Bloqueos Nerviosos. Bases Anatómicas del Dolor Somático Abdomino-Pélvico / Nerve Blocks. Anatomy of the Somatic Innervation of the Abdomino-Pelvic Cavity

El dolor abdominal es una de las sintomatologías que afectan con frecuencia la cavidad abdomino-pélvica. Dicha cavidad posee una inervación somática en la que intervienen del séptimo a doceavo nervios intercostales, ramos colaterales y terminales del plexo lumbar y el nervio pudendo; siendo objetivo de este trabajo la descripción anatómica del dolor abdominopélvico a través del plexo lumbar, nervios intercostales y nervio pudendo, sus diferentes patrones y variaciones de conformación, y las implicancias de éstas últimas en las distintas maniobras clínico-quirúrgicas. Se realizó un estudio descriptivo, observacional y morfométrico de la inervación somática de la cavidad abdomino-pélvica, en 50 preparaciones cadavéricas, fijadas en solución de formaldehído, de la Tercera Cátedra de Anatomía, Facultad de Medicina, Universidad de Buenos Aires, entre Agosto/2017-Diciembre/2019. La descripción clásica del plexo lumbar se encontró en 35 casos; la presencia del nervio femoral accesorio en ningún caso; así como también la ausencia del nervio iliohipogástrico en ningún caso; el nervio obturador accesorio se halló en 2 casos; el nervio genitofemoral dividiéndose dentro de la masa muscular del psoas mayor en 6 casos; el nervio cutáneo femoral lateral emergiendo únicamente de la segunda raíz lumbar en 6 casos y por último se encontró la presencia de un ramo del nervio obturador uniéndose al tronco lumbosacro en un caso. Los nervios intercostales y el nervio pudendo presentaron una disposición clásica en todos los casos analizados. Es esencial un adecuado conocimiento y descripción del plexo lumbar, nervios intercostales y nervio pudendo para un adecuado abordaje de la cavidad abdomino-pélvica en los bloqueos nerviosos.

SUMMARY: Abdominal pain is one of the symptoms that affect the abdominal-pelvic cavity. The abdominal-pelvic cavity has a somatic innervation involving the seventh to twelfth intercostal nerves, collateral and terminal branches of the lumbar plexus and the pudendal nerve. The objective of this work is the description of the lumbar plexus, intercostal nerves and pudendal nerve, its different patterns and structure variations, as well as its implications during pain management in patients. A descriptive, observational, and morphometric study of patterns and structure variations of the lumbar plexus, intercostal nerves and pudendal nerve was conducted in 50 formalin-fixed cadaveric dissections of the Third Chair of Anatomy at the School of Medicine in the Universidad de Buenos Aires from August 2017 to December/2019. The standard description of the lumbar plexus was found in 35 cases; accessory femoral nerve was not present in any of the cases; absence of the iliohipogastric nerve was also not found in any case, while the accessory obturating nerve was found in 2 cases; genitofemoral nerve dividing within the muscle mass of psoas in 6 cases; lateral femoral cutaneous nerve emerging only from the second lumbar root in 6 cases and finally, presence of a branch of the obturating nerve was found joining the lumbosacral trunk in one case. The pudendal and intercostal nerve patterns presented a typical pathway in all cases. Adequate knowledge and description of the lumbar plexus, intercostal nerves and pudendal nerve is essential for an adequate approach of the abdominal-pelvic cavity in nerve blocks.

Cooled Radiofrequency Ablation for Intercostal Neuralgia.

