Yashar Eshraghi

An evaluation of a zero-heat-flux cutaneous thermometer in cardiac surgical patients.

BACKGROUND:Although core temperature can be measured invasively, there are currently no widely available, reliable, noninvasive thermometers for its measurement. We thus compared a prototype zero-heat-flux thermometer with simultaneous measurements from a pulmonary artery catheter. Specifically, we tested the hypothesis that zero-heat-flux temperatures are sufficiently accurate for routine clinical use. METHODS:Core temperature was measured from the thermistor of a standard pulmonary artery catheter and with a prototype zero-heat-flux deep-tissue thermometer in 105 patients having nonemergent cardiac surgery. Zero-heat-flux probes were positioned on the lateral forehead and lateral neck. Skin surface temperature probes were attached to the forehead just adjacent to the zero-heat-flux probe. Temperatures were recorded at 1-minute intervals, excluding the period of cardiopulmonary bypass, and for the first 4 postoperative hours. Zero-heat-flux and pulmonary artery temperatures were compared with bias analysis; differences exceeding 0.5°C were considered to be potentially clinically important. RESULTS:The mean duration in the operating room was 279 ± 75 minutes, and the mean cross-clamp time was 118 ± 50 minutes. All subjects were monitored for an additional 4 hours in the intensive care unit. The average overall difference between forehead zero-heat-flux and pulmonary artery temperatures (i.e., forehead minus pulmonary artery) was −0.23°C (95% limits of agreement of ±0.82); 78% of the differences were ⩽0.5°C. The average intraoperative temperature difference was −0.08°C (95% limits of agreement of ±0.88); 84% of the differences were ⩽0.5°C. The average postoperative difference was −0.32°C (95% limits of agreement of ±0.75); 84% of the differences were ⩽0.5°C. Bias and precision values for neck site were similar to the forehead values. Uncorrected forehead skin temperature showed an increasing negative bias as core temperature decreased. CONCLUSIONS:Core temperature can be noninvasively measured using the zero-heat-flux method. Bias was small, but precision was slightly worse than our designated 0.5°C limits compared with measurements from a pulmonary artery catheter.

The Frequency of Surgical Maneuvers during Open Rhinoplasty

Background: The improved exposure afforded by the external rhinoplasty approach has allowed for more precise surgical maneuvers and makes more consistent results possible. This study examines the frequency and array of surgical maneuvers during primary aesthetic rhinoplasty in a single surgeons practice. Methods: A retrospective review of 100 consecutive primary external cosmetic rhinoplasty patients with a minimum follow-up of approximately 1 year was conducted. Surgical maneuvers were reviewed and tabulated. Special attention was devoted to the number of cartilage grafts and suturing techniques used. Operative times and incidence of revision surgery were investigated. Results: The mean duration of surgery was 1 hour 50 minutes. The majority of rhinoplasties involved concomitant septal surgery for deviation and airway occlusion or cartilage harvesting. Osteotomies were performed on over 95 percent of patients. The dorsal hump was removed on 84 percent of the patients. The most common grafts used included alar rim grafts in 88 percent, subdomal grafts in 77 percent, and spreader grafts in 74 percent. Sutures used to contour the cartilage included transdomal sutures in 62 percent, followed by footplate approximation sutures in 32 percent. Seventy-seven patients had interdomal sutures placed as a component of subdomal grafting. Conclusions: The senior surgeon has found that common incorporation of certain maneuvers offers more consistent, aesthetically pleasing, and superior functional outcomes. Careful review of this article may guide the reader to consider the more frequent use of some maneuvers or reduction of other maneuvers to reflect that of a streamlined and higher-volume rhinoplasty practice.

