Lateral Oblique Position Research Articles

Ultrasonographic Measurement of Pharyngeal-Airway Dimension and Its Relationship with Obesity and Sleep-Disordered Breathing

Previous studies based on magnetic resonance imaging (MRI) or computed tomography (CT) have shown that pharyngeal airway diameter during wakefulness is different between healthy controls and patients with a high risk of sleep-disordered breathing (SDB). However, MRI and CT are expensive and not easily accessible. Conversely, ultrasonography is more accessible and is getting more attention as a point-of-care technology to assess physiologic systems, such as the pharynx. Thus, we aimed to evaluate the feasibility of ultrasonography in estimating the pharyngeal airway dimension. To evaluate the pharyngeal airway with ultrasonography, we measured the parasagittal anterior–posterior (PAP) diameter and transverse diameter. For PAP diameter measurements, the transducer probe was placed in a submandibular lateral oblique position, with its superior margin abutting the angle of the left mandible. For the transverse measurement, the ultrasound probe was positioned in a submandibular location, in a near-coronal plane, just above the hyoid bone so that the tongue could be seen in cross-section. The diameter measurements were performed manually by two technicians. The reliability of these measurements was assessed by the intra-class correlation coefficient (ICC). To validate our measurements, we compared the measured PAP diameter with the average pharyngeal airway cross-sectional area from vellum to glottis measured by acoustic pharyngometry. Furthermore, we compared the influence of obesity and SDB in the measured pharyngeal diameters. Eighteen controls and 13 individuals with a high risk of SDB participated in this study. Reliability analysis of the PAP measurements yielded an ICC of 0.97 (95% confidence interval: 0.94–0.98). Furthermore, measured PAP diameters were significantly correlated with the pharyngeal airway cross-sectional area (r = 0.76, p < 0.01). Moreover, obesity and SDB were associated with decreases in PAP diameter. Our study shows that ultrasonography measurement of the PAP diameter may provide a quantitative assessment of the pharyngeal airway and may be useful for screening of SDB.

Robot-Assisted Simultaneous Pyeloplasty and Ureteric Reimplantation for Unilateral Double Obstruction of the Ureter: Technical feasibility, Tips and Tricks

ObjectiveTo highlight the feasibility and technical details of performing simultaneous ipsilateral pyeloplasty and ureteric re-implantation for simultaneous proximal and distal obstruction of the ureter. MethodsTwo patients with preoperative diagnosis of proximal and distal ureteric obstruction underwent robot-assisted simultaneous pyeloplasty and ureteric re-implantation. The patients were placed in right lateral oblique position and pyeloplasty was performed in standard manner. In both cases, Double J stent could not be negotiated beyond the vesicoureteric junction into the bladder. The robot was dedocked and recentred around different ports to successfully perform uretero-neocystostomy over a 4.8 F double J stent. ResultsThe mean operative times were 154 minutes with operative blood loss of approximately 50 ml. The postoperative convalescence was good in both cases and Double J stents were removed after 6 weeks. Follow-up diuretic renograms demonstrated stable renal function with unobstructed drainage. ConclusionSimultaneous repair of ipsilateral pelviureteric and vesicoureteric junction obstruction is safe and feasible contrary to traditional teachings. To the best of our knowledge this is the first description of robotic simultaneous pyeloplasty and ureteric reimplantation.

Purely endoscopic resection of pineal region tumors using infratentorial supracerebellar approach: How I do it.

Infratentorial supracerebellar approach via microscope still has some limitations in resection of pineal region tumors. The authors describe a purely endoscopic infratentorial supracerebellar approach for resection of pineal region tumors with matched air-driven arm and navigation. The lateral oblique position is adopted. The same bimanual microsurgical techniques are utilized in this endoscopic approach with panoramic view and satisfying comfort. Purely endoscopic resection of pineal region tumors using infratentorial supracerebellar approach is feasible. It may be considered as an alternative approach for certain pineal region tumors.

Selective indication for check cystogram before catheter removal following robot assisted radical prostatectomy.

Introduction:With the improvement in anastomotic technique, it is rare to find anastomotic site leak after robot-assisted radical prostatectomy (RARP). It may not always be necessary to do regular check cystogram before catheter removal. We evaluated our 230 consecutive RARP patients and their cystograms to determine the indications for selective use of cystogram before catheter removal.Materials and Methods:We reviewed our prospectively collected RARP database of 230 consecutive patients. Cystography was performed at low pressure by gravity instillation of diluted contrast through the catheter. Patients were observed under fluoroscopy in lateral oblique position for any contrast leak at the site of anastomosis. All patients were followed for a minimum of 6 months, and the longest follow-up was 5 years.Results:A total of 207 patients (90%) underwent catheter removal on postoperative day 7. Nine patients (3.9%) had extravasation on initial cystogram. Two patients with leak had a history of transurethral resection of prostate (TURP) and seven other had bladder neck reconstruction for wide bladder neck. Three patients with minimal leak did not require catheter replacement. In rest of the 6 patient with leak, continued catheter drainage was done. No significant difference in the intraoperative variables, blood loss, duration of drain, length of hospital stay, and continence outcomes was noted between the patients with leak compared to rest of the patients. None of the patient needed any procedure/intervention related to the surgery and none developed bladder neck stenosis.Conclusion:In usual circumstances, catheter removal can be done safely on a postoperative day 7 without routine cystography. Selective use of check cystogram can be done in the case where bladder neck reconstruction is performed or those had a prior TURP and a wide bladder neck.

