Incision Planning in Thyroid Compartment Surgery: Getting it Perfect

OBJECTIVE

This study evaluated changes in thyroid compartment incision site locations with patient positioning to define a reliable method for placing the scar in the optimal vertical location.

METHODS

The optimal incision location was marked with the patient sitting upright before surgery. The distance from the sternal notch to this mark was measured with the patient in the upright, supine, and final surgical positions.

RESULTS

Complete data were available for 104 procedures. The mean distances from the sternal notch to the incision site were 4.8, 21.5, and 31.9 mm in the sitting, supine, and surgical positions, respectively. Each of these distances were significantly different from one another (P<.0001) and were independent of patient age, sex, body mass index (BMI), or height.

CONCLUSIONS

Cutaneous cervical landmarks migrate significantly during patient positioning. Marking the thyroid compartment incision site while the patient is in an upright position results in a more predictable final scar location.

Thyroid ala perichondrial flaps for subglottic reconstruction

OBJECTIVES/HYPOTHESIS

Techniques available for reconstruction of the cricotracheal region in adults are currently suboptimal. We sought to 1) understand the anatomic basis for the thyroid ala perichondrial flap, 2) describe the technique of harvesting and intraluminal placement, and 3) learn the limitations of defects for which it can be used.

STUDY DESIGN

Cadaveric anatomical study.

METHODS

In fresh cadaveric specimens, the perichondrium of the outer layer of the thyroid cartilage was elevated by tracing the superior, medial, and lateral borders of each thyroid cartilage ala. The inferiorly based flap was then placed into the airway through the cricothyroid membrane. The extent of coverage was measured.

RESULTS

A total of 10 flaps were performed (6 male and 4 female). The average length of thyroid perichondrial flaps obtained was 1.67 cm. All flaps were able to completely cover the cricoid cartilage and extended to but did not cover the first tracheal ring. Once placed intraluminally, the flaps extended 2.4 cm below the vocal cords. Using both flaps enabled coverage of the entire anterior 180 degrees of the airway lumen in all specimens. There were no significant differences in male/female or right-sided/left-sided flaps.

CONCLUSIONS

The thyroid ala perichondrial flap is technically feasible and can provide coverage of anterior airway defects up to approximately 2.4 cm below the true vocal cords. This flap could enable transfer of vascularized tissue to aid in cricotracheal reconstruction.

Defining the biomechanical properties of the rabbit trachea

OBJECTIVES/HYPOTHESIS

Surgical advancements rely heavily on validated animal models. The New Zealand White (NZW) rabbit is a widely used model for airway research, including regenerative medicine applications. Currently, the biomechanical properties of the normal rabbit trachea are not known. Our objective was to define these properties to assist in the standardization and understanding of future airway research using this model.

STUDY DESIGN

Laboratory-based study.

METHODS

Fresh tracheas from four adult NZW rabbits were dissected into 20 segments. To examine the biomechanical properties, segments were subjected to uniaxial tension (n = 9) and compression (n = 11) testing. Yield and maximum load (tension) and force at 50% displacement (compression) were recorded, and differences between segments were examined using analysis of covariance.

RESULTS

Normative data for native rabbit trachea show mean maximum load = 6.44 newtons (N), yield load = 5.93 N, and compressive strength = 2.10 N. In addition to establishing the baseline measurements, statistically significant differences in tensile measures based on location along the trachea and diameter were identified. Proximal segments had significantly higher maximum load (P = .0029) and yield load (P = .0062) than distal segments. Association between diameter and both maximum load (P = .0139) and yield load (P = .0082) was observed.

CONCLUSIONS

The adult NZW rabbit trachea is intrinsically less able to withstand tensile and compressive forces, compared to other airway models such as sheep or cadaveric human. Establishment of normative values will enable future research into changes in tracheal biomechanical properties during regenerative medicine manipulation and processing.

Epidemiologic factors and surgical outcomes in patients with nasal polyposis and asthma

BACKGROUND/AIM

To evaluate the role of epidemiologic factors in surgical outcomes for patients with nasal polyposis (NP) and asthma.

METHODS

Data was prospectively collected on patients who underwent endoscopic sinus surgery over a 7-year period. Among patients with chronic rhinosinusitis (CRS) with NP and asthma, surgical outcomes were analyzed according to gender and race.

RESULTS

Patients with NP and asthma had significantly higher Lund-Kennedy and SNOT-20 scores--pre- and postoperatively--compared to CRS patients without NP or asthma. Both Caucasians and African-Americans in the CRS with NP/asthma group showed a statistically significant improvement at 6 months. Caucasians continued to have a significant improvement at 12 months, whereas African-Americans did not. There were no differences according to gender.