Von Willebrand Disease: Screening, Diagnosis, and Management

Von Willebrand disease (vWD), a hemorrhagic disorder mimicking a defect in platelet function, is the most commonly inherited coagulopathy, resulting in a deficiency that may prolong bleeding time and increase risk for major bleeding complications during surgery. Von Willebrand factor (vWF) serves a dual role in hemostasis: mediating the initial platelet adhesion to damaged endothelium at the site of vessel injury and stabilizing coagulation factor VIII, an important cofactor in the generation of a fibrin clot. Although quantitative or qualitative defects in vWF protein can manifest as a mild to severe bleeding disorder, many cases of vWD remain subclinical, barring major invasive stimuli, and undetected by either patient or clinician. Nevertheless, the frequency of this coagulation disorder would almost ensure that every plastic surgeon will encounter affected patients, making a thorough understanding of vWD and its management absolutely necessary. Surprisingly, there is little information concerning vWD in the plastic surgery literature. Our goal is to familiarize the plastic surgeon with vWD, including physiology, diagnostic criteria, classification, and molecular basis for multiple vWD variants, and diagnosis and management.

Nonviral transfection of mouse calvarial organ in vitro using accell-modified siRNA

Background: Understanding the biology of cranial suture fusion and the precise role of involved molecules implicated in the process will help to identify key factors involved in regulation of suture fusion. Modulation of these key factors may serve as a tissue-engineering technique to replace the traditional surgical procedures for the correction of premature suture fusion. Modulation of gene expression by RNA interference is a widely used technique with high potential. Because there is no available report of calvarial organ transfection in vitro, the authors studied the development of a successful nonviral delivery technique of small inhibitory RNA (siRNA) to an in vitro calvarial organ culture system. Methods: In this study, 19-day-old male CD1 mice were euthanized and parallel craniotomies made through the parietal and frontal calvaria, 2 mm to either side of the sagittal suture, with care taken to preserve the underlying dura mater. Organs grown in vitro in a defined medium were transfected with transforming growth factor-&bgr;1–specific Accell-modified siRNA followed by RNA isolation and quantitative polymerase chain reaction analysis. Results: Transfection of a calvarial organ with transforming growth factor-&bgr;1–specific Accell-modified siRNA effectively knocks down the mRNA level. Conclusions: Observations from this study indicate that in an in vitro calvarial organ culture system, a specific, efficient, and durable RNA interference activity can be achieved when Accell-modified siRNA is used. In addition to bypassing the need for toxic lipid carriers, the modifications introduced in Accell-modified siRNAs make it more stable and less off-target. This technique can potentially be used for in vivo studies once the initial effect of gene-specific siRNA on in vitro suture fusion has been determined.

Chronic Intermittent Hypoxia Is Independently Associated with Reduced Postoperative Opioid Consumption in Bariatric Patients Suffering from Sleep-Disordered Breathing

Background Evidence suggests that recurrent nocturnal hypoxemia may affect pain response and/or the sensitivity to opioid analgesia. We tested the hypothesis that nocturnal hypoxemia, quantified by sleep time spent at an arterial saturation (SaO2) < 90% and minimum nocturnal SaO2 on polysomnography, are associated with decreased pain and reduced opioid consumption during the initial 72 postoperative hours in patients having laparoscopic bariatric surgery. Methods With Institutional Review Board approval, we examined the records of all patients who underwent laparoscopic bariatric surgery between 2004 and 2010 and had an available nocturnal polysomnography study. We assessed the relationships between the time-weighted average of pain score and total opioid consumption during the initial 72 postoperative hours, and: (a) the percentage of total sleep time spent at SaO2 < 90%, (b) the minimum nocturnal SaO2, and (c) the number of apnea/hypopnea episodes per hour of sleep. We used multivariable regression models to adjust for both clinical and sleep-related confounders. Results Two hundred eighteen patients were included in the analysis. Percentage of total sleep time spent at SaO2 < 90% was inversely associated with total postoperative opioid consumption; a 5-%- absolute increase in the former would relatively decrease median opioid consumption by 16% (98.75% CI: 2% to 28%, P = 0.006). However, the percentage of total sleep time spent at SaO2 < 90% was not associated with pain. The minimum nocturnal SaO2 was associated neither with total postoperative opioid consumption nor with pain. In addition, neither pain nor total opioid consumption was significantly associated with the number of apnea/hypopnea episodes per hour of sleep. Conclusions Preoperative nocturnal intermittent hypoxia may enhance sensitivity to opioids.

