Intraoperative Bronchoscopic Inspection Facilitates Thoracoscopic Repair of Esophageal Atresia with Tracheoesophageal Fistula.

Aim: The value of intraoperative bronchoscopic inspection (IBI) for accurate confirmation of the location and distance between the distal tracheoesophageal fistula (TEF) and the proximal blind end of the esophagus (GAP) was evaluated in Type C esophageal atresia (EA)+TEF. Methods: IBI involved inserting the tip of a bronchoscope into the TEF and a nasogastric tube into the blind end of the EA and measuring GAP with fluoroscopy. EA+TEF patients (n = 23) treated thoracoscopically between 2007 and 2020 were classified according to IBI as IBI+ (n = 16) and IBI- (n = 7) to compare demographics, operative time, and time taken for TEF division. Results: Demographics were similar. Mean time for TEF division (15.4 ± 4.6 minutes for IBI+ versus 38.6 ± 20.9 minutes for IBI-; p < .05) and mean operative time (215.3 ± 48.9 minutes for IBI+ versus 286.4 ± 51.7 minutes for IBI+; p < .05) were significantly shorter. Mean GAP measured radiographically was 0.5 cm (range: 0-1.2 cm); mean GAP measured with IBI was 0.9 cm (range: 0-2.2 cm). Postoperative complications were 3 anastomotic leakages (1/16 in IBI+ and 2/7 in IBI-) that resolved without surgery and 8 strictures (3/16 in IBI+ and 5/7 in IBI-) treated by dilatation. Conclusions: IBI was effective for measuring GAP and is recommended for improving the efficiency of thoracoscopic repair.

Retroperitoneoscopic Surgery in Children Does Not Cause Pathological Desaturation in Cerebral/Renal Oxygenation on Near-Infrared Spectroscopy Compared with Laparoscopic and Thoracoscopic Surgery.

Introduction: Cerebral and renal regional oxygen saturation (C-rSO2 and R-rSO2, respectively) were monitored using near-infrared spectroscopy in pediatric patients (range: 0.3-14.3 years) during minimally invasive surgery (MIS) taking at least 3 hours performed by laparoscopy (Lap), thoracoscopy (Tho), or retroperitoneoscopy (Ret) from January 2019 to December 2021. Materials and Methods: Criteria compared were operative time, preoperative/intraoperative hemoglobin, blood loss, mean arterial pressure, arterial partial pressure of carbon dioxide (PaCO2), peripheral oxygen saturation (SpO2), C-rSO2, and R-rSO2. Pathological desaturation (PD) was defined as >20% decrease from baseline, and statistical significance as P < .05. Results: Subjects (n = 79) were similar for gender, age, and body mass index. MIS procedures were: Lap = 45, Tho = 20, Ret = 14; one Lap case required conversion for severe adhesions, not PD. Intraoperative PaCO2 (mmHg) was significantly higher in Tho (maximum: 59.5 ± 17.0, minimum: 39.9 ± 7.5) versus Lap (maximum: 39.9 ± 5.1, minimum: 34.6 ± 3.9) and Ret (maximum: 37.8 ± 4.2, minimum: 35.0 ± 3.3); P < .0001 (maximum), P = .0013 (minimum). Minimum intraoperative SpO2 was significantly lower in Tho (P < .0001). Mean operative times were significantly shorter in Tho (259 ± 114 minutes) versus Lap (433 ± 154 minutes) and Ret (342 ± 100 minutes); P < .0001, respectively. PD was absent during Ret (C-rSO2: 0/14 = 0% and R-rSO2: 0/14 = 0%). Differences in PD for Lap (C-rSO2: 7/45 = 15.6% and R-rSO2: 10/45 = 22.2%) and Tho (C-rSO2: 9/20 = 45.0%, and R-rSO2: 7/20 = 35.0%) were significant; P = .0028 for C-rSO2 and P = .0497 for R-rSO2. Hemoglobin and blood loss were similar. Conclusions: PD was absent during Ret, despite longer operative times. If Ret is indicated for a procedure, neurodevelopmental sequelae of MIS could be minimized.

Significant neonatal intraoperative cerebral and renal oxygen desaturation identified with near-infrared spectroscopy.

