Differential gene expression in trigeminal ganglia of male and female rats following chronic constriction of the infraorbital nerve

BACKGROUND

The mechanisms underlying sex-based differences in pain and analgesia are poorly understood. In this study, we investigated gene expression changes in trigeminal ganglia (TG) of male and female rats exposed to infraorbital nerve chronic constriction injury (IoN-CCI).

METHODS

Somatosensory assessments were performed prior to IoN-CCI and at selected time points postsurgery. Selected gene expression changes were examined with real-time quantitative polymerase chain reaction (RT-PCR) in ipsilateral TG at 21 days postsurgery.

RESULTS

Rats exposed to IoN-CCI developed significant mechanical allodynia and hyperalgesia on days 19 and 21 postsurgery. During this period, females developed significantly more allodynia but not hyperalgesia compared to males. At 21 days postsurgery, expression levels of 44 of the 84 investigated pain-related genes in ipsilateral TG were significantly regulated relative to naïve rats in either sex. Csf1 and Cx3cr1 were up-regulated in both sexes, but the magnitude of regulation was significantly higher in females (p = 0.02 and p = 0.001, respectively). Htr1a and Scn9a were down-regulated in both sexes, but the down-regulation was significantly more pronounced in males (p = 0.04 and p = 0.02, respectively). Additionally, Cck, Il1a, Pla2g1b and Tnf genes were significantly regulated in females but not in males, and Chrna4 gene was significantly down-regulated in males but not in females.

CONCLUSIONS

Our findings suggest sex-dependent gene regulation in response to nerve injury, which may contribute to sex dimorphism of trigeminal neuropathic pain. Further studies are needed to establish gene expression changes over time and correlate these with hormonal and other physiological parameters in male and female.

SIGNIFICANCE

We present novel sex-specific transcriptional regulation in trigeminal ganglia that may contribute to male-/female-based differences in trigeminal neuropathic pain. These findings are expected to open new research horizons, particularly in male versus female targeted therapeutic regimens.

Differential gene expression in trigeminal ganglia of male and female rats following chronic constriction of the infraorbital nerve

BACKGROUND

The mechanisms underlying sex-based differences in pain and analgesia are poorly understood. In this study, we investigated gene expression changes in trigeminal ganglia (TG) of male and female rats exposed to infraorbital nerve chronic constriction injury (IoN-CCI).

METHODS

Somatosensory assessments were performed prior to IoN-CCI and at selected time points postsurgery. Selected gene expression changes were examined with real-time quantitative polymerase chain reaction (RT-PCR) in ipsilateral TG at 21 days postsurgery.

RESULTS

Rats exposed to IoN-CCI developed significant mechanical allodynia and hyperalgesia on days 19 and 21 postsurgery. During this period, females developed significantly more allodynia but not hyperalgesia compared to males. At 21 days postsurgery, expression levels of 44 of the 84 investigated pain-related genes in ipsilateral TG were significantly regulated relative to naïve rats in either sex. Csf1 and Cx3cr1 were up-regulated in both sexes, but the magnitude of regulation was significantly higher in females (p = 0.02 and p = 0.001, respectively). Htr1a and Scn9a were down-regulated in both sexes, but the down-regulation was significantly more pronounced in males (p = 0.04 and p = 0.02, respectively). Additionally, Cck, Il1a, Pla2g1b and Tnf genes were significantly regulated in females but not in males, and Chrna4 gene was significantly down-regulated in males but not in females.

CONCLUSIONS

Our findings suggest sex-dependent gene regulation in response to nerve injury, which may contribute to sex dimorphism of trigeminal neuropathic pain. Further studies are needed to establish gene expression changes over time and correlate these with hormonal and other physiological parameters in male and female.

SIGNIFICANCE

We present novel sex-specific transcriptional regulation in trigeminal ganglia that may contribute to male-/female-based differences in trigeminal neuropathic pain. These findings are expected to open new research horizons, particularly in male versus female targeted therapeutic regimens.

Robotic vs laparoscopic rectal surgery in high-risk patients

AIM

Laparoscopic rectal surgery is associated with a steep learning curve and high conversion rate despite progress in equipment design and consistent practice. The robotic system has shown an advantage over the laparoscopic approach due to stable three-dimensional views, improved dexterity and better ergonomics. These factors make the robotic approach more favourable for rectal surgery. The aim of this study was to compare the perioperative outcomes of laparoscopic and robotic rectal cancer surgery in high-risk patients.

