Efficacy and Safety of Pectoral Nerve Block (Pecs) Compared With Control, Paravertebral Block, Erector Spinae Plane Block, and Local Anesthesia in Patients Undergoing Breast Cancer Surgeries: A Systematic Review and Meta-analysis.

OBJECTIVE: We aimed to compare the safety and efficacy of pectoral nerve block (Pecs) I and II with control or other techniques used during breast cancer surgeries such as local anesthesia, paravertebral block, and erector spinae plane block (ESPB). METHODS: We searched 4 search engines (PubMed, Cochrane Library, Scopus, and Web of Science) for relevant trials, then extracted the data and combined them under random-effect model using Review Manager Software. RESULTS: We found 47 studies, 37 of them were included in our meta-analysis. Regarding intraoperative opioid consumption, compared with control, a significant reduction was detected in Pecs II (standardized mean difference [SMD]=-1.75, 95% confidence interval [CI] [-2.66, -0.85], P=0.0001) and Pecs I combined with serratus plane block (SMD=-0.90, 95% CI [-1.37, -0.44], P=0.0002). Postoperative opioid consumption was significantly lowered in Pecs II (SMD=-2.28, 95% CI [-3.10, -1.46], P<0.00001) compared with control and Pecs II compared with ESPB (SMD=-1.75, 95% CI [-2.53, -0.98], P<0.00001). Furthermore, addition of dexmedetomidine to Pecs II significantly reduced postoperative opioid consumption compared with Pecs II alone (SMD=-1.33, 95% CI [-2.28, -0.38], P=0.006). CONCLUSION: Pecs block is a safe and effective analgesic procedure during breast cancer surgeries. It shows lower intra and postoperative opioid consumption than ESPB, and reduces pain compared with control, paravertebral block, and local anesthesia, with better effect when combined with dexmedetomidine.

Combined caudal retrocostal and lateral ultrasound-guided approach for transversus abdominis plane injection: A descriptive pilot study in pig cadavers.

Transversus abdominis plane (TAP) block is a regional anesthetic technique used to desensitize the abdominal wall in several species. This study aimed to describe the anatomical characteristics of the abdominal wall and to identify a feasible approach for an US-guided TAP injection that would result in adequate staining of the relevant nerves in the abdominal wall in pig cadavers. Fresh cadavers from five Landrace pigs (age, 12 weeks; body weight, 35.5 ± 1.6 kg) were used. One pig (n = 1) was anatomically dissected, and four pigs (n = 4; i.e., 8 hemiabdomens) were used for TAP injections and evaluation of dye spread. The volume of 0.3 mL/kg/injection point of methylene blue was injected bilaterally. In the caudal retrocostal approach, the injection was performed ventral to the most caudal part of the costal arch. In the lateral approach, the injection was performed between the last rib and iliac crest. A needle was inserted in plane for the caudal retrocostal and the lateral approach caudocranially and craniocaudally, respectively. Successful staining was defined as presence of dye on the nerve for a length of >1 cm in its entire circumference. The TAP was found between different muscle layers in the described anatomical regions. In the caudal retrocostal approach the TAP was found between the external abdominal oblique and transversus abdominis muscle bellies. In the lateral approach the TAP was found between the internal abdominal oblique and transversus abdominis muscles. The approach combining lateral and caudal retrocostal injections at the studied volume stained a median of 5 (3-6) target nerves from the fourth-last thoracic nerve to L2 (six nerves). Combined caudal retrocostal and lateral TAP injections of 0.3 mL/kg/injection point, resulted in staining of target nerve branches which supply the periumbilical and caudal abdominal wall in pig cadavers.

Breast surgery and peripheral blocks. Is it worth it?

PURPOSE OF REVIEW: The objective of this review is to identify the potential of peripheral nerve blocks established over the last years for perioperative pain management in breast surgery. These new blocks will be discussed with respect to their clinical effect and necessity. RECENT FINDINGS: After case reports and cadaver studies for the Pecs block and its variations sufficient clinical data from randomized controlled trial (RCT) and meta-analyses exist now. The modified Pecs block or Pecs II leads to a reduction of postoperative 24-h opioid consumption. The recently invented Erector spine block addresses the intercostal nerves. The benefits in analgesia of this approach were tested in few RCTs and showed superiority to the control group in terms of requested postoperative morphine. Most studies showed low intraoperative opioid doses and no study more than low to moderate postoperative pain scores. SUMMARY: Taking the pain levels after breast surgery into account, the request of additional nerve blocks has to be pondered against the potential risks and resource requirement. To reduce or avoid intraoperative or postoperative opioids, an ultrasound-guided Pecs II block proves to be the best option for perioperative pain relief.

