Evaluation of a curved surgical prototype in a human larynx.

PURPOSE: It is not always possible to create linear access to the larynx using a rigid operating laryngoscope for microlaryngoscopy. In this study, we evaluate the usability of a novel curved surgical prototype with flexible instruments for the larynx (sMAC) in a simulation dummy and human body donor. METHODS: In a user study (n = 6), head and neck surgeons as well as medical students tested the system for visualization quality and accessibility of laryngeal landmarks on an intubation dummy and human cadaver. A biopsy of the epiglottis was taken from the body donor. Photographic and time documentation was carried out. RESULTS: The sMAC system demonstrated general feasibility for laryngeal surgery. Unlike conventional microlaryngoscopy, all landmarks could be visualized and manipulated in both setups. Biopsy removal was possible. Visibility of the surgical field remained largely unobstructed even with an endotracheal tube in place. Overall handling of the sMAC prototype was satisfactorily feasible at all times. CONCLUSION: The sMAC system could offer an alternative for patients, where microlaryngoscopy is not applicable. A clinical trial has to clarify if the system benefits in clinical routine.

[Robot-assisted head and neck surgery]. / Robotik in der Kopf-Hals-Chirurgie.

Robot-assisted surgery (RAS) has already been approved for several clinical applications in head and neck surgery. In some Anglo-American regions, RAS is currently the common standard for treatment of oropharyngeal diseases. Systematic randomized studies comparing established surgical procedures with RAS in a large number of patients are unavailable so far. Experimental publications rather describe how to reach poorly accessible anatomical regions using RAS, or represent feasibility studies on the use of transoral robotic surgery (TORS) in established surgical operations. With general application of RAS in clinical practice, the question of financial reimbursement arises. Furthermore, the technical applications currently on the market still require some specific improvements for routine use in head and neck surgery.

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.

Planning for sex, marriage, contraception, and pregnancy.

PIP: Authors Graber, Christman and Boehm contend careful planning for marriage, contraceptive use and pregnancy is warranted when a chronic health problem such as diabetes is evident. Prospective mates should be fully aware of the problems and management of diabetes. Diabetic women who wish to delay pregnancy should consider using an effective contraceptive. It is suggested that the lowest dosage of oral contraceptive pill be used with full understanding of adverse side effects and agreement to discontinue their use if complications arise. IUDs can also be effectively used by diabetics. Sterilization should be considered if the woman has a 20 year history of diabetes, is older than 35 years or has diabetic vascular complications. Sterilization for male diabetic or mates of diabetic women is another option. Planning in regard to pregnancy should begin in the middle teens if a woman is diabetic. Pregnancy should be delayed until the following criteria are met: 1) Both partners should fully understand diabetes and its management; 2) Diabetes should be under control prior to pregnancy since it is likely to be aggravated by pregnancy; 3) Women should reach ideal body weight prior to pregnancy; 4) Pregnancy should be delayed 1 year after diagnosis of diabetes; 5) There should be an acceptance of additional difficulties associated with pregnancy; 6) Understanding the effects of diabetes on infants is crucial; and 7) Spouses should accept the possibility of greater health problems with diabetic mates when planning a family.^ieng

Search for neutrino oscillations at the palo verde nuclear reactors

We report on the initial results from a measurement of the antineutrino flux and spectrum at a distance of about 800 m from the three reactors of the Palo Verde Nuclear Generating Station using a segmented gadolinium-loaded scintillation detector. We find that the antineutrino flux agrees with that predicted in the absence of oscillations excluding at 90% C.L. nu;(e)-nu;(x) oscillations with Deltam(2)>1.12x10(-3) eV(2) for maximal mixing and sin (2)2straight theta>0.21 for large Deltam(2). Our results support the conclusion that the atmospheric neutrino oscillations observed by Super-Kamiokande do not involve nu(e).

Prolonged end stage fetal heart rate deceleration.

With the use of routine monitoring of all patients in labor, a number of confusing, seemingly ominous fetal heart rate tracings in otherwise normal, healthy patients have been observed. This report described one such type of pattern called prolonged end stage deceleration.

Documentation of recent fetal demise with simultaneous maternal and fetal heart rate monitoring.

A case of recent fetal demise with maternal-fetal electrocardiogram (ECG) signal conduction is presented. Diagnosis and graphic documentation of fetal demise were made by comparison of heart tracings obtained from the maternal precordium and from the fetal scalp. Combined monitoring is suggested as a diagnostic procedure and as a method of graphic documentation.

Prolonged end-stage fetal heart rate deceleration: a reanalysis.

