William D. Mauck

Preoperative Gabapentin for Acute Post-thoracotomy Analgesia: A Randomized, Double-Blinded, Active Placebo-Controlled Study

Background:  The role of preoperative gabapentin in postoperative pain management is not clear, particularly in patients receiving regional blockade. Patients undergoing thoracotomy benefit from epidural analgesia but still may experience significant postoperative pain. We examined the effect of preoperative gabapentin in thoracotomy patients.

Efficacy of intervertebral disc regeneration with stem cells - A systematic review and meta-analysis of animal controlled trials

Management of intervertebral disc (IVD) degenerative disease is challenging, as it is accompanied by irreversible loss of IVD cells. Stem cell transplantation to the disc has shown promise in decelerating or arresting the degenerative process. Multiple pre-clinical animal trials have been conducted, but with conflicting outcomes. To assess the effect of stem cell transplantation, a systematic review and meta-analysis was performed. A comprehensive literature search was conducted through Week 3, 2015. Inclusion criteria consisted of controlled animal trials. Two reviewers screened abstracts and full texts. Disagreements were resolved by a third reviewer. Random effects models were constructed to pool standardized mean difference (SMD). Twenty two studies were included; nine of which were randomized. Statistically significant differences were found with the stem cell group exhibiting increased disc height index (SMD=3.64, 95% confidence interval (CI): 2.49, 4.78; p<0.001), increased MRI T2 signal intensity (SMD=2.28, 95% CI: 1.48, 3.08; p<0.001), increased Type II collagen mRNA expression (SMD=3.68, 95% CI: 1.66, 5.70; p<0.001), and decreased histologic disc degeneration grade (SMD=-2.97, 95% CI: -3.97, -1.97; p<0.001). There was statistical heterogeneity between studies that could not be explained with pre-planned subgroup analyses based on animal species, study designs, and transplanted cell types. Stem cells transplanted to the IVD in quadruped animals decelerate or arrest the IVD degenerative process. Further studies in human clinical trials will be needed to understand if such benefit can be translated to bipedal humans.

Incidence of Clinically Significant Percutaneous Spinal Cord Stimulator Lead Migration

To examine the incidence of percutaneous spinal cord stimulator lead migration, given current hardware and surgical technique.

Incidence of neuropathic pain after radiofrequency denervation of the third occipital nerve

The purpose of this study was to identify the incidence of neuropathic pain occurring after radiofrequency neurotomy of the third occipital nerve (TON). This study was conducted at a teaching hospital from January 1, 2008, to March 31, 2010. With institutional review board approval, Current Procedural Terminology codes were used to identify patients who received radiofrequency ablation (RFA) of the nerves supplying the C2-3 facet joint and the TON. The C3 dorsal ramus provides innervation to the C2-3 facet joint and the suboccipital cutaneous region, and procedures that included ablation to this region were reviewed for complications. Postprocedural data were collected by reviewing follow-up appointment notes and telephone calls. Included were patients who had new neuropathic pain in the distribution of the TON after RFA. They described what they were feeling as burning, tingling, or numbness. All patients who presented with complaints had normal neurologic findings and no secondary cause for their symptoms. The included patient medical records were then reviewed for severity and duration of symptoms and the need for treatment with pain medication. Sixty-four patients underwent C2-3 RFA or TON RFA, and 12 patients were identified as experiencing ablation-induced third occipital neuralgia, an incidence rate of 19%. This finding suggests that patients undergoing RFA of the nerves supplying the C2-3 joint or TON are at risk for postprocedural third occipital neuralgia. This possibility may affect providing informed consent as well as anticipating and managing postprocedural pain.

Dual-epidural catheter technique and perioperative outcomes after Ivor-Lewis esophagectomy.