PECS II block is associated with lower incidence of chronic pain after breast surgery

BACKGROUND: Breast cancer is complicated by a high incidence of chronic postoperative pain (25%–60%). Regional anesthesia might play an important role in lowering the incidence of chronic pain; however it is not known if the pectoral nerve block (PECS block), which is commonly used for breast surgery, is able to prevent this complication. Our main objective was therefore to detect any association between the PECS block and chronic pain at 3, 6, 9, and 12 months in patients undergoing breast surgery. METHODS: We conducted a prospective, monocentric, observational study. We enrolled 140 consecutive patients undergoing breast surgery and divided them in patients receiving a PECS block and general anesthesia (PECS group) and patients receiving only general anesthesia (GA group). Then we considered both intraoperative variables (intravenous opioids administration), postoperative data (pain suffered by the patients during the first 24 postoperative hours and the need for additional analgesic administration) and development and persistence of chronic pain (at 3, 6, 9, and 12 mo). RESULTS: The PECS group had a lower incidence of chronic pain at 3 months (14.9% vs. 31.8%, P = 0.039), needed less intraoperative opioids (fentanyl 1.61 μg/kg/hr vs. 3.3 μg/kg/hr, P < 0.001) and had less postoperative pain (3 vs. 4, P = 0.017). CONCLUSIONS: The PECS block might play an important role in lowering incidence of chronic pain, but further studies are needed.

Transthoracic Arteriovenous Graft Repair With the Pectoralis (PECS) II Nerve Block for Primary Intraoperative Anesthesia and Postoperative Analgesia: A Case Report.

The PECS II nerve block is a relatively new regional anesthetic technique that targets the medial and lateral pectoral nerves, as well as the lateral cutaneous branches of the intercostal nerves. It has been described for surgical cases involving the breast, as an adjunct or alternative to neuraxial or paravertebral techniques. This case report describes the first successful use of the PECS II nerve block placed using ultrasound guidance as the primary anesthetic and postoperative analgesic in a non-breast-related chest wall surgery.

Antiarrhythmic effects of stimulating the left dorsal branch of the thoracic nerve in a canine model of paroxysmal atrial tachyarrhythmias.

BACKGROUND: Stellate ganglion nerve activity (SGNA) precedes paroxysmal atrial tachyarrhythmia (PAT) episodes in dogs with intermittent rapid left atrial (LA) pacing. The left dorsal branch of the thoracic nerve (LDTN) contains sympathetic nerves originating from the stellate ganglia. OBJECTIVE: The purpose of this study was to test the hypothesis that high-frequency electrical stimulation of the LDTN can cause stellate ganglia damage and suppress PATs. METHODS: We performed long-term LDTN stimulation in 6 dogs with and 2 dogs without intermittent rapid LA pacing while monitoring SGNA. RESULTS: LDTN stimulation reduced average SGNA from 4.36 µV (95% confidence interval [CI] 4.10-4.62 µV) at baseline to 3.22 µV (95% CI 3.04-3.40 µV) after 2 weeks (P = .028) and completely suppressed all PAT episodes in all dogs studied. Tyrosine hydroxylase staining showed large damaged regions in both stellate ganglia, with increased percentages of tyrosine hydroxylase-negative cells. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that 23.36% (95% CI 18.74%-27.98%) of ganglion cells in the left stellate ganglia and 11.15% (95% CI 9.34%-12.96%) ganglion cells in the right stellate ganglia were positive, indicating extensive cell death. A reduction of both SGNA and heart rate was also observed in dogs with LDTN stimulation but without rapid LA pacing. Histological studies in the 2 dogs without intermittent rapid LA pacing confirmed the presence of extensive stellate ganglia damage, along with a high percentage of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. CONCLUSION: LDTN stimulation damages both left and right stellate ganglia, reduces left SGNA, and is antiarrhythmic in this canine model of PAT.

Surgical excision of the breast giant fibroadenoma under regional anesthesia by Pecs II and internal intercostal plane block: a case report and brief technical description: a case report / 대한마취과학회지

A 22-years-old female patient at 171 cm and 67 kg visited the Department of Breast Surgery of the hospital with a mass accompanied with pain on the left side breast as chief complaints. Since physical examination revealed a suspected huge mass, breast surgeon decided to perform surgical excision and requested anesthesia to our department. Surgery of breast tumor is often under local anesthesia. However, in case of big size tumor, surgery is usually performed under general anesthesia. The patient feared general anesthesia. Unlike abdominal surgery, there is no need to control visceral pain for breast and anterior thoracic wall surgery. Therefore, we decided to perform resection under regional anesthesia. Herein, we report a successful anesthetic and pain management of the patient undergoing excision of a huge breast fibroadenoma under regional anesthesia using Pecs II and internal intercostal plane block.

