injury is in an area that can be viewed from the operative entry point chosen.
  • Laparotomy or thoracotomy – this is the ultimate choice and should be nearly 100% accurate. It is almost the most invasive and has more potential associated complications.

EAST reviewed a large body of literature and selected 56 pertinent papers for their quality and design. They critically reviewed them and applied a standard methodology to answer several questions.

Here are the questions with the recommendations from EAST, along with my comments:

  • Should laparoscopy or CT be used to evaluate left-sided thoraco-abdominal stab wounds? First, these patients must be hemodynamically stable and not have peritonitis. If either is present, there is no further need for diagnosis; a therapeutic procedure must be performed.
    Left sided diaphragm injuries from stabs are evil. The hole is small, and since the pressure within the abdomen is greater that the chest, things always try to wiggle their way through this small hole. It can remain asymptomatic if the wiggler is just a piece of fat, but can be catastrophic if a bit of the stomach or colon pushes through and becomes strangulated. Furthermore, these holes enlarge over time, so more and more stuff can push up into the chest.
    EAST recommends the use of laparoscopy for evaluation to decrease the incidence of missed injury. However, if the injury is in a less accessible location (posterior), the patient has body habitus issues, or adhesions from previous surgery may lead to incomplete evaluation, laparotomy should be strongly considered.
  • Should operative or nonoperative management be used to evaluate right-sided thoraco-abdominal penetrating wounds? Note that this is different than the last question. All penetrating injuries are included (stabs and gunshots), and this one is for management, not evaluation. And the same caveats regarding hemodynamic stability and peritonitis apply. It applies to both stabs and gunshots.
    Unlike left-sided injuries, right-sided ones are much more benign. The liver keeps anything from pushing up through small holes, and they do not tend to enlarge over time due to this protection. For that reason, EAST recommends nonoperative management to reduce mortality and morbidity related to operation.
  • Should stable patients with acute diaphragm injury undergo repair via an abdominal or thoracic approach? This question applies to any diaphragm injury that requires operation, such as right-sided penetrating injury or any blunt injury. EAST recommends an approach from the abdomen to reduce morbidity and mortality. Since abdominal injury frequently occurs in these cases, an approach from the chest limits the ability to identify and repair abdominal injuries. Otherwise, you may find yourself doing a laparotomy in addition to the thoracotomy.
  • Should patients with delayed visceral herniation through a diaphragm injury undergo repair via an abdominal or thoracic approach?  For years, the preferred approach for delayed presentations has been through the chest because the injury is easier to appreciate and repair.  However, if ischemic or gangrenous viscera are present, it will be more difficult to manage and repair from the chest. EAST does not make a specific recommendation for this question and suggests the surgical approach be determined on a case by case basis.
  • Should patients with an acute diaphragm injury from penetrating injury without concern for other intra-abdominal injuries undergo open or laparoscopic repair? The quality and quantity of data addressing this question were very low, but EAST recommends laparoscopy for repair of these injuries to reduce morbidity and mortality. This includes blunt injuries, which tend to be larger. There were some conversions to an open procedure, especially in the blunt cases. The usual caveats on exposure, injury location, body habitus and previous surgery apply.

Reference: Evaluation and management of traumatic diaphragmatic injuries: A Practice Management Guideline from the Eastern Association for the Surgery of Trauma. J Trauma 85(1):198-207.

How To Evaluate A Stab To The Diaphragm – Part 2

Yesterday I gave a little perspective on the use of CT in assessing the diaphragm after penetrating injury. Today, I’ll break it down into some practical steps you can follow the next time you see one.

Step 1. Stable or unstable? If your patient arrives with unstable vital signs, and there is no other source but the abdomen, the answer is simple. Go to the OR for a laparotomy. Period. They are exsanguinating and the hemorrhage needs to be stopped.

Step 2. Mark the sites of penetration and take a chest x-ray. This will let you evaluate the potential trajectory of the object, and will give you your first glimpse of the diaphragm.

Step 3. Examine the abdomen. Actually, you should be doing this at the same time you are setting up for Step 2. If your patient has peritoneal signs, no further evaluation is needed. Just go to the OR for laparotomy. Look at the chest x-ray once you get there.