INTRODUCTION: Near-infrared spectroscopy (NIRS) was used to monitor intraoperative regional oxygen saturation (rSO2) during open (Op) and minimally invasive (MI) surgery performed in neonates (N) and children. MATERIALS AND METHODS: NIRS sensors were applied to the forehead and flanks for cerebral rSO2 (C-rSO2) and renal rSO2 (R-rSO2), respectively. MI included laparoscopy (La), retroperitoneoscopy (Re) and thoracoscopy (Th). In children, Op and MI were major operations taking at least 3 h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO2. RESULTS: Mean ages at surgery were N: 5.2 ± 8.2 days, MOp: 2.4 ± 2.9 years, and MMI: 3.8 ± 4.3 years. Despite significantly shorter operative times in N (169 ± 94 min; p < 0.0001), PD was significantly worse; PD(C-rSO2): N = 14/35 (40.0%) versus MOp = 3/36 (8.3%) and MMI = 7/58 (12.1%); p = 0.0006, and PD(R-rSO2): N = 27/35 (77.1%) versus MOp = 6/36 (16.7%) and MMI = 7/58 (12.1%); p < 0.0001, respectively. PD(R-rSO2) occurred immediately with visceral reduction in NOp (Fig. 1) and PD was frequent during NMI(Th) (Fig. 2). rSO2 was stable throughout MOp and MMI (Fig. 3). Fig. 1 Pathological desaturation in renal rSO2 after visceral reduction for gastroschisis. Renal rSO2 deteriorated immediately after viscera were returned to the abdominal cavity rSO2 regional oxygen saturation Fig. 2 Fragility of tissue perfusion during thoracoscopic lung lobectomy in a neonate. Pathological desaturation occurred frequently during neonatal thoracoscopic surgery rSO2 regional oxygen saturation Fig. 3 Changes in cerebral and renal rSO2 according to operative time. Cerebral and renal rSO2 did not appear to change according to operative time during major open and major minimally invasive surgery in children. rSO2 regional oxygen saturation CONCLUSIONS: NIRS is a non-invasive technique for monitoring rSO2 as an indicator of intraoperative stress and vascular perfusion. PD was so significant in neonates that intraoperative NIRS is highly recommended during thoracoscopy and procedures requiring visceral manipulation.

Congenital Pulmonary Airway Malformation in Children: Advantages of an Additional Trocar in the Lower Thorax for Pulmonary Lobectomy.

Aim: To present the use of an additional trocar (AT) in the lower thorax during thoracoscopic pulmonary lobectomy (TPL) in children with congenital pulmonary airway malformation. Methods: For a lower lobe TPL (LL), an AT is inserted in the 10th intercostal space (IS) in the posterior axillary line after trocars for a 5-mm 30° scope, and the surgeon's left and right hands are inserted conventionally in the 6th, 4th, and 8th IS in the anterior axillary line, respectively. For an upper lobe TPL (UL), the AT is inserted in the 9th IS, and trocars are inserted in the 5th, 3rd, and 7th IS, respectively. By switching between trocars (6th↔8th for the scope, 4th↔6th for the left hand, and 8th↔10th for the right hand during LL and 5th↔7th, 3rd↔5th, and 7th↔9th during UL, respectively), vital anatomic landmarks (pulmonary veins, bronchi, and feeding arteries) can be viewed posteriorly. The value of AT was assessed from blood loss, operative time, duration of chest tube insertion, requirement for post-operative analgesia, and incidence of perioperative complications. Results: On comparing AT+ (n = 28) and AT- (n = 27), mean intraoperative blood loss (5.6 vs. 13.0 ml), operative time (3.9 vs. 5.1 h), and duration of chest tube insertion (2.2 vs. 3.4 days) were significantly decreased with AT (p < 0.05, respectively). Differences in post-operative analgesia were not significant. There were three complications requiring conversion to open/mini-thoracotomy: AT- (n = 2; bleeding), AT+: (n = 1; erroneous stapling). Conclusions: An AT and switching facilitated posterior dissection during TPL in children with congenital pulmonary airway malformation enhancing safety and efficiency.

Expression of Genes Involved in Offensive and Defensive Phenotype Induction in the Pituitary Gland of the Hokkaido Salamander (Hynobius retardatus).