The effect of serratus plane block performed under direct vision on postoperative pain in breast surgery.

STUDY OBJECTIVES: To determine the effectiveness of serratus plane block performed under direct vision on postoperative pain after mastectomy. DESIGN: We performed a retrospective study of elective breast surgery patients undergoing mastectomy over 6 months. We collected data on the outcomes for the pain score and use of analgesia in recovery, the use of analgesia and antiemetics overnight, and the pain score and mobilization status of the patient 1 day after the operation. SETTING: Breast cancer is the most common cancer in women, and mastectomy is commonly performed as part of the management. A mastectomy can cause significant acute pain which progresses to chronic pain in 25% to 60% of women. Recent studies have suggested that a serratus plane block is a viable alternative to regional anesthetic techniques without the side effect profile and that injection of local anesthetic into serratus anterior provided predictable and effective anesthesia to the chest wall. Serratus blocks target the thoracic nerves more selectively than pectoral blocks, and local blocks can reduce the use of opiates postoperatively thereby lessening opiate-related side effects. PATIENTS: Our sample included 16 patients who had received a serratus block and 11 patients who only had wound infiltration with levobupivacaine with adrenaline and clonidine. INTERVENTION: Serratus plane block was conducted by injecting 50% of the totally available levobupivacaine 0.375% with adrenaline and clonidine deep to serratus anterior under direct observation. MAIN RESULTS: No patients receiving a serratus block suffered severe pain in recovery or day 1 postoperatively. Patients receiving wound infiltration alone had 2 patients suffering severe pain in recovery and 3 patients suffering severe pain day 1 postoperatively. CONCLUSION: Serratus block provides effective regional anesthesia, suitable for mastectomies, and currently appears to be superior to wound infiltration alone. However, further data will need to be collected to support this finding.

Octopamine stabilizes conduction reliability of an unmyelinated axon during hypoxic stress.

Mechanisms that could mitigate the effects of hypoxia on neuronal signaling are incompletely understood. We show that axonal performance of a locust visual interneuron varied depending on oxygen availability. To induce hypoxia, tracheae supplying the thoracic nervous system were surgically lesioned and action potentials in the axon of the descending contralateral movement detector (DCMD) neuron passing through this region were monitored extracellularly. The conduction velocity and fidelity of action potentials decreased throughout a 45-min experiment in hypoxic preparations, whereas conduction reliability remained constant when the tracheae were left intact. The reduction in conduction velocity was exacerbated for action potentials firing at high instantaneous frequencies. Bath application of octopamine mitigated the loss of conduction velocity and fidelity. Action potential conduction was more vulnerable in portions of the axon passing through the mesothoracic ganglion than in the connectives between ganglia, indicating that hypoxic modulation of the extracellular environment of the neuropil has an important role to play. In intact locusts, octopamine and its antagonist, epinastine, had effects on the entry to, and recovery from, anoxic coma consistent with octopamine increasing overall neural performance during hypoxia. These effects could have functional relevance for the animal during periods of environmental or activity-induced hypoxia.

Subcutaneous nerve activity is more accurate than heart rate variability in estimating cardiac sympathetic tone in ambulatory dogs with myocardial infarction.

BACKGROUND: We recently reported that subcutaneous nerve activity (SCNA) can be used to estimate sympathetic tone. OBJECTIVE: The purpose of this study was to test the hypothesis that left thoracic SCNA is more accurate than heart rate variability (HRV) in estimating cardiac sympathetic tone in ambulatory dogs with myocardial infarction (MI). METHODS: We used an implanted radiotransmitter to study left stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA), and thoracic SCNA in 9 dogs at baseline and up to 8 weeks after MI. HRV was determined based on time-domain, frequency-domain, and nonlinear analyses. RESULTS: The correlation coefficients between integrated SGNA and SCNA averaged 0.74 (95% confidence interval [CI] 0.41-1.06) at baseline and 0.82 (95% CI, 0.63-1.01) after MI (P <.05 for both). The absolute values of the correlation coefficients were significantly larger than that between SGNA and HRV analysis based on time-domain, frequency-domain, and nonlinear analyses, respectively, at baseline (P <.05 for all) and after MI (P <.05 for all). There was a clear increment of SGNA and SCNA at 2, 4, 6, and 8 weeks after MI, whereas HRV parameters showed no significant changes. Significant circadian variations were noted in SCNA, SGNA, and all HRV parameters at baseline and after MI, respectively. Atrial tachycardia (AT) episodes were invariably preceded by SCNA and SGNA, which were progressively increased from 120th, 90th, 60th, to 30th seconds before AT onset. No such changes of HRV parameters were observed before AT onset. CONCLUSION: SCNA is more accurate than HRV in estimating cardiac sympathetic tone in ambulatory dogs with MI.