Experiences with the Sitting Position in Posterior Fossa Surgery in 310 Patients

Introduction: The sitting position for lesions in the posterior fossa has been controversially discussed in the literature because of high risk of air embolism. We report our experience with the sitting position and evaluate the risk of air embolism. Material and Methods: We performed a retrospective analysis of patient charts (N=310), surgical and anesthesiological reports to evaluate the occurrence of intraoperative complications. Pre and post-operative MRIs were also evaluated for occurrence of embolic infarctions. The patients were operated in our department from 2009–2013. Results: Only 0.6% of patients suffered from embolic infarctions. Most of the complications were similar to the complications which occur in the lateral oblique position. Preoperatively, all patients were evaluated with echocardiography to exclude a patent foramen ovale (those patients were not operated in the sitting position). Conclusion: The sitting position is excellent for surgery in the posterior fossa since blood is washed out and does not intervene with the surgical field. The risk of air embolism is very low when a patent foramen ovale has been excluded. Intraoperatively, a right ventricular catheter is inserted to aspirate air if needed. Meticulous coagulation, irrigation of the surgical domane and application of bone wax to the craniotomy edges reduces the risk of venous air embolism.

Posterolateral approach for spinal intradural meningioma with ventral attachment.

Background:Spinal meningioma with ventral attachment is a challenging pathology. Several technical modifications have been proposed to secure safe and precise resection of these tumors.Materials and Methods:This retrospective study focused on the precise and safe surgery of spinal meningiomas with strictly ventral attachment of cervical or thoracic spine. The surgical technique included a lateral oblique position for the patient, laminectomy with unilateral medial facetectomy on the tumor side, and spinal cord rotation with the dentate ligament. The neurological status of patients was assessed using the modified McCormick functional schema (mMFS) and sensory pain scale (SPS) before and at least 3 months after surgery. Patients were followed-up for a mean of 23.7 months. Tumor removal was graded using the Simpson grade for removal of meningiomas, and the extent of excision was confirmed using early postoperative magnetic resonance imaging.Results:Simpson grade 1 or 2 resections were achieved in all cases. No major surgery-related complications were encountered, postoperatively. The mean mMFS score before surgery was 3.1, improving significantly to 1.7 after surgery (P < 0.05). The mean SPS score before surgery was 2.4, improving significantly to 1.6 after surgery (P < 0.05).Conclusions:This surgical technique offers a posterolateral surgical corridor to the ventral canal of both cervical and thoracic spine. The present preliminary analysis suggests that functional outcomes were satisfactory with minimal surgery-related complications, although considerable surgical experience is needed to achieve a high level of surgical confidence.

False-Positive Pericardial Effusion Due to Breast Attenuation on Equilibrium Radionuclide Angiocardiography

Equilibrium radionuclide angiocardiography (ERNA) scans are used to evaluate left ventricular function and pericardial anatomy. A photopenic "U-halo" around the cardiac blood pool in the left anterior oblique (LAO) view is commonly seen with pericardial effusion. We describe findings of false-positive pericardial effusion due to breast attenuation in cancer patients. Several cases that demonstrated the photopenic U-halo in the LAO view did not have true pericardial effusion. The patients' breast size and how far the breast sagged in reference to the heart silhouette were visually observed in topograms. The oblique tilt position was evaluated to determine the effect it may have in creating the photopenic U-halo. A unique ERNA case demonstrating collateral vessels bilaterally in the breasts was used as a reference marker image to determine the effect of a slightly more anterior versus left lateral oblique tilt in the LAO view. Large breasts can overlie the heart in the LAO projection. The overlying breast can cause the appearance of pericardial effusion in the resulting image by attenuating tissues surrounding the heart. The positioning of the breast also affected the appearance of the photopenic halo. A patient with breast implants who had more upright breasts demonstrated a photopenic area anterior to the left ventricle, whereas a large breast that sagged more laterally demonstrated no photopenic area. Patients with large breasts may show a photopenic U-halo in the LAO view dependent on how far the breast sags in reference to the heart silhouette and on the positioning of the oblique tilt. The anterior image should be used to distinguish breast attenuation from a photopenic area surrounding the heart. If both the anterior view and the LAO view demonstrate the U-halo, acquiring another view with a slightly more anterior or lateral oblique position will demonstrate any inconsistency in the photopenic area, thereby excluding a diagnosis of pericardial effusion.

