Complications of CPN are rare, occurring in approximately 1.5-2% of patients. Possible complications, however, do include transient, usually asymptomatic hypotension, retroperitoneal abscess, and severe self-limited post-procedural pain. Transient complications include post-procedural diarrhea and hypotension due to sympathetic blockade. Permanent, unremitting diarrhea has been reported in very rare cases (16). There is also a risk of cephalic spread of the neurolytic agent, which may result in involvement of the cardiac nerves and plexus (17). Spinal complications have also been reported, particularly with posterior approaches; fortunately, these are rare, occurring in less than 1% of patients. Lower extremity weakness, paresthesias, paraplegia have all been reported. This is likely due to the alcohol injection causing spasm or thrombosis of the Artery of Adamkiewicz, which supplies the inferior spinal cord (18,19). At least one fatality has been reported from associated complications (20).
The first description of palliative chemical splanchnicectomy dates back to 1969. The first description of bilateral splanchnicectomy for pain secondary to pancreatic cancer was described by Sadar et al. in 1974 (21,22). Splanchnicectomy was initially performed under direct vision at the time of thoracotomy and combined with sympathectomy (22). The use of the thoracoscope to aid in the performance of splanchnicectomy for palliation of pain associated with pancreatic cancer was later described in 1993 in the British Journal of Surgery (23). Since then, several short case series have been published as techniques continue to be refined. Today, thoracoscopic splanchnicectomy may be performed either unilaterally or bilaterally. Prior to consideration for splanchnicectomy, we ensure patients have failed medical management. Failure of medical managements is a subjective opinion, but if a patient’s pain is able to be controlled by fewer than three daily doses of moderate strength narcotics, and they are able to maintain a productive life, surgical management may be avoided or at least delayed. We define pain control as a patient rating his or her pain as ≤3/10 on a visual analog score, and a productive life as being able to leave one’s home and/or accomplish activities of daily living in line with the expectations of the patient. If these criteria are not met, consideration for bilateral thoracoscopic splanchnicectomy (BTS) is given.
When interviewing the patient, special attention should be given to his or her pulmonary reserve as well as to previous thoracic disease and/or interventions. Clues to possible thoracic adhesions should be explored. These include previous severe pulmonary infections with associated empyema or parapneumonic effusions, the need for previous thoracostomy drainage or thoracentesis, thoracic trauma with associated hemothorax, previous pneumothorax, and previous thoracoscopy or thoracotomy. If any of these situations apply, the patient should be informed that it may be challenging to visualize the splanchnic nerves on the affected side without extensive dissection and/or thoracotomy. In a palliative operation, these patients should be largely avoided because of increased morbidity. Counseling should also be provided on the limited but distinct possibility of continued pain despite a technically successful operation. Following appropriate preoperative discussions, the patient is consented for the procedure.
At our institution, we perform BTS. Although this has not been compared head-to-head with unilateral splanchnicectomy, we are of the opinion that pain control is better with a bilateral neurectomy. This procedure can be easily executed with a single-lumen endotracheal tube; there is no need for continuous arterial blood pressure monitoring or central venous access. We prefer a posterior approach as described by Cuschieri et al. (24). The patient is placed in the prone position with the arms abducted and flexed at the elbow. To perform a BTS, we use two 5 mm trochars. We start initially on the left side, as it has been our experience that the left pleura is often thicker with more retro pleural fat, which can make visualization of the nerves on the left side often harder than the right. Despite that, the nerves are typically easy to find if one is familiar with their normal position, a skill that is acquired after only a few operations. The first trochar is placed at the inferior apex of the scapula while the anesthetist suspends respirations. Once placed, carbon dioxide (CO2) insufflation is instilled at a pressure of 12 mmHg. A 5 mm, 30-degree angled scope is used to assess for successful trochar placement. Once the surgeon is satisfied, respirations can be resumed. In all, this initial step generally takes less than 1 minute. Next, the second trochar is placed two intercostal spaces inferior to the first and about 2 cm medially (Figure 2). It may also be placed two intercostal spaces superior to the first in the event there is elevation of the hemi-diaphragm. A third trochar may be used if needed, but this is rarely the case. The surgeon will then turn his or her attention to the posterior thorax to identify the sympathetic trunk. The arch of the aorta is used as a landmark, above which the splanchnics do not lie. The costophrenic angle is seen as well, below which the splanchnics are never found. The splanchnic nerves are seen running in an inferior and medial position from the sympathetic trunk (Figure 3). Once the splanchnics are identified, a small opening is made in the pleura on either side of the nerve with a right angle cautery. To avoid the risk of bleeding, the nerve is divided on the corpora of the vertebral body between the intercostal vessels. We recommend lifting the nerve with the right angle cautery so that division is obvious once the nerve recedes into the pleura (Figure 4). There are typically two to five nerves easily found on each side. After searching for and dividing all of the nerves, the insufflation is released, a rubber catheter is placed into the hemithorax, and large tidal volumes are given by the anesthetist. The exterior end of the rubber catheter is placed under water at the level of the skin, creating a water seal. Once the lungs are fully re-inflated, the trochars and catheter are removed, the skin incisions closed, and the procedure is repeated on the right side.
At this point, the patient is awakened and a chest X-ray is performed in the recovery room to assess for retained CO2. If the patient is stable, even in the presence of pneumothorax, observation is safe and an X-ray should be repeated on post-operative day 1. In the event the patient is unstable during or after emergence from anesthesia, urgent X-ray in the operating room (if possible, quickly) and auscultation of the chest are used to assess for tension pneumothorax. A chest thoracostomy tube is then placed on the affected side. We admit our patients for overnight observation in a non-telemetry room; however, outpatient procedures have been reported without complication. Operative time is usually less than 1 hour and the total hospital length of stay rarely exceeds 1 post-operative day.