Reimer Andresen

Imaging of hamate bone fractures in conventional X-rays and high-resolution computed tomography. An in vitro study.

RATIONALE AND OBJECTIVES To examine the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and high-resolution computed tomography (HR-CT). MATERIALS AND METHODS In an in vitro experiment using 18 cadaver hands, the hamate bone was fractured at different places. Before and after fracture, conventional X-rays were taken in different planes (anteroposterior, lateral, oblique, and carpal tunnel), and HR-CT was performed with 2-mm layer thickness in the axial, sagittal, and coronal plane. RESULTS Taking into account all the conventional X-ray projections applied, the in vivo experiment revealed a sensitivity of 72.2%, a specificity of 88.8%, and an accuracy of 80.5%. For the HR-CT, the sensitivity was 100%, the specificity was 94.4%, and the accuracy was 97.2%. CONCLUSIONS Fractures of the body and hook of the hamate cannot always be detected with certainty in the conventional X-ray image, even if different projectional planes are used. The HR-CT is the imaging procedure of choice for further clarification, and an axial or sagittal plane should be selected.

Treatment of Peyronie's disease with local interferon-alpha 2b.

Peyronies disease is an illdefined condition that often leads to severe penile deformity. Various conservative treatments have failed to have any impact, and surgery remains the mainstay of therapy in advanced cases. Recent reports of successful treatment of related diseases, notably keloid formation, with interferons (INF) have prompted us to use this biologic response modifier to alter the behavior of the myofibroblast, the cell most likely responsible for the development of Peyronies disease. From December 1992 to July 1994, 25 patients suffering from Peyronies disease were treated with five local injections of 1 million units of INF-alpha 2b each into a single designated and ultrasonographically measured plaque. The interval between the injections was 1 week. The patients were assessed clinically and ultrasonographically 1 and 6 months after the last injection. The condition improved clinically in only 1 case, but progressed in none. The measured plaque size decreased in 7 no or mildly calcified cases, remained stable in 12 cases, and increased in 6 patients, (solely calcified plaques). Side effects (myalgia, fever) occurred in 4 patients; of these 2 patients withdrew from treatment. INF-alpha 2b given according to our regimen is at best usefull for the treatment of Peyronies disease in the early, noncalcified stage during which it displays verifiable impact on the plaque treated and also helps alleviate the plaque-associated pain; but further dose-finding studies will have to be performed to identify clinically relevant treatment regimens.

Leydig Cell Tumor–Comparison of Results of Radical and Testis-Sparing Surgery in a Single Center

Between January 1981 and December 1995, 15 patients were treated for Leydig cell tumor at our institution -- 12 by radical orchiectomy, 3 by tumor enucleation. All patients were contacted to assess the long-term outcome depending on the treatment initially chosen. Follow-up ranged from 8 to 161 months (mean 56). In no case was progressive disease documented, in 1 case local recurrence was witnessed 4 months after tumor enucleation despite negative resection margins. We conclude that a small Leydig cell tumor can safely be managed by local enucleation alone.

Investigation of TRAM flap oxygenation and perfusion by near-infrared reflection spectroscopy and color-coded duplex sonography.

Near-infrared reflection spectroscopy, used experimentally for investigation of tissue hemoglobin content and oxygenation in various flaps, was tested in the pedicled transverse rectus abdominis musculocutaneous (TRAM) flap, chosen as a simple clinical model because of its well-known vascular anatomy and clinical relevance. The study intended to answer the following questions: Does the near-infrared reflection spectroscopy system used in this study measure tissue hemoglobin content and oxygenation in the superficial skin layers only, as proposed by the manufacturer? Is near-infrared reflection spectroscopy able to detect differences of tissue hemoglobin content and oxygenation in distinct zones of the TRAM flap skin before, early, and late after surgery? Does tissue hemoglobin content and oxygenation correspond to blood flow in the supplying superior epigastric artery and to clinical signs of TRAM flap perfusion and viability? In 11 patients, tissue hemoglobin content and oxygenation in the lower abdomen/TRAM flap, mastectomy skin flap, and contralateral breast were measured by a new near-infrared reflection spectroscopy system preoperatively, early postoperatively, and late postoperatively. Simultaneously, systolic peak flow in the ipsilateral superior epigastric artery was obtained by color-coded duplex sonography. Routine clinical monitoring was performed throughout the early postoperative period. Tissue hemoglobin content and oxygenation in the lower abdomen, mastectomy skin flap, and contralateral breast were similar before surgery but varied considerably between different patients. There were no significant differences among preoperative, early postoperative, and late postoperative values of tissue hemoglobin content and oxygenation in the mastectomy skin flap and contralateral breast. However, near-infrared reflection spectroscopy measurements of the TRAM flap revealed significant differences between preoperative and early postoperative values of tissue hemoglobin content and oxygenation and among zones I, II, and III early after surgery. Tissue hemoglobin content in the TRAM flap skin increased and oxygenation decreased early after surgery. Near-infrared reflection spectroscopy values corresponded to clinical signs of venous congestion predominantly in zone III. Late postoperative return of hemoglobin content and oxygenation in the TRAM flap toward preoperative values can be attributed to improved venous return by reversed flow across regurgitant valves and development of collateral circulation. Finally, there was a significant increase of systolic peak flow in the ipsilateral superior epigastric artery early after surgery. This could be related to the opening of small-caliber choke arteries between the superior and deep inferior epigastric arteries following ligation of the dominant deep inferior epigastric artery and TRAM flap transfer to the chest. Systolic peak flow returned to preoperative values late after surgery. The near-infrared reflection spectroscopy system used in this study appeared to measure hemoglobin content and oxygenation in the superficial skin layers only. Near-infrared reflection spectroscopy was able to detect differences of tissue hemoglobin content and oxygenation in the TRAM flap between preoperative and postoperative measurements and between distinct zones of the TRAM flap early postoperatively. Postoperative changes in near-infrared reflection spectroscopy values corresponded to clinical observations and blood flow in the superior epigastric artery measured by color-coded duplex sonography. Further experience is needed before near-infrared reflection spectroscopy can be advocated for routine clinical flap monitoring.

