Relapsing Exophiala jeanselmei phaeohyphomycosis in a lung-transplant patient.

Dematiaceous fungi are a cause of a variety of human infections, including phaeohyphomycosis, that may affect patients with solid organ or bone marrow transplants. Exophiala jeanselmei, the most common cause of the pheomycotic cyst/subcutaneous phaeohyphomycosis in the United States, has been shown to cause disease in transplant recipients. We report a lung-transplant patient with relapsing and invasive E. jeanselmei phaeohyphomycosis, who previously had a pheomycotic cyst excised and treated with oral fluconazole. The patient was subsequently treated with re-excision and an 8-month course of oral itraconazole without relapse as to date.

Improved perfusion after subcritical ischemia in muscle flaps treated with vascular endothelial growth factor.

Vascular endothelial growth factor (VEGF), a potent endothelial mitogen, is secreted in ischemic tissue and plays a pivotal role in angiogenesis. We studied whether VEGF administered to a rat muscle flap at the time of ischemia induction would increase microcirculatory flow to the flap. The cremaster muscle flap was isolated on its neurovascular pedicle. Ischemia was induced by clamping the vascular pedicle, and 0.2 ml of either VEGF (0.1 microg) or vehicle (phosphate-buffered saline) was immediately infused into the muscle. After 4 or 6 hours, the clamps were released, and the cremaster was placed in a pocket in the medial thigh for 24 hours. The muscle was then dissected, and microcirculatory measurements were made under intravital microscopy. Six animals were used in each of the four groups. All flaps exposed to 6 hours of ischemia, the duration considered to be critical ischemia, had no significant microcirculatory flow, regardless of treatment with VEGF. In the 4-hour ischemia group, or subcritical ischemia group, red blood cell velocity in arterioles was 14 mm/sec in muscles treated with VEGF and 9 mm/sec in controls (p = 0.02), and capillary flow was 7 per high-power field in muscles treated with VEGF versus 2 per high-power field in controls (p = 0.0005). Thus, VEGF did not alter microcirculatory flow in a muscle flap exposed to critical ischemia, but it did enhance flow to a flap exposed to subcritical ischemia.

Muscle flaps' triphasic microcirculatory response to sympathectomy and denervation.

Whether sympathectomy and somatic denervation in muscle flaps increased microcirculatory flow in the short or long term, thus producing an effect similar to the delay phenomenon, which increases survival in transferred skin flaps, was determined. The rat cremaster muscle flap model was used for in vivo microscopy. In the left cremasters of 30 Sprague-Dawley rats, the genitofemoral nerve was divided and the proximal vessels were stripped of their adventitia. The muscle was not elevated. In each rat, the contralateral cremaster served as the control. The rats were assigned to one of five groups: no delay before observation, a 24-hour delay, a 48-hour delay, a 7-day delay, or a 14-day delay. After the delay, red blood cell velocity, vessel diameters, number of functional capillaries, and leukocyte-endothelial interactions were measured. Microvessel response to topical vasoactive substances was measured. Immediately after denervation, red blood cell velocity increased transiently (71 percent; p = 0.006). Main arterioles dilated (20 percent; p = 0.02) at 24 hours, and capillary perfusion increased 36 percent (p = 0.001) at 2 weeks. The microvessels had hyperactive responses to all vasoactive agents 2 weeks after denervation. These findings indicate that proximal sympathectomy with somatic denervation leads to a triphasic, dynamic response in the peripheral microcirculation of the cremaster muscle flap. An initial acute hyperadrenergic phase was followed by a nonadrenergic phase, with significant vasodilatation, and a sensitized phase, with increased capillary perfusion and hyperresponsiveness to vasoactive substances. This study shows that with minimal access to the cremaster muscle flap neurovascular pedicle and without changing the blood supply to the flap, significant hemodynamic improvements can be made in the peripheral microcirculation.

Arteriovenous cross-flow flap in rats: a novel skin flap.

Angiosomes are blocks of tissues, composed of the integument and underlying deep structures, supplied and drained by a named artery and its accompanying vein. The purpose of the current study is to describe a new principle, which allows extension of the territory of an angiosome into the adjacent angiosome, thus enabling the creation of a large skin flap (arteriovenous cross-flow flap). Epigastric skin flaps, measuring 8 x 8 cm, were raised in 30 Sprague-Dawley male rats. In group A (single-pedicle flap), the flaps were based on the epigastric artery and vein on the ipsilateral side, and the contralateral pedicle was divided. In group B (cross-flow flap), the epigastric vein on the ipsilateral side and the epigastric artery on the contralateral side of the flap were divided. In group C (skin graft), the vascular pedicles were divided bilaterally. A definitive assessment was made on the seventh day. Digital images of the flaps were analyzed using an imaging software and the areas of skin survival and necrosis were determined. Lead oxide microangiogram was performed in another set of flaps both acutely and 1 week after flap elevation. The percent survival flap area in group A was 69.94, in group B was 89.07, and in group C was 13.00. All the groups are statistically different, with a p value < 0.001. The microangiograms showed striking differences in the vascular pattern in the cross-flow and the single-pedicle flaps. It is clearly demonstrated that the arteriovenous cross-flow flaps have increased survival of skin when compared with the conventional axial-pattern flaps.

Primary squamous cell carcinoma within a solitary nonparasitic hepatic cyst.

A case report is presented of a patient who developed primary squamous cell carcinoma in a solitary nonparasitic hepatic cyst. The clinical presentation, operative management, and pathological findings are discussed. This case is unusual as the histology demonstrates transition from columnar cell architecture through squamous cell metaplasia and carcinoma in situ to invasive carcinoma.