CONCLUSION

In our patient population, African-Americans with NP and asthma had poorer outcomes following functional endoscopic sinus surgery.

Transnasal esophagoscopy

Since the mid 1900s, esophagoscopy has been performed under sedation or general anesthesia. With transnasal esophagoscopy (TNE), there has been a return to awake, in-office esophagoscopy. Technologic advances have allowed the advent of a ultrathin, flexible esophagoscope that is introduced transnasally, allowing esophagoscopy to be performed in unsedated patients. TNE correlates with conventional esophagoscopy (sedated, flexible esophagoscopy) in diagnostic capacity. Over time, as the benefits of TNE have become elucidated, the procedure has gained wider acceptance and continues to have its role in patient care defined.

New technology applications: Knotless barbed suture for tracheal resection anastomosis

OBJECTIVES/HYPOTHESIS

Tracheal resection anastomoses are often under tension and can be technically challenging. New suture materials such as V-loc (barbed, knotless wound closure device) may offer advantages over conventional methods. The objective of this study is to determine if a running V-loc suture is of comparable tensile strength to conventional closure.

STUDY DESIGN

Laboratory based study of human cadaveric tissue.

METHODS

Fresh human cadaveric tracheas were dissected and incised into segments. Anastomosis of adjacent segments was then performed with either submucosal interrupted 3-0 Vicryl, or a running submucosal 3-0 V-loc suture. Anastomosed specimens were stretched to failure on an Instron force tension machine. Surgeon satisfaction was recorded by visual analog scale (VAS).

RESULTS

The tensile strength of 12 tracheal anastomoses was tested. Video documentation of V-loc suture technique and anastomosis failure was recorded. In both Vicryl (80%) and V-loc (100%) anastomoses, failure occurred at the membranous intercartilaginous region. In 20% of the Vicryl anastomoses, the suture was noted to break prior to tissue failure. Anastomoses with V-loc suture had equivalent failure force (mean, 59 N) compared to interrupted Vicryl (51 N), with P = .57. On VAS, surgeons were more satisfied with V-loc suture closure compared to interrupted Vicryl closure (paired t test, P = .003).

CONCLUSIONS

Tracheal anastomosis with running v-loc suture is a feasible alternative to conventional closure with interrupted Vicryl suture. V-loc suture provided a surgical advantage by improved ease of use.

Pediatric injuries from cardiopulmonary resuscitation

STUDY OBJECTIVE

To assess the type, rate, and severity of unanticipated complications of CPR (external cardiac compressions and ventilation) in a pediatric population.

METHODS

A retrospective review was undertaken of the records from all deceased children ( < 12 years old) who had been given CPR during an 8-year period (1988 through 1995). Patients with historical or physical evidence of preceding trauma were excluded. Clinical and autopsy records were abstracted for patient demographics, clinical findings, duration of CPR, persons administering CPR, and medical examiner summaries.

RESULTS

Two hundred eleven children (mean age, 19.0 months) met the inclusion criteria and were entered into the study. The most common cause of cardiac arrest was sudden infant death syndrome (56%), followed by drowning (8%), congenital heart disease (7%), and pneumonia (4%). Mean duration of CPR was 45 minutes (range, 3 to 180 minutes). Fifteen children (7%) had at least one injury as a result of CPR; 7 (3%) had injuries that were considered medically significant. These included retroperitoneal hemorrhage (n = 2), pneumothorax (n = 1), pulmonary hemorrhage (n = 1), epicardial hematoma (n = 1), and gastric perforation (n = 1); in spite of prolonged resuscitation performed with variable degrees of skill, only one patient was noted to have rib fractures.

CONCLUSION

Significant iatrogenic injuries are rare in children who receive CPR; they occur in approximately 3% of cases. Recognizing the possibility of a complication may help in the management of children who survive cardiac arrest. Regardless of resuscitation history, abuse should be considered whenever traumatic injuries are encountered.

A radiographic method for measuring steady-state functional residual capacity in the supine patient. A method suitable for sleep studies

We have devised a method to measure functional residual capacity (FRC) in the recumbent, spontaneously breathing patient. Simultaneous anteroposterior and lateral chest radiographs were exposed at the end of an exhalation, as determined by tracings of flow sensed by a nasal thermistor. The volume of the lungs was then planimetrically measured. Functional residual capacity was sequentially measured in 20 supine subjects, both by a helium dilution technique and by the radiographic technique. Planimetric measurement of FRC correlated well with the helium dilution technique, with a range of FRC measurements from 1.53 to 6.41 L (r = 0.94). This method of measuring lung volume should be useful in evaluating changes in FRC associated with different sleep stages and in explaining the mechanisms causing nocturnal oxygen desaturation in patients with chronic obstructive lung disease.