[Prospective study on patients outcome following laparoscopic vs. open cholecystectomy]

AIMS OF THE STUDY

Differences in outcome between patients undergoing laparoscopic (LC) vs. open cholecystectomy (OC) should be examined under objective and subjective aspects.

METHODS

We prospectively evaluated the postoperative course of 135 patients who underwent LC or OC in 1999. In the first step we examined the recover period with the help of the modified McPeek-Index. In the second phase during a 35 postoperative days-spanned analysis all patients noted there physical, emotional and social well-being in a circulating standard questionnaire, based on the modified Gastrointestinal Quality Life Index (GIQLI).

RESULTS

Responses were obtained from 103 patients (76.3 %) undergoing 29 OC and 74 LC. 21.4 % of the patients aged 70 and older or had perioperative risks > II in ASA-Classification (LC 19.8 vs. OC 30.1 %). The (objective) McPeek-Outcome was similar in both groups, with no statistical advantage for LC (best score: 69 % LC vs. 62 % OC). The subjective assessment of the patients showed that patients having LC felt fully fit 10.2 days earlier than patients after OC (23.9 vs. 34.1 days). Patients in the LC-group returned to work after an average of 24.7 days, compared with 42.2 days following OC. The main finding of the postal questionnaire was a significantly earlier recruitment in physical, emotional and social status following LC in the group of aged > 70 and > ASA II-Score-patients, in contrast to control-OC-group.

CONCLUSION

The study suggests an additional advantage in surgical outcome after LC, in comparison to OC. The laparoscopic approach is the preferable procedure to treat especially older and comorbide patients, when local or anesthesiological contraindications are absent.

Cross-protection against challenge by intravenous Escherichia coli verocytotoxin 1 (VT1) in rabbits immunized with VT2 toxoid

Rabbits challenged intravenously with Escherichia coli verocytotoxin (VT1, Shiga toxin 1, Stx1) die after developing diarrhea and paralysis, and this outcome can be prevented by pre-immunization with VT1 toxoid. In nonimmune rabbits, intravenously administered 125I-VT1 binds to the central nervous system and gastrointestinal tract, whereas in immunized animals, these organs are spared and the toxin localizes in the liver and spleen. In rabbits immunized with either VT1 or VT2 toxoids, both the homologous or heterologous toxins are prevented from binding to target organs. This has lead to the advancement of a hypothesis that cross-protection in vivo can be induced to both toxins by immunization with a toxoid even though these toxins do not exhibit cross-neutralization in vitro. It was shown that rabbits immunized with VT2 were fully protected from the intravenous administration of 10 LD50 and 50 LD50 of VT1, and this correlated directly with the protection from binding of this toxin to target organs. These findings have important implications on the design of the vaccination strategies to prevent human VT-mediated diseases and also validate the concept of testing for immunity to VT by monitoring the inhibition of binding of the 125I-VT to target organs in preference to performing LD50 assays.

[An extended CT scale technique for evaluating periprosthetic bone lesions - an in vitro study]

PURPOSE

In the present study the reduction of artifacts using an extended CT scale technique was examined in 5 vitallium and 5 titanium-aluminium-vanadium tumor prostheses.

METHODS

5 titanium-aluminium-vanadium and 5 vitallium distal femur Mutars(R) tumor prostheses (Mutars(R) - Modular Universal Tumor And Revision System) were implanted in 10 human femur specimens. 110 artifical drill hole lesions of 1 mm, 2 mm, 3 mm, 5 mm and 8 mm diameter were placed in the bone around the hexagonal stem of the tumor prosthesis and furthermore in the proximal part of the femur. All specimens were examined using conventional CT and an extended CT scale technique in a slice thickness of 3 mm.

RESULTS

In the proximal part of the femur all drill holes could be detected using 3 mm slices, no artefacts were observed. Along the hexagonal stem smooth lines arising from each hexagonal plane could be observed. This made it impossible to detect a 1 mm drill in 1 vitallium and in 1 titanium-aluminium-vanadium stem. There was no difference between the extended CT scale and conventional CT.

CONCLUSION

The extended CT scale did not significantly (p > 0.05, t-test) improve the imaging of artificial drill hole lesions along the hexagonal Mutras(R) stem.

