A safe procedure? The unusual case of a fatal airway obstruction by silicone during the production process of a tracheostomal epithesis in a 13-year-old boy.

A tracheostomal epithesis is a plastic prosthesis that serves for sealing a tracheostoma and ensuring the position of the tracheostomy tube. The production of a tracheostomal epithesis requires an impression of the tracheostoma. To this end, silicone impression material is applied by an anaplastologist in and around the tracheostomal region, including the trachea. The blocked cuff of the tracheostomy tube serves to prevent aspiration of the material. We report on a 13-year-old boy who died during this procedure because the lower airways were obstructed with cured silicone. Forensic autopsy confirmed asphyctic suffocation as cause of death. Forensic physical investigation of the tracheostomy tube and its cuff revealed no structural or functional defects. Yet, the investigation results prove that the viscous silicone must have passed the cuff. To conclude, this case report demonstrates that the production of an impression of a tracheostoma is a procedure with a potentially lethal outcome. Hence, professional guidelines, including clear safety precautions, are urgently needed.

Wound formation, wound size, and progression of wound healing after intratumoral treatment of mast cell tumors in dogs with tigilanol tiglate.

BACKGROUND: Tigilanol tiglate (TT) is a novel small molecule for intratumoral treatment of nonmetastatic mast cell tumors (MCTs) in dogs. In a randomized controlled clinical study, 75% of dogs that received a single TT treatment achieved complete resolution of the MCT by 28 days, with no recurrence in 93% of dogs at 84 days. Critical to TT's efficacy was the area of the wound (tissue deficit) after slough of the necrotic tumor relative to pretreatment tumor volume. OBJECTIVES: To analyze data collected during the previous study to (a) describe wounds after slough of treated MCTs and (b) identify determinants of wound area and speed of wound healing. METHODS: Wound presence, condition, and area were determined from clinical records of 117 dogs over 84 days after a single intratumoral TT treatment. RESULTS: Tumor slough occurred 3 to 14 days after treatment, exposing granulation tissue in the wound bed. Wound area after tumor slough in general was related to pretreatment tumor volume, with maximal recorded wound area fully evident in 89% of dogs by day 7. In dogs achieving complete tumor resolution, all wounds were left to heal by secondary intention. Bandaging and other wound management interventions only were required in 5 dogs. Time to healing (ie, full re-epithelialization of treatment site) depended on wound area and location on the body, with most wounds being fully healed between 28 and 42 days after treatment. CONCLUSIONS: Wound area and healing after slough of TT-treated tumors follow a consistent clinical pattern for most dogs.

Randomized controlled clinical study evaluating the efficacy and safety of intratumoral treatment of canine mast cell tumors with tigilanol tiglate (EBC-46).

OBJECTIVE: To evaluate the efficacy and safety of tigilanol tiglate (TT) for local intratumoral treatment of mast cell tumors (MCTs) in dogs. METHODS: A randomized controlled clinical study in 2 phases involving 123 dogs with cytologically diagnosed MCT. Phase 1 compared 81 TT-treated dogs with 42 control dogs; phase 2 allowed TT treatment of control dogs and retreatment of dogs that failed to achieve tumor resolution after TT treatment in phase 1. Tigilanol tiglate (1 mg/mL) was injected intratumorally with dose based on tumor volume. Concomitant medications were used to minimize potential for MCT degranulation. Modified response evaluation criteria in solid tumors were used to evaluate treatment response at 28 and 84 days. Adverse events and quality of life were also assessed. RESULTS: A single TT treatment resulted in 75% complete response (CR) (95% confidence interval [CI] = 61-86) by 28 days, with no recurrence in 93% (95% CI = 82-97) of dogs by 84 days. Eight TT-treated dogs that did not achieve CR in phase 1 achieved CR after retreatment, increasing the overall CR to 88% (95% CI = 77-93). Control dogs had 5% CR (95% CI = 1-17) at 28 days. Wound formation after tumor slough and wound size relative to tumor volume were strongly associated with efficacy. Adverse events typically were low grade, transient, and directly associated with TT's mode of action. CONCLUSIONS: Tigilanol tiglate is efficacious and well tolerated, providing a new option for the local treatment of MCTs in dogs.

Retrograde venous cerebral air embolism from disconnected central venous catheter: an experimental model.

There are few reported cases of death attributed to retrograde cerebral air embolism from central venous catheter. The pathophysiological mechanism and the necessary conditions are not fully understood, also because of missing experimental data. We performed experimental simulation while working on a possible case of retrograde cerebral air embolism. A hermetic system consisting of two containers connected to each other and to an electric pump by means of rubber hoses was built. In this system, a fluid (water and blood) could continuously flow under conditions similar to those of the common jugular vein. The part of the system representing the jugular vein could be freely positioned at angles between 0 and 90°. A central venous catheter was inserted into this part. After disconnection, the behavior of the air bubbles entering the hose through the tip of the catheter was evaluated at different positions. At angles between 0 and 45°, the air bubbles followed the fluid flow. At angles >45°, the air bubbles showed the tendency to flow upstream; this phenomenon was more evident the more vertically the hose was located. We were able to demonstrate that a retrograde air embolism can be caused by a disconnected catheter and is even more likely if the neck is in a vertical position.

July 2003: 62-year-old female with progressive muscular weakness.

The July 2003 Case of the Month (COM). A 62-year-old female patient experienced progressive muscular weakness over the last ten years, involving shoulder and pelvic girdle muscles, paraspinal and facial muscles. A biopsy was taken from the left deltoid muscle where hepatitis vaccination had taken place 4 weeks previously. The specimen revealed macrophagic myofasciitis due to the injection of aluminium-bound vaccines. The finding can be reproduced experimentally by injecting vaccines in rats. The pathomechanism is supposed to involve immune stimulation due to long term persistence of the adjuvant. Macrophagic myofasciitis has been suggested to occasionally cause myopathy but is supposed to be unrelated to the underlying myopathy in our patient.

Single photon emission computed tomography of pulmonary emboli and venous thrombi using anti-D-dimer.

Previous attempts to diagnose thromboemboli using radiolabeled antibodies and nuclear medicine imaging have been disappointing. We present the results of experiments with intravenous technetium-99m-labeled deimmunized antifibrin Fab' fragments to diagnose thromboemboli using single photon emission computed tomography (SPECT), a highly sensitive scintigraphic imaging technique. Pulmonary emboli (PEs) and lower extremity deep vein thrombi (DVTs) were formed in five dogs, then technetium-99m-labeled Fab' ( approximately 400 mg, approximately 260 MBq) were injected via forelimb veins. Thoracic and lower extremity SPECT scans were performed at 2-hour intervals after antibody infusion to visualize the thromboemboli. Four hours after antibody infusion, all PEs and DVTs of mass 0.4 g or greater were clearly visualized on SPECT scans as 'hot spots' within the lungs and legs, respectively. PEs (0.48 +/- 0.09 g) were intensely radiolabeled, yielding clot/blood radioactivity ratios of 22.8 +/- 5.6. DVTs (0.45 +/- 0.31 g) also had high clot/blood ratios (11.7 +/- 2.6). Infusion of these radiolabeled antibody fragments, combined with SPECT, produces clear images of PEs and DVTs within a clinically feasible time frame. The technique reliably identified even peripheral thromboemboli of relatively small size, which are difficult to diagnose with currently available imaging techniques, and may enable imaging of PEs, DVTs, or both in the same patient.