In an earlier publication we reported on 18 patients who had what was described as prolonged fetal heart rate (FHR) deceleration in the second stage of labor and who had uniformly good outcome. It was believed that the reason for the good outcome was early diagnosis and rapid delivery when the FHR deceleration did not improve by the time the patient entered the delivery room. We have continued to handle this type of deceleration pattern in a similar fashion with good results, but 18 additional cases of prolonged end-stage FHR deceleration associated with a poor outcome are reported along with 1 case of intrauterine demise. Physicians who use the fetal monitor need to be aware of this potentially ominous FHR pattern.

Xerox telecopier transmission of fetal monitor tracings: a 4-year experience.

A telephone consultation system using the Xerox 400 Telecopier has been established to transmit fetal monitor data to a tertiary center from regional hospitals with limited experience in interpreting this data. This report reviews a 4-year experience with this consultative device, discusses both the advantages and disadvantages of such a program, and recommends the establishment of similar services in other tertiary centers. We believe that the establishment of such services can be of diagnostic and therapeutic benefit to inexperienced medical personnel when first confronted with the concept of fetal monitoring. Hopefully, by so doing, hospital use of fetal monitoring will increase.

Acute effect of cigarette smoking on the fetal heart nonstress test.

A major limitation in the use of the nonstress test (NST) has been the high frequency of nonreactive NSTs in the absence of fetal distress. Exogenous factors causing loss of fetal heart rate reactivity (FHRR) have not been fully evaluated, although it has previously been shown that chronic smokers have an increased incidence of nonreactive NSTs in the absence of fetal distress. A group of chronically smoking high-risk pregnant women at 31 to 44 weeks' gestation was studied to determine if the acute effects of smoking caused the NST to become nonreactive. After a reactive NST was obtained, each patient smoked 1 cigarette and the effects of the fetus were observed. Twenty-six studies were performed on 25 patients. A transient mild elevation of baseline fetal heart rate was noted after smoking in several studies; however, no significant change was found in FHRR, indicating that the acute effects of smoking a single cigarette are not responsible for the increased incidence of nonreactive NSTs in smokers.

Improved outcome of twice weekly nonstress testing.

The nonstress test is a commonly used tool for fetal well-being assessment. The antenatal death rate using the nonstress test as a primary modality is significantly higher than that with the use of the contraction stress test. The nonstress test is commonly performed on a once-a-week basis. The rate of stillbirths with reactive nonstress tests, performed once a week, was 6.1 per 1000 in the author's previously published report. Nonstress tests were performed on a twice-a-week basis beginning January 1981, and results are reported on 913 such patients. The rate of stillbirths with reactive nonstress tests was reduced to 1.9 per 1000 in this second group. It is suggested that the patients who are at risk for fetal stress should be evaluated on a twice-a-week basis when the nonstress test is used as the primary test.

Ferning of amniotic fluid contaminated with blood.

The diagnosis of rupture of the membranes by traditional methods of nitrazine paper determination and fern crystallization has been reported to be 93-98% accurate. Although the presence of contaminants in amniotic fluid has been reported to reduce this accuracy, the literature is conflicting concerning these effects. We examined the effect of blood contamination on the accuracy of diagnosing ruptured membranes. Amniotic fluid was obtained from 38 patients between 16-38 weeks' gestational age who underwent amniocentesis. Amniotic fluid was immediately mixed with freshly obtained, heparinized fetal cord blood in varying concentrations (blood to amniotic fluid 1:5, 1:10, 1:20). The slides were examined microscopically for the presence of ferning. All samples were fern-positive, but many had atypical ferns described as "skeletonized." As the concentration of blood to amniotic fluid increased, the number of atypical ferns increased (32 of 38 at 1:5, 22 of 38 at 1:10, and nine of 38 at 1:20). We conclude that the presence of blood may alter the morphology of the fern, but does not act as a contaminant that would affect the accuracy of the test.

Antepartum diagnosis of fetal intracranial hemorrhage by ultrasound.

Presented is a patient with acute onset of preeclampsia and abruptio placenta at approximately 26 weeks' gestation. Ultrasonography demonstrated evidence of in utero fetal intracranial hemorrhage, which was confirmed at autopsy. The implication of this finding is discussed.

Prostaglandin E2 vaginal suppositories in pregnancy with an anencephalic fetus.

Three patients with anencephalic fetuses were delivered vaginally following use of prostaglandin E2 (PGE2) vaginal suppositories with minimal side effects and minimal delay until delivery, even though the cervix was unfavorable. One patient had laminaria inserted 12 hours prior to a single PGE2 suppository. The fetuses were stillborn, although all had had fetal heart tones when the first suppository was inserted. The observed uterine tachysystole and hypertonus under these circumstances may be advantageous if they prevent the additional emotional stress involved with the birth of a "live" anencephalic infant.

Umbilical artery velocimetry as a predictor of adverse outcome in pregnancies complicated by oligohydramnios.

