Celiac Plexus Block - Indications, Contraindications, and Technique.

Introduction:

Abdominal discomfort caused by chronic pancreatitis and pancreatic cancer is frequently debilitating and is initially treated with medications. Non-opioid medications are used to treat pancreatic cancer pain. More potent opioid drugs are commonly required since non-narcotic treatments are ineffective for pain management and are linked with many side effects, such as nausea and constipation. If patients have persistent pain or are unable to tolerate increasing doses of opioid medicines, endoscopic ultrasound (EUS)-guided celiac plexus block (CPB) and celiac plexus neurolysis (CPN) can help. Celiac plexus block (CPB) is a brief therapy that involves administering a steroid and a long-acting local anesthetic into the celiac plexus.

The celiac plexus block targets afferent nociceptive fibers and can be utilized as a diagnostic and therapeutic method for controlling intra-abdominal discomfort. Intractable intra-abdominal pain and pain associated with malignant or benign cancers involving the pancreas or other retroperitoneal organs, biliary tree, or other abdominal organs may benefit from celiac plexus blocks. The celiac plexus block is utilized as a multimodal adjuvant to manage abdominal visceral discomfort. The celiac plexus comprises three ganglia: celiac ganglia, superior mesenteric ganglia, and aortic renal ganglia. In addition, the celiac plexus provides an autonomic supply to many abdominal organs.

What Is the Anatomy of the Celiac Plexus?

• The celiac plexus is also known as the solar plexus because of the presence of an extensive network of nerve fibers.

• The celiac plexus provides autonomic innervates to several abdominal organs, including the liver, gallbladder, stomach, pancreas, spleen, kidneys, the whole small intestine, and the first two-thirds of the large intestine.

• The celiac plexus comprises the celiac, aortic, renal, and superior mesenteric ganglia and is located anterolateral to the aorta diaphragm at the first lumbar vertebrae. The celiac plexus is made up of both sympathetic and parasympathetic nerves.

• The sympathetic innervation of the celiac plexus originates in the spinal cord's anterolateral horn, between the thoracic fifth and the thoracic twelve vertebrae.

What Are the Indications of the Celiac Plexus Block?

• The most common indications for celiac plexus block (CPB) include stomach discomfort that is unresponsive to analgesic treatments, and these patients are frequently unresponsive to high-dose opioid therapy.

• A celiac plexus block is used to treat refractory intra-abdominal pain, including discomfort caused by malignant and benign neoplasms of the pancreas, biliary tree, retroperitoneal organs, and other abdominal organs.

• For the treatment of pancreatic cancer-related abdominal discomfort.

What Are the Contraindications of the Celiac Plexus Block?

• Contraindications to CPB are the same as those for any other blocks. They include patient refusal or unwillingness to consent, coagulopathy or anticoagulation use, continuing infection, and abnormal anatomy that obstructs the needle's pathway and makes it challenging to target the appropriate structures.

• Cancer patients receiving chemotherapy or radiation therapies may be immunocompromised, making them vulnerable to infection after injection.

• Patients might be coagulopathic or thrombocytopenic, which increases the risk of vascular events.

• Bowel blockage owing to enhanced peristalsis caused by uncontrolled parasympathetic activity generated by the block.

• Patients on Disulfiram are not ideal candidates because they might develop tachycardia, nausea, vomiting, and headache due to acetaldehyde buildup since they cannot break down the alcohol.

What Is the Technique of Celiac Plexus Block?

Various celiac plexus block (CPB) methods have been reported. The two most frequently used techniques are the posterior and anterior para-aortic approaches. The clinician should consider the anterior para-aortic approach for patients with severe illness who have stomach pain and find it difficult to lie flat with the face downward and for individuals who had an abdominal intervention. Before the neurolytic block, one should carry out a diagnostic block with a local anesthetic to verify the effectiveness and pain alleviation attributed to the CPB. Alcohol is the recommended medication for neurolytic celiac plexus blocks since it is more efficacious.

What Is the Posterior Para-Aortic Approach?

• The patient should be positioned flat with face downwards with stabilization underneath the belly to improve the thoracic spine's kyphosis.

• Keep a record of the following anatomical landmarks before executing the block: midline of the spine and the central portion of the vertebrae, iliac crests of the pelvis, the 12th ribs, and the lateral margin of the paraspinal muscles.

• The patient’s skin should be thoroughly cleansed, and the region should be wrapped appropriately. Next, locate the 12th thoracic and first lumbar vertebral bodies using radiography techniques.

• The inferior margin of the 12th rib should be recognized and aseptically labeled. A skin wheal should be positioned at about six to eight centimeters from the midline on the lower margin of the 12th rib.

• A suitable spinal needle should be inserted from posterior to anterior at a forty-five-degree angle toward the ventral surface of the 12th thoracic to first lumbar intervertebral region till the vertebral body is reached.

• After touching the vertebral body, the spinal needle should move roughly one centimeter deeper into the prevertebral fascial plane. Once the needle is in the correct location, the surgeon can verify the accurate location using Computerised tomography or fluoroscopic assistance.

• A diagnostic block with a local anesthetic or a therapeutic neurolytic block can be administered at such a moment. In the case of a single-side block, the left-sided method has proven to be appropriate. However, a block on both sides can be done if the unilateral block does not produce satisfactory results.

What Is the Anterior Para-Aortic Approach?

• This technique is particularly beneficial in patients with severe illness who may be experiencing stomach pain and cannot lie flat with the face in the downward position, as well as those who had an abdominal intervention.

• First, the needle's course is traced using computerized tomography or fluoroscopic guidance while the patient lies with the face upward.

• Next, the patient's skin should be thoroughly cleansed, and the region should be wrapped appropriately. Finally, a local anesthetic skin wheal should be administered in the abdomen wall, anterior to the 12th thoracic vertebral body.

• Next, a suitable spinal needle should be placed and guided into the abdominal aorta; the needle's path will usually pass through the abdominal wall, including the lower part of the digestive system, stomach, or liver.

• Later, the neurolytic substance is administered into the antecrural space with the tip of the needle positioned anterior to the aorta and diaphragmatic crura.

• This route is frequently faster than the posterior para-aortic technique and is generally accepted by patients; nonetheless, its usage is restricted due to organ damage.

What Are the Complications of the Celiac Plexus Block?

• Postprocedural diarrhea is caused by uncontrolled parasympathetic nerve stimulation and is caused by a blockage of the sympathetic supply to the abdominal wall.

• A decrease in blood pressure is caused by dilatation of the splanchnic blood vessels and can be managed with intravenous fluids. In addition, an intravenous hydration bolus before the surgery can help avoid decreased blood pressure.

• Other problems include pus collected inside a body cavity, retroperitoneal abscess, blood in the urine produced by needles penetrating the kidney, intravascular injection, which can induce local anesthetic toxicity or elevated blood alcohol levels, neurolysis, and collapsed lung.

• Infections, tissue death due to inadequate liver or spleen blood supply, and peritonitis are all dangers of this surgery. Other problems include pulmonary embolism. According to research, significant issues occur in less than one percent of individuals.

Conclusion:

Celiac plexus block is generally safe and effective for relieving pain caused by pancreatitis and pancreatic cancer. A celiac plexus block and neurolysis can reduce pain in these patients, reduce total opioid intake, and increase patient satisfaction.