Imaging Modalities in Peyronie’s Disease

Objective: Peyronie’s disease is an ill-understood condition afflicting men in their 40s with the reported age ranging from 18 to 68 years. It is characterized by a plaque in the tunica albuginea which leads to penile deformity making sexual intercourse difficult if not impossible and is often accompanied by severe pain upon erection in the early stage; erectile dysfunction is present in about 2% of cases. Diagnosis rests upon medical history, clinical examination with plaque palpation and autophotography in two planes. These diagnostic steps are not plaque-specific and therefore we wanted to assess which imaging modalities would allow for an objective determination of the plaque status. Materials and Methods: We evaluated 20 patients with Peyronie’s disease. All patients underwent clinical examination including autophotography and the subsequent use of the following imaging techniques: (1) ultrasound (US) using a 7.5-MHz transducer with a profile for semiquantitative density analysis; (2) X-ray in mammography technique in two planes; (3) computerized tomography (CT) with a density profile, and (4) magnetic resonance imaging (NMR). Results: (1) Degree of deviation: Penile deviation ranged from 15° to 63°. It was best assessed using radiography in mammography technique reflecting the results obtained by autophotography. (2) Calcifications: Plaque calcifications were seen in 12 patients, 8 had no calcifications but thickening of the tunica albuginea only, 2 also had a fibrosis of the corpus cavernosum distant to the plaque. Calcifications were visualized using ultrasound sonography (12/12), radiographically (12/12), CT (12/12), NMR (9/12). Thickening of the tunica albuginea only was visualized using ultrasound sonography (7/8), radiographically (0/8), CT (2/8), NMR (6/8). (3) Morphological pattern in ultrasound: Three distinct patterns could be detected: (type 1) the plaque appeared as a thickening of the tunica albuginea without acoustic shadowing and only minimal density increase in the histogram profile; (type 2) moderately calcified plaque with typical ultrasound shadow but minimal density increase in the density profile; (type 3) severely calcified plaque with typical acoustic shadowing and density increase in the histogram profile. (4) Plaque inflammation: Only NMR with gadolinium DTPA showed periplaque inflammation. Conclusions: High-resolution ultrasound sonography is the best imaging modality in assessment of plaques. NMR is the modality of choice to monitor the inflamed plaque. X-ray in mammography technique and CT are not necessary in daily routine.

Clinical results of TRAM flap delay by selective embolization of the deep inferior epigastric arteries.

Preoperative selective embolization of the deep inferior epigastric arteries constitutes a new technique in TRAM flap delay. Whereas surgical ligation of these vessels has proved to be an effective delay procedure in experimental and clinical settings, it requires an additional operative step under general anesthesia. Despite the introduction of the free TRAM leading to improved flap perfusion, this microsurgical technique is not always available because of the requirements of specialized equipment and staff, longer operating hours, and subsequently higher expenses. The search for a minimally invasive, easy, and inexpensive technique to improve perfusion of the pedicled TRAM flap led us to selective embolization of the deep inferior epigastric arteries by an angiographic procedure. After 4 years of experience with this technique, we now present the first clinical results. Breast reconstruction by a delayed pedicled TRAM flap was performed in 40 patients with a mean age of 48.4 years (range, 31 to 66 years). The mean interval between embolization and surgery was 3.6 months. Postoperative data concerning flap survival and complications were available for all patients. Embolization of the deep inferior epigastric arteries was performed bilaterally in 35 patients (87.5 percent) and unilaterally in 5 patients (12.5 percent). Radiotherapy had been applied in 21 patients (52.5 percent) before surgery. Postoperative flap complications consisted of partial necrosis in three (7.5 percent), fat necrosis in one (2.5 percent), impaired wound healing in five (12.5 percent), and postoperative bleeding in two patients (5 percent). Abdominal wound healing complications occurred in six patients (15 percent), abdominal wall weakness in eight (20 percent), and hernia formation in four (10 percent). Surgical corrections were performed at the breast (TRAM flap) in 22 patients (55 percent) and at the abdomen (donor site) in 9 (22.5 percent). Preoperative selective embolization of the deep inferior epigastric arteries constitutes an alternative delay procedure for the pedicled TRAM flap. It is superior to the conventional procedure without delay, offers several advantages compared with surgical ligation of these vessels, and represents an alternative to the free TRAM flap in selected cases. (Plast. Reconstr. Surg. 105: 1320, 2000.)