Background Ivor-Lewis esophagectomy is associated with significant postoperative analgesic requirements and perioperative complications. A dual-epidural technique may improve perioperative outcomes compared with single thoracic epidural analgesia. Methods This study identified all cases of Ivor-Lewis esophagectomy over a 3-year period. Eighty-one patients undergoing Ivor-Lewis esophagectomy who received general anesthesia supplemented by neuraxial analgesia with dual-epidural catheters (DECs) were matched 1:1 with patients who received general anesthesia and a single thoracic epidural catheter. Primary outcomes included quality of analgesia at rest and with movement on each of the first 3 postoperative days. Secondary outcomes included adverse events and the incidence of 4 major postoperative complications (anastomotic leak, pulmonary complications, atrial fibrillation, and sepsis). Results A DEC technique significantly improved analgesia (evidenced by reduced pain with movement on each of the first 3 postoperative days) when compared with a single epidural catheter technique. The placement of DECs did not increase catheter-related adverse events. A DEC technique was associated with a 50% reduction in the combined rate of major postoperative complications (36% vs 18%; odds ratio, 0.40; P = 0.01) and increased number of hospital-free days measured at day 28 (21.2 vs 22.3; P = 0.04). Conclusions The DEC technique improved postoperative analgesia and reduced the incidence of major postoperative complications and hospital length of stay in patients undergoing Ivor-Lewis esophagectomy. Future studies should evaluate the efficacy of this technique in a controlled randomized clinical trial.

Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps

IntroductionPatients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several pumps. Because of the rare potential “for a delay in the return of proper drug infusion” and “for a delay in the logging of motor stall events,” “a patient’s pump must be interrogated after MRI exposure in order to confirm proper pump functionality.” This is particularly important in patients receiving intrathecal baclofen, for whom a delay in return of proper pump infusion could lead to life-threatening baclofen withdrawal syndrome. The objective of this report is to present our experience and protocol of performing magnetic resonance imaging in patients with implanted SynchroMed EL pumps.MethodsWe retrospectively reviewed records of 86 patients with implanted SynchroMed EL spinal infusion pumps who underwent 112 examinations on 1.5-T magnetic resonance imaging scanners from September 1, 1998 to July 7, 2004.ResultsNo SynchroMed EL pumps were damaged by magnetic resonance imaging, and the programmable settings remained unchanged in all patients.ConclusionsOur data suggest that SynchroMed EL pump malfunction is indeed rare after routine clinical 1.5-T magnetic resonance imaging examinations. However, based on the Medtronic correction report, we perform pump interrogation before and after imaging.

Bleeding Complications in Patients Undergoing Celiac Plexus Block.

Background and Objectives Celiac plexus blockade has known risks including bleeding and neurologic injury because of the close proximity of vascular and neuraxial structures. The aim of this study was to determine the incidence of bleeding complications in patients undergoing celiac plexus block (CPB), with an emphasis on preprocedural antiplatelet medication use and coagulation status. Methods This is a retrospective study from 2005 to 2014 of adult patients undergoing CPB by the pain medicine division at a tertiary care center. The primary outcome was red blood cell (RBC) transfusion within 72 hours of needle placement, with a secondary outcome of bleeding complications requiring emergency medicine, neurology, or neurosurgical evaluation within 31 days. Results A total of 402 procedures were performed on 298 unique patients, with 58 patients (14.4%) receiving aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) preoperatively. Five patients (1.2%) received RBC transfusion within 72 hours, of which one had received preprocedure NSAIDs. A platelet count measured within 30 days was available for 268 patients, with 7 patients (2.6%) having platelet counts of 100 × 109/L or less at the time of needle placement. A total of 187 patients had a valid preoperative international normalized ratio (INR), with 9 (4.8%) having an INR of 1.5 or higher (range, 1.5–2.6). One patient (11.1%) required RBC transfusion compared with an RBC transfusion rate of 2.3% (4 of 178) in those with normal INR (P = 0.221). We identified no bleeding complications requiring emergency medicine, neurology, or neurosurgical evaluation. Conclusions This study suggests that CPBs may be safely performed in patients receiving aspirin and/or NSAID therapy.

Interventional modalities to treat cancer-related pain.

Abstract Cancer-related pain is a significant cause of morbidity in those affected by both primary and metastatic disease. Although oral, transdermal, and parenteral opioid medications are an integral part of the World Health Organizations analgesic ladder, their use may be limited by side effects. Fortunately, there are advanced interventional pain management strategies effective in reducing pain in the cancer patient while mitigating the aforementioned side effects. Celiac plexus blocks and neurolysis have been proven effective in treating cancers of the abdominal viscera (ie, pancreas). Transversus abdominis plane blocks, neurolysis, and catheter placement can be used to treat cancer pain associated with the abdominal wall. Peripheral nerve blocks and catheter placement at the brachial and lumbosacral plexus or peripheral nerves treat cancer pain associated with the upper and lower limbs, whereas paravertebral and intercostal blocks treat cancer pain associated with the chest wall and ribs. Finally, alternate drug delivery methods such as intrathecal drug delivery systems concentrate medication at central opioid receptors without affecting the peripheral receptors implicated in unwanted side effects. This article provides an overview of these interventions, including indications, contraindications, and potential complications of advanced interventional pain management options available for the treatment of intractable cancer-related pain.