METHOD

A prospectively collected dataset for high-risk patients who underwent rectal cancer surgery between May 2013 and November 2015 was analysed. Patients with any of the following characteristics were defined as high risk: a body mass index ≥30, male gender, preoperative chemoradiotherapy, tumour <8 cm from the anal verge and previous abdominal surgery.

RESULTS

In total, 184 high-risk patients were identified: 99 in the robotic group and 85 in the laparoscopic group. Robotic surgery was associated with a significantly higher sphincter preservation rate (86% vs 74%, P = 0.045), shorter operative time (240 vs 270 min, P = 0.013) and hospital stay (7 vs 9 days, P = 0.001), less blood loss (10 vs 100 ml, P < 0.001) and a smaller conversion rate to open surgery (0% vs 5%, P = 0.043) compared with the laparoscopic technique. Reoperation, anastomotic leak rate, 30-day mortality and oncological outcomes were comparable between the two techniques.

CONCLUSION

Robotic surgery in high-risk patients is associated with higher sphincter preservation, reduced blood loss, smaller conversion rates, and shorter operating time and hospital stay. However, further studies are required to evaluate this notion.

Quantitative assessment and characterization of glenoid bone loss in a spectrum of patients with glenohumeral osteoarthritis

PURPOSE

Eccentric posterior bone loss and associated glenoid retroversion represent challenges to glenoid placement during total shoulder arthroplasty. This bone loss can lead to poor stability and perforation of the glenoid during arthroplasty. The purpose of this study was to evaluate the morphology of glenoid bone loss for a spectrum of osteoarthritis patients using 3D computed tomography imaging and simulation software.

METHODS

This study included 29 patients with glenohumeral osteoarthritis treated with shoulder arthroplasty. Three-dimensional reconstruction of preoperative CT images was performed. Glenoid bone loss was measured at ten, vertically equidistant axial planes along the glenoid surface at four distinct anterior-posterior points on each plane. The images were fitted with modeled pegged glenoid implants to predict glenoid perforation.

RESULTS

The 3D maps demonstrated greatest average bone loss posteriorly in the AP plane at the central axis of the glenoid in the SI plane. The average amount of bone loss was 3.85 mm. Walch A2 and B1 shoulders showed more central bone loss, while Walch B2 shoulders displayed more posterior and inferior bone loss. Patients with predicted peg perforation displayed significantly greater bone loss than those without predicted peg perforation (p = 0.037). Peg perforation was most common in Walch B2 shoulders occurring in the posterior direction involving the central and posterior-inferior peg.

CONCLUSIONS

These data demonstrate an anatomic pattern of glenoid bone loss for different classes of glenohumeral arthritis. These findings can be used to develop various models of glenoid bone loss to guide surgeons, predict failures, and develop better glenoid implants. This study has been approved by the Cleveland Clinic IRB: Number 6235.

Three-step standardized approach for complete mobilization of the splenic flexure during robotic rectal cancer surgery

AIM

The aim of this technical note is to describe a three-step technique for expeditious and complete mobilization of the splenic flexure (CMSF) during single docking totally robotic rectal cancer surgery.

METHOD

A prospectively maintained database was searched for all patients who underwent single docking totally robotic rectal cancer surgery with CMSF through a stepwise technique.

RESULTS

We studied 89 patients underwent CMSF during single docking totally robotic lower anterior resection for rectal cancer.

CONCLUSION

The technique demonstrates that CMSF can be performed with a standardized approach using the natural embryological planes of surgery. Moreover, this technique does not involve any change in patient's position on the operating table or undocking the robotic system. We have included an intra-operative video recording to demonstrate the technique.

Totally robotic rectal resection: an experience of the first 100 consecutive cases

INTRODUCTION

Robotic surgery provides an alternative option for a minimal access approach. It provides a stable platform with high definition three-dimensional views and improved access, which enhances the capabilities for precise dissection in a narrow surgical field. These distinctive features have made it an attractive option for colorectal surgeons.

AIM

The aim of this study was to present a standardised technique for single-docking robotic rectal resection and to analyse clinical outcomes of the first 100 robotic rectal procedures performed in a single centre between May 2013 and April 2015.

METHOD

Prospectively collected data related to 100 consecutive patients who underwent single-docking robotic rectal surgery was analysed for surgical and oncological outcomes.