Lateral supracerebellar transtentorial approach for petroclival meningiomas: operative technique and outcome

The retrosigmoid intradural suprameatal approach with the patient in a semisitting position is an effective alternative to transpetrosal approaches for the treatment of petroclival meningiomas. The authors have made a simple modification to the retrosigmoid intradural suprameatal approach by using the lateral oblique position and preferentially dividing the tentorium with limited drilling of the suprameatal bone, which is termed the "lateral supracerebellar transtentorial approach." Twenty-six patients with petroclival meningiomas surgically treated via the lateral supracerebellar transtentorial approach were analyzed. All tumors had most of their bulk in the posterior fossa with some degree of extension into the middle fossa and/or Meckel cave. The patient is placed in the lateral oblique position, and a standard retrosigmoid craniotomy is performed. The tentorium medial to the trigeminal nerve is incised toward the free edge, which improves exposure to the petroclival region without extensive resection of the suprameatal petrous bone. Gross-total resection was achieved in 11 patients (42%). Ten patients (38%) underwent subtotal resection, and 5 patients (19%) underwent partial resection. There was no incidence of operative death, and the postoperative permanent morbidity rate was 15%. All patients except one did well postoperatively and were independent at the time of their last follow-up examinations. The lateral supracerebellar transtentorial approach provides the simplest and safest access to the petroclival region. It offers an advantageous approach to petroclival meningiomas exclusively located in the posterior fossa with minimal extension into the Meckel cave and middle fossa.

Surgery of Spinal Nerve Sheath Tumors Originating From C1 or C2 of High Cervical Spine -Technical Note-

Spinal nerve sheath tumors (NSTs) originating from the C1 or C2 level are unique from both anatomical and clinical perspectives. Surgical technique to accomplish radical but safe resection of these tumors is described in 8 cases treated during the past 5 years. Surgical measures included positioning the patient in the lateral oblique position, unilateral posterior approach, exposure of the tumor along the surgical plane of the dural or perineural boundary, and proximal and distal amputation of the tumor with resection of dural penetration. Excessive bone resection and soft tissue manipulation were unnecessary. Microscopic complete removal of the tumor was accomplished in seven of eight cases. Subtotal resection was done in one case where the tumor extended beyond the vertebral artery. Functional assessment demonstrated satisfactory improvement after surgery in all cases. Surgery-related complications were not encountered in any case. Exposure of the tumor along the surgical plane of the dural or perineural boundary may be the key procedure required to accomplish radical but safe resection of spinal NSTs originating from the C1 or C2 level.

Choosing the location for non‐image guided abdominal paracentesis

The optimal location for paracentesis has not been studied scientifically. The evolving obesity epidemic has changed the physique of many patients with cirrhosis and ascites such that needles inserted into the abdominal wall may not reach fluid. We aimed to determine the location for paracentesis that would have the thinnest abdominal wall and the deepest amount of fluid. Ultrasound measurements of abdominal wall thickness and depth of ascites were recorded in two locations, the infraumbilical midline (ML) and the left lower quadrant (LLQ), in 52 patients with cirrhosis and ascites admitted to a single inpatient liver unit. The abdominal wall was significantly thinner (1.8 vs. 2.4 cm; P<0.001) and the depth of ascites greater (2.86 vs. 2.29 cm; P=0.017) in the LLQ as compared with the infraumbilical ML position. In the left lateral oblique position, the difference in the depth of ascites was more pronounced when comparing the LLQ with the infraumbilical ML (4.57 vs. 2.78 cm; P<0.0001). The LLQ is preferable to the ML infraumbilical location for performing paracentesis.

脊髄動静脈奇形の診断と治療

Spinal arteriovenous malformation (spinal AVM) is a rare but clinically important disease in that it presents with progressive, somewhat stepwise worsening myelopathy, and its outcome of natural course is very poor. Classification of spinal AVM based on angiographical features has been very difficult to understand, and we propose here a comprehensive one based upon the sites of A-V shunts. For diagnostic purposes, MRI gives us not only the location of AVM but also the existence of venous congestion in the spinal cord itself. But selective spinal angiography still remains the gold standard for confirming the shunt points and planning the strategy of treatment. Both surgical and endovascular interventions are available for its treatment, and we detail all the surgical treatment procedures. The lateral oblique position reduces the risk of venous hypertension during surgery and is also comfortable for the operator. Using microdoppler monitoring with meticulous temporary clipping is somewhat laborious but the best method for understanding the complex vasculature as well as accurately implementing treatment. What is most essential is that the total extirpation of abnormal A-V shunts be realized for this disease to achieve total cure. The treatment strategy should be based on this point, and palliative therapy, which would produce a more complicated condition afterwards, should be avoided.