Complete response to neoadjuvant chemoradiation for rectal cancer does not influence survival

BACKGROUND

Up to 30% of patients with locally advanced rectal cancer have a complete clinical or pathologic response to neoadjuvant chemoradiation. This study analyzes complete clinical and pathologic responders among a large group of rectal cancer patients treated with neoadjuvant chemoradiation.

METHODS

From 1987 to 2000, 141 consecutive patients with biopsy-proven, locally advanced rectal cancer were treated with preoperative 5-fluorouracil-based chemotherapy and radiation. Clinical restaging after treatment consisted of proctoscopic examination and often computed tomography scan. One hundred forty patients then underwent operative resection, with results tracked in a database. Standard statistical methods were used to examine the outcomes of those patients with complete clinical or pathologic responses.

RESULTS

No demographic differences were detected between either clinical complete and clinical partial responders or pathologic complete and pathologic partial responders. The positive predictive value of clinical restaging was 60%, and accuracy was 82%. By use of the Kaplan-Meier life table analysis, clinical complete responders had no advantage in local recurrence, disease-free survival, or overall survival rates when compared with clinical partial responders. Pathologic complete responders also had no recurrence or survival advantage when compared with pathologic partial responders. Of the 34 pathologic T0 tumors, 4 (13%) had lymph node metastases.

CONCLUSIONS

Clinical assessment of complete response to neoadjuvant chemoradiation is unreliable. Micrometastatic disease persists in a proportion of patients despite pathologic complete response. Observation or local excision for patients thought to be complete responders should be undertaken with caution.

Vitreoretinal surgery: pre-emptive analgesia

AIM

Vitrectomies are performed either under general anesthesia (GA), local anesthesia (LA), or a combination of both. Postoperative pain is expected to be less in patients with LA because of prolonged action of the local anaesthetic. Pre-emptive analgesia is based on the idea that analgesia initiated before a nociceptive event will be more effective than analgesia commenced afterwards. The authors compared postoperative analgesia in patients with GA combined with preoperative or postoperative LA.

METHODS

90 patients scheduled for vitrectomy without buckling were enrolled in the study. 60 patients underwent GA, 30 without LA, 15 with preoperative LA, and 15 with postoperative LA. 30 patients received LA alone. Subjective postoperative pain was determined using the visual analogue scale.

RESULTS

Postoperative pain was less under LA alone compared to GA alone (p < 0.0001). Additional preoperative application of LA resulted in less pain than additional postoperative application (p <0.05). Additional postoperative peribulbar aneasthesia did not differ from GA alone.

CONCLUSION

The authors conclude that LA alone or preoperatively in addition to GA provides the best comfort for the patient in vitreoretinal surgery.

[Surgical therapy in cholecysto-/choledocholithiasis. Results of a Germany-wide questionnaire sent to 859 clinics with 123,090 cases of cholecystectomy]

BACKGROUND

With the advent of laparoscopic cholecystectomy, the choice of procedure (laparoscopic vs open) and surgical management in gallstone disease are of interest. The purpose of this study was to examine the current approach and various strategies for cholecystectomy in Germany.

METHODS

A retrospective survey at 859 (of 1,200, 67.6%) hospitals in Germany was conducted. Data from 123,090 patients that had undergone cholecystectomy were analyzed.

RESULTS

71.9% of the procedures were finished laparoscopically (LC: 88.537), whereas 22.5% (27.727) were done in the open technique (KC). Conversion to open surgery was required in 7.1% of the laparoscopically started operations, mainly in cases of adhesions and unclear anatomic situations (64.3%). When common bile duct (CBD) stones were diagnosed preoperatively, 74.4% of the participants favored primary endoscopic extraction (ERC), followed by LC. In cases of intraoperative diagnoses, the LC was finished and postoperative ERC and extraction were carried out in more than half of the hospitals (58.4%). Sixteen percent were converted to an open operation with simultaneous exploration of the CBD. Laparoscopic desobstruction of the CBD was extremely rare (4.4%). The intraoperative cholangiography (IOC) was the most strongly recommended approach for intraoperative diagnostics, but was generally routine practice in only 6% of the hospitals conducting LCs. Forty-nine percent of the respondents reported the use of IOC in selected cases and 43% of the hospitals did not perform any intraoperative diagnostics in LC. Compared with OC, the results show a lower incidence of postoperative reinterventions (0.9 vs 1.8%) and fatal outcomes (0.04 vs 0.53%) for LC. In contrast, CBD injuries were more frequent in the LC group (0.32 vs 0.12%). The median duration of hospitalization was 6.1 days (range 2.8-12) in the LC group compared with 10.4 days (range 3-28) in the OC group.