Step 4. Right side? If your appreciation of the path of penetration involves just the liver, take the patient to CT for evaluation of chest, abdomen, and pelvis. You need to see all three of these areas to assess for blood and fluid in both body cavities. After the study, if you still think the injury is limited to the liver, admit the patient for observation.

Step 5. Left side? Look at that chest x-ray again. If there are any irregularities at all, strongly consider going to the OR and starting with diagnostic laparoscopy. These irregularities can be glaring, like in the x-ray above. But they can be subtle, like some haziness above the diaphragm or small hemothorax. Obviously, if the injury is as clear as on the x-ray above, just open the abdomen. But if in doubt, start small. And remember my advice on “lunchothorax.”

Step 6. Admit and observe. Check the abdomen periodically, and repeat the chest x-ray daily. If anything changes, consider diagnostic laparoscopy. As a general rule, I don’t keep patients NPO “just in case.” Most will pass this test, and I don’t see a reason to starve my patients for the low likelihood they need to go to the OR.

Step 7. Make sure your patient gets a follow up evaluation. See them in your outpatient clinic, get a final chest x-ray and abdominal exam before you completely clear them.

How To Evaluate A Stab To The Diaphragm – Part 1

Penetrating injury to the diaphragm, and specifically stab wounds, have been notoriously hard to diagnose since just about forever. Way back in the day (before CT), we tried all kinds of interesting things to help figure out if the patient had a real injury. Of course, we could just go to the OR and lap the patient (laparoscopy did not exist then). But the negative lap rate was significant, so we tried a host of less invasive techniques.

Remember diagnostic peritoneal lavage? Yeah, we tried that. The problem was that the threshold for red cells per cubic mm was not well defined. Some would supplement this technique with a chest tube to see if lavage fluid would drain out. And one paper described instilling nuclear medicine tracer into the abdomen and sitting the patient under a gamma camera for a few hours to see if any ended up in the chest. Groan!

We thought that CT would save us. Unfortunately, resolution was terrible in the early years. If you could actually see the injury on CT, it was probably because a large piece of stomach or colon had already fallen through it. But as detectors multiplied and resolution improved, we could begin to see some smaller defects. But we still missed a few. And the problem is that left-sided diaphragmatic holes slowly enlarge over time (years), until the stomach or colon falls through it. (See below)

A group of radiologists and surgeons in a Turkish trauma hospital recently published a modest series of patients with left-sided diaphragm injuries evaluated by CT. They looked at about 5 years of their experience in a group of patient who were at risk for the injury due to a thoraco-abdominal stab wound. Unstable patients were immediately taken to OR. All of the remaining patients underwent an initial CT scan, followed by diagnostic laparoscopy after 48 hours if they remained symptom free.

Here are the factoids:

  • A total of 43 stable patients with a left thoraco-abdominal stab were evaluated
  • 30 patients had a normal CT, and 13 had the appearance of an injury
  • Of those who were CT positive, only 9 of 13 (69%) actually had the injury at operation
  • Two of the 30 (7%) who were CT negative were found to have a diaphragm injury during followup laparoscopy
  • So in the author’s hands, there was 82% sensitivity, 88% specificity, a positive predictive value of only  69%, and a negative predictive value of 93%

Bottom line: The authors somehow looked at the numbers and concluded that CT is valuable for detecting left diaphragm injury. Huh? They missed 7% of injuries, only finding them later at laparoscopy. And they had a 31% negative laparotomy rate. 

Now, it could be that the authors were using crappy equipment. Nowhere in their paper do they state how many detectors, or what technique was used. Since it took place over a 5 year period, it is quite possible that the earlier years of the study used equipment now considered to be out of date, or that there was no standardized technique.

CT may not yet be ready for prime time. But it can be a valuable tool. Tune in tomorrow for some tips on how and when to look for this insidious injury.

Reference: Evaluation of diaphragm in penetrating left thoracoabdominal
stab injuries: The role of multislice computed tomography. Injury 46:1734-1737, 2015.

What Is: Lunchothorax?

Here’s an operative tip for trauma professionals who find themselves in the OR. Heard of “lunchothorax?” I’m sure most of you haven’t. The term originated in a 1993 paper on the history of thoracoscopic surgery. It really hasn’t been written about in the context of trauma surgery, though.

