Evaluation of intercostal cryoanalgesia versus conventional analgesia in postthoracotomy pain

Cryoanalgesia: Review with Respect to Peripheral Nerve

BACKGROUND

 Cryoanalgesia is a tool being used by interventional radiology to treat chronic pain. Within a certain cold temperature range, peripheral nerve function is interrupted and recovers, without neuroma formation. Cryoanalgesia has most often been applied to the intercostal nerve. Cryoanalgesia has applications to peripheral nerve surgery, yet is poorly understood by reconstructive microsurgeons.

METHODS

 Histopathology of nerve injury was reviewed to understand cold applied to peripheral nerve. Literature review was performed utilizing the PubMed and MEDLINE databases to identify comparative studies of the efficacy of intraoperative cryoanalgesia versus thoracic epidural anesthesia following thoracotomy. Data were analyzed using Fisher's exact and analysis of variance tests. A similar approach was used for pudendal cryoanalgesia.

RESULTS

 Application of inclusion and exclusion criteria resulted in 16 comparative clinical studies of intercostal nerve for this review. For thoracotomy, nine studies compared cryoanalgesia with pharmaceutical analgesia, with seven demonstrating significant reduction in postoperative opioid use or postoperative acute pain scores. In these nine studies, there was no association between the number of nerves treated and the reduction in acute postoperative pain. One study compared cryoanalgesia with local anesthetic and demonstrated a significant reduction in acute pain with cryoanalgesia. Three studies compared cryoanalgesia with epidural analgesia and demonstrated no significant difference in postoperative pain or postoperative opioid use. Interventional radiology targets pudendal nerves using computed tomography imaging with positive outcomes for the patient with pain of pudendal nerve origin.

CONCLUSION

 Cryoanalgesia is a term used for the treatment of peripheral nerve problems that would benefit from a proverbial reset of peripheral nerve function. It does not ablate the nerve. Intraoperative cryoanalgesia to intercostal nerves is a safe and effective means of postoperative analgesia following thoracotomy. For pudendal nerve injury, where an intrapelvic surgical approach may be difficult, cryoanalgesia may provide sufficient clinical relief, thereby preserving pudendal nerve function.

Limited cryoablation reduces hospital stay and opioid consumption compared to thoracic epidural analgesia after minimally invasive repair of pectus excavatum

pain following minimally invasive repair of pectus excavatum (MIRPE) is a critical concern that leads to a prolonged hospital stay and high doses of opiates administered to the patients. This study aimed to evaluate the efficacy of intraoperative cryoanalgesia (cryoablation of the intercostal nerves) during MIRPE. We retrospectively analyzed the data of 64 patients who underwent MIRPE and received cryoanalgesia or epidural analgesia between January 2019 and January 2021. The oral morphine milligram equivalent (MME) was used to calculate the dosage of opioid agents. The median age was 15 years (range, 4-33 years). The median postoperative hospital stay was 4 days (range, 2-6 days), with a median oral MME consumption of 45 mg (ranging from 0 to 1360 mg). Cryoanalgesia was performed in 38 patients, and epidural analgesia was administered to the remaining 26 patients. The cryoanalgesia group had a significantly lesser pain score, shorter postoperative hospital stay and lower oral MME consumption than the epidural analgesia group (5 vs 2; P < .001, 3 days vs 5 days; P < .001, 19 mg vs 634 mg; P < .001). Cryoanalgesia appears to reduce postoperative hospital stay and opioid consumption compared with epidural analgesia. The outcomes of this study indicate that cryoanalgesia might be a safe and effective method for pain control following MIRPE.

Cryoanalgesia for postsurgical pain relief in adults: A systematic review and meta-analysis

Background

Despite advances in pain management, postoperative pain continues to be an important problem with significant burden. Many current therapies have dose-limiting adverse effects and are limited by their short duration of action. This review examines the evidence for the efficacy and safety of cryoanalgesia in postoperative pain.

Materials and methods

This review was registered in PROSPERO and prepared in accordance with PRISMA. MEDLINE, EMBASE, and Cochrane databases were searched until July 2020. We included randomized controlled trials (RCTs) of adults evaluating perioperatively administered cryoanalgesia for postoperative pain relief.