Amphibians exhibit phenotypic plasticity, which allows flexible adaptation to fluctuating environments. Although genes involved in expression of plastic phenotypes have been identified, the endocrine bases of plastic responses are largely unknown. Larvae of the Hokkaido salamander (Hynobius retardatus) plastically display distinct phenotypes, an "offensive phenotype" characterized as larger body with broadened gape and a "defensive phenotype" characterized as enlarged gills and tail and less active behavior, in the presence of prey larval amphibians and predatory larval dragonfly, respectively. In the presence of both prey and predators, the degree of induction of both phenotypes is reduced, suggesting cross-talk between the molecular signaling pathways of these phenotypes. We conducted a transcriptomic analysis to examine how endocrine regulation affects the phenotypic expression by focusing on the pituitary gland. We found that five endocrine genes, i.e., calcitonin related polypeptide alpha (CALCA), growth hormone (GH), neuropeptide B (NPB), parathyroid hormone 2 (PTH2), and prolactin 1 (PRL1), were involved in the expression of both phenotypes. However, we conducted only RNA-seq analysis, and no confirmation of significant up-regulation or down-regulation has been conducted. These results suggest that these genes were up-regulated for induction of the offensive phenotype and down-regulated for induction of the defensive phenotype. Phylogenetic analysis indicated that possible gene duplications of PRL and CALCA have occurred during amphibian evolution. Based on these findings, it is suggested that a trade-off of molecular signaling pathways exists between the two distinct phenotypic expressions. The results also suggest that hormonal-gene duplications might have contributed to the acquisition of phenotypic plasticity in amphibians.

Volatile anesthetic sevoflurane pretreatment alleviates hypoxia-induced potentiation of excitatory inputs to striatal medium spiny neurons of mice.

Sevoflurane, a commonly used anesthetic in surgery, has drawn attention because of its preconditioning effects in hypoxic conditions. To investigate the preconditioning effects in the striatum, a common site for ischemic stroke, we collected whole-cell current-clamp recordings from striatal medium spiny neurons. In our in vitro brain slice experiments, deprivation of oxygen and glucose depolarized the striatal neurons to subthreshold potentials, and the pre-administration of sevoflurane (4%, 15 min) prolonged the time to depolarization. Furthermore, transient hypoxia induced the potentiation of excitatory postsynaptic potentials, which play a part in post-ischemic excitotoxicity. Glibenclamide, a KATP channel inhibitor, reversed the prolonged time to depolarization and the prevention of the pathological potentiation of excitatory responses, indicating that the short exposure to sevoflurane likely participates in neuroprotection against hypoxia via activation of KATP channels. A monocarboxylate transporter blocker, 4-CIN, also depolarized striatal neurons. Interestingly, the blockade of monocarboxylate transporters that supply lactate to neurons caused the pathological potentiation, even in the presence of enough oxygen and glucose. In this case, sevoflurane could not prevent the pathological potentiation, suggesting the involvement of monocarboxylate transporters in the sevoflurane-mediated effects. These results indicate that sevoflurane protects striatal neurons from hypoxic damage and alleviates the pathological potentiation. Under these conditions, sevoflurane may become an effective intervention for patients undergoing surgery.

Thoracoscopic Pulmonary Lobectomy for Densely Fused Pulmonary Lobes in Children with Congenital Pulmonary Airway Malformation: Technical Tips.

AIM: Thoracoscopic pulmonary lobectomy (TPL) is extremely challenging in cases where severe incomplete fissure causes densely fused pulmonary lobes (DFPL) since pulmonary arteries (PAs) are buried and completely concealed by DFPL. We describe TPL for DFPL including a technical tip to prevent pitfalls. MATERIALS AND METHODS: Four congenital pulmonary airway malformation (CPAM) and DFPL (left-upper: 2, left-lower: 1, right-middle: 1) were treated. During TPL, DFPL prevent interlobar PAs from being identified and searching for them only promotes bleeding and air leakage, serious pitfalls that affect the safety and success of TPL. Our tip is to ligate and divide the pulmonary veins (PVs) at the pulmonary hilum and the hilar PA supplying the CPAM lobe to expose the bronchus of the lobe, which is then ligated and divided. The main PA supplying the lobe running underneath the DFPL is exposed and visible from the pulmonary hilum allowing the PA supplying the lobe to be ligated and divided safely. A line demarcating the fused fissure becomes apparent, and an endoscopic stapler or EnSeal® device can be used to divide the DFPL along the line taking great care not to injure the main PA or interlobar PAs. RESULTS: There were no intra-/postoperative complications in any case. All patients performed well without respiratory tract-related symptoms after a mean follow-up of 4.6 years. CONCLUSIONS: TPL for DFPL in children with CPAM can be performed safely and successfully as a virtually bloodless procedure and without incidence of air leakage by ligating and dividing the PA after dividing the PVs and bronchus to the lobe.