Oligohydramnios is associated with increased perinatal mortality and morbidity. Traditional methods of in utero fetal evaluation have been unsuccessful in reliably distinguishing oligohydramnios with normal outcome from that associated with increased perinatal morbidity. A prospective study was undertaken to establish the predictive value of Doppler velocimetry in identifying the fetus with oligohydramnios at increased risk of adverse perinatal outcome. Twenty-two gravid women with subjective oligohydramnios on ultrasound had continuous-wave umbilical artery velocimetry. Subjects were divided into two groups based on the results of Doppler analysis. Group 1 (N = 13) had normal umbilical Doppler waveforms. In this group, 12 of 13 patients had normal perinatal outcome, defined by the absence of intrapartum fetal distress or evidence of intrauterine growth retardation. Group 2 consisted of nine subjects with abnormal waveforms. Perinatal morbidity occurred in 100% in this group. We conclude that an abnormal umbilical artery waveform may provide confirmatory evidence of impending fetal compromise when the antenatal sonographic diagnosis of oligohydramnios is made.

Selective termination in multiple pregnancies: ethical considerations.

PIP: For those patients who have multiple pregnancies there are several considerations that must be made. When the pregnancies are the result of induced ovulation there is a significant iatrogenic element. Counselling must be provided for couples throughout the entire process. From the beginning of the inductio n program emphasis on the risks associated with multiple gestations must be clearly explained. Such events increase the risk of fetal anomalies, premature births, and poorer outcomes. The alternatives, including selective reduction must be discussed because of these risks. Also, while the patient may recognize the risks of such therapy, it is critical that they be provided with numerous chances to reassess their decision. Thus, informed consent is much broader than merely signing a form. It must be an on going process in which the patient is given any chance necessary to modify the therapy. Further, selective reduction, if it is chosen as an option, must be performed by caring and competent health professionals who are fully cognizant of the ethical and moral issues that are involved with the procedure. It is essential that physicians recognize the fact that abortion is not always something that women plan deliberately or necessarily regard as morally correct. Often times it is viewed as a necessary intervention resorted to only if the alternatives would be worse than the act itself.^ieng

Phenytoin protects against hypoxia-induced death of cultured hippocampal neurons.

The neuroprotective actions of the anticonvulsant phenytoin (diphenylhydantoin, PHT) were evaluated using 3 week old primary hippocampal cultures derived from 19 day embryonic rat. When added to the culture medium prior to a hypoxic insult, PHT increased neuronal viability two-fold. Doubling extracellular Mg2+ concentration was similarly neuroprotective. In contrast, PHT was unable to protect against hypoxia-induced death in one week old cultures, nor was PHT protective against N-methyl-D-aspartate (NMDA)-induced neurotoxicity in cultures of either age. These findings suggest that non-NMDA receptor mechanisms are important in hypoxia-induced neuronal death, and may have important implications for the treatment of stroke.

Transcallosal, transventricular approach to a basilar apex aneurysm.

A new approach to the basilar apex in a patient with a megadolichobasilar anomaly and an abnormally rostral basilar apex aneurysm is described. The details of the surgical approach and the advantages and limitations of this transcallosal, interseptal approach are described.

Direct repair of an extracranial vertebral artery pseudoaneurysm: case report and review of the literature.

A case of a 47-year-old man with weakness secondary to ossification of the posterior longitudinal ligament is presented. During removal of the ossified ligament, the patient's dominant right vertebral artery was injured. Although the bleeding from this artery was controlled intraoperatively, the patient developed an expanding cervical hematoma on the 3rd postoperative day. An angiogram demonstrated a large pseudoaneurysm of the right vertebral artery. The patient was taken back to the operating room where the cervical hematoma was removed, and direct repair of the pseudoaneurysm of the vertebral artery was performed. The previously reported cases of pseudoaneurysms of the extracranial vertebral artery are reviewed. We advocate the use of direct vascular repair as the treatment of choice in these lesions.

Pregnancy-related rupture of arterial aneurysms.

Over 50 per cent of ruptured arterial aneurysms in women under the age of 40 are pregnancy-related. The hemodynamic and endocrine changes of pregnancy appear to be the cause of arterial alterations which may lead to new aneurysm formation and/or weakening of preexisting aneurysms. The most commonly reported arteries to have aneurysms rupture during pregnancy are the aorta, cerebral arteries, splenic artery, renal artery, coronary artery, and ovarian artery. In many instances, the rupture of an arterial aneurysm will initially simulate other less serious disease processes, thus delaying the correct diagnosis until a catastrophic event occurs. Early diagnosis and treatment of a ruptured arterial aneurysm are imperative in order to give optimal chances of survival to the mother and fetus.