Results

Twenty-four RCTS were included. Twenty studies examined cryoanalgesia for thoracotomy, two for herniorrhaphy, one for nephrectomy and one for tonsillectomy. Meta-analysis was performed for thoracic studies. We found that cryoanalgesia with opioids was more efficacious than opioid analgesia alone for acute pain (mean difference [MD] 2.32 units, 95 % confidence interval [CI] -3.35 to -1.30) and persistent pain (MD 0.81 units, 95 % CI -1.10 to -0.53) after thoracotomy. Cryoanalgesia with opioids also resulted in less postoperative nausea compared to opioid analgesia alone (relative risk [RR] 0.23, 95 % CI 0.06 to 0.95), but there was no difference in atelectasis (RR 0.38, 95 % CI 0.07 to 2.17).

Conclusion

Heterogeneity in comparators and outcomes were important limitations. In general, reporting of adverse events was incomplete and inconsistent. Many studies were over two decades old, and most were limited in how they described their methodology. Considering the potential, larger RCTs should be performed to better understand the role of cryoanalgesia in postoperative pain management.

Percutaneous cryoneurolysis for acute pain management: current status and future prospects

Introduction: Conventional nerve blocks utilize local anesthetic drugs to provide pain relief for hours or days following surgery or trauma. However, postoperative and trauma pain can last weeks or months. Ultrasound-guided percutaneous cryoneurolysis is an anesthetic modality that offers substantially longer pain relief compared to local anesthetic-based nerve blocks.Areas covered: In this review, we discuss the history, mechanism of action, and use of ultrasound-guided percutaneous cryoneurolysis by anesthesiologists in the setting of acute pain management.Expert opinion: Ultrasound-guided percutaneous cryoneurolysis offers the potential to provide weeks or months of pain relief following surgery or trauma. Compared to continuous local anesthetic-based peripheral nerve blocks, currently the gold standard for providing long duration postoperative analgesia, cryoneurolysis has benefits that include: 1) longer duration measured in weeks or months rather than days; 2) no external reservoir of local anesthetic to be carried by the patient; 3) no risk of infection; and 4) no risk of catheter dislodgement. However, cryoneurolysis can induce a prolonged motor block in addition to the sensory block, decreasing the appropriate indications to those in which potential sensory and motor deficits are acceptable. Additionally, cryoneurolysis of multiple nerves can have a substantial time requirement relative to conventional nerve blocks.

Cryoneurolysis and Percutaneous Peripheral Nerve Stimulation to Treat Acute Pain

Two regional analgesic modalities currently cleared by the U.S. Food and Drug Administration hold promise to provide postoperative analgesia free of many of the limitations of both opioids and local anesthetic-based techniques. Cryoneurolysis uses exceptionally low temperature to reversibly ablate a peripheral nerve, resulting in temporary analgesia. Where applicable, it offers a unique option given its extended duration of action measured in weeks to months after a single application. Percutaneous peripheral nerve stimulation involves inserting an insulated lead through a needle to lie adjacent to a peripheral nerve. Analgesia is produced by introducing electrical current with an external pulse generator. It is a unique regional analgesic in that it does not induce sensory, motor, or proprioception deficits and is cleared for up to 60 days of use. However, both modalities have limited validation when applied to acute pain, and randomized, controlled trials are required to define both benefits and risks.

Interventional Cryoneurolysis: An Illustrative Approach

The application of advanced imaging guidance and the interventional radiology skill set has expanded the breadth of nerve and nerve plexus targets in the body for potential cryoneurolysis. Advancement of the basic science supporting cryoneurolysis has further solidified proceduralists' confidence and ability to select and manage patients clinically. As these procedures continue to evolve, a structured approach to the wide variety of indications is necessary.

Interventional Cryoneurolysis: What Is the Same, What Is Different, What Is New?

Cryoneurolysis is the deliberate application of cold temperatures to nerves for therapeutic purposes. The idea of treating pain with this technique is thousands of years old and has evolved over time through the application of surgical techniques, nerve stimulation and/or landmark guidance, and through device development. Recent integration of the interventional radiology skill set to this space has unlocked a myriad of opportunities-primarily through a unique ability to percutaneously access deep structures in the body with accuracy and precision, and the capacity to monitor ablation zones. Understanding of the specific neurohistological process that follows targeted cryoneurolysis leads to new options for treating patients in pain without drugs and opens doors for the potential modification of a wide array of disease states.

Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management

Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery.

The role of intercostal cryoanalgesia in post-thoracotomy analgesia

OBJECTIVES

Patients undergoing thoracotomy were studied to compare the effects of cryoanalgesia, combined with intravenous patient-controlled analgesia (IVPCA), against IVPCA alone during the four days following surgery.

