Performance of microvascular anastomosis with a new robotic visualization system: proof of concept

Microvascular procedures require visual magnification of the surgical field, e.g. by a microscope. This can be accompanied by an unergonomic posture with musculoskeletal pain or long-term degenerative changes as the eye is bound to the ocular throughout the whole procedure. The presented study describes the advantages and drawbacks of a 3D exoscope camera system. The RoboticScope^®-system (BHS Technologies^®, Innsbruck, Austria) features a high-resolution 3D-camera that is placed over the surgical field and a head-mounted-display (HMD) that the camera pictures are transferred to. A motion sensor in the HMD allows for hands-free change of the exoscope position via head movements. For general evaluation of the system functions coronary artery anastomoses of ex-vivo pig hearts were performed. Second, the system was evaluated for anastomosis of a radial-forearm-free-flap in a clinical setting/in vivo. The system positioning was possible entirely hands-free using head movements. Camera control was intuitive; visualization of the operation site was adequate and independent from head or body position. Besides technical instructions of the providing company, there was no special surgical training of the surgeons or involved staff upfront performing the procedures necessary. An ergonomic assessment questionnaire showed a favorable ergonomic position in comparison to surgery with a microscope. The outcome of the operated patient was good. There were no intra- or postoperative complications. The exoscope facilitates a change of head and body position without losing focus of the operation site and an ergonomic working position. Repeated applications have to clarify if the system benefits in clinical routine.

[Robotics in otorhinolaryngology, head and neck surgery]

In many surgical specialities, e.g., visceral surgery or urology, the use of robotic assistance is widely regarded as standard for many interventions. By contrast, in European otorhinolaryngology, robotic-assisted surgery (RAS) is rarely conducted. This is because currently available robotic systems are not adequately adapted to the restricted space and partially difficult access to surgical fields in the head and neck area. Furthermore, RAS is associated with high costs at present. In some Anglo-American regions, robot-assisted surgery is already used regularly for different indications, particularly in transoral surgery of oropharyngeal tumors. Several feasibility studies demonstrate multiple fields of application for RAS in head and neck surgery. For standard use, the robotic systems and surgical instruments need to be reduced in size and adapted to application in the head and neck area.

[Diagnostic accuracy of outpatient polygraphy devices : A comparison with inpatient polysomnography in clinical routine]

BACKGROUND

Cardiorespiratory polysomnography (PSG) is considered the reference method for diagnosis of obstructive sleep apnea (OSA). Due to waiting times and high costs, payers increasingly request outpatient polygraphy (PG) as an alternative to inpatient PSG. The aim of the present study was to evaluate the diagnostic accuracy of different outpatient PG devices compared to stationary PSG in clinical practice.

MATERIALS AND METHODS

Externally collected outpatient PG findings of 406 patients were retrospectively compared with the corresponding PSG findings.

RESULTS

Among the 406 patients were 343 men (85%) and 63 women (15%), with mean age 50 years. Mean body mass index (BMI) was 30 kg/m². The rank correlation coefficient for PG- and PSG- derived apnea-hypopnea index (AHI) values was r = 0.574. On average, PG underestimated the AHI by 6.4 (±20.5) events/h. OSAS severity was determined correctly by PG in only 43% of cases. Sensitivity (90.7%) and specificity (45.2%) of ambulatory PG was calculated for the threshold value AHI ≥ 5/h. Based on the results of PG, an indicated therapy would have been omitted in 35 cases (9%) and unnecessary treatment initiated in 17 cases (4%). The PG devices used showed a comparable diagnostic accuracy (r = 0.513-0.657), with a sensitivity of 81.3-96.9% and a specificity of 33.3-50.0%.

CONCLUSION

Outpatient PG cannot reliably assess OSA severity in clinical routine. Confirmation by PSG in a sleep lab in symptomatic patients is obligatory. Outpatient PG devices should only be used as an upstream screening method. The automatic evaluation of the PG should always be proofed.