Background: Intercostal neuralgia is pain associated with the intercostal nerves along the rib, chest, and upper abdominal wall. Intercostal neuralgia has various etiologies, and current conventional treatment options include intercostal nerve blocks, nonsteroidal anti-inflammatory drugs, transcutaneous electrical nerve stimulation, topical medications, opioids, tricyclic antidepressants, and anticonvulsants. For a subset of patients, these conventional treatment options provide little relief. Radiofrequency ablation (RFA) is an emerging procedure for the treatment of chronic pain and neuralgias. Cooled RFA (CRFA) is a specific type of RFA that has been trialed as a treatment for intercostal neuralgia in patients refractory to conventional treatment modalities. This case series assesses the efficacy of CRFA for the treatment of intercostal neuralgia in 6 patients. Case Series: Three female and 3 male patients underwent CRFA of the intercostal nerves to treat intercostal neuralgia. The patients had an average age of 50.7 years and demonstrated an average pain reduction of 81.3%. Conclusion: This case series suggests that CRFA may be an effective treatment option for patients with intercostal neuralgia that is not responsive to conservative treatment options. To determine the duration of pain improvement, large research studies need to be conducted.

Ultrasound-Guided Percutaneous Intercostal Cryoneurolysis for Acute-on-Chronic Pain in CLOVES Syndrome.

Cryoneurolysis is an analgesic method that has been shown to provide extended pain relief in postoperative patients. However, to date, this method has not been described in nonsurgical inpatients with chronic pain experiencing an acute exacerbation. This analgesic modality has the potential to provide pain relief for patients whose expected duration of severe acute pain would outlast that of other regional anesthetic techniques while avoiding opioid escalation and facilitating discharge. We present a patient with acute exacerbation of chronic pain from breast ulcerations caused by congenital lipomatous overgrowth, vascular malformations, epidermal nevis, spinal/skeletal anomalies/scoliosis (CLOVES) syndrome that was successfully treated as an inpatient with a portable cryoneurolysis device.  This is the first reported use of cryoneurolysis in an inpatient setting to treat acute-on-chronic pain in a nonsurgical patient. The authors recommend regional anesthesiologists and acute pain specialists to utilize this technique to provide analgesia in patients with complex pain to facilitate hospital throughput.

Efficacy of ultrasound guided intercostal nerve pulse radiofrequency combined with nerve block in the treatment of post-herpetic neuralgia / 中国基层医药

Objective:To analyze the efficacy and safety of ultrasound-guided intercostal nerve pulse radiofrequency combined with nerve block in the treatment of post-herpetic neuralgia.Methods:The clinical data of 62 patients with post-herpetic neuralgia who received treatment in The Affiliated Hospital of Southwest Medical University from May 2017 to May 2021 were retrospectively analyzed. These patients underwent nerve block (NB group, n = 30) or pulsed radiofrequency plus nerve block (PRF + NB group, n = 32). Before and after treatment, The Numerical Rating Scale (NRS) score and Pittsburgh Sleep Quality Index (PSQI) score were compared between the two groups. After treatment, the occurrence of complications including pneumothorax, infection, and skin numbness was evaluated in each group. Results:Before treatment, there were no significant differences in NRS and PSQI scores between the two groups (all P > 0.05). Immediately, 1 week and 1 month after treatment, there was no significant difference in PSQI score between the two groups (all P > 0.05). At 3 and 6 months after treatment, the NRS score in the NB +PRF group was (1.71 ± 0.35) points and (1.68 ± 0.36) points, which were significantly lower than (2.72 ± 0.68) points and (3.26 ± 0.76) points in the NB group ( t = 54.40, 78.18, both P < 0.05). There were no treatment-related complications such as pneumothorax, infection, nerve numbness, or muscle weakness in the two groups. Conclusion:Ultrasound-guided pulsed radiofrequency combined with nerve block has a definite curative effect on post-herpetic neuralgia and is highly safe. The medium- and long-term efficacy of the combined therapy is superior to that of nerve block alone.

Chronic abdominal pain due to entrapment of the anterior abdominal cutaneous nerve (ACNES): About a case.

Anterior abdominal cutaneous nerve entrapment syndrome (ACNES) is a chronic neuropathic abdominal pain that can radiate dorsally and occurs as a result of entrapment of the thoracic intercostal nerves in the abdominal muscles. This pain increases with the contraction of the abdominal muscles and is not related to meals or bowel habits. Its diagnosis is based on history and physical examination without the need for additional tests. The treatment of this pathology consists of the infiltration of a local anesthetic together with corticosteroids at the point of greatest pain, which achieves an immediate resolution of the pain.