METHODS

Fifty patients were randomized into two groups: an IVPCA group (n = 25) and an IVPCA-cryo group (n = 25). Subjective pain intensity was assessed on a verbal analogue scale at rest and during coughing. The intensity and the incidence of post-thoracotomy pain, numbness, epigastric distension and/or back pain, the analgesic requirements, as well as the blood gas values and respiratory function tests were evaluated up to the second postoperative (postop) month. Haemodynamic data and episodes of nausea and/or vomiting were recorded over the four postop days.

RESULTS

In the cryo group there was a statistically significant improvement in postop pain scores (P = 10(-4)), reduction in consumption of morphine (P = 10(-4)) and other analgesics (P = 10(-4)), optimization (less acidosis) of the pH values of blood gases (P < 0.015 over 72 hours postop and P < 0.03 on the first and second postop months), increase in systolic blood pressure (P < 0.05 over 96 hours postop), reduction in heart rate (P < 0.05 over 96 hours postop), increase in values of FEV1 (P < 0.02) and FVC (P < 0.05) at the first and second postop months, reduction in the incidence of nausea (0.05 < P < 0.1 over 18 hours postop), numbness, epigastric distension and back pain (P < 0.05 at days 5, 6, 7, 14, 30 and 60 following surgery).

CONCLUSIONS

We suggest that cryoanalgesia be considered as a simple, safe, inexpensive, long-term form of post-thoracotomy pain relief. Cryoanalgesia effectively restores FEV1 values at the second postop month.

Painful neuromas

OBJECTIVES

To perform a topical review of the published literature on painful neuromas.

METHODS

A MEDLINE search was performed using the MESH terms "neuroma", "pain", "diagnosis", and "treatment" for all dates.

RESULTS

Acoustic neuromas and intraabdominal neuromas were excluded from a total of 7616 articles. The reference lists from these articles were further reviewed to obtain other relevant articles.

DISCUSSION

Neuromas develop as part of a normal reparative process following peripheral nerve injury. Painful neuromas can induce intense pain resulting in immense suffering and disability. MRI aids the diagnosis, but, ultrasound imaging allows cost effective accurate diagnosis and localization of neuromas by demonstrating their direct contiguity with the nerve of origin. Management options for painful neuromas include pharmacotherapy, prosthetic adjustments, steroid injection, chemical neurolysis, cryoablation, and radiofrequency ablation. Ultrasound imaging guidance has improved the success in localizing and targeting the neuromas. This review discusses the patho-physiology and accumulated evidence for various therapies and the current percutaneous interventional management options for painful neuromas.

An innovative case report detailing the successful treatment of post-thoracotomy syndrome with peripheral nerve field stimulation

INTRODUCTION

The detrimental effects of post-thoracotomy pain syndrome is experienced worldwide; however, an effective treatment regimen remains elusive.

METHODS

We report a case of post-thoracotomy pain syndrome effectively treated with peripheral nerve field stimulation (PNfS).

RESULTS

In the presented case, the patient underwent permanent placement of the PSfS device after a successful trial period. Upon follow-up the patient has reported even better coverage over her painful areas and admits to 80% and higher reductions in her painful symptoms.

CONCLUSION

Although the data are limited, in the aforesaid case report, post-thoracotomy syndrome was effectively treated with the use of PNfS. This resulted in a significant pain perception reduction, increased quality of life and mobility, as well as decreased usage of oral pain medications. This adds to the accumulating case report and case series data that suggest PNfS is showing great promise as a pain reduction modality. Further, it is minimally invasive, can be trialled prior to implantation, and is reversible. Large prospective studies will be required in the future to further evaluate its efficacy before it can be widely accepted and adopted.

[Fast track in thoracic surgery]

Patients undergoing thoracic surgery are threatened by pulmonary complications such as pneumonia and atelectasis. Age, preoperative FEV(1), operative time and extent of resection are predictors for adverse outcome. Reported morbidity after lung resection is as high as 42% and mortality up to 7%. Fast track in thoracic surgery aims at reducing morbidity and mortality rates after lung resection by introducing specific measures into the pre-, intra- and postoperative periods. Basic fast track elements in thoracic surgery are smoking cessation, preoperative physiotherapy, micronutrient supplementation, high thoracic epidural anesthesia, fluid restriction, early mobilization and enteral feeding. The effectiveness of these individual measures has been proven of value in perioperative care, however, evidence on multimodal therapy regimens in thoracic surgery is limited. In particular it remains to be elucidated which patients should be fast tracked in order to improve outcomes.