An interaction-driven cannibalistic reaction norm.

Cannibalism is induced in larval-stage populations of the Hokkaido salamander, Hynobius retardatus, under the control of a cannibalism reaction norm. Here, I examined phenotypic expression under the cannibalism reaction norm, and how the induction of a cannibalistic morph under the norm leads to populational morphological diversification. I conducted a set of experiments in which density was manipulated to be either low or high. In the high-density treatment, the populations become dimorphic with some individuals developing into the cannibal morph type. I performed an exploratory analysis based on geometric morphometrics and showed that shape characteristics differed between not only cannibal and noncannibal morph types in the high-density treatment but also between those morph types and the solitary morph type in the low-density treatment. Size and shape of cannibal and noncannibal individuals were found to be located at either end of a continuum of expression following a unique size-shape integration rule that was different from the rule governing the size and shape variations of the solitary morph type. This result implies that the high-density-driven inducible morphology of an individual is governed by a common integration rule during the development of dimorphism under the control of the cannibalism reaction norm. Phenotypic expression under the cannibalism reaction norm is driven not only by population density but also by social interactions among the members of a population: variation in the populational expression of dimorphism is associated with contingent social interaction events among population members. The induced cannibalistic morph thus reflects not only by contest-type exploitative competition but also interference competition.

Modulation of hyperpolarization-activated cation current Ih by volatile anesthetic sevoflurane in the mouse striatum during postnatal development.

Volatile anesthetics have been reported to inhibit hyperpolarization-activated cyclic-nucleotide gated channels underlying the hyperpolarization-activated cation current (Ih) that contributes to generation of synchronized oscillatory neural rhythms. Meanwhile, the developmental change of Ih has been speculated to play a pivotal role during maturation. In this study, we examined the effect of the volatile anesthetic sevoflurane, which is widely used in pediatric surgery, on Ih and on functional Ih activation kinetics of cholinergic interneurons in developing striatum. Our analyses showed that the changes in Ih of cholinergic interneurons occurred in conjunction with maturation. Sevoflurane application (1-4%) caused significant inhibition of Ih in a dose-dependent manner, and apparently slowed Ih activation. In current-clamp recordings, sevoflurane significantly decreased spike firing during the rebound activation, which is essential for responses to the sensory inputs from the cortex and thalamus. The sevoflurane-induced inhibition of Ih in striatal cholinergic interneurons may lead to alterations of the acetylcholine-dopamine balance in the neural circuits during the early postnatal period.

Leucine-rich α2-glycoprotein overexpression in the brain contributes to memory impairment.

We previously reported increase in leucine-rich α2-glycoprotein (LRG) concentration in cerebrospinal fluid is associated with cognitive decline in humans. To investigate relationship between LRG expression in the brain and memory impairment, we analyzed transgenic mice overexpressing LRG in the brain (LRG-Tg) focusing on hippocampus. Immunostaining and Western blotting revealed age-related increase in LRG expression in hippocampal neurons in 8-, 24-, and 48-week-old controls and LRG-Tg. Y-maze and Morris water maze tests indicated retained spatial memory in 8- and 24-week-old LRG-Tg, while deteriorated in 48-week-old LRG-Tg compared with age-matched controls. Field excitatory postsynaptic potentials declined with age in LRG-Tg compared with controls at 8, 24, and 48 weeks. Paired-pulse ratio decreased with age in LRG-Tg, while increased in controls. As a result, long-term potentiation was retained in 8- and 24-week-old LRG-Tg, whereas diminished in 48-week-old LRG-Tg compared with age-matched controls. Electron microscopy observations revealed fewer synaptic vesicles and junctions in LRG-Tg compared with age-matched controls, which became significant with age. Hippocampal LRG overexpression contributes to synaptic dysfunction, which leads to memory impairment with advance of age.

Pulmonary lobectomy techniques in infants and children.

