What is a Gold Probe Endoscopy?
An endoscopy utilizing a gold probe is a specialized procedure for treating bleeding sites in the gastrointestinal (GI) tract. The gold probe is a type of bipolar electrohemostasis catheter that works by applying an electrical current and pressure to coagulate blood vessels and stop bleeding. The current flows only between the two electrodes on the tip of the probe, minimizing the depth and spread of tissue injury compared to other thermal methods. Additionally, many models, known as Injection Gold Probes, have the capability to inject pharmacological agents, such as epinephrine, directly into the bleeding site to aid in vasoconstriction and mechanical compression.
How Bipolar Electrocoagulation Works
Bipolar electrocoagulation relies on the principle of passing a high-frequency electrical current through the tissue to generate heat. The key features include:
- Localized Current: The current flows between two closely spaced electrodes at the probe's tip, limiting the energy's path. This confines the thermal effect to the area directly in contact with the tissue.
- Coaptive Pressure: The physician applies firm pressure with the probe tip directly to the bleeding vessel. This mechanical compression, combined with the electrical energy, welds the vessel walls together, effectively sealing the bleed.
- Controlled Heat: The system is designed to provide sufficient heat for coagulation while preventing excessive tissue damage. The resistance of the desiccated tissue increases exponentially, which helps limit deeper coagulation.
The Step-by-Step Procedure for Using a Gold Probe
Using a gold probe requires careful preparation and a precise technique, performed by a trained physician in an endoscopy suite.
Pre-Procedure Patient Preparation
Patient preparation is crucial for safety and procedural success.
- Fasting: The patient must fast for a specified period (typically 6-8 hours for solids and 4 hours for liquids) to ensure the stomach is empty, allowing for a clear view and reducing aspiration risk.
- Medication Review: Blood-thinning medications and NSAIDs are often temporarily discontinued prior to the procedure to minimize bleeding risk, with specific instructions provided by the doctor.
- Sedation: The patient is sedated to ensure comfort and cooperation during the procedure. A numbing throat spray may also be used.
Instrument Setup and Testing
Before the probe is inserted, the equipment must be properly configured.
- Generator Connection: The probe is connected to a compatible bipolar electrosurgical generator. No patient plate is needed for bipolar devices.
- Irrigation Setup: A syringe filled with saline is connected to the probe's irrigation hub. The probe is flushed to confirm clear flow at the distal tip.
- Activation Test: The tip of the probe is briefly submerged in a small amount of saline or jelly and activated with the foot pedal. Bubbles and steam should be visible, confirming the device is working correctly.
The Therapeutic Endoscopy Steps
Once the endoscope is in position, the gold probe is advanced to the target.
- Advance the Endoscope: The physician inserts the endoscope through the mouth and guides it to the location of the bleeding lesion in the esophagus, stomach, or duodenum.
- Insert the Probe: The gold probe is passed through the endoscope's working channel. The electrosurgical generator is turned off during insertion to prevent accidental activation.
- Position the Probe: The probe is advanced until the golden tip is visible. The endoscopist positions the tip perpendicular or tangential to the bleeding site.
- Apply Pressure: Firm, coaptive pressure is applied to the bleeding vessel to compress the tissue.
- Activate Cautery: While maintaining pressure, the physician activates the probe using the foot pedal for a short duration (2-5 seconds). Appropriate power settings are used depending on the lesion type and location.
- Irrigate and Detach: Before removing the probe from the cauterized site, it is irrigated with saline to prevent the tip from adhering to and pulling off the treated tissue, which could cause rebleeding.
- Repeat as Necessary: The process is repeated until hemostasis is achieved. If using an Injection Gold Probe, the injection of epinephrine is performed before cautery.
Comparison of Hemostasis Techniques
| Feature | Gold Probe (Bipolar Coagulation) | Heater Probe | Endoscopic Clips | Injection Therapy (Monotherapy) |
|---|---|---|---|---|
| Mechanism | Electrical current and coaptive pressure coagulate vessel. | Heat-induced coagulation via heated saline at the tip. | Mechanical closure and compression of the bleeding vessel. | Injection of a sclerosing agent or vasoconstrictor (e.g., epinephrine). |
| Speed of Action | Fast and effective. | Fast and effective. | Instant mechanical hemostasis upon deployment. | Immediate mechanical tamponade but requires a secondary therapy for definitive hemostasis. |
| Depth Control | Controlled, localized depth due to bipolar current. | Deeper, less localized thermal effect. | Precise, limited to the clipped tissue. | Diffuse and dependent on injection technique. |
| Effectiveness | High efficacy, especially combined with injection therapy. | Highly effective; standardized technique widely used. | Very effective for discrete vessels; can be technically challenging. | Not recommended as monotherapy due to high rebleeding rates. |
| Potential Risks | Localized tissue burns, perforation, rebleeding. | Deeper tissue damage, perforation. | Clip misplacement, tissue tears, rebleeding. | Systemic effects (tachycardia with epinephrine), tissue necrosis, rebleeding. |
| Application | Suitable for peptic ulcers, AVMs, Mallory-Weiss tears. | Similar applications to the gold probe. | Excellent for visible vessels, diverticular bleeding, and prophylactic closure. | Often used in combination with thermal or mechanical methods. |
Potential Risks and Patient Aftercare
While gold probe endoscopy is a safe and common procedure, potential risks exist, including bleeding, perforation, and infection. Device-related malfunctions have also been reported, highlighting the need for proper training and device handling.
Following the procedure, patients are monitored in a recovery area until the sedation effects wear off. Aftercare instructions are critical for a smooth recovery.
Post-Procedure Care
- Recovery Room: Patients are monitored for a few hours until the sedative effects have worn off.
- Diet: Start with clear liquids and slowly progress to solid foods as tolerated. Avoid spicy, greasy, or acidic foods that might irritate the GI tract.
- Rest: Take it easy for at least 24 hours. Avoid driving, operating machinery, and making important decisions.
- Discomfort Management: A mild sore throat, bloating, or cramping is common and usually resolves within a day or two. Over-the-counter pain relievers can be used if approved by the physician, but aspirin and NSAIDs should be avoided due to the increased risk of bleeding.
- When to Seek Medical Attention: Patients should contact their doctor immediately if they experience severe or persistent abdominal pain, difficulty swallowing, fever, or signs of rebleeding (e.g., blood in vomit or dark, tarry stools).
Conclusion
Gold probe endoscopy is an established, effective, and safe method for controlling gastrointestinal bleeding. By using bipolar electrocoagulation and coaptive pressure, and sometimes in combination with injection therapy, physicians can achieve precise hemostasis for a variety of conditions, including peptic ulcers and Dieulafoy lesions. While the procedure is generally safe, proper patient preparation, skilled technique, and careful post-procedure care are essential to minimize risks and ensure a successful outcome. It is a vital tool in the endoscopist's armamentarium, playing a crucial role in improving patient outcomes for GI bleeding episodes.
For more detailed information on endoscopic hemostasis devices and guidelines, consult resources from authoritative sources like the American Society for Gastrointestinal Endoscopy.
