Takashi Igarashi

The fiberscopic findings of the epidural space in pregnant women

Background The spread of epidural analgesia is facilitated by pregnancy. Changes in the epidural structure during pregnancy may affect the spread of analgesia in pregnant women. To investigate the changes in the epidural space produced by pregnancy, the authors performed epiduroscopy in pregnant women. Methods Using a flexible fiberscope, the authors evaluated the epidural space in 73 women undergoing lumbar epidural anesthesia. Patients were classified into three groups: a nonpregnant group (n = 21), a first trimester pregnant group (8–13 weeks, n = 23), and a third-trimester pregnant group (27–39 weeks, n = 29). A 17-gauge Tuohy needle was inserted using the paramedian technique and the loss-of-resistance method with 5 ml air. The epiduroscope was introduced into the lumbar epidural space via the Tuohy needle and was advanced approximately 10 cm in a cephalad direction from the needle tip within the epidural space. The differences in the epidural space among the three groups then was evaluated. Results The epiduroscopy showed that the epidural pneumatic space, after injection of a given amount of air, was narrower and the density of the vascular network greater in the third-trimester group than in the other two groups. The amount of engorged blood vessels was greater in the third and first trimester groups than in the nonpregnant group. The amount of bleeding at the needle tip and the amount of fatty and fibrous connective tissue did not differ among the three groups. Conclusions Epidural blood vessels become engorged in the first trimester; the density of the vascular networks increase in the third trimester. These changes in the epidural space during pregnancy may affect the spread of epidural analgesia in pregnant women.

The epidural structure changes during deep breathing.

PurposePrevious experience has suggested that the insertion of an epidural catheter becomes easier when the patient takes a deep breath. The purpose of this study is to investigate the effects of respiration on the epidural space.MethodsWe examined the epidural space using a flexible epiduroscope in 20 patients undergoing thoracic epidural anesthesia. A 17-gauge Tuohy needle was inserted using the paramedian technique and the loss-of-resistance method with 5 ml air. The epiduroscope was introduced into the epidural space via the Tuohy needle. Each patient was requested to take a deep breath when the epiduroscope was positioned at the needle tip and at approximately 10 cm cephalad from the needle tip within the epidural space. The changes in the epidural structure during deep breathing at each site were then measured.ResultsIn 80% of the patients, fatty tissue occupied the needle tip. Through the patients’ maximal inspiration, the fatty tissue moved and a visible cavity expanded at the needle tip. Cross section area of the visible cavity at the needle tip was greater at the maximal inspiratory level than at the resting expiratory level: 12.1 ± 6.7 % vs 2.8 ± 2.1 % (mean ± SD,P < 0.0001). In all patients, the visible cavity within the epidural space, which had already been expanded by injected air, became more expanded after maximal inspiration. Cross section area of the visible cavity at the 10 cm cephalad position was greater at the maximal inspiratory level than at the resting expiratory level: 20.6 ± 10.0 % vs 7.0 ± 5.3 % (P < 0.0001).ConclusionEpiduroscopy showed that deep breathing expanded the potential cavity of the epidural space. We suggest that the changes in the epidural structure during deep breathing may assist in the insertion of an epidural catheter.RésuméObjectifL’expérience antérieure nous a suggéré que l’insertion d’un cathéter épidural est plus facile quand le patient inspire profondément. L’objectif de notre étude est d’examiner les effets de la respiration sur l’espace épidural.MéthodeNous avons examiné l’espace épidural au moyen d’un épiduroscope flexible chez 20 patients devant subir une anesthésie péridurale thoracique. Une aiguille Tuohy de calibre 17 a été insérée selon la technique paramédiane et la méthode de perte de résistance avec 5 ml d’air. L’épiduroscope a été introduit dans l’espace épidural au travers de l’aiguille Tuohy, On a demandé à chaque patient de respirer profondément au moment du positionnement de l’épiduroscope à la pointe de l’aiguille et à 10 cm environ en direction céphalique, par rapport à la pointe de l’aiguille, à l’intérieur de l’espace épidural. On a mesuré les changements de structure épidurale survenus pendant la respiration profonde à chaque site.RésultatsChez 80 % des patients, le tissu adipeux a rempli la pointe de l’aiguille. Pendant l’inspiration maximale, le tissu adipeux s’est déplacé et une cavité visible est apparue à la pointe de l’aiguille. L’aire transversale de la cavité visible à la pointe de l’aiguille était plus grande lors de l’inspiration maximale qu’au repos expiratoire: 12,1 ± 6,7 %vs 2,8 ± 2,1 % (moyenne ± écart-type,P < 0, 0001). Chez tous les patients, la cavité visible à l’intérieur de l’espace épidural, déjà agrandie par une injection d’air, s’est encore agrandie après l’inspiration maximale. L’aire transversale de la cavité visible à 10 cm en direction céphalique était plus grande lors de l’inspiration maximale qu’au repos expiratoire: 20,6 ± 10,0% vs 7,0± 5,3 %P < 0, 0001).ConclusionL’épiduroscopie a montré que l’inspiration profonde augmente la cavité potentielle de l’espace épidural. Nous croyons que les modifications de la structure épidurale pendant la respiration profonde peuvent faciliter l’insertion d’un cathéter épidural.

