Pancreatic pain is very difficult to manage clinically. Most patients with CP ultimately develop severe, incapacitating, intractable epigastric pain that markedly alters their quality of life. Initial treatment is always conservative and includes nonopioid analgesics, such as nonsteroidal antiinflammatory drugs (NSAIDs) and acetaminophen (Tylenol). However, the nonopioid group of drugs provides poor pain control and increases the risk of bleeding.
Another treatment option is opioid analgesics, such as morphine, meperidine, and tramadol. Opioids provide adequate pain control in most patients with CP; however, morphine causes spasm of the sphincter of Oddi( a muscular valve that controls flow of pancreatic juice and bile into the duodenum), which might exacerbate their condition. Attempts to conservatively control pain leads to a vicious circle:an ever-increasing need for narcotic analgesics increases the possibility of opioid addiction.
About a third of patients with CP will require surgery for intractable pain, which is the major indication for surgery in this group. Unfortunately, surgery leads to a complete or partial loss of both the exocrine and endocrine functions of the pancreas.
Pain in patients with CP represents a challenge for physicians. The common methods of pain management are not effective in all patients or at different stages of CP. New treatment strategies need to be developed for this patient population.
Enzyme replacement therapy is an important component of treatment for patients with CP. Its goal is to help with malabsorption and to manage diarrhea. The replacement of pancreatic enzymes is based on the concept of feedback inhibition of pancreatic exocrine secretion. Administration of pancreatic enzyme replacement therapy to alleviate pain is based on the theory that exogenously administered enzymes will provide feedback inhibition of pancreatic secretion, therefore reducing pain. Several preparations of pancreatic enzymes are available (such as Viokaze-16, Cotazym, Pancreatin, and Pancrease MT), yet their efficacy is still a matter of controversy.
Inhibition of gastric acid secretion is widely employed, despite the lack of studies addressing its efficacy in patients with CP pain. This treatment leads to a higher duodenal pH and therefore reduces pancreatic acid secretion, which supposedly helps relieve pain. Additionally, this treatment prevents acid inactivation of oral enzymes.
Octreotide is a somatostatin analog that inhibits pancreatic secretion and lowers the levels of CCK. Although octreotide relieves pain in many patients with CP who could not find relief from other methods of treatment, its efficacy is a subject of debate, per the results of several clinical trials.
Surgery:
Two principal types of surgical interventions are available for CP patients: drainage and resection procedures. Note that “-stomy” means the surgical creation of an opening; “-ectomy,” surgical removal. The jejunum is the 2nd section of the small intestine; the pylorus is the most distal (the lowest) part of the stomach.
Drainage operations include the Puestow procedure (named for surgeon Charles Bernard Puestow). During a Puestow procedure, also known as a lateral pancreaticojejunostomy, the abdomen is opened with an incision from the sternum (breastbone) to the umbilicus (navel). The pancreas is exposed, and the main pancreatic duct is opened from the head to the tail of the pancreas. Any loose masses within the pancreatic duct are removed. The opened pancreatic duct is then connected to a loop of small intestine, so that the pancreas drains directly into the intestines. This procedure has a low operative complication rate and a very low mortality rate. The major drawback is that it does not provide long-term pain relief in most patients.
The classical pancreatic head resection procedures are the Kausch-Whipple operation, the pylorus-preserving pancreaticoduodenectomy, and the duodenum-preserving pancreatic head resection (DPPHR, also known as the Beger procedure). Several modifications of the DPPHR have been suggested, including the Frey procedure, the Izbicki operation, a longitudinal V-shaped excision of the ventral pancreas combined with a longitudinal pancreaticojejunostomy, and most recently, the Berne operation.
The Kausch-Whipple operation has served for decades as the standard operation for treating patients with CP. It is also done for patients with strictures (abnormal narrowing) of the bile duct or of the pancreatic duct. The original procedure was performed by Professor W. Kausch in 1909 in Germany, and later modified by American surgeon Allen O. Whipple. The current operation consists of removing the gallbladder, part of the bile duct, the duodenum, the head of the pancreas, and sometimes the lower portion of the stomach. Then, the remaining pancreas and the bile duct are sutured back into the remnants of the duodenum, in order to direct the gastrointestinal secretions back into the intestine. Though it generally provides pain relief without complications to neighboring organs, this operation is associated with severe exocrine and endocrine dysfunction of the pancreas, so it is not the operation of choice for patients with CP.