[Drug therapy of otorhinolaryngological diseases in pregnancy : An update]

The majority of women take at least one form of medication during pregnancy. Due to often discrepant information about the risk assessment of pharmaceuticals during pregnancy, physicians are often beset by uncertainty with respect to prescription and the fear of medicolegal consequences is high. As prospective clinical trials on drug safety during pregnancy are prohibited due to ethical reasons and animal studies are of limited applicability to humans, drug recommendations often only rely on observational data. An objective examination of the topic not only contributes to effective treatment of illnesses in pregnancy but also prevents impairment of fetal outcome by omission of necessary maternal treatment. The aim of this article is to give a structured presentation of medications that can be used during pregnancy for treating medical conditions of the ear, nose and throat, in the sense of practical guidelines.

Transnasal endoscopic treatment of bilateral choanal atresia in newborns using balloon dilatation: own results and review of literature

OBJECTIVES

Congenital choanal atresia is a complete obliteration of the posterior nasal aperture leading to life-threatening airway emergencies. Several surgical options including sublabial, transpalatal, transseptal or external approaches have been developed for the repair of choanal atresia. So far, no gold standard has been established, but transnasal endoscopic approaches have been favored by many surgeons in recent years.

METHODS

Since 2008 a standard procedure for bilateral choanal atresia repair in neonates using an endoscopic transnasal approach supported by balloon dilatation has been established at the Department of Otorhinolaryngology at Ulm University Medical Center. During the last five years, six cases of bilateral choanal atresia were diagnosed and treated, including two male and four female patients aged between three days and two months, at the date of surgery. All interventions were performed in transnasal endoscopic technique. In all patients the abnormally thick posterior vomer and the atretic bony plate were resected and the mucosa was perforated. A balloon dilator was used to dilate the neochoanae and prevent restenosis. All six patients were intraoperatively stented for at least six weeks.

RESULTS

All six neonates with bilateral choanal atresia, who were operated in endoscopic transnasal technique had patent neo-choanae on both sides. No severe postoperative complications were found. The number of revisions depends on the age at primary surgery.

CONCLUSIONS

Endonasal endoscopic approach and balloon dilatation is a safe, reproducible technique for surgical repair of choanal atresia. We recommend the use of bilateral stents, especially in very young patients, as a prerequisite to prevent early restenosis.

High altitude increases circulating interleukin-6, interleukin-1 receptor antagonist and C-reactive protein

Hypoxic pulmonary vasoconstriction is associated with but may not be sufficient for the development of high-altitude pulmonary oedema (HAPO). Hypoxia is known to induce an inflammatory response in immune cells and endothelial cells. It has been speculated that hypoxia-induced inflammatory cytokines at high altitude may contribute to the development of HAPO by causing capillary leakage in the lung. We were interested if such an inflammatory response, possibly involved in a later development of HAPO, is detectable at high altitude in individuals without HAPO. We examined the plasma levels of interleukin 6 (IL-6), interleukin 1 receptor antagonist (IL-1ra) and C-reactive protein (CRP) in two independent studies: study A, Jungfraujoch, Switzerland, three overnight stays at 3458 m, n=12; study B: Capanna Regina Margherita, Italy, 3 overnight stays at 3647 m and one overnight stay at 4559 m, n=10. In both studies, probands showed symptoms of acute mountain sickness but no signs of HAPO. At the Jungfraujoch, IL-6 increased from 0.1+/-0.03 pg/ml to 2. 0+/-0.5 pg/ml (day 2, P=0.03), IL-1ra from 101+/-21 to 284+/-73 pg/ml (day 2, P=0.01), and CRP from 1.0+/-0.4 to 5.8+/-1.5 micrograms/ml (day 4, P=0.01). At the Capanna Margherita, IL-6 increased from 0. 5+/-0.2 pg/ml to 2.0+/-0.8 pg/ml (P=0.02), IL-1ra from 118+/-25 to 213+/-28 pg/ml (P=0.02), and CRP from 0.4+/-0.03 to 3.5+/-1.1 micrograms/ml (P=0.03). IL-8 was below the detection limit of the ELISA (<25 pg/ml) in both studies. The increase of IL-6 and IL-1ra in response to high altitude was delayed and preceded the increase of CRP. We conclude that: (1) circulating IL-6, IL-1ra and CRP are upregulated in response to hypobaric hypoxic conditions at high altitude, and (2) the moderate systemic increase of these inflammatory markers may reflect considerable local inflammation. The existence and the kinetics of high altitude-induced cytokines found in this study support the hypothesis that inflammation is involved in the development of HAPO.