Tranquilli-Leali or Atasoy flap: an anatomical cadaveric study

BACKGROUND The Tranquilli-Leali and Atasoy volar V-Y advancement flaps are considered workhorse flaps in the reconstruction of fingertip amputations. However, their description in the literature in terms of surgical dissection and blood supply is often indistinct. This study describes the differences between the two flaps and highlights their unique blood supply based on a thorough cadaveric study and review of the literature. METHODS Using 16 fresh cadaveric fingers, eight Tranquilli-Leali and eight Atasoy volar V-Y advancement flaps were dissected, mapping the arterial blood supply using an injectable blue resin. In addition, a thorough literature search on the subject was done. RESULTS In all eight fingertips dissected as decribed by Tranquilli-Leali, the flap was supplied by the anastomotic connections between the terminal branches of the palmar digital arteries and dorsal nail-bed arcades via the fibro-osseous hiatus. In contrast, in all eight fingertips which were dissected as described by Atasoy, the flaps were perfused through the terminal branches of the palmar digital arteries. CONCLUSIONS The Tranquilli-Leali and Atasoy volar V-Y advancement flaps, used to reconstruct fingertip amputations, are distinct from one another in several ways. The most obvious difference is their technique of flap dissection, which, in turn, dictates a unique blood supply. Through careful dissection and a review of the literature, this anatomical study has brought to light the specific vascular supply to each flap that was evaluated.

Double-opposing Z-palatoplasty for secondary surgical management of velopharyngeal incompetence in the absence of a primary furlow palatoplasty

Objective The present study was performed to identify factors that lead to a favorable outcome of postpalatoplasty velopharyngeal incompetence using the double-opposing Z-palatoplasty. Design A retrospective analysis was performed on 23 consecutive nonsyndromic patients who underwent secondary surgical management of velopharyngeal incompetence using a double-opposing Z-palatoplasty technique following primary, non-Furlow palatoplasty for overt cleft palate. Main Outcome Measures All subjects were evaluated preoperatively using a perceptual speech assessment scale, nasendoscopy, and videofluoroscopy. Inclusion criteria consisted of a velopharyngeal gap of 9 mm or less on phonation. Patients were followed with perceptual speech assessment for at least 1 year following secondary surgery. Results The perceptual speech assessment score for all patients decreased from 6.48 ± 2.26 (mean ± standard deviation; range, 3 to 11) to 1.90 ± 1.51 (range, 0 to 6) at 6 months or more postoperatively (P < .0001). Of the 21 patients with follow-up data 1 year or more post–op, 16 (76%) achieved velopharyngeal competence and five (24%) had borderline competence. Preoperative assessment factors associated with compromised outcome included a large velopharyngeal gap of 7 to 9 mm, poor lateral wall motion of 40% or less, and an elevated perceptual speech assessment score. Conclusion Double-opposing Z-palatoplasty is a surgical technique that can be used successfully to correct velopharyngeal incompetence in selected secondary palatoplasty patients. This technique permits correction of velopharyngeal incompetence and restoration of the velopharyngeal mechanism irrespective of prior intravelar veloplasty and without accompanying loss in the nasal airway. Preoperative assessment can better identify those patients who are less likely to achieve velopharyngeal competence following double-opposing Z-palatoplasty alone.

Effect of different suture materials on cartilage reshaping.