CONCLUSIONS

LC is the standard procedure for the treatment of uncomplicated gallstone disease. Even after adjustment for differences in patient comorbidities, there are logical differences between the hospitals as to the type of cholecystectomy used for acute cholecystitis, the management of CBD stones, and the intraoperative diagnostics in LC.

[Management of hemorrhage and perforation following endoscopic sphincterotomy]

Bleeding and perforation are rare but dangerous complications of diagnostic and therapeutic ERCP and endoscopic sphincterotomy (EST). To evaluate the clinical outcome of patients treated for complicated EST in our surgical department, data were collected prospectively between 1/1995 and 3/2000. A total of 9 patients were admitted to our department, 7 women and 2 men, average age 60 (range 41-72) years. 5 patients were treated for severe hemorrhage, all of them underwent laparotomy following duodenotomy and oversewing of the sphincterotomy site. In average 10 hours (range 4-20) after endoscopy. One of these patients died due to multiple organ failure. In 4 additional patients a retroperitoneal perforation was discovered, 2 of these patients underwent laparotomy and drainage of the retroperitoneal cavity. The other two patients were sufficiently treated by percutaneous drainage. One of the patients, who underwent surgical drainage for retroperitoneal perforation died. In conclusion for severe hemorrhage duodenotomy and oversewing of the bleeding site is recommended in combination with common bile duct T-drain or other draining procedures. The treatment for perforation should depend on the clinical finding. A laparotomy seems not always to be necessary.

Stochastic simulation of hemagglutinin-mediated fusion pore formation

Studies on fusion between cell pairs have provided evidence that opening and subsequent dilation of a fusion pore are stochastic events. Therefore, adequate modeling of fusion pore formation requires a stochastic approach. Here we present stochastic simulations of hemagglutinin (HA)-mediated fusion pore formation between HA-expressing cells and erythrocytes based on numerical solutions of a master equation. The following elementary processes are taken into account: 1) lateral diffusion of HA-trimers and receptors, 2) aggregation of HA-trimers to immobilized clusters, 3) reversible formation of HA-receptor contacts, and 4) irreversible conversion of HA-receptor contacts into stable links between HA and the target membrane. The contact sites between fusing cells are modeled as superimposed square lattices. The model simulates well the statistical distribution of time delays measured for the various intermediates of fusion pore formation between cell-cell fusion complexes. In particular, these are the formation of small ion-permissive and subsequent lipid-permissive fusion pores detected experimentally (R. Blumenthal, D. P. Sarkar, S. Durell, D. E. Howard, and S. J., J. Cell Biol. 135:63-71). Moreover, by averaging the simulated individual stochastic time courses across a larger population of cell-cell-complexes the model also provides a reasonable description of kinetic measurements on lipid mixing in cell suspensions (T. Danieli, S. L. Pelletier, Y.I. Henis, and J. M. White, 1996, J. Cell Biol. 133:559-569).

Preoperative evaluation of limbal dermoids using high-resolution biomicroscopy

BACKGROUND

Only a few case reports have described the ultrasound biomicroscopic features of limbal dermoids. It remains unclear whether examination by ultrasound biomicroscopy (UBM) can detect the corneal depth of penetration which would improve planning of surgery.

METHODS

Eight consecutive patients [two female, six male, 1-24 years old (median 8.5 years)] examined by UBM (Zeiss-Humphrey, 50 MHz) were retrospectively studied. Five of the dermoids were excised without corneal grafting and histopathological evaluation was obtained.

RESULTS

Seven out of eight dermoids were located in the temporal lower quadrant. A Goldenhar syndrome was known in three cases. In all cases but one, UBM showed a more reflective and predominantly homogeneous lesion compared with the unaffected corneal stroma, so that the lateral margins of the lesion could be clearly identified. Incomplete stromal penetration of the dermoid was noticed in four cases; one eye showed a corneal full thickness dermoid. An intraocular protrusion was seen in one eye. Two more cases remained unclear because of reduced compliance. Descemet's membrane beneath the dermoid could not be visualized in most cases (seven out of eight) because of strong sound attenuation inside the lesion. Histopathological evaluation of five cases revealed the typical signs of a limbal dermoid.

