Should we use Doppler endoscopic probe for management of patients with severe non-variceal gastrointestinal hemorrhage? No.

This is half of a two-part debate — read the opposing argument.

Recurrent bleeding, along with advanced age and medical co-morbidities, is an independent predictor of mortality in patients with upper gastrointestinal (GI) hemorrhage. Although we as endoscopists cannot alter the patient’s age or their comorbidities, we may be able to reduce the risk of recurrent GI bleeding with correct risk stratification and effective endoscopic hemostasis.1-3 Currently, we use visual inspection for risk stratification of the endoscopic stigmata of hemorrhage (e.g., Forrest classification) and then post-hemostasis to assess the adequacy of endoscopic therapy.  This visual approach remains subjective and limited by interobserver variability in identifying high versus low risk endoscopic stigmata as well as in determining the effectiveness of hemostasis.  The need for a more objective method such as Doppler ultrasound, used as an adjunct to visual inspection, is indeed warranted.  Since most of the data on the utility of Doppler ultrasound in GI bleeding has focused on non-variceal bleeding, more specifically peptic ulcer hemorrhage, I will limit my commentary to this patient population.

The utility of a Doppler ultrasound endoscopic probe (DOP-US) in GI bleeding was first reported in the 1980s. European and North American investigators have subsequently published studies on this subject, yet there has been great, recent interest in DOP-US in GI bleeding from Dr. Dennis Jensen and the UCLA Hemostasis Research Group.4,5 As compared to visually guided endoscopic hemostasis, the use of DOP-US may provide improved risk stratification for endoscopic stigmata of bleeding and significantly reduce post-hemostasis 30-day re-bleeding rates.4,5 Secondary outcomes — including the need for blood transfusion, surgery, and mortality — may be reduced, but have thus far failed to meet statistical significance.5 Some have suggested the adoption of DOP-US as an additional, necessary tool in our endoscopic hemostasis armamentarium.6

Given the above, why do I take the contrarian view? In my opinion, DOP-US for use in GI bleeding is not yet ready for prime time because there are still important questions that remain to be asked and answered adequately. For example, do we have adequate data on the test characteristics of DOP-US in GI bleeding? In other words, what are the false positive and false negative Doppler signal rates both for risk stratifying lesions and for then confirming the effectiveness of hemostasis? Moreover, what are the interobserver variability data for DOP-US in GI bleeding? What are the endoscopic technical skills that are required when using DOP-US? Are these skills readily learned? What does the learning curve look like? What are the risks of adverse events in the hands of non-experts? What are the economic costs? The up-front costs, the downstream costs, and cost-effectiveness? We currently have no answers to these questions.  Moreover, and importantly, I believe we need additional data, originating from outside of specialized centers that focus on GI bleeding, that confirm the utility of DOP-US before I jump on the DOP-US bandwagon.


In my opinion, DOP-US for use in GI bleeding is not yet ready for prime time because there are still important questions that remain to be asked and answered adequately.


Although DOP-US is not endoscopic ultrasound (EUS) and does not require advanced endoscopic training, education of the endoscopist is required.7 There are no published data on the learning curve required to achieve competence in the use of DOP-US in GI bleeding.  In order to use DOP-US effectively in GI bleeding, the endoscopist must first wash the ulcer base to remove any debris that may interfere with the DOP-US auditory signal. The probe must be properly aligned to the mucosa to detect the doppler signal since perpendicular alignment will fail to detect blood flow and the endoscopist must continually vary the angle of the doppler probe at multiple points of contact on the ulcer base to maximize the doppler signal.4,5 These manipulations must be repeated in all four quadrants of the ulcer base while varying the depth setting of the DOP-US probe signal. The endoscopist must also learn to correctly differentiate the arterial from the venous doppler signal.  Furthermore, concerted attention must be paid by the endoscopist in cases where submucosal injection (e.g., dilute epinephrine) was made, an adherent clot is present, or endoscopic clip(s) were placed since a false negative and/or obscured doppler signal may be encountered.6,7

To date, the evidence supporting the utility of DOP-US in GI bleeding comes from only a few centers, all highly specialized in GI bleeding, and by investigators who are very skilled at endoscopic hemostasis. Extrapolating the results from the current limited published data to the community-based “Joe or Joanne” gastroenterologist cannot and should not be assumed. Many gastroenterologists have not even been fully trained on all the available endoscopic hemostasis modalities we already have in our toolbox, let alone learning to use a DOP-US probe.

There are limitations to the use of DOP-US. In the most recent publications using DOP-US in peptic ulcer bleeding, large-channel therapeutic upper endoscopes were used.11,12 Despite GI bleeding guidelines recommending the use of large channel endoscopes in the setting of acute upper GI bleeding, such endoscopes may not be readily available or be routinely used in every day community practice. In addition, the Doppler signal may be overly sensitive (false positive signal) in low risk appearing lesions (e.g., Forrest IIc, III) that may lead to over treatment and thereby potentially increase adverse events. Conversely, a post-hemostasis false negative signal may lead to a false sense of security when the patient is still at risk for rebleeding. In other words, we do not yet have accurate test characteristics for DOP-US in GI bleeding. Last, adverse events have been reported to be low, but this may be an underestimation since GI bleed experts were the investigators conducting these studies.

DOP-US may indeed have a role in GI bleeding, especially in the post-hemostasis setting in high-risk endoscopic stigmata, to ensure the adequacy of endoscopic therapy and thereby reduce the risk of rebleeding. However, in my opinion, additional high-level evidence coming from community-based studies, are required to convince me that DOP-US in peptic ulcer hemorrhage is ready for wide spread adoption. Please convince me!

Disclosures: Dr. Gralnek has a retainer agreement with Motus GI. Professor Gralnek is the Secretary General of the European Society of Gastrointestinal Endoscopy (ESGE).


Dr. Jensen describes why Dopler should be used.


References

1.  Gralnek I.M., Barkun A.N., Bardou M., Watson D.I. Management of acute bleeding from a peptic ulcer. N Engl J Med. 2008;359:928-937.

2. Laine L., Jensen D.M. Management of patients with ulcer bleeding. Am J Gastroenterol. 2012;107:345-360.

3. Gralnek I.M., Dumonceau J.M., Kuipers E.J., et al. Diagnosis and management of nonvariceal upper gastrointestinal hemorrhage: European society of gastrointestinal endoscopy (ESGE) guideline. Endoscopy. 2015;47:a1-a46.

4. Broeders J.A., Roks D.J., Jamieson G.G., Devitt P.G., Baigrie R.J., Watson D.I. Doppler endoscopic probe as a guide to risk stratification and definitive hemostasis of peptic ulcer bleeding. Gastrointest Endosc. 2016;83:129-136.

5. Jensen D.M., Kovacs T.O.G., Ohning G.V., et al. Doppler endoscopic probe monitoring of blood flow improves risk stratification and outcomes of patients with severe nonvariceal upper gastrointestinal hemorrhage. Gastroenterology. 2017;152:1310-1318.

6. Nayor J., Saltzman J.R. Should we all be using the doppler endoscopic probe in nonvariceal upper gastrointestinal bleeding? Gastroenterology. 2017;152:1280-1282.

7. Wong R.C.K. Technology review: Endoscopic doppler ultrasound probe for acute peptic ulcer hemorrhage. Gastrointest Endosc. 2004;60:804-812.

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