Effects of low-intensity atrial ganglionated plexi stimulation on ventricular electrophysiology and arrhythmogenesis.

BACKGROUND: Atrial ganglionated plexi (GP) have been shown to modulate sinus rate, atrioventricular conduction and atrial electrophysiology. The aim of this study was to investigate the effect of low-intensity GP stimulation (GPS) on ventricular electrophysiological properties in normal heart and on ventricular arrhythmogenesis after acute myocardial ischemia (AMI) in canine. METHODS AND RESULTS: Thirty-nine dogs were assigned into the normal heart group (n=12) and the acute myocardial ischemia (AMI) group (n=27, 12 in control and 15 in low-intensity GPS). In the normal heart group, ventricular effective refractory period (ERP), dynamic restitution and electrical alternans were measured at baseline and after 6-hour low-intensity GPS. In the AMI group, the incidence of ventricular arrhythmias was determined during 1-hour recording after AMI was induced. In the normal heart, 6-hour low-intensity GPS significantly prolonged ventricular ERP and action potential duration (APD) at each site (all P<0.05) but did not change their spatial dispersions when compared with baseline. Low-intensity GPS also caused an upward shift of ventricular restitution curves in each site but did not change the slope of restitution curves. APD alternans after low-intensity GPS occurred at longer pacing cycle length at each site when compared with baseline (all P<0.05). In the AMI heart, the incidence of ventricular arrhythmias in low-intensity GPS group was significantly lower than that in control group (P<0.05). CONCLUSIONS: Low-intensity GPS induces no increase in the risk of ventricular arrhythmias in the normal heart as well as protects against ventricular arrhythmogenesis during AMI.

Neurotization from Two Medial Pectoral Nerves to Musculocutaneous Nerve in a Pediatric Brachial Plexus Injury

Traumatic brachial plexus injuries can be devastating, causing partial to total denervation of the muscles of the upper extremities. Surgical reconstruction can restore motor and/or sensory function following nerve injuries. Direct nerve-to-nerve transfers can provide a closer nerve source to the target muscle, thereby enhancing the quality and rate of recovery. Restoration of elbow flexion is the primary goal for patients with brachial plexus injuries. A 4-year-old right-hand-dominant male sustained a fracture of the left scapula in a car accident. He was treated conservatively. After the accident, he presented with motor weakness of the left upper extremity. Shoulder abduction was grade 3 and elbow flexor was grade 0. Hand function was intact. Nerve conduction studies and an electromyogram were performed, which revealed left lateral and posterior cord brachial plexopathy with axonotmesis. He was admitted to Rehabilitation Medicine and treated. However, marked neurological dysfunction in the left upper extremity was still observed. Six months after trauma, under general anesthesia with the patient in the supine position, the brachial plexus was explored through infraclavicular and supraclavicular incisions. Each terminal branch was confirmed by electrophysiology. Avulsion of the C5 roots and absence of usable stump proximally were confirmed intraoperatively. Under a microscope, neurotization from the musculocutaneous nerve to two medial pectoral nerves was performed with nylon 8-0. Physical treatment and electrostimulation started 2 weeks postoperatively. At a 3-month postoperative visit, evidence of reinnervation of the elbow flexors was observed. At his last follow-up, 2 years following trauma, the patient had recovered Medical Research Council (MRC) grade 4+ elbow flexors. We propose that neurotization from medial pectoral nerves to musculocutaneous nerve can be used successfully to restore elbow flexion in patients with brachial plexus injuries.

[The experience with thoracoscopic sympathectomy for the treatment of distal lesions of limb arteries].

The study included 107 patients with distal lesions of limb arteries treated with the use of thoracoscopic sympathectomy. The best results in the early postoperative period were obtained in patients with Raynaud's disease. Modifications introduced into the methods of its treatment permitted to retain effectiveness of sympathectomy till the late postoperative period in 90% of the patients. Surgery for obliterative endarteritis and atherosclerosis was viewed as a possibility to preserve the supporting function of the limb. This purpose was attained in 73.2 and 62.5% of the patients respectively in the early and in 62 and 25% in the late postoperative periods.