See Doctor Gruessner perform a Whipple procedure
See Doctor Ong perform a Whipple procedure
The Beger procedure was designed to avoid the poor quality of life that patients suffer after undergoing the Kausch-Whipple operation. Through subtotal resection of the pancreatic head that preserves the body and tail of the pancreas, the Beger procedure can alleviate common bile duct obstructions, resulting in long-term pain relief and a low endocrine insufficiency rate.
A modification of the Beger procedure, introduced by Frey, combines a limited local pancreatic head resection with drainage of the main pancreatic duct.
The Berne operation is a pure resection procedure consisting of partial resection of the pancreatic head without dividing the pancreas.
A modification of the Frey procedure introduced by Izbicki involves a longitudinal V-shaped excision of the ventral (anterior) pancreas, followed by drainage of the secondary and tertiary branches of the pancreatic duct system via a longitudinal pancreaticojejunostomy.
For disease located in the pancreatic body or tail, a distal pancreatectomy or even a total pancreatectomy can be performed.
See Intro Video featuring Doctors Greussner, Rilo, and Ong
In addition to drainage and resection procedures, the following invasive interventions are also performed for patients with CP:
Celiac nerve block is frequently performed for patients with CP, but it does not achieve long-term pain relief. Currently, injections of steroids are recommended instead of alcohol, given concerns about irreversible nerve injury. Because of the lack of long-term follow-up studies in patients with CP who undergo celiac nerve block, this procedure should be limited to patients with intractable pain who have no other therapeutic options.
Relief of abdominal and back pain in patients with CP is a complex clinical problem that remains the main focus of many disease management decisions. For example, pancreatic denervation attempts to interrupt the flow of painful stimuli from the pancreas through the CNS. Initially reported by Mallet-Guy in 1943, pancreatic denervation can be accomplished either by (1) ablation (removal) of the greater splanchnic nerves as they traverse the chest carrying impulses from the celiac ganglion to the CNS (splanchnicectomy) or by (2) direct resection (ganglionectomy) or chemical ablation (neurolysis) of the celiac ganglion. Pancreatic denervation is safe and simple, but it does not provide long-term pain relief, so most patients require additional interventions.
Endoscopic retrograde sphincterotomy (ERS) was originally introduced as a way to endoscopically remove stones and stretch strictures. (An endoscope is used to visually inspect the interior of a body part; “-tomy” refers to cutting or incision.) ERS has since been extended to include draining bile from blocked ducts and treating various abnormalities of the pancreatic duct. During ERS, a number of instruments are inserted through the endoscope in order to cut or stretch the sphincter. Then, additional instruments are passed that enable the crushing and removal of stones as well as the widening of narrowed regions of the ducts. Drains (stents) can also be used to prevent a narrowed area from rapidly collapsing to its previously narrowed state. The mechanism by which ERS provides short-term pain relief is temporary decompression of the pancreatic duct.
Spinal cord stimulation (SCS) has successfully treated some patients with neuropathic (arising from nerve injury) pain since 1967. Recent studies suggest that SCS may become an additional treatment for patients with CP. In the study by Kapura, a patient with an 18-year history of CP who underwent SCS successfully obtained pain relief (quantified as from 8 to 1 cm on a visual analog scale) and became opioid-free.
An SCS system generates mild electrical pulses and sends them to the spinal cord. These electrical pulses replace the feeling of pain with a tingling sensation. The procedure introduces a stimulator lead into the epidural or subarachnoidal space (between the spinal cord and the vertebrae), either by a percutaneous (through the skin) approach or by surgical laminectomy (removal of part of the vertebrae). A pulse generator is implanted in the abdomen or buttocks. SCS seems to be an attractive alternative to the conventional methods of pain management. Complications are generally related to implantation and include lead migration, hematoma (blood-filled swelling), and paralysis.