Role of an Intercostobrachial Nerve Block in Alleviating Tourniquet Pain: A Randomized Clinical Trial.

Introduction Tourniquet pain may have cutaneous and ischemic components. It is questionable whether blockade of a sensory nerve will help reduce ischemic pain. In addition, complete anesthesia of the axilla in the intercostobrachial nerve (ICBN) distribution is challenging to execute, and ICBN blockade has an inherently higher failure rate because of its variable anatomic location and source of innervation. We sought to determine the utility of an ICBN block for the prevention of tourniquet pain. Methods We conducted a single-center randomized controlled trial at a major academic medical center involving patients scheduled to undergo distal upper extremity surgery under ultrasound-guided supraclavicular brachial plexus block. Forty patients were randomized to receive an additional ICBN block or no ICBN block, with 22 allocated to the intervention and 18 to control. We collected data on the incidence of tourniquet pain and systemic anesthetic requirements. Results Initial contingency analysis examining the relationship between ICBN block placement and the development of pain using the two-tailed Fisher exact test failed to show that the presence or absence of ICBN block was associated with the development of tourniquet pain. χ2 analysis failed to show that tourniquet time was significantly related to the development of tourniquet pain. Conclusions The overall incidence of tourniquet pain in the setting of a dense supraclavicular brachial plexus block for surgical anesthesia was low even without an ICBN block and even with tourniquet times greater than 90 min. Tourniquet pain was easily managed with small amounts of systemic analgesics.

Modified radical mastectomy for level III axillary lymph node clearance: a case report.

While modified radical mastectomy with level I and level II axillary lymph node clearance is a typical operating method in breast surgery, level III axillary lymph node clearance is necessary in some cases such as those involving apical axillary nodes. Level III dissection can provide accurate postoperative staging and essential guidance for postoperative adjuvant therapy. Although it is often difficult to expose the subclavian region and dissect level III axillary lymph nodes, in this case, the author split the pectoralis major muscle 2 cm inferior to the collarbone and performed a skeletonized complete level III axillary lymph node dissection. The author cut apart the fat on the surface of subclavian vein, lifted the fascia on the surface of the subclavian vein, removed the lymphoid adipose tissue along the fascial space completely and skeletonized subclavian vein. This approach provides less operating space, but it can fully expose the subclavian area, making it easier to dissociate and dissect the parasternal ligament, subclavian vein, medial border of the pectoralis minor muscle, and other important anatomical landmarks. In addition, the pectoralis branches of the thoracoacromial artery and the lateral cutaneous branches of the intercostal nerves were protected when removing the axillary nodes, which reduced postoperative complications such as upper limb numbness, tingling sensation, and muscle atrophy. Axillary lymph nodes were completely resected from inside to outside, and the important anatomical markers of axilla such as axillary vein, long thoracic nerve, thoracodorsal nerve and thoracodorsal vessels were clearly exposed.

The External Oblique Intercostal Block: Anatomic Evaluation and Case Series.

STUDY OBJECTIVE: We report a modified block technique aimed at obtaining upper midline and lateral abdominal wall analgesia: the external oblique intercostal (EOI) block. DESIGN: A cadaveric study and retrospective cohort study assessing the potential analgesic effect of the EOI block. SETTING: Cadaver lab and operating room. PATIENTS: Two unembalmed cadavers and 22 patients. INTERVENTIONS: Bilateral ultrasound-guided EOI blocks on cadavers with 29 mL of bupivacaine 0.25% with 1 mL of India ink; single-injection or continuous EOI blocks in patients. MEASUREMENTS: Dye spread in cadavers and loss of cutaneous sensation in patients. MAIN RESULTS: In the cadaveric specimens, we identified consistent staining of both lateral and anterior branches of intercostal nerves from T7 to T10. We also found consistent dermatomal sensory blockade of T6-T10 at the anterior axillary line and T6-T9 at the midline in patients receiving the EOI block. CONCLUSIONS: We demonstrate the potential mechanism of this technique with a cadaveric study that shows consistent staining of both lateral and anterior branches of intercostal nerves T7-T10. Patients who received this block exhibited consistent dermatomal sensory blockade of T6-T10 at the anterior axillary line and T6-T9 at the midline. This block can be used in multiple clinical settings for upper abdominal wall analgesia.