Ultrasound-Guided Intercostal Nerve Cryoablation

Ultrasound technology has advanced regional anesthesia and pain management, by improving accuracy and reducing complication rates. We have successfully performed cryoablation of intercostal nerves with ultrasound guidance with no complications. Four patients with postthoracotomy pain syndrome had pain relief for at least 1 mo after selective cryoablation of intercostal nerves at the mid-axillary line. Visualizing the pleura during the procedure is the greatest benefit of using ultrasonography, especially in thin patients whose intercostal groove to pleural distance may be <0.5 cm. Although further studies are needed, we feel that this new technique should reduce the risk of pneumothorax as well as improve the success of cryoablation.

Randomized comparative clinical study of cryoanalgesia versus topical anesthesia in clear corneal phacoemulsification

PURPOSE

To compare intraoperative pain scores and objective stress signs during clear corneal phacoemulsification under cryoanalgesia and topical anesthesia.

SETTING

Hospital Ramón y Cajal, Madrid, and Hospital Universitario Nuestra Sra. de la Candelaria, Tenerife, Canary Islands, Spain.

METHODS

Eighty-two patients were randomized to have phacoemulsification under cryoanalgesia or topical anesthesia. Uncooperative patients and those with shallow anterior chamber and small pupils were excluded. In case of breakthrough pain during the surgery, a supplemental anesthesia protocol was established. Each patient was asked to grade the severity of pain on a 4-point scale (verbal description score; 0=none, 1=little, 2=some, or 3=much). Immediately after surgery, the general discomfort and pain were evaluated. Surgeon stress was evaluated during surgery. A comparison of the 2 groups was performed using a statistical analysis of variance.

RESULTS

Supplemental anesthesia was required in 1 patient in each group. A total of 95.23% of patients would repeat the same technique under cryoanalgesia versus 97.5% under topical anesthesia. Similar pain levels and surgical stress scores were noted in both groups.

CONCLUSIONS

Cryoanalgesia clear corneal phacoemulsification was safe with an acceptable level of pain. It induced a physiological stress response to that of topical anesthesia (blood pressure and heart rate). Cryoanalgesia was preferred over topical anesthesia by some patients. It is a suitable technique for anesthetic allergy cases.

Pain Management in Trauma Patients

Trauma is a major cause of mortality throughout the world. In recent years, major advances have been made in the management of trauma, the end result of which has been reduced mortality and enhanced function. One of these areas is pain control. Improved pain management has not only led to increased comfort in trauma patients, but has also been shown to reduce morbidity and improve long-term outcomes. This review focuses on the treatment of pain in the setting of acute injury and on pain management in trauma patients who go on to develop chronic pain. Emphasis is placed on pharmacologic interventions, invasive and noninvasive pain management techniques, analgesia in challenging patients, and pain control in commonly encountered trauma conditions.

Effects of cryoanalgesia on post-thoracotomy pain and on the structure of intercostal nerves: a human prospective randomized trial and a histological study

OBJECTIVE

The choice of analgesia in the management of post-thoracotomy pain remains controversial. Although several alternative forms of post-thoracotomy analgesia exist, all have their disadvantages. Cryoanalgesia, localized freezing of intercostal nerves, has been reported to have variable effectiveness and an incidence of long-term cutaneous sensory changes. We carried out an animal study to assess the reversibility of histological changes induced by cryoanalgesia and a prospective randomized trial to compare the effectiveness of cryoanalgesia with conventional analgesia (parenteral opiates).

METHODS

In six anaesthetized dogs, intercostal nerves were exposed to a varying duration of cryo-application (30, 60, 90 and 120 s). The nerves were biopsied and examined histologically at regular intervals over the following 6 months. In the clinical study, 200 consecutive patients undergoing thoracotomy were randomized to cryoanalgesia and conventional (parenteral opiates) analgesia groups. Postoperative pain scores, respiratory function tests and use of opiate analgesia were measured for the two groups.

RESULTS

Following application of the cryoprobe, degeneration and fragmentation of the axons was evident with associated inflammatory changes. As the endoneurium remained intact, axonal regeneration took place after the resolution of axonal swelling. Over the course of weeks, recovery of the intercostal nerve occurred and was complete after 1 month for the 30 and 60 s groups. For nerves exposed to longer durations of cryoanalgesia, the time taken for complete recovery was proportionally increased. Clinically, there was a statistically significant (P<0.05) improvement in postoperative pain scores and use of opiate analgesia and an improvement (P>0.05) in respiratory function tests for patients in the cryoanalgesia group. The previously suggested cutaneous sensory changes resolved within 6 months with complete restoration of function.

CONCLUSIONS

We suggest that cryoanalgesia be considered as a simple, inexpensive, long-term form of post-thoracotomy pain relief, which does not cause any long-term histological damage to intercostal nerves.