The Montreal split ring applicator: Towards highly adaptive gynecological brachytherapy using 3D-printed biocompatible patient-specific interstitial caps.

Purpose: The addition of interstitial (IS) needles to intra-cavitary (IC) brachytherapy applicators is associated with improved outcomes in locally advanced cervical cancers involving parametrial tumor extensions. The purpose of this work was to validate a clinical workflow involving 3D-printed caps for a commercial IC split ring applicator that enable using IS needle trajectories tailored to each treatment. Material and methods: A dedicated software module was developed in this work allowing users to design patient-specific IS caps without knowledge of computer-aided design (CAD) software. This software module was integrated to 3D Brachy, a commercial software developed by Adaptiiv Medical Technologies Inc. For validation of the workflow, CAD models of ground truth caps with five IS needle trajectories were designed with Fusion 360™, 3D-printed, assembled with a split ring applicator, and CT-scanned with radio-opaque markers. 3D Brachy was then applied to generate a replica based on trajectories reconstructed from the radio-opaque markers. A comparison between ground truth and replicated IS needle trajectories was done using intersection points with planes at the level of the cervix (z = 0 cm) and a representative needle depth (z = 3 cm). Results: Prototypes of interstitial caps 3D-printed in both BioMed Amber and BioMed Clear SLA resins were tested to be functional both pre- and post-sterilization for IS needles with obliquity angles ≤ 45°. Distance-to-agreement at z = 0 cm and 3 cm as well as deviations in pitch and yaw angles of the five IS needle trajectories were found to have mean values of 3.3 ±2.1 mm, 7.3 ±2.0 mm, 2.9° ±2.3°, and 7.0° ±7.0°, respectively. Conclusions: The clinical workflow for image-guided adaptive cervical cancer brachytherapy using the Montreal split ring applicator was validated.

Use of HFPV for adults with ARDS: the protocolized use of high-frequency percussive ventilation for adults with acute respiratory failure treated with extracorporeal membrane oxygenation.

Historically, patients on extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome have received ventilatory "lung rest" with conventional or high-frequency oscillating ventilators. We present a series of adults treated with high-frequency percussive ventilation (HFPV) to enhance recovery and recruitment during ECMO. Adult respiratory patients, treated between January 2009 and December 2012 were cared for with a combination of standard ECMO practices and a protocol of recruitment strategies, including HFPV. Data are reported as mean ± standard error of the mean, percentage, or median. Comparisons are made by χ for categorical variables and by t-test and Mann-Whitney test for continuous variables. Significance is noted at the 95% confidence level (p < 0.05). There were 39 HFPV patients. They were 39.9 ± 2.2 years of age and had 3.0 ± 0.37 days of mechanical ventilation before the initiation of ECMO. Their pre-ECMO PaO2 to FiO2 ratio (PF ratio) was 52.3 ± 3.0 and their pCO2 was 50.22 ± 2.4. HFPV patients required a mean of 143.1 ± 17.6 hours and a median of 106 hours (range 45.75-350.25) of ECMO support and had a 62% survival to discharge. The post-ECMO PF ratio in the HFPV cohort was 301.8 ± 16.7. A protocolized practice of active recruitment that includes HFPV is associated with reduced duration of ECMO support in adults with respiratory failure.

The effect of voluntary pharyngeal swallowing maneuvers on esophageal swallowing physiology.

The purpose of our study was to evaluate whether swallowing maneuvers designed to impact pharyngeal physiology would also impact esophageal physiology. Healthy volunteers underwent high-resolution manometry while performing three randomized swallowing maneuvers with and without a 5-ml bolus: normal swallowing, Mendelsohn maneuver, and effortful swallowing. We examined esophageal parameters of peristaltic swallows, hypotensive or failed swallows ("nonperistaltic swallows"), distal contractile integral (DCI), contractile front velocity (CFV), intrabolus pressure, and transition zone (TZ) defect. Four females and six males (median age 39 years; range 25-53) were included in the study. The overall number of nonperistaltic swallows was 21/40 (53 %) during normal swallowing, 27/40 (66 %) during the Mendelsohn maneuver, and 13/40 (33 %) during effortful swallowing. There were significantly more overall nonperistaltic swallows with the Mendelsohn maneuver compared with effortful swallowing (p = 0.003). While swallowing a 5-ml bolus, there were more nonperistaltic swallows during the Mendelsohn maneuver (12/20, 60 %) compared to that during normal swallowing (6/20, 30 %) (p = 0.05) and more peristaltic swallows during effortful swallowing as compared to Mendelsohn maneuver (p = 0.003). Intrabolus esophageal pressure was greater during the Mendelsohn maneuver swallows in the bolus-swallowing condition as compared to normal swallowing (p = 0.02). There was no statistical difference in DCI, CFV, or TZ defect between swallowing conditions. The Mendelsohn maneuver may result in decreased esophageal peristalsis while effortful swallowing may improve esophageal peristalsis. Because it is important to understand the implications for the entire swallowing mechanism when considering retraining techniques for our patients, further investigation is warranted.

Pandemic flu and the sudden demand for ECMO resources: a mature trauma program can provide surge capacity in acute critical care crises.