Thoracoscopic pulmonary lobectomy (TPL) techniques in infants and children are presented practically with concise descriptions and numerous illustrations. TPL is the treatment of choice for congenital pulmonary airway malformation and intralobar pulmonary sequestration, both now commonly diagnosed prenatally. Timing of surgery is somewhat controversial in asymptomatic cases with small isolated lesions. Incomplete fissures and history of chest infections are most problematic. Thorough understanding of anatomic relations preoperatively is vital for successful outcome and thin-slice computed tomography with 3D reconstruction of vessels is valuable. Judicious placement of trocars and switching instruments between trocars improves visualization and safety. Specific techniques for all commonly performed TPL are included.

Population Structure and Evolution after Speciation of the Hokkaido Salamander (Hynobius retardatus).

The Hokkaido salamander (Hynobius retardatus) is endemic to Hokkaido Island, Japan, and shows intriguing flexible phenotypic plasticity and regional morphological diversity. However, to date, allozymes and partial mitochondria DNA sequences have provided only an outline of its demographic histories and the pattern of its genetic diversification. To understand the finer details of the population structure of this species and its evolution since speciation, we genotyped five regional populations by using 12 recently developed microsatellite polymorphic markers. We found a clear population structure with low gene flow among the five populations, but a close genetic relationship between the Teshio and Kitami populations. Our demographic analysis suggested that Teshio and Erimo had the largest effective population sizes among the five populations. These findings regarding the population structure and demography of H. retardatus improve our understanding of the faunal phylogeography on Hokkaido Island and also provide fundamental genetic information that will be useful for future studies.

Nicotinic acetylcholine receptor-mediated GABAergic inputs to cholinergic interneurons in the striosomes and the matrix compartments of the mouse striatum.

The striatum consists of two neurochemically distinct compartments: the striosomes (or patches) and the extrastriosomal matrix. Although striatal neurons are strongly innervated by intrinsic cholinergic interneurons, acetylcholinesterase is expressed more abundantly in the matrix than in the striosomes. At present, little is known about the different cholinergic functions of the striatal compartments. In this study, we examined gamma-aminobutyric acidergic (GABAergic) inputs to cholinergic interneurons in both compartments. We found that nicotinic receptor-mediated GABAergic responses were evoked more frequently in the matrix than in the striosomes. Furthermore, a single action potential of cholinergic neurons induced nicotinic receptor-mediated GABAergic inputs to the cholinergic neurons themselves, suggesting mutual connections that shape the temporal firing pattern of cholinergic neurons. The nicotinic receptor-mediated GABAergic responses were attenuated by continuous application of acetylcholine or the acetylcholinesterase inhibitor eserine and were enhanced by desformylflustrabromine, a positive allosteric modulator of the α4ß2 subunit containing a nicotinic receptor. These results suggest that the nicotinic impact on the GABAergic responses are not uniform despite the massive and continuous cholinergic innervation. It has been reported that differential activation of neurons in the striosomes and the matrix produce a repetitive behavior called stereotypy. Drugs acting on α4ß2 nicotinic receptors might provide potential tools for moderating the imbalanced activities between the compartments.

Safety of surgery for neonatal congenital diaphragmatic hernia as reflected by arterial blood gas monitoring: thoracoscopic versus open repair.

PURPOSE: We monitored arterial blood gases during thoracoscopic (TR) and open repair (OR) of congenital diaphragmatic hernia (CDH) to assess the safety of intraoperative hypercapnia and acidosis. METHODS: We reviewed 30 neonatal CDH cases (OR = 10, TR = 20) diagnosed prenatally or within 6 h of birth at out institution from 2002 to 2014 not requiring inhaled nitric oxide (NO) intraoperatively. OR, routine until 2006 was replaced by TR in 2007. All subjects were managed identically. RESULTS: Five TR cases requiring conversion to OR were excluded. Prenatal diagnosis, gestational age at birth, gender, birth weight, and side of CDH were similar. Preoperative PaCO2 and pH were not significantly different. However, while intraoperative increase in mean PaCO2 (38.8-62.8 mmHg; p < 0.01) and decrease in mean pH (7.44-7.25; p < 0.01) were significant in TR, intraoperative PaCO2 was <70 mmHg in 12/15 cases and intraoperative pH was >7.20 in 11/15 cases. Both PaCO2 and pH reverted to normal on completion of surgery; pre- and postoperative results were comparable. There were no postoperative complications. CONCLUSIONS: It would appear that neonatal cases of CDH not requiring NO can tolerate TR, despite transient reversible deterioration in acid/base balance, indicating that TR is safe for the treatment of selected cases of CDH.