RESULTS

Sixty-six patients were male, the median age was 67 years (range-24-92). Eighteen patients had neo-adjuvant chemoradiotherapy whilst 23 patients had BMI >30. Procedures performed included anterior resection (n = 74), abdominoperineal resection (n = 10), completion proctectomy (n = 9), restorative proctectomy with ileal pouch-anal anastomosis (IPAA) (n = 5) and Hartmann's procedure (n = 2). The median operating time was 240 min (range-135-456), and median blood loss was 10 ml (range 0-200). There was no conversion or intra-operative complication. Median length of stay was 7 days (range, 3-48) and readmission rate was 12 %. Thirty-day mortality was zero. Postoperatively, two patients had an anastomotic leak whilst two had small bowel obstruction. The median lymph node harvest was 18 (range, 6-43).

CONCLUSION

The single-docking robotic technique should be considered as an alternative option for rectal surgery. This approach is safe and feasible and in our study it has demonstrated favourable clinical outcomes.

Trigeminal neuralgia (part I): Revisiting the clinical phenotype

Aims

We conducted a cross-sectional study to re-examine the clinical profile of patients with a clinical diagnosis of classical trigeminal neuralgia (CTN).

Methods

Inclusion criteria consisted of the International Headache Society’s published classification of CTN. For the specific purposes of the study, features such as autonomic signs, persistent background pain, attack durations of >2 minutes and reports of pain-related awakening were included. The demographic and clinical phenotype of each patient were carefully recorded for analysis.

Results

The study cohort consisted of 81 patients and based on reported attack duration these were divided into short (≤ 2 minutes, n = 61) and long (> 2 minutes, n = 20) groups for further analysis. The group with short attack duration neatly fit most of the criteria for CTN while the long attack group presents a more challenging diagnosis. There were no significant differences in pain severity, quality and location between the short and long attack groups. The frequency of persistent background pain was significantly higher in the long (70%) compared to the short attack group (29.5%, p = 0.001). There were significantly more reports of pain-related awakenings in the long (55%) than in the short attack groups (29.5%, p = 0.04). There were no significant differences in the frequency of autonomic signs between the short (21.3%) and long attack groups (40%, p = 0.1). In the short attack group, the presence of autonomic signs was significantly associated with longer disease duration, increased pain-related awakenings, and a reduced prognosis.

Conclusion

There are clear diagnostic criteria for CTN but often patients present with features, such as long pain attacks, that challenge such accepted criteria. In our cohort the clinical phenotype of trigeminal, neuralgiform pain with or without autonomic signs and background pain was observed across both short and long attack groups and the clinical implications of this are discussed.

Trigeminal neuralgia (part II): Factors affecting early pharmacotherapeutic outcome

Aims

We conducted a cohort study to examine demographic and clinical features associated with the pharmacotherapeutic outcome in classical trigeminal neuralgia (CTN) patients.

Methods

Patients with a clinical profile indicating a diagnosis of CTN, as per the International Headache Society’s published classification, were enrolled prospectively. Demographic and pain-related characteristics were carefully collected. For the purposes of the study, patients with features such as autonomic signs and longer attack duration were included. All patients were then initiated on a standardised and accepted stepped pharmacotherapeutic protocol for the management of CTN. Initial pain scores and prospectively collected pain scores from pain diaries were used to assess the treatment outcome, with a ≥50% reduction considered significant.

Results

A total of 86 patients were seen, of whom five had an underlying disorder that could account for the pain. The study cohort therefore consisted of 81 patients, and based on attack duration these were divided into short (≤2 minutes, n = 61) and long (>2 minutes, n = 20) groups, for further analysis. The features of these patients and a discussion on the differential diagnosis have been presented in part 1 of this report. Employing an accepted stepped pharmacotherapeutic protocol for the management of CTN, significant improvement was more frequent in the short (74%) than in the long attack group (50%, p = 0.05). In the short attack group there were statistically significant associations between a poor treatment response and longer disease duration, the presence of autonomic signs and atypical pain descriptors for pain quality ( p < 0.05).

Conclusion

This report supports previous findings that prolonged disease duration and autonomic signs are negative prognostic indicators. The present study now adds long attack duration as a further negative prognostic sign.

Neuraxial block and postoperative epidural analgesia: effects on outcomes in the POISE-2 trial†

BACKGROUND

We assessed associations between intraoperative neuraxial block and postoperative epidural analgesia, and a composite primary outcome of death or non-fatal myocardial infarction, at 30 days post-randomization in POISE-2 Trial subjects.