Alcoholización de nervios intercostales en el postoperatorio de la cirugía torácica / Alcoholization of the Intercostal Nerves on the Postoperative Period of Thoracic Surgery

Introducción: La cirugía torácica figura entre los procedimientos quirúrgicos más dolorosos. Objetivo: Describir los resultados de la alcoholización de nervios intercostales para analgesia postoperatoria. Métodos: Se realizó un estudio prospectivo, observacional y descriptivo de pacientes tratados quirúrgicamente por afecciones torácicas durante 2018-2019. La muestra incluyó 50 pacientes que cumplieron los criterios de inclusión: operados por el autor principal, mayores de 18 años, acceso intercostal y firmaron el consentimiento informado. Se excluyeron los operados por otros cirujanos o presentaron afectación de la pared torácica. La intensidad del dolor se categorizó en cuatro grupos: leve, moderado, intenso e insoportable, según escala análogo visual. Resultados: Durante la primera noche, predominaron el dolor leve (25/50 por ciento) y moderado (9/18 por ciento). El dolor intenso se presentó en dos (4 por ciento) pacientes y 14(28 por ciento) no necesitaron medicación adicional. Al día siguiente no hubo casos con dolor intenso y solo 9 acusaron dolor moderado. La analgesia peridural solo se utilizó la primera noche y al siguiente día. La tendencia a disminuir el dolor se mantuvo al segundo y tercer día. No hubo casos con dolor insoportable. A largo plazo solo un paciente presentó dolor intenso que necesitó tratamiento con bloqueos. Conclusiones: La alcoholización disminuyó el uso adicional de analgésicos. No hubo complicaciones ni dolor insoportable, por lo que consideramos que este método podría ser una alternativa segura, sobre todo cuando no se dispone de fármacos costosos o personal entrenado en las técnicas modernas de analgesia postoperatoria(AU)

Introduction: Thoracic surgery is among the most painful surgical procedures. Objective: To describe the outcomes of the alcoholization of the intercostal nerves for postoperative analgesia. Methods: A prospective, observational and descriptive study was carried out, with patients treated surgically for thoracic conditions during 2018-2019. The sample included fifty patients who met the inclusion criteria: operated by the corresponding author, older than eighteen years, intercostal access and patients who signed the informed consent. Those operated on by other surgeons or who had chest wall involvement were excluded. Pain intensity was categorized into four groups: mild, moderate, intense and unbearable, according to the analog-visual scale. Results: During the first night, mild (25: 50 percent) and moderate (9: 18 percent) pain predominated. Severe pain occurred in two (4 percent) patients, while 14 (28 percent) did not require any additional medication. The next day, there were no cases of severe pain and only nine reported moderate pain. Epidural analgesia was only used the first night and the next day. The tendency to decrease in pain was maintained on the second and third days. There were no cases with unbearable pain. In the long term, only one patient had severe pain and required, therefore, treatment with blocks. Conclusions: Alcoholization decreased the additional use of analgesics. There were no complications or unbearable pain, a reason why we consider that this method could be a safe alternative, especially when expensive drugs or personnel trained in modern postoperative analgesia techniques are not available(AU)

Comparison of Ultrasound-Guided Modified BRILMA Block with Subcostal Transversus Abdominis Plane Block for Postoperative Analgesia in Laparoscopic Cholecystectomy - A Randomized Controlled Trial.