Noninvasive assessment of stiffness and failure load of human vertebrae from CT-data.

A calculational method based on noninvasively derived data for the assessment of the mechanical quality of individual vertebrae is presented. Dimensional data obtained from serial, segmented CT scans were used as the geometric input for a newly developed finite element model designed to calculate stiffness and failure load of these complex bone structures. Mechanical, structural data for cancellous bone was obtained by measurements of the compressive strength and failure load of actual vertebral specimens obtained at autopsy. The stiffness and failure load calculated by the newly developed finite element model were compared with the data obtained from mechanical measurements of vertebral specimens. A high correlation between measured and calculated failure load was found (r = 0.89, p < 0.001, n = 16). The correlation between the failure load and bone mineral density (BMD) was significant (r = 0.82, p < 0.001, n = 16). A similar correlation between calculated and measured stiffness (r = 0.81, p < 0.001, n = 15) was also found using the finite element model described herein. Thus the newly developed calculation methodology has been verified and can be used to predict the failure load and stiffness of osteoporotic vertebrae using data obtained non-invasively from CT scans.

Prognostic factors in necrotizing fasciitis and myositis : Analysis of 16 consecutive cases at a single institution in Switzerland

Necrotizing fasciitis and myositis are life-threatening infections involving the superficial fascia and musculature, respectively. Outcome depends on early diagnosis and aggressive treatment. Here, we aimed to determine prognostic factors for necrotizing soft tissue infections. The medical records of 16 consecutive patients diagnosed with necrotizing fasciitis (n = 13) and necrotizing myositis (n = 3) from 1999 to 2004 were retrospectively reviewed. Overall survival was 81.3% for necrotizing soft tissue infections, 84.6% for necrotizing fasciitis, and 66.7% for necrotizing myositis. Injection drug use was the most common cause of infection (31.3%). Frequent comorbidities were diabetes mellitus and hepatitis B and C (25.0%). As infectious agents, group A streptococci (GAS) were identified in 10 patients and multiple pathogens in 6 patients. Lethal outcome was always associated with GAS infection and streptococcal toxic shock syndrome (STSS). In our patients, myonecrosis, GAS infection, and STSS appeared to be negative prognostic factors for survival in necrotizing soft tissue infections.

Noninvasive Assessment of Stiffness and Failure Load of Human Vertebrae from CT-Data. Nichtinvasive Abschätzung von Steifigkeit und Versagenslast von osteoporotischen Wirbelkörpern nach CT-Daten

A calculational method based on noninvasively derived data for the assessment of the mechanical quality of individual vertebrae is presented. Dimensional data obtained from serial, segmented CT scans were used as the geometric input for a newly developed finite element model designed to calculate stiffness and failure load of these complex bone structures. Mechanical, structural data for cancellous bone was obtained by measurements of the compressive strength and failure load of actual vertebral specimens obtained at autopsy. The stiffness and failure load calculated by the newly developed finite element model were compared with the data obtained from mechanical measurements of vertebral specimens. A high correlation between measured and calculated failure load was found (r = 0.89, p < 0.001, n = 16). The correlation between the failure load and bone mineral density (BMD) was significant (r = 0.82, p < 0.001, n = 16). A similar correlation between calculated and measured stiffness (r = 0.81, p < 0.001, n = 15) was also found using the finite element model described herein. Thus the newly developed calculation methodology has been verified and can be used to predict the failure load and stiffness of osteoporotic vertebrae using data obtained non-invasively from CT scans.

EVALUATION OF PENILE ARTERIES WITH COLOR-CODED DUPLEX SONOGRAPHY: PREVALENCE AND POSSIBLE THERAPEUTIC IMPLICATIONS OF CONNECTIONS BETWEEN DORSAL AND CAVERNOUS ARTERIES IN IMPOTENT MEN

Penile revascularization for cases of arteriogenic impotence is based on the assumption of hemodynamically relevant connections between the dorsal penile and cavernous arteries. In 325 clinically impotent patients color-coded duplex sonography was performed with the penis flaccid and tumescent after intracavernous injection of 10 micrograms prostaglandin E1. We measured peak flow velocity, end diastolic flow velocity and resistance in the dorsal arteries, deep cavernous arteries and connections perforating the tunica albuginea between the 2 systems. Of our patients 14% had at least 1 such anastomosis with a peak flow velocity exceeding 25 cm. per second after stimulation. Peak flow velocities less than 20 cm. per second were noted only in arteriogenically impotent patients, while those exceeding 25 cm. per second without later rigid erection occurred only in patients with venous occlusive dysfunction and end diastolic flow velocity exceeded 5 cm. per second. We conclude that penile revascularization should be contemplated only if hemodynamically relevant connections are detected, peak flow velocity in the cavernous arteries is less than 20 cm. per second and end diastolic flow velocity is less than 5 cm. per second.