Landmark-based versus ultrasound-guided ilioinguinal/iliohypogastric nerve blocks in the treatment of chronic postherniorrhaphy groin pain: a retrospective study

Background Chronic postherniorrhaphy groin pain (CPGP) is a debilitating condition, which is often refractory to conservative medical management. To our knowledge, there have been no studies directly comparing landmarked-based and ultrasound-guided approaches in this population. Objective To compare the effectiveness of landmark-based and ultrasound-guided ilioinguinal/iliohypogastric nerve blocks in the treatment of CPGP. Study design This is a retrospective chart review of patients who presented to our tertiary care pain medicine clinic with a diagnosis of CPGP. Inclusion criteria were the following: age >18 years, diagnosis of groin pain, and prior history of herniorrhaphy. Exclusion criteria included those who were seen for initial consultation but were lost to follow-up. Primary outcomes were 50% or greater reduction in pain on visual analog scale (VAS). Secondary outcomes were 30% or greater reduction in VAS pain score, changes in VAS pain scores, and reported complications. Results A total of 36 patients were included in the study. Of them, 20 patients underwent the landmark-based and 16 underwent the ultrasound-guided techniques. There was no significant difference in baseline demographics. The average VAS score preinjection was 7.08 in the landmark-based and 7.0 in the ultrasound-guided groups (P=0.65). A total of 14 patients (70%) in the landmark-based and eleven patients (79%) in the ultrasound-guided groups experienced at least a 50% reduction in VAS scores. There was no statistically significant difference between the two groups (P=1.0), and no complications were noted. We also did not find a significant difference in terms of number of patients with 30% or greater reduction (P=0.71) and changes in VAS pain scores (P=0.64). No complications were reported in either group. Conclusion In our study, there was no statistically significant difference between the landmark-based and ultrasound-guided groups in terms of a reduction in VAS pain scores, and no complications were noted in either group.

Combined Celiac Ganglia and Plexus Neurolysis Shortens Survival, Without Benefit, vs Plexus Neurolysis Alone

Background & Aims: Pancreatic cancer produces debilitating pain that opioids often ineffectively manage. The suboptimal efficacy of celiac plexus neurolysis (CPN) might result from brief contact of the injectate with celiac ganglia. We compared the effects of endoscopic ultrasound‐guided celiac ganglia neurolysis (CGN) vs the effects of CPN on pain, quality of life (QOL), and survival. Methods: We performed a randomized, double‐blind trial of patients with unresectable pancreatic ductal adenocarcinoma and abdominal pain; 60 patients (age 66.4±11.6 years; male 66%) received CPN and 50 patients (age 66.8±10.0 years; male 56%) received CGN. Primary outcomes included pain control and QOL at week 12 and survival (overall median and 12 months). Secondary outcomes included morphine response, performance status, secondary neurolytic effects, and adverse events. Results: Rates of pain response at 12 weeks were 46.2% for CGN and 40.4% for CPN (P = .84). There was no significant difference in improvement of QOL between the techniques. The median survival time was significantly shorter for patients receiving CGN (5.59 months) compared to (10.46 months) (hazard ratio for CGN, 1.49; 95% CI, 1.02–2.19; P = .042), particularly for patients with non‐metastatic disease (hazard ratio for CGN, 2.95; 95% CI, 1.61–5.45; P < .001). Rates of survival at 12 months were 42% for patients who underwent CPN vs 26% for patients who underwent CGN. The number of adverse events did not differ between techniques. Conclusion: In a prospective study of patients with unresectable pancreatic ductal adenocarcinoma and abdominal pain, we found CGN to reduce median survival time without improving pain, QOL, or adverse events, compared to CPN. The role of CGN must be therefore be reassessed. Clinicaltrials.gov no: NCT01615653.