BACKGROUND Suturing techniques are one of the most commonly used means to reshape the nasal cartilage; however, no data exist regarding the optimal suture material and its long-term effect. OBJECTIVES The aim of the present study was to determine whether any absorbable materials will provide the same long-lasting effect on cartilage reshaping as permanent materials. METHODS Thirty-six New Zealand white rabbits were divided into three groups of 12. A 3 mm x 4 mm cartilaginous fold was created on a 5 mm x 10 mm in situ strip of cartilage on the posteromedial surface of each ear with different suture materials to simulate transdomal sutures. Nylon was used as a control suture material on the right ear of every rabbit, while plain catgut, monocryl, or polydioxanone (PDS) was used on the left ear, depending on the study group. At the end of 3 months, the folds were harvested and their dimensions and histology were compared. RESULTS The cartilaginous folds were graded on a scale of 1 to 4 based on the final fold height measurement. The mean grades were 3.51 for nylon, 3.50 for PDS, 2.08 for monocryl, and 1.83 for plain catgut. Nylon provided a significantly better fold grade compared to monocryl and plain catgut (P < .05 for both groups), whereas there was no difference between the fold created with nylon and PDS (P > .05). Among the pathologic factors examined, only the amount of adipose tissue between the fold correlates with a higher fold grade (P < .05). CONCLUSIONS Cartilaginous folds created using PDS are comparable to those created using nylon and are significantly better than monocryl and plain catgut materials. On this animal model, it appears that permanent suture material is not required to maintain a long lasting cartilaginous fold as long as the suture material holds the fold in shape for a certain period of time.

Review of pediatric migraine headaches refractory to medical management

Objective: The surgical treatment of migraine headache is a recent innovation that has broadened the potential patient population who may benefit from craniofacial surgical techniques to millions of affected adults. However, the population at risk in the pediatric age group has not been clearly established. The present retrospective review was performed to provide demographic information of the adolescent migraine in a major childrens hospital. This information is essential before considering surgical treatment of migraine in this age group. Methods: Five hundred eighty-eight charts of patients aged 12 to 18 years who presented to the pediatric neurology clinic with headache in 2006 were retrospectively reviewed to evaluate for the diagnosis of migraine. Data collected included headache location, frequency, duration, intensity, associated migraine symptoms, and headache precipitants, as well as the response to medical treatment. Results: Two hundred ten (36%) of 588 patients had the diagnosis of migraine headache, and 51 patients (24%) were considered refractory to the medical treatment offered. In 101 of the 210 migraine patients, anatomic location of the headaches could be identified. Thirty-nine children (19%) with refractory migraines (mean age, 14.7 years [SD, 0.3 years]) reported definitive migraine triggers. Conclusions: A significant percentage of pediatric patients with migraine headache remain refractory to medical treatment. At present, there is no good treatment regimen for migraine headaches in the pediatric population. We believe that surgical treatment of migraine headaches may be a realistic option for these patients.

Relationship between Chronic Intermittent Hypoxia and Intraoperative Mean Arterial Pressure in Obstructive Sleep Apnea Patients Having Laparoscopic Bariatric Surgery

Background:Recurrent nocturnal hypoxemia in obstructive sleep apnea enhances sympathetic function, decreases baroreceptor sensitivity, and weakens peripheral vascular responses to adrenergic signals. The authors hypothesized that the percentage of total sleep time spent at oxyhemoglobin saturation (SaO2) less than 90% and minimum nocturnal SaO2 on preoperative polysomnography are associated with decreased intraoperative mean arterial pressure. Methods:The authors examined the records of all patients who had laparoscopic bariatric surgery at Cleveland Clinic between 2005 and 2009 and an available polysomnography study. The authors assessed the relationships between the percentage of total sleep time spent at SaO2 less than 90% and minimum nocturnal SaO2, and the time-weighted average of mean arterial pressure. The authors used multivariable regression models to adjust for prespecified clinical confounders. Results:Two hundred eighty-one patients were included in the analysis. The average change in the time-weighted average of mean arterial pressure was −0.02 (97.5% CI, −0.08, 0.04) mmHg for each 1% absolute increase in the percentage of sleep time spent at SaO2 less than 90% (P = 0.50). The average change was −0.13 (97.5% CI, −0.27, 0.01) mmHg, for each 1% absolute decrease in the minimum SaO2 (P = 0.04 > significance criterion of 0.025, Bonferroni correction). An unplanned analysis estimated 1% absolute decrease in minimum SaO2 was associated with −0.22 (98.75% CI, −0.39, −0.04) mmHg, change in mean arterial pressure (P = 0.002) in the time period between endotracheal intubation and trocar insertion. Conclusion:Recurrent nocturnal hypoxemia in obstructive sleep apnea is not a risk marker for intraoperative hypotension.