[Outpatient or short-stay videothoracoscopy-assisted thoracic sympathectomy: anesthesia in 445 cases]. / Anestesia para simpatectomía torácica por videotoracoscopia en régimen ambulatorio o corta estancia: experiencia en 445 casos.

OBJECTIVE: To demonstrate the safety of outpatient or short-stay bilateral videothoracoscopy-assisted thoracic sympathectomy. PATIENTS AND METHODS: The medical records of 445 who underwent bilateral videothoracoscopy-assisted thoracic sympathectomy were reviewed; the same protocols were used to guide these outpatient or short-stay procedures in all cases. Intravenous anesthesia was provided. An orotracheal tube allowed for carrying out the sympathectomy procedure during short periods of apnea. A 2% lidocaine solution was infused through the thoracic drains, which were removed soon after surgery. Data on intraoperative respiratory variables, pain, and intra- and postoperative complications were gathered. The data for patients undergoing the procedure on an outpatient or short-stay basis were compared. RESULTS: No significant differences in demographic or perioperative variables were found between the 2 groups. In 3.6% of the patients in the series, there was a record of a postoperative pulmonary complication: 4 therapeutic minithoracotomies; 1 subcutaneous emphysema without radiologic changes; 9 residual pneumothoraces, 2 requiring pleural drainage; 1 chylothorax; and 1 delayed hemothorax. With the exception of the late-developing hemothorax, all complications were diagnosed and treated in the immediate postoperative period. In the outpatient surgery group, unplanned admissions because of patient refusal to leave occurred in 6.5% of the cases. CONCLUSION: The low incidence of complications, and especially the finding that complications are detected in the early recovery period, indicate that this procedure can be performed on an outpatient basis.

Nerve stimulator-guided repetitive paravertebral block for thoracic myofascial pain syndrome.

Myofascial pain syndrome (MPS) may persist for many years and is often refractory to traditional therapeutic approaches including pharmacotherapy, focal tenderness infiltration by local anesthetic and corticosteroids, physical therapy and behavioral modification. This report describes three cases of MPS following coronary artery bypass graft, inadequate positioning during abdominal hysterectomy, and excessive physical effort refractory to conventional therapeutic approaches. Three patients were successfully treated with repeated nerve stimulator-guided paravertebral block using a mixture of bupivacaine and clonidine. Physical examinations including a complete neurological assessments were unremarkable. Relevant diagnostic imaging (X-ray, magnetic resonance imaging, computed tomography) and laboratory evaluations also failed to demonstrate any significant structural disorders or systemic diseases that might have been responsible for their pain. Nerve stimulator-guided paravertebral block was performed at the dermatomes corresponding to the thoracic myofascial pain region. Each point was injected with 4 mL of the local anesthetic solution. If the pain returned, a second paravertebral block was performed. The three patients were pain-free over a follow-up period up to 2 years. Our report suggests that nerve stimulator-guided paravertebral blockade could be a useful treatment for MPS refractory to traditional therapeutic approaches.

[Anatomical basis and technique of thoracic paravertebral blockade]. / Podstawy anatomiczne i technika wykonania piersiowej blokady przykregowej.

This article presents in illustrations the classical technique of transdermal identification and anatomy of paravertebral space (PVS) comparing to other techniques. This have to be acknowledged by anaesthesiologists as well as by other specialists to perform thoracic paravertebral blockade (TPVB)--earlier elapsed but nowadays getting more popular--safely. In addition the article contains a short description of author's own modification of Eason's and Wyatt's technique.

[Thoracic paravertebral blockade--history or present time?]. / Blokada przykregowa--historia czy wspólczesnosc?

This article discusses thoracic paravertebral blockade (TPVB)--a popular in early XX-th century method of local anaesthesia used also for diagnosis and treatment--being revitalized lately. Authors present modem indications for TPVB comparing it to other methods of regional anaesthesia.

An isolated long thoracic nerve injury in a Navy Airman.

A palsy of the long thoracic nerve of Bell is a cause of scapular winging that has been reported after trauma, surgery, infection, electrocution, chiropractic manipulation, exposure to toxins, and various sports-related injuries that include tennis, hockey, bowling, soccer, gymnastics, and weight lifting. Scapular winging can result from repetitive or sudden external biomechanical forces that may either exert compression or place extraordinary traction in the distribution of the long thoracic nerve. We describe an active duty Navy Airman who developed scapular winging secondary to traction to the long thoracic nerve injury while working on the flight line. A thorough history and physical is essential in determining the mechanism of injury. Treatment should initially include refraining from strenuous use of the involved extremity, avoidance of the precipitating activity, and physical therapy to focus on maintaining range of motion and strengthening associated muscles, with most cases resolving within 9 months.