Key words: Anesthetic: local. Catheter: paravertebral. Pancreatitis. Splanchnicectomy.
DEVELOPMENT of a thoracoscopic method of performing surgical splanchnicectomy has caused a resurgence of interest in this once nearly abandoned method of alleviating intractable pain of pancreatic origin. We describe a case in which comparison of the extent of relief obtained after injections of local anesthetic solution or saline through indwelling thoracic paravertebral sympathetic (splanchnic) catheters permitted successful prediction of a patient's response to videothoracoscopic splanchnicectomy. This anesthetic technique may have promise as a method of screening patients considered to be potential candidates for performance of this relatively new procedure.
The pain service was consulted regarding management of a 33-yr-old man with an 18-yr history of recurrent, excruciating upper abdominal pain, believed to be of pancreatic origin. He had been admitted to the hospital because his pain, nausea, and vomiting were preventing eating and drinking. The patient denied risk factors for acute, chronic, or recurrent pancreatitis, and he had no symptoms of pancreatic insufficiency. Medical history was otherwise negative.
The patient was an emaciated (1.7-m, 44.5-kg), anxious man receiving total parenteral nutrition. Pertinent physical findings included a scaphoid abdomen and extreme tenderness in the epigastrium without rebound.
Laboratory studies performed on admission were normal except for mildly increased serum bilirubin, lactic dehydrogenase (LD), aspartate aminotransferase (AST), alkaline phosphatase, and lipase and decreased serum albumin (2.9 g/dl, an increase from the previous month's lowest-ever value of 1.7 g/dl). Chest x-ray results were normal.
Chart review documented numerous clinic and emergency room visits as well as many hospitalizations for nasogastric suction and parenteral hydration similar to the current admission. The patient's weight had varied between 46 and 56 kg. Serum amylase had been increased on some occasions. Results of the plain abdominal x-rays, computed tomograms, upper gastrointestinal endoscopies, and barium swallows performed had always been normal. A suggestion of stenosis of the major papilla during performance of an endoscopic retrograde cholangiopancreatogram (ERCP) prompted endoscopic radiofrequency sphincteroplasty 30 months before the current admission. This procedure failed to provide any relief, however. Neither was relief obtained from performance of cholecystectomy and open sphincteroplasty 5 months before the current admission. The patient's weight had decreased 13 kg since the time of the later procedure. His chart also revealed a psychiatric admission for depression 10 yr previously and that his outpatient treatment had occasionally included opioids (which the patient considered to have provided little benefit).
Considering that (1) the patient's pancreaticobiliary drainage system was widely patent, (2) normal pancreatic duct diameter precluded pancreaticojejunostomy, [1,2]and (3) total resection of the patient's normally functioning gland would entail major morbidity with likely reduced survival but would offer no guarantee of lasting pain relief, [1-3]the recommendation of the pain service was to perform a series of diagnostic (local anesthetic and saline) splanchnic blocks to be followed by thoracoscopic splanchnicectomy if relief provided by pharmacologic blocks was substantially superior to relief provided by placebo injections. Splanchnic, rather than celiac, blocks were selected despite a possibly greater risk of pneumothorax with the former technique because local anesthetic solution injected cephalad to the diaphragm is less likely to spread to lumbar sympathetic fibers, which may transmit pancreatic nociception in some patients, but would not be interrupted during splanchnicectomy performed thoracoscopically.
The catheters were inserted under local anesthesia and minimal nonanalgesic sedation using biplane fluoroscopy. Our technique for catheter insertion is as follows [6-8]: The patient lies prone with a pillow placed under the abdomen. Relevant bony landmarks are located using a combination of palpation and fluoroscopy. After sterile preparation and drape, two 24- to 22-G, 10- to 13-cm pencil-point needles are inserted, preferably no more than 4-5 cm to the right and left of the dorsal midline. Needles are directed approximately 30 degrees medially (Figure 1) and sufficiently cephalad that their tips, when advanced, contact the posterolateral surface of the T11 vertebral body, posterior to the pleural reflections. The needle tips are then progressively "walked" forward around the T11 vertebral body until they lie just anterior to the T11 mid-body as viewed during lateral fluoroscopy. A small volume of dilute radiocontrast solution is injected through each needle to confirm injectate spread within the proper tissue plane. Fifteen milliliters 0.25% bupivacaine are administered in increments through each needle. To facilitate performance of repeated blocks, two 17-G, 15-cm Tuohy needles are inserted through the same puncture sites as the (still present) pencil-point needles. These larger needles are advanced under biplane fluoroscopic guidance along the same paths taken by the narrower needles. After verification of the correct position of the Tuohy needles' tips by contrast injection, 20-G nylon epidural catheters are inserted 4 cm beyond the Tuohy needles' tips. The pencil-point needles are withdrawn as 0.25% bupivacaine solution is injected through them to reduce post-procedure back pain. The Tuohy needles are removed, more concentrated contrast dye is injected through the catheters to confirm proper injectate spread, and the catheters are secured in position.