BACKGROUND AND AIMS: Subcostal Transversus Abdominis Plane (TAP) block is the standard practice for postoperative analgesia following laparoscopic cholecystectomy. This study aimed to compare the efficacy of modified BRILMA Block (blocking the BRanches of Intercostal nerves at the Level of Mid-Axillary line) with Subcostal TAP block for pain relief following laparoscopic cholecystectomy. METHODS: Sixty cases scheduled for laparoscopic cholecystectomy were randomly divided into two groups: modified BRILMA block (Group B) and Subcostal TAP block (Group T). General anesthesia was standardized for both groups. Blocks were performed with 20 mL of 0.2% Ropivacaine under ultrasound guidance after induction of anesthesia. Patients were administered morphine through patient controlled analgesia (PCA) pump with a bolus dose of 1 mg, 10 min lockout interval, and a basal infusion rate of 0.1 mg/h. The pain was assessed by the Visual Analog Scale (VAS) scores of one to ten. The total morphine consumption, time to first request for rescue analgesia, and VAS scores at rest and with movement, and complications, if any, were recorded. RESULTS: The morphine consumption in Group B was 5.67 ± 1.98 mg and in Group T was 5.17 ± 1.85 mg, which was found to be statistically insignificant (p-value = 0.317). The time to first request for rescue analgesia was 759.33 ± 80.29 min in Group B which was comparable to 854 ± 93.01 min in Group T and statistically insignificant (p-value = 0.295). The average VAS scores at rest as well as on movement were comparable in both the groups during the entire 24 h postoperative period. No complications were encountered in our study. CONCLUSION: Ultrasound-guided modified BRILMA block is equally efficacious as subcostal TAP block in providing postoperative analgesia with similar morphine consumption and no significant difference in VAS scores at rest and movement following laparoscopic cholecystectomy. TRIAL REGISTRATION NUMBER: CTRI/2020/02/023457.

Twelfth rib syndrome: a case report.

Twelfth rib syndrome is a rare condition that causes severe pain in the loin. The diagnosis of this phenomenon is based on the patient's medical history and physical examination findings. However, many clinicians still lack an understanding of the disease; this delays an accurate diagnosis, causing patients to experience prolonged pain without proper treatment. We herein describe a 72-year-old woman and a 47-year-old woman with loin pain. They had undergone various imaging tests, but the cause of the pain remained unknown. Their pain was reproduced by the hooking maneuver, and twelfth rib syndrome was diagnosed. Both patients were immediately relieved of pain after a twelfth intercostal nerve block. Early diagnosis and appropriate treatment are needed for pain relief in patients with twelfth rib syndrome.

A Novel Technique in Fibrin Gluing of Intercostal Nerves: Splint and Weld.

Splint and weld technique ensures a sound coaptation of intercostal and musculocutaneous nerves with minimal introduction of synthetic suture through the neural tissue.

[Clinical study of exploring new axillary zone in sentinel lymph node biopsy of breast cancer].

Objective: To explore the application of axillary reverse mapping (ARM) in breast cancer sentinel lymph node biopsy (SLNB), and to collect and record patient's data during operation. Through the specific experimental data, the anatomical location and morphology of the intercostal brachial nerve (ICBN) and the anatomic relationship of the axillary lymph nodes were analyzed to accurately locate the anatomical division of the axillary fossa of sentinel lymph node (SLN) and ARM lymph nodes. Methods: The technique of methylene blue staining for SLN combined with indocyanine green fluorescent staining for axillary reverse mapping was used to analyze the patients of Tianjin Central Hospital of Gynecology Obstetrics from June 2017 to June 2018. The clinical data of 35 patients with T1-2N0M0 breast cancer were analyzed. Results: Of the 35 patients, two cases were excluded from metastatic carcinoma of the SLN. Thirty-three cases were included in the data analysis. Three cases of ICBN were located 0-2.0 cm (9.09%) from the lower edge of the iliac vein, 27 cases were located at 2.0-4.0 cm (81.82%), and 3 cases of ICBN were located greater than 4.0 cm (9.09%). In the region of 0-2.0 cm from the lower edge of the iliac vein, 1-2 ARM lymph nodes were found in 5 cases; in the 2.0-4.0 cm area, SLN was found in 33 cases, 4 of which found 1 coincident lymph node; at>4.0 cm ARM lymph nodes and overlapping lymph nodes were not found in the cm region, and 1-2 SLNs were found in 3 cases. Conclusions: Individual ICBNs vary greatly, with different shapes and distances from the lower edge of the axillary vein. The axillary region below the iliac vein can be divided into three regions: ARM region (0-2.0 cm); SLN region (2.0-4.0 cm); and sentinel gate region (>4.0 cm). The position 2.0 cm from the lower edge of the iliac vein can be used as the boundary between the ARM lymph node and the SLN. 4. There is a certain proportion of coincidence rate between SLN and ARM lymph nodes.