METHODS

10 010 high-risk noncardiac surgical patients were randomized aspirin or placebo and clonidine or placebo. Neuraxial block was defined as intraoperative spinal anaesthesia, or thoracic or lumbar epidural anaesthesia. Postoperative epidural analgesia was defined as postoperative epidural local anaesthetic and/or opioid administration. We used logistic regression with weighting using estimated propensity scores.

RESULTS

Neuraxial block was not associated with the primary outcome [7.5% vs 6.5%; odds ratio (OR), 0.89; 95% CI (confidence interval), 0.73-1.08; P=0.24], death (1.0% vs 1.4%; OR, 0.84; 95% CI, 0.53-1.35; P=0.48), myocardial infarction (6.9% vs 5.5%; OR, 0.91; 95% CI, 0.74-1.12; P=0.36) or stroke (0.3% vs 0.4%; OR, 1.05; 95% CI, 0.44-2.49; P=0.91). Neuraxial block was associated with less clinically important hypotension (39% vs 46%; OR, 0.90; 95% CI, 0.81-1.00; P=0.04). Postoperative epidural analgesia was not associated with the primary outcome (11.8% vs 6.2%; OR, 1.48; 95% CI, 0.89-2.48; P=0.13), death (1.3% vs 0.8%; OR, 0.84; 95% CI, 0.35-1.99; P=0.68], myocardial infarction (11.0% vs 5.7%; OR, 1.53; 95% CI, 0.90-2.61; P=0.11], stroke (0.4% vs 0.4%; OR, 0.65; 95% CI, 0.18-2.32; P=0.50] or clinically important hypotension (63% vs 36%; OR, 1.40; 95% CI, 0.95-2.09; P=0.09).

CONCLUSIONS

Neuraxial block and postoperative epidural analgesia were not associated with adverse cardiovascular outcomes among POISE-2 subjects.

Postoperative atrial fibrillation in non-cardiac and cardiac surgery: an overview

Postoperative atrial fibrillation (POAF) is the most common perioperative cardiac arrhythmia. A major risk factor for POAF is advanced age, both in non-cardiac and cardiac surgery. Following non-cardiac surgery, it is important to correct reversible conditions such as electrolytes imbalances to prevent the occurrence of POAF. Management of POAF consists of rate control and therapeutic anticoagulation if POAF persists for > 48 h and CHADS2 score > 2. After cardiac surgery, POAF affects a larger amount of patients. In addition to age, valve surgery carries the greatest risk for new AF. Rate control is the mainstay therapy in these patients. Prediction, prevention, and management of POAF should be further studied.

Major postoperative complications following elective resection for colorectal cancer decrease long-term survival but not the time to recurrence

AIM

The aim of the study was to determine the effect of major complications after colorectal cancer surgery on survival and time to recurrence.

METHOD

Patients having a curative colorectal cancer resection and a follow-up of at least 3 years were identified from a prospective database. Major complications were defined as Clavien-Dindo Grades 3b or 4 and their impact on time to recurrence and mortality was analysed by univariate and multivariable analysis. Postoperative death within 30 days or during the initial hospitalization (Clavien-Dindo Grade 5) was a priori excluded.

RESULTS

From 2003 to 2012, 868 colorectal cancer resections resulting in 63 (7%) major postoperative complications including deaths (Clavien-Dindo ≥ 3b) were identified. After exclusion of Grade 5 complications (postoperative or in-hospital deaths), 844 resections with 39 (5%) major complications remained for analysis. Median follow-up time was 5.7 years. Using the Kaplan-Meier method, the estimated crude 5-year overall survival probability was 78% (95% CI 75-81) in the group without and 65% (95% CI 51-83) in the group with major complications (P = 0.009, log-rank test). Major complications were a significant negative predictor for overall survival (hazard ratio 2.42, 95% CI 1.41-4.14) when adjusted for sex, age, American Society of Anesthesiologists grade, tumour site (colon vs rectum), R stage and tumour stage. However, in both univariate and multivariable analysis, major complications were not a significant predictor for time to recurrence (hazard ratio 1.29, 95% CI 0.56-2.99).

CONCLUSION

Non-lethal major postoperative complications seem to have a negative long-term impact on survival but not on time to recurrence.