After completion of the procedure, our patient moved himself to the stretcher and reported that his abdominal pain had abated completely. That evening, the patient was, for the first time in recent memory, able to drink without experiencing nausea, vomiting, or abdominal pain. Over the ensuing 5 days, four bupivacaine injections and two saline injections were administered in response to complaints of returning abdominal pain. Unfortunately, only the right catheter could be used, because the left catheter developed a kink beneath the skin. (The left-sided catheter was not immediately replaced based on reports that, at least with celiac catheters, unilateral injection sometimes provides adequate analgesia. ) All injections were performed in a single-blinded fashion in an operating room. Bupivacaine injections through the catheters provided good or very good relief of 1-2 days duration. Saline injections provided no or fair relief of 0-1 day duration. Injection of contrast dye through the right catheter on the 6th day after catheter placement confirmed continued correct (though unilateral) injectate spread. The right catheter was removed the following day because of solution leakage at the skin entry site. For the remainder of that day and throughout the 2 following days, the patient reported experiencing severe epigastric pain. He remained in bed with legs bent and was unable to eat or drink.
Considering (1) the patient's continuing pain and inability to eat or drink, (2) the favorable results of local anesthetic blocks compared to saline injections, and (3) the apparent lack of applicable noninvasive analgesic options, it was recommended that the patient undergo surgical splanchnicectomy. Thoracoscopic rather than open splanchnicectomy was recommended because of the lesser perioperative morbidity. [10-12]Nonsurgical neurolytic techniques (alcohol or phenol injection or radiofrequency sympatholysis) were not selected despite the fact that these would have avoided a surgical procedure and general anesthesia, because (1) it was believed interruption of the splanchnic nerves under direct visualization offered the patient the best chance of avoiding the most common complication of splanchnicectomy: recurrence of pain, (2) neurolytic blocks often afford patients with chronic pancreatic pain relief of only a few months' duration [2,3,13]yet can produce complications (neuralgia and paraplegia) as objectionable as the complications of surgical splanchnicectomy, and (3) successful percutaneous radiofrequency splanchnic nerve destruction has not been reported and may entail an unacceptable risk of causing necrosis to vital structures adjacent to splanchnic nerves (Figure 1). Our recommendation for performance of thoracoscopic splanchnicectomy was accepted by the patient and the referring surgeon.
Despite opinion that unilateral splanchnicectomy is sometimes adequate to control intractable pancreatic pain, our patient's surgeon chose to perform a bilateral procedure. Surgery and anesthesia were uneventful, and postoperatively, the patient described complete freedom from abdominal pain and tolerated a normal diet. He complained of right hypochondrial dysesthesia (possibly the result of an electrocautery injury to an intercostal nerve) for several months postoperatively. Twenty-five months after surgery, the patient remains asymptomatic, takes no medications, has gained 20 kg, remains fully employed in his original profession as a manual laborer, and engages in outdoor sports.
In 1942, Mallet-Guy performed the first splanchnicectomy to alleviate intractable pancreatic pain. Forty years later, the same surgeon reported that, among the 215 patients (most with advanced chronic pancreatitis) for whom he performed open splanchnicectomy and who survived at least 5 yr postoperatively, 89% obtained prolonged pain relief. Success was even higher in the subset of patients who were not alcoholic. Mallet-Guy, and subsequently other investigators, [2,3,16]emphasized that splanchnicectomy can produce such favorable results only in patients who are not candidates for a specific therapeutic procedure such as drainage of a pseudocyst or clearance of a blockage within the pancreaticobiliary drainage system.
After the many early favorable accounts of benefit from splanchnicectomy, the procedure fell from favor in the 1960s after reports that the relief it affords patients with chronic pancreatitis (especially alcohol-induced) is often short-lived. [1,10,16-19]Recently, because of the development of a minimally invasive technique for its performance, there has been a resurgence of interest in performance of splanchnicectomy to alleviate intractable pancreatic pain. The relatively minor morbidity associated with performance of even bilateral thoracoscopic splanchnicectomy [11,12]is enhancing the attractiveness of pancreatic denervation even though the long-term results from this new procedure may be no better than those from open splanchnicectomy.
The concept of performing prognostic (usually celiac) blocks to help select patients for splanchnicectomy is not new, but the usefulness of this technique before (either open or thoracoscopic) splanchnicectomy has never been validated experimentally. [18,20]There are some problems inherent in attempting to use splanchnic blocks to predict surgical benefit (Table 1). That our patient did not have alcohol-induced chronic pancreatitis made him a good candidate for performance of thoracoscopic splanchnicectomy. Variables other than the nature of the disease process, however, can influence patient satisfaction with splanchnicectomy. These include coexistence of opioid dependency or somatization disorder, presence of secondary gain, technical adequacy of the operative procedure, and occurrence of operative complications. Relevant medical information, in addition to a patient's differential response to local anesthetic and placebo splanchnic blocks, must be considered, therefore, before recommending pancreatic denervation over alternative methods of providing analgesia.
The authors thank Isadore Cohn, MD, Norman McSwain, MD, Henry Laws, MD, Kennan Buechter, MD, and John Ferrara, MD, for their communications regarding the surgical management of chronic pancreatic pain, including performance splanchnicectomy. They thank Gene New, for drawing the diagram.