Mechanical effects of leg position on vertebral structures examined by magnetic resonance imaging

Background and Objectives Leg manipulation has been postulated to affect spinal curvature and position of the cauda equina within the dural sac. However, no evidence of such mechanical effects has been shown in living subjects. We used magnetic resonance imaging to evaluate the mechanical effects of leg position on these 2 parameters. Methods Sagittal and axial magnetic resonance images of the lumbosacral vertebral canal were obtained in 5 healthy, female volunteers with the subject in the supine position with knees straight, knees slightly flexed, and knees fully flexed. Results In the straight leg position, physiologic lumbar lordosis was evident in all subjects on midline sagittal slices, whereas lumbar lordosis disappeared in the fully flexed leg position. On the axial slices the cauda equina moved ventrally within the dural sac in all subjects in the fully flexed leg position. In 1 of the 5 subjects the cauda equina moved ventrally and also separated completely into right and left parts. Conclusions Our findings indicate that 2 potential factors, flattening of the lumbar lordosis and some added tension on the lumbosacral nerve roots, may contribute to postoperative back and leg aching after spinal anesthesia in the lithotomy position.

In vitro study of patient's and physician's radiation exposure in the performance of epiduroscopy.

Background and Objectives: Epiduroscopy is a minimally invasive diagnostic and therapeutic technique, useful in the management of patients with back and leg pain. However, the dose of radiation exposure by fluoroscopy during epiduroscopy is not known. The endpoint of our study was to evaluate the amount of radiation exposure for patients and health care workers during epiduroscopy. Methods: First, we measured the radiation dose during a 10‐minute fluoroscopy exposure in humanoid models, which substituted for the patient and the physician. Second, we measured the duration of fluoroscopy during our clinical epiduroscopy in 14 patients and observed for radiation injury in these patients. Results: In the humanoid models, the patient model skin exposure dose over a 10‐minute period was measured as 238 mGy. The physicians exposure dose for 10 minutes was measured as 0.67 mGy outside the lead apron and 0.0084 mGy inside the lead apron. For the clinical epiduroscopic procedures, the average duration of fluoroscopy was 9 minutes and 26 seconds. No skin injuries in the patients were observed at a 1‐month postprocedure assessment. Conclusions: The radiological dosages in the patient humanoid model were less than the threshold doses that could lead to organ injuries for 1 epiduroscopic procedure. However, care should be taken for cumulative exposures in repeated procedures.

Potential use of spinal canal endoscopy for successful treatment of cauda equina tumour and epidural abscess

AbstractSpinal canal endoscopy is recognised as a new technique for treatment of chronic low back and leg pain due to lumbar epidural adhesions involving nerve roots. In this paper, the cases of two patients who received orthopaedic surgery combined with spinal canal endoscopy are discussed. In case 1, the patient had a cauda equina tumour and underwent extirpation of the tumour assisted by spinal canal endoscopy. In case 2, the patient was suffering from extensive epidural abscess. He was treated with antibiotics and underwent single-level laminectomy and drainage assisted by spinal canal endoscopy. In case 1, small tumours that could not be identified by magnetic resonance imaging were identified with spinal canal endoscopy: the tumours were then partially removed from the T12 vertebral level to the S1 vertebral level by right hemilaminectomy of S1, and laminectomy of L5 and T12. In case 2, the use of spinal canal endoscopy enabled drainage and lavage of the wide lesion of the abscess by the single–leve...