Gastrointestinal involvement in patients with diabetes mellitus: Part I (first of two parts). Epidemiology, pathophysiology, clinical findings

In patients with type 1 or type 2 diabetes mellitus disturbances of the gastrointestinal transit are well recognized. In decreasing order of frequency, transit disturbance through the colon, stomach, small intestine and esophagus as well as altered motility of the gallbladder occur. Acute changes of blood glucose concentrations have a major, however, reversible influence on motility in various parts of the intestinal tract. Long-term hyperglycemia may influence the incidence of gastrointestinal involvement via the occurrence of neuropathic changes of the autonomic nervous system. Early satiety, nausea, vomiting, weight loss, constipation, diarrhea and epigastric pain are often reported. These symptoms and recurrent episodes of hypoglycemia or prolonged hyperglycemia can result from intestinal transit disturbances.

Gastrointestinal involvement in patients with diabetes mellitus: Part II (second of two parts). Diagnostic procedures, pharmacological and nonpharmacological therapy

Diagnostic work-up in patients with diabetes mellitus, in whom gastrointestinal involvement is suspected comprises the assessment of gastrointestinal transit times, endoscopy, esophageal pH-metry or manometry, sonography and lactulose- or glucose-H2-breath tests. Prokinetic agents such as metoclopramide, cisapride or erythromycin and substances like loperamide, octreotide or clonidine are used to improve gastrointestinal dysfunction. Furthermore, in recent trials which aimed for the modulation of gastrointestinal transit times, cholecystokinin, proteinase inhibitors or amylin were administered in patients with diabetes mellitus. Nonpharmacological interventions include pancreas and kidney transplantation, gastric pacemakers and biofeedback training.

Combined ultrasonographic and neurographic examination: a new technique to evaluate phrenic nerve function

In this report a new technique for simultaneous assessment of the electrical and mechanical properties of the diaphragm is presented. The phrenic nerve of 9 healthy persons was stimulated at the neck using magnetic stimulation. Electrical activity was recorded using chest surface electrodes. The mechanical function of the diaphragm was evaluated by performing combined B- and M-mode ultrasonographic examination. The data show that this method helps to distinguish the diaphragm muscle compound action potential from electrical activity derived from neighboring muscles activated by the brachial plexus. Furthermore, it provides a non-invasive tool which can easily be used in clinical practice to study the mechanical properties of the diaphragm.

Gallbladder dynamics in chronic pancreatitis. Relationship to exocrine pancreatic function, CCK, and PP release

Gallbladder dynamics, cholecystokinin (CCK), and pancreatic polypeptide (PP) release were studied in 14 patients with chronic pancreatitis (CP) (2 females, 12 males; age range 24-56 years) and 12 control subjects (4 females, 8 males, 21-50 years). On day 1, gallbladder contractility was investigated after ceruletide intravenous infusion (2.5 ng/kg/min for 10 min). On day 2, a mixed standard test meal (1450 kJ) was administered orally. Gallbladder volume was assessed at three time intervals before (-30, -15, 0 min) and at 5, 10, 20, 30, 40, 50, 60, 80, 100 and 120 min after stimulation by means of ultrasonography. CCK and PP plasma levels were determined at each time interval. Exocrine pancreatic function was assessed using the pancreolauryl serum test (PLT). Six patients with CP had severe exocrine pancreatic insufficiency (EPI) (PLT < 1.8 micrograms/ml) with steatorrhea, eight patients had mild-moderate EPI. Fasting gallbladder volume was increased in CP (32.3 +/- 3.1 cm3) as compared to controls (20.5 +/- 1.2 cm3) (P < 0.01). Peak gallbladder contraction (percent of initial volume) in CP ranged from 5 to 55% (controls: 8-46%) following ceruletide and from 17 to 86% (controls: 27-80%) following the test meal (NS). There was no correlation between the degree of EPI according to PLT and peak gallbladder contraction. Gallbladder emptying in CP patients was not different from controls, although the postprandial CCK response was significantly impaired (P < 0.01). Postprandial PP response in CP was correlated with the PLT result (r = 0.78; P < 0.01) but not with gallbladder emptying or refilling time.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of experimental endogenous gram-negative peritonitis on the pancreas of the rat as evaluated by cationic trypsin-like immunoreactivity in peritoneal fluid and serum and by electron microscopy of pancreatic tissue