Transcriptome analysis of predator- and prey-induced phenotypic plasticity in the Hokkaido salamander (Hynobius retardatus).

Predator- and prey-induced phenotypic plasticity is widely observed among amphibian species. Although ecological factors inducing diverse phenotypic responses have been extensively characterized, we know little about the molecular bases of variation in phenotypic plasticity. Larvae of the Hokkaido salamander, Hynobius retardatus, exhibit two distinct morphs: the presence of their prey, Rana pirica tadpoles, induces a broad-headed attack morph, and the presence of predatory dragonfly nymphs (Aeshna nigroflava) induces a defence morph with enlarged external gills and a high tail. To compare the genes involved in predator- and prey-induced phenotypic plasticity, we carried out a de novo transcriptome analysis of Hokkaido salamander larvae exposed to either prey or predator individuals. First, we found that the number of genes involved in the expression of the defence morph was approximately five times the number involved in the expression of the attack morph. This result is consistent with the fact that the predator-induced plasticity involves more drastic morphological changes than the prey-induced plasticity. Second, we found that particular sets of genes were upregulated during the induction of both the attack and defence morphs, but others were specific to the expression of one or the other morph. Because both shared and unique molecular mechanisms were used in the expression of each morph, the evolution of a new plastic phenotype might involve both the co-option of pre-existing molecular mechanisms and the acquisition of novel regulatory mechanisms.

Gene expression profiles in Rana pirica tadpoles following exposure to a predation threat.

BACKGROUND: Rana pirica tadpoles show morphological changes in response to a predation threat: larvae of the dragonfly Aeshna nigroflava induce heightened tail depth, whereas larval salamander Hynobius retardatus induce a bulgy morphology with heightened tail depth. Although both predators induce similar tail morphologies, it is possible that there are functional differences between these tail morphs. RESULTS: Here, we performed a discriminant microarray analysis using Xenopus laevis genome arrays to compare tail tissues of control and predator-exposed tadpoles. We identified 9 genes showing large-scale changes in their expression profile: ELAV-like1, methyltransferase like 7A, dolichyl-phosphate mannosyltransferase, laminin subunit beta-1, gremlin 1, BCL6 corepressor-like 1, and three genes of unknown identity. A further 80 genes showed greater than 5 fold differences in expression after exposure to dragonfly larvae and 81 genes showed altered expression after exposure to larval salamanders. Predation-threat responsive genes were identified by selecting genes that reverted to control levels of expression following removal of the predator. Thirteen genes were induced specifically by dragonfly larvae, nine others were salamander-specific, and sixteen were induced by both. Functional analyses indicated that some of the genes induced by dragonfly larvae caused an increase in laminins necessary for cell adhesion in the extracellular matrix. The higher expression of gremlin 1 and HIF1a genes after exposure to dragonfly larvae indicated an in vivo hypoxic reaction, while down-regulation of syndecan-2 may indicate impairment of angiogenesis. Exposure to larval salamanders caused down-regulation of XCIRP-1, which is known to inhibit expression of adhesion molecules; the tadpoles showed reduced expression of cα(E)-catenin, small muscle protein, dystrophin, and myosin light chain genes. CONCLUSION: The connective tissue of tadpoles exposed to larval salamanders may be looser. The differences in gene expression profiles induced by the two predators suggest that there are functional differences between the altered tail tissues of the two groups of tadpoles.

Effects of the volatile anesthetic sevoflurane on tonic GABA currents in the mouse striatum during postnatal development.

The volatile anesthetic sevoflurane, which is widely used in pediatric surgery, has proposed effects on GABAA receptor-mediated extrasynaptic tonic inhibition. In the developing striatum, medium-sized spiny projection neurons have tonic GABA currents, which function in the excitatory/inhibitory balance and maturation of striatal neural circuits. In this study, we examined the effects of sevoflurane on the tonic GABA currents of medium spiny neurons in developing striatal slices. Sevoflurane strongly increased GABAA receptor-mediated tonic conductance at postnatal days 3-35. The antagonist of the GABA transporter-1, 1-[2-[[(diphenylmethylene)imino]oxy]ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid hydrochloride further increased tonic GABA conductance during the application of sevoflurane, thereby increasing the total magnitude of tonic currents. Both GABA (5 µM) and 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol hydrochloride, the δ-subunit-containing GABAA receptor agonist, induced tonic GABA currents in medium spiny neurons but not in cholinergic neurons. However, sevoflurane additively potentiated the tonic GABA currents in both cells. Interestingly, 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol hydrochloride-sensitive neurons made a large current response to sevoflurane, indicating the contribution of the δ-subunit on sevoflurane-enhanced tonic GABA currents. Our findings suggest that sevoflurane can affect the tone of tonic GABA inhibition in a developing striatal neural network.