BRILMA block for costal cartilage excision: Case report. / Bloqueo BRILMA para extirpación de cartílago costal: caso clínico.

The block of the lateral branches of the intercostal nerves in the middle axillary line (BRILMA) is an interfascial ultrasound-guided block for analgesia in thoracic wall and upper abdominal surgery, presenting as an adequate alternative to neuraxial techniques. We present the case of a 49-year-old female scheduled for idiopathic subglottic stenosis repair with a costal cartilage graft from the 10th rib and tracheotomy. At the end of the surgery, unilateral ultrasound-guided BRILMA block with 20ml of ropivacaine 0.2% was performed at the level of the 6th rib, uneventfully. Postoperatively, the patient referred a maximum level of pain of 3/10. There was no opioid consumption after the 2nd postoperative day, although a subcostal incision may produce considerable pain. BRILMA is a superficial block, easily reproducible in most patients. It diminishes the number of punctures needed in the thoracic wall, as well as the risk for pneumothorax and local anesthetic toxicity.

Rectus abdominis muscle atrophy after thoracotomy.

Intercostal nerve injury is known to occur during thoracotomy; however, rectus abdominis muscle atrophy has rarely been reported. We describe a 52-year-old man who underwent primary closure of esophageal perforation and lung decortication via left thoracotomy. He was discharged 40 days postoperatively without any complications. He noticed an abdominal bulge 2 months later, and computed tomography revealed left rectus abdominis muscle atrophy. We report thoracotomy induced denervation causing rectus abdominis muscle atrophy.

Prospective, randomized comparative study of ultrasound-guided blocking of the lateral cutaneous branches of the intercostal nerves versus conventional analgesia in non-reconstructive breast surgery. / Estudio prospectivo, aleatorizado comparativo entre el bloqueo guiado por ultrasonidos de las ramas cutáneas laterales de los nervios intercostales frente a analgesia convencional en cirugía no reconstructiva de mama.

OBJECTIVE: The objective of this study is to determine whether the accomplishment of an interfascial blockade, the blocking of the cutaneous branches of the intercostal nerves in the axillary line (BRILMA) associated with a multimodal analgesic regimen improves post-operative analgesia and allows saving opioids after non-reconstructive surgery of breast. MATERIAL AND METHODS: A prospective, randomised and simple blind study was conducted on patients that underwent non-reconstructive breast surgery. The patients were randomly assigned to the blocking group, or to the standard post-operative analgesia group (paracetamol and dexketoprofen). The main variables analysed were the pain intensity assessed by the verbal numerical scale and the analgesic rescue needs with tramadol. RESULTS: Statistically significant differences were observed in the consumption of tramadol during the study period (10.5mg in the BRILMA group, compared to 34.3 in the control group, P=.0001). There were also differences in the pain assessment, with lower values found in the BRILMA group. CONCLUSIONS: In non-reconstructive breast surgery, performing a BRILMA block allows obtaining lower pain scores, which implies less need for rescue analgesics and a significant saving of tramadol in the study period.

Non-intercostal access for video-assisted thoracic surgery-analysis of technical advantages and disadvantages.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) lobectomy has become an accepted method for the treatment of early-stage non-small-cell lung cancer (NSCLC). The standard VATS approach is an intercostal one which is often followed by postoperative pain due to injury of the intercostal nerve. The non-intercostal techniques of VATS include the subxiphoid, transcervical, transdiaphragmatic and transoral procedures. METHODS: The technical difficulty of operative management of the anatomical structures during VATS anatomical resection are compared for the intercostal, subxiphoid and transcervical approaches. RESULTS: Some operative steps have different range of difficulty, which are analyzed in detail. CONCLUSIONS: The clearest advantages of the non-intercostal approaches include less postoperative pain and superradial bilateral mediastinal lymphadenectomy in case of the transcervical approach. However, the non-intercostal approaches are more technically demanding procedures, which therapeutic role has to be clarified in the future.