Nicorandil successfully abolished intraoperative torsade de pointes.

Torsade de Pointes (TdP), polymorphic ventricular tachycardia with QT interval prolongation, is one of the life-threatening arrhythmias and may occur in association with intracranial. 1-6 Nicorandil, a potassium-channel opener, has been used as a coronary vasodilator. 7 Recently antiarrhythmic therapy using nicorandil has been attempted. Chinushi et al. 8 reported that nicorandil suppressed TdP in patients with idiopathic long QT syndrome. We experienced a case in which TdP occurred during surgery and was clearly abolished by nicorandil

Current and potential use of spinal canal endoscopy/epiduroscopy

AbstractWith the recent ageing of society, we frequently encounter patients with lower back and leg pain. In most patients, various conservative treatment methods are initially selected according to their pathological physiology. For patients who do not respond to conservative treatment, invasive treatment such as surgery is considered. However, patients that cannot be successfully treated conservatively do not always tolerate surgery. In recent years, minimally invasive treatment methods lying between conservative and invasive methods have shown favourable effects.

Adhesions in the epidural space caused by frequent epidural blocks

We report a case of adhesions in the epidural space caused by more than 200 times epidural blocks that were observed with epiduroscopy. A 41-year-old man had repeatedly undergone lumbar epidural blocks to treat pain in his leg, resulting in decreased efficacy of the epidural block. We described endoscopic findings that these adhesions were mostly consisted of adhesions formed from the soft connective tissue.

Intra-abdominal adhesions: vaginal or abdominal delivery?

We read Herzberger et al.’s article regarding intra-abdominal adhesions [1], and the subsequent comment [2] and reply [3] with great interest. Adhesions can result from a cesarean section (CS) and seem to be greatly influenced by individual factors [1]. Patients who form adhesions are likely to have more adhesions at a subsequent operation. This fits my clinical impression based on a four decadelong obstetric practice. If adhesions are anticipated before CS, obstetricians can prepare for it, exercising greater caution and deployment of more experienced obstetricians. Does the anticipation of severe adhesions influence not only the preparation for CS but also the mode of delivery itself (vaginal or abdominal)? For the sake of discussion, let us assume a particular patient who underwent adhesiolysis for endometriosis and also was abdominally delivered due to a breech presentation, when severe intra-abdominal adhesions were noted. In a second pregnancy, with a head presentation, ultrasound indicates a placental-edge cord-insertion, with a risk of intrapartum non-reassuring fetal status (NRFS). Which is better for this patient and her baby, a trial of labor or a planned CS? The question is whether adhesions favor ‘‘vaginal’’ over ‘‘abdominal’’ delivery, or vice versa. Of course, the answer may depend on the patient’s desire and also on the situation at the particular hospital. The experience of the staff and their availability may influence the type of delivery that is best for this patient. For simplicity, we here do not take the effect of CS on the next pregnancy into consideration. In our view, many, or at least not a small percentage of obstetricians, may answer, ‘‘A trial of labor may be better because severe adhesions may be present at this second CS’’. If a vaginal delivery was performed, one would never encounter severe adhesions because abdomen had not been opened. Thus, a trial of labor may be a good choice in this situation. However, if NRFS occurred during the night, an emergent CS is obviously needed. In some institutions, a relatively less experienced practitioner (compared with those available during daytime) may have to perform an emergent CS in the presence of severe adhesions. All the bad outcomes, i.e., long-time to infant delivery, bladder injury, large amount of blood loss, are more likely to occur. We fundamentally believe that adhesions favor a planned CS over a trial of labor. As the likelihood of severe adhesions increases, we are more likely to employ a planned CS. We necessarily encounter severe adhesions because we open the abdomen. However, experienced clinicians who are available during the daytime can manage this situation. There is an analogous situation, which occurs in anesthesia practice, with a patient for whom intubation is expected to be difficult. The decision is whether to perform general anesthesia with endotracheal intubation or regional anesthesia. In the case of massive bleeding or hemodynamic instability during the operation, intubation may be This comment refers to the article available at doi:10.1007/s00404015-3718-x.