Lunchothorax is an empyema caused by pleural contamination in patients with concomitant diaphragm and hollow viscus injury. This most commonly occurs with penetrating injuries to the left upper quadrant and/or left lower back. The two penetrations tend to be in close proximity (diaphragm + stomach), but may occasionally be further away (diaphragm + colon).

One of the earlier papers describing the correlation of gastric injury and empyema was written by one of my mentors, John Weigelt. Although gastric repair is usually simple and heals well, his group did note a few severe complications. Of 243 patients with this injury, 15 developed ones that were considered severe, and 10 of those were empyema! What gives?

It turns out that the combination of gastric contents and pleural space is not a good one. It’s not really clear why this is. Is it bacterial? The acid? Undigested food? I’ve seen cases with what I would consider minimal contamination go on to develop a nasty empyema. This is also borne out in a National Trauma Databank review from 2009. It looked at complications in patients with a diaphragm injury and found that a gastric injury increased the probability of empyema by 3x. Interestingly, there was no increased risk of empyema with a concomitant colon injury.

Bottom line: Lunchothorax, or empyema after even minimal contamination from a hollow viscus, is a dreaded complication of thoraco-abdominal penetrating injury. Any time the stomach and diaphragm are violated, I recommend thoroughly irrigating the chest. It’s probably a good idea for concomitant colon injury as well, but there’s less literature support.

This can be done through the diaphragm injury if it is large enough, or through a chest tube inserted separately. Most of the time, you’ll be placing the chest tube anyway because the pleural space has been violated via the abdomen. In either case, copious lavage with saline is recommended to clear all particulate material, with a few extra liters just for good measure. There’s no data on use of antibiotics, but standard perioperative coverage for the abdominal injuries should be sufficient if the lavage was properly performed.

References:

  • The history of thoracoscopic surgery. Ann Thoracic Surg 56(3):610-614, 1993.
  • Penetrating injuries to the stomach. SGO 172(4):298-302, 1991.
  • Risk factors for empyema after diaphragmatic injury: results of a National Trauma Databank analysis. J Trauma 66(6):1672-1676, 2009. 

How To Evaluate A Stab To The Diaphragm – Part 2

Yesterday I gave a little perspective on the use of CT in assessing the diaphragm after penetrating injury. Today, I’ll break it down into some practical steps you can follow the next time you see one.

Step 1. Stable or unstable? If your patient arrives with unstable vital signs, and there is no other source but the abdomen, the answer is simple. Go to the OR for a laparotomy. Period. They are exsanguinating and the hemorrhage needs to be stopped.

Step 2. Mark the sites of penetration and take a chest x-ray. This will let you evaluate the potential trajectory of the object, and will give you your first glimpse of the diaphragm.

Step 3. Examine the abdomen. Actually, you should be doing this at the same time you are setting up for Step 2. If your patient has peritoneal signs, no further evaluation is needed. Just go to the OR for laparotomy. Look at the chest x-ray once you get there.

Step 4. Right side? If your appreciation of the path of penetration involves just the liver, take the patient to CT for evaluation of chest, abdomen, and pelvis. You need to see all three of these areas to assess for blood and fluid in both body cavities. After the study, if you still think the injury is limited to the liver, admit the patient for observation.

Step 5. Left side? Look at that chest x-ray again. If there are any irregularities at all, strongly consider going to the OR and starting with diagnostic laparoscopy. These irregularities can be glaring, like in the x-ray above. But they can be subtle, like some haziness above the diaphragm or small hemothorax. Obviously, if the injury is as clear as on the x-ray above, just open the abdomen. But if in doubt, start small.

Step 6. Admit and observe. Check the abdomen periodically, and repeat the chest x-ray daily. If anything changes, consider diagnostic laparoscopy. As a general rule, I don’t keep patients NPO “just in case.” Most will pass this test, and I don’t see a reason to starve my patients for the low likelihood they need to go to the OR.

Step 7. Make sure your patient gets a follow up evaluation. See them in your outpatient clinic, get a final chest x-ray and abdominal exam before you completely clear them.

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