Radiological study to evaluate the spreading of two volumes (10 vs. 20ml) of radiological contrast in the block of cutaneous branches of intercostal nerves in medial axillary line (BRILMA) in a porcine experimental model. / Estudio radiológico para evaluar la difusión de dos volúmenes (10 vs. 20ml) de contraste radiopaco en el bloqueo de las ramas cutáneas de los nervios intercostales en la línea medio axilar (BRILMA) en un modelo experimental porcino.

OBJECTIVE: Interfascial blocks of the thoracic wall are being developed as an alternative to central blocks in breast surgery. However, there are few studies that have evaluated the anatomical extension of the local anaesthetic. The objective of this study was to analyse, using fluoroscopy, the spreading of two volumes (10 vs. 20ml) of radiological contrast in the serratus-intercostal plane block in an experimental pig model. MATERIAL AND METHODS: Ten Large-White breed pigs were selected to have a bilateral ultrasound serratus-intercostal plane block performed, with the administering of 10ml and 20ml of iopamidol in the right and left hemithorax, respectively. The spreading of contrast was analysed by fluoroscopy. The Spearman test correlation was used to evaluate the relationship between the administered volume and radiological spreading. A value of P<.05 was considered significant. RESULTS: Twenty anaesthetic blocks were performed, being able to analyse 18 of them. The administration of 10ml of contrast was associated with a mean spreading of 2.28±0.31 (95% CI; 2.01-2.54) intercostal spaces, while the administration of 20ml showed a spreading of 3±0.25 (95% CI; 2.81-3.18) intercostal spaces. There was a significant correlation between the injected volume and the spreading of the contrast (Spearman correlation coefficient of 0.81; P=.0001). CONCLUSION: The results showed a spreading of volume subject to the serratus-intercostal plane block, although not maintaining a 1:1 ratio. Doubling the volume increased the blocked segments by 31%. These findings, if corroborated in the clinical practice, would allow a more precise adjustment in the anaesthetic volume administered.

Sympathetic Discharges in intercostal and abdominal nerves.

There are hardly any published data on the characteristics of muscle nerve sympathetic discharges occurring in parallel with the somatic motoneurone discharges in the same nerves. Here, we take advantage of the naturally occurring respiratory activity in recordings of efferent discharges from branches of the intercostal and abdominal nerves in anesthetized cats to make this comparison. The occurrence of efferent spikes with amplitudes below that for alpha motoneurones were analyzed for cardiac modulation, using cross-correlation between the times of the R-wave of the ECG and the efferent spikes. The modulation was observed in nearly all recordings, and for all categories of nerves. It was strongest for the smallest amplitude spikes or spike-like waveforms, which were deduced to comprise postsynaptic sympathetic discharges. New observations were: (1) that the cardiac modulation of these discharges was modest compared to most previous reports for muscle nerves; (2) that the amplitudes of the sympathetic discharges compared to those of the somatic spikes were strongly positively correlated to nerve diameter, such that, for the larger nerves, their amplitudes overlapped considerably with those of gamma motoneurone spikes. This could be explained by random summation of high rates of unit sympathetic spikes. We suggest that under some experimental circumstances this overlap could lead to considerable ambiguity in the identity of the discharges in efferent neurograms.

Sequential robotic-assisted lung resection with a subxiphoid utility incision.

For the past two years, the authors have used a subxiphoid utility incision for robot-assisted lobectomies. This approach prevents unnecessary rib pressure, offers a good angle of approach to the hilum, and allows specimen retrieval with minimal resistance. Robot-assisted lung resection is an established technique that facilitates postoperative recovery by minimizing operative trauma and postoperative pain. We believe the subxiphoid utility incision further enhances recovery and facilitates early repeat surgery. We present two cases of staged sequential robot-assisted anatomical lung resection using the same subxiphoid utility incision on each occasion.