Endogenous gram-negative peritonitis leading to septic shock was induced in rats by a defined perforation of the coecum. Cationic trypsin-like immunoreactivity (CTLI) was measured in peritoneal fluid and serum by a radioimmunoassay method. Five, 10, and 15 h after the coecal perforation, CTLI in peritoneal fluid was significantly higher than before the coecal perforation and also higher than in the corresponding control rats. Moreover, CTLI in serum was under the same conditions significantly higher 10 and 15 h after the induction of peritonitis. Gel chromatography of peritoneal fluid and serum during peritonitis showed free CTLI and CTLI bound to both alpha-1-antitrypsin and alpha-2-macroglobulin, whereas only free CTLI could be detected in serum from control rats. These findings were accompanied by local ultrastructural changes in the acinar cells as evaluated by electron microscopy. The pathophysiologic implications of the findings are discussed.

Na-taurodeoxycholate acts as a specific intestinal stimulus of exocrine pancreatic secretion in man

The effect of intraduodenally administered cattle bile, Na-taurodeoxycholate, and Na-taurocholate on secretin-stimulated exocrine pancreatic secretion was investigated on 40 fasting young healthy volunteers. Intraduodenal bile stimulated significantly and dose-dependently hydrokinetic and ecbolic pancreatic secretion. Only bile, but not secretin intravenously, both applied in a dosage equivalent with respect to their hydrokinetic action, caused a significant increase of enzyme output and enzyme concentration as well. Intraduodenal Na-taurodeoxycholate enhanced also dose-dependently secretin-stimulated volume, bicarbonate, and enzyme secretion. The effect was related to the load, not to the concentration of this bile salt. On the other side, Na-taurocholate had only a weak and not dose-dependent hydrokinetic and no ecbolic effect. It is concluded that not bile salts in general, but only certain of them--like Na-taurodeoxycholate--are the effective constituents of bile, acting as specific intraduodenal stimulants of hydrokinetic and ecbolic pancreatic secretion.

[Increase of plasma cholecystokinin by Escherichia coli endotoxin-induced shock in swine]

The gastrointestinal tract is the source of numerous peptide hormones. Since the gut will be altered severely during prolonged general circulatory low flow states, the reactions of the gut hormones are of great interest. In this study 18 anesthetized pigs were put into shock states to get first informations about the changes of the plasma levels of cholecystokinin (CCK). 12 pigs (group I and II) were exposed to a general circulatory shock state by a 2-hr intravenous infusion of a sublethal dose of Escherichia coli endotoxin. 6 of them (gr. II) first received a gastroenterectomy apart from a small duodenal remnant proximal and distal to the papilla of Vater. The remaining 6 pigs (gr. III) suffered a severe hemorrhagic-hypovolemic shock over a 150-min period by arterial bleeding. Plasma CCK increased significantly (p less than 0.05) in the aorta (gr. I, II), the portal vein (gr. I, II), the superior caval vein (gr. I), and the internal jugular vein (gr. I) at the end of the 2-hr endotoxin infusion. In group II, the rise of CCK levels in the superior caval vein was also marked, but insignificant. The CCK-concentrations in the internal jugular vein were measured only in group I. By contrast, no changes in plasma CCK were seen in hemorrhagic shock (gr. III). Within each group plasma samples taken from the various blood vessels at identical time points showed no significant differences. Since the plasma concentrations of CCK remained unchanged during hemorrhagic shock, the release of CCK by E. coli endotoxin is not due to the general circulatory low flow state.(ABSTRACT TRUNCATED AT 250 WORDS)