BACKGROUND: Patients with severe H1N1 pneumonia created a sudden demand for extracorporeal membrane oxygenation (ECMO) capacity. In a single referral center, the established procedures, protocols, and staff of the Level I trauma service were adapted to help manage this nontrauma critical care crisis. METHODS: When airway pressure release ventilation and high-frequency oscillator ventilation failed, we used standard ECMO circuits and the VDR-4 critical care ventilator. We cannulated patients percutaneously in the intensive care unit and transported them on ECMO. Trauma service resources included a mobile surgical transport team, direct to OR resuscitations, massive transfusion protocols, trauma performance improvement processes, trauma resuscitation nurses, in-house attending doctors, and experienced staff familiar with protocol-driven care. RESULTS: During an 84-day period, 15 patients with severe H1N1 pneumonia were treated with ECMO. All patients were referred; 10 were transported on ECMO. Patients were aged 34.4 ± 4.1 years (6-58 years); 47% were male, and they had been ventilated 3.5 ± 0.8 days. Pre-ECMO PaO2/FIO2 ratios were 62.3 ± 6.1; ECMO duration was 9.4 ± 1.3 days for survivors; and post-ECMO PaO2/FIO2 ratio was 295.0 ± 35.1. Recovery occurred in 67% and 60% survived to discharge. No patient died of lung failure. Surviving patients were discharged at their neurologic baseline. CONCLUSION: H1N1 created a severe public health challenge for referral centers with ECMO capability. The resources of our trauma service were adapted to this nontrauma critical care crisis without disruption of other hospital services. These H1N1 patients treated with ECMO had a 67% recovery rate and a 60% survival rate. All survivors were discharged to home. LEVEL OF EVIDENCE: Therapeutic/epidemiologic study, level V.

Adult refractory hypoxemic acute respiratory distress syndrome treated with extracorporeal membrane oxygenation: the role of a regional referral center.

BACKGROUND: The investigators present a series of adults with severe acute respiratory distress syndrome (ARDS) who were treated with extracorporeal membrane oxygenation (ECMO) at a regional referral center. METHODS: Patients with refractory hypoxic ARDS received ECMO until they recovered lung function or demonstrated futility. ECMO was initiated at the referring facility if necessary, and aggressive critical care was maintained throughout. RESULTS: ARDS due to multiple etiologies was managed with ECMO in 36 adults. The pre-ECMO ratio of partial pressure of oxygen to fraction of inspired oxygen was 48.3 ± 2.2. Regional facilities referred 89% of these patients, and 69% required ECMO for transport. The mean duration of ECMO was 7.1 ± .9 days for survivors, and the mean post-ECMO ratio of partial pressure of oxygen to fraction of inspired oxygen was 281.2 ± 11. ECMO was successfully weaned in 67% of patients, and 60% survived to discharge. CONCLUSIONS: ECMO provides support that prevents ventilator-induced lung injury while the lungs heal. The investigators present a series of 36 adults with refractory hypoxemic ARDS (ratio of partial pressure of oxygen to fraction of inspired oxygen <50) from 17 different facilities who, treated with ECMO at a single referral center, had a 60% survival rate.

The natural history of stab wounds of the diaphragm: implications for a new management scheme for patients with penetrating thoracoabdominal trauma.

For most patients with abdominal stab wounds expectant management has become the norm. Thoracoabdominal stab wounds, however, raise concern about possible diaphragmatic injury, and diagnostic minilaparotomy, laparoscopy, or thoracoscopy have been advocated in such patients. The present study examined the natural course of an untreated diaphragmatic stab wound. With Institutional Review Board approval eight 25- to 30-kg anesthetized pigs underwent a small upper-midline laparotomy. A 1.5- to 2-cm incision was made in each diaphragm-in the muscular portion on one side and in the tendinous area on the other side. Thereafter a 12-F catheter was placed into each thoracic cavity and attached to suction to resolve pneumothoraces. The laparotomy incision was closed, and the thoracic catheters were removed. Six weeks later the animals were reanesthetized, and the diaphragmatic stab wounds were examined at laparotomy. Fifteen of the 16 (93.8 per cent) diaphragmatic wounds were completely healed. All eight stab wounds in the muscular portion of either diaphragm healed spontaneously. In one animal there was a persistent defect in the tendinous portion of the left diaphragm at the site of the stab wound. The tip of the left lateral segment of the liver and the superior pole of the spleen were found in the defect at laparotomy. We conclude that the vast majority of stab wounds to either the muscular or tendinous diaphragm heal spontaneously. Thus invasive procedures to assess the status of the diaphragm in all patients with thoracoabdominal stab wounds is unwarranted.

Characteristics of twice-transferred, rural trauma patients.

OBJECTIVE: Undertriage has seldom been evaluated in the trauma population. In rural states patients often go to the nearest hospital first, where they are evaluated and, if necessary, transferred to another hospital. If they are undertriaged when transferred to the second hospital, they will require a second transfer to a higher-level trauma center. METHODS: The authors retrospectively reviewed the charts of all trauma patients at a level I trauma center from 1996 to 1999 who were seen at two acute care facilities because of a single acute traumatic event before reaching the trauma center. Ninety-three patient charts were analyzed. RESULTS: Forty-six percent of the patients were victims of a motor vehicle crash. Patients were mostly transferred to the level I trauma center for non-spine orthopedic injuries (28%), followed by spine injuries (14%) and head injuries (13%). These patients were stable, as manifested by an average trauma score of 11.6. However, there was a significant positive interaction between injury severity score and time to definitive care. CONCLUSIONS: The authors infer from the data analysis that more serious or complex injuries took longer to evaluate. Since these patients were physiologically stable, reducing the number of twice-transferred trauma patients will involve refining transfer protocols concerning the need for specialty care.