Comparison of the value of tissue-sealing devices for thoracoscopic pulmonary lobectomy in small children: a first report.

Accurate division and sealing of lung parenchyma particularly in cases of total or near total incomplete fissure are crucial for preventing air leakage following thoracoscopic pulmonary lobectomy (TPL). However, conventional endoscopic stapling devices cannot be used during TPL in small children because of limited space. Consequently, Ligasure (LS) and Enseal (ES) devices are being used instead. We are the first to compare LS and ES for efficacy and efficiency during TPL. Of 26 TPL (6 upper, 3 middle, and 17 lower) performed for congenital adenomatoid malformation (n = 16) and sequestration (n = 10), incomplete fissure was found in 14. TPL (LS = 11; ES = 15) was performed conventionally in the lateral decubitus position with single lung ventilation using four 5 mm trocars. All cases had a chest tube inserted intraoperatively that was left in situ. Patient demographics, location of pathology, incidence of incomplete fissure, mean age/weight at TPL, mean blood loss, and mean operative time were all similar. However, duration of chest tube insertion was significantly shorter in ES because there was less postoperative air leakage (1.3 vs. 3.9 days; p < 0.05). ES would appear to seal lung parenchyma more effectively during TPL based on the shorter duration of chest tube insertion.

Thoracoscopic plication for diaphragmatic eventration in a neonate.

BACKGROUND: Currently, thoracoscopic surgery is replacing thoracotomy for an ever increasing number of indications, even in pediatric surgery. However, there are few reports describing thoracoscopic plication (TP) for diaphragmatic eventration in children, particularly in neonates. We report a case of TP under single-lung ventilation in a neonate with diaphragmatic eventration. CASE REPORT: A 10-day-old boy was referred for surgical management of right diaphragmatic eventration. Birth was at term, following an uncomplicated pregnancy and delivery. Shortness of breath, labored respiration and chest retraction presented soon after birth, necessitating mechanical ventilation. Chest radiography and computed tomography revealed an elevated right hemidiaphragm. Attempted weaning off mechanical ventilation failed with persistence of respiratory symptoms, requiring nasal directional positive airway pressure. However, because there was no resolution of symptoms, TP was performed using a 3 port technique under single-lung ventilation on day 17 of life. The postoperative course was excellent with complete resolution of respiratory symptoms with no recurrence for 9 months. CONCLUSION: To the best of our knowledge, this is the youngest case of TP for diaphragmatic eventration performed under single-lung ventilation. TP is safe, effective and minimally invasive and should be considered actively for the treatment of symptomatic diaphragmatic eventration even in neonates.

Traction sutures allow endoscopic staples to be used safely during thoracoscopic pulmonary lobectomy in children weighing less than 15 kg.

PURPOSE: During thoracoscopic pulmonary lobectomy (TPL) in larger children (>15 kg), an endoscopic stapler (ES) and endoscopic clipper (EC) are used during dissection and division of the pulmonary vessels (PVs) and bronchus. However, in smaller children (<15 kg), ES/EC cannot be used because of limited space. We report our technique for thoracoscopic dissection and division of the PVs and bronchus in smaller children. SUBJECTS AND METHODS: Fifteen cases of sequestration/congenital cystic adenomatoid malformation weighing less than 15 kg (range, 8-15 kg; mean, 11 kg) were the subjects for this review. With the patient under single-lung ventilation in the lateral decubitus position, four ports ranging from 5 to 12 mm were placed. After the PVs and bronchus were exposed, thick silk was used to encircle them as a traction suture. By applying traction, the PVs and bronchus could be exposed, and ES/EC were used safely by applying countertraction. RESULTS: All cases had uneventful TPL (upper in 3 patients, middle in 3 patients, and lower in 9 patients). ES/EC were easy to use. Mean operative time was 220 minutes. CONCLUSIONS: Our technique allows the PVs and bronchus in children weighing less than 15 kg to be divided safely using ES/EC. We strongly recommend our technique, although simple, be used during TPL in smaller children.