CONCLUSION

UBM improves the preoperative evaluation of limbal dermoids. Subtle examination technique for the depth of corneal penetration is required because of the strong sound attenuation in this tissue, reducing the visibility of deep corneal structures.

Neoadjuvant chemoradiation for rectal cancer: analysis of clinical outcomes from a 13-year institutional experience

OBJECTIVE

To examine clinical outcomes in patients receiving neoadjuvant chemoradiation for locally advanced rectal adenocarcinoma.

SUMMARY BACKGROUND DATA

Preoperative radiation therapy, either alone or in combination with 5-fluorouracil-based chemotherapy, has proven both safe and effective in the treatment of rectal cancer. However, data are lacking regarding which subgroups of patients benefit from the therapy in terms of decreased local recurrence and increased survival rates.

METHODS

A retrospective chart review was performed on 141 consecutive patients who received neoadjuvant chemoradiation (5-fluorouracil +/- cisplatin and 4,500-5,040 cGy) for biopsy-proven locally advanced adenocarcinoma of the rectum. Surgery was performed 4 to 8 weeks after completion of chemoradiation. Standard statistical methods were used to analyze recurrence and survival.

RESULTS

Median follow-up was 27 months, and mean age was 59 years (range 28-81). Mean tumor distance from the anal verge was 6 cm (range 1-15). Of those staged before surgery with endorectal ultrasound or magnetic resonance imaging, 57% of stage II patients and 82% of stage III patients were downstaged. The chemotherapeutic regimens were well tolerated, and resections were performed on 140 patients. The percentage of sphincter-sparing procedures increased from 20% before 1996 to 76% after 1996. On pathologic analysis, 24% of specimens were T0. However, postoperative pathologic T stage had no effect on either recurrence or survival. Positive lymph node status predicted increased local recurrence and decreased survival.

CONCLUSIONS

Neoadjuvant chemoradiation is safe, effective, and well tolerated. Postoperative lymph node status is the only independent predictor of recurrence and survival.

Antibody response to Shiga toxins Stx2 and Stx1 in children with enteropathic hemolytic-uremic syndrome

A Western blot (immunoblot) assay (WBA) for the detection of immunoglobulin G antibodies to Shiga toxins Stx2 and Stx1 in sera from 110 patients with enteropathic hemolytic-uremic syndrome (53 culture confirmed to have Shiga toxin-producing Escherichia coli [STEC] infection) and 110 age-matched controls was established by using a chemiluminescence detection system. Thirty-nine (74%) of the 53 culture-confirmed cases were infections with STEC serotype O157, and 14 (26%) were associated with infection by other STEC serotypes. The frequency of an anti-Stx2 response following infection by a Stx2-producing strain (34 of 48 cases; 71%) was higher than that of an anti-Stx1 response following Stx1-producing STEC infection (4 of 10). Furthermore, the frequency of an anti-Stx2 response in 110 control sera (10%) was significantly higher than the frequency of an anti-Stx1 response (1.8%) (P = 0.0325). For STEC O157 culture-confirmed cases WBA for toxin detection had a diagnostic sensitivity of 71% and a specificity of 90%. Because of its high specificity the assay might be a helpful tool for diagnosing suspected STEC infection when tests of stool samples or serological tests against various lipopolysaccharide antigens are negative. Furthermore, the prevalence of anti-Stx antibodies in healthy controls probably reflects the population immunity to systemic Stx-associated disease. It can thus serve as a basis for comparing immunity levels in different populations and for considering future Stx toxoid immunization strategies.

Deep prosthesis infection in incisional hernia repair: predictive factors and clinical outcome

OBJECTIVE

To evaluate the incidence of prosthetic infection in incisional hernia repairs, to determine whether there are any factors associated with prosthetic infection and to describe the clinical outcome.

DESIGN

Retrospective clinical study.

SETTING

Teaching hospital, Germany.

SUBJECTS

121 consecutive patients who underwent incisional hernia repair in our department from December 1994 to December 1999.

INTERVENTION

Hernia repair by implantation of an alloplastic prosthesis by the Stoppa-Rives technique.

MAIN OUTCOME MEASURES

Postoperative deep prosthetic infection and associated factors.

RESULTS

All 121 patients had the mesh implanted in the subfascial plane, 77 had a polypropylene mesh (Prolene) (64%), 7 had a polyester mesh (Mersilene) (6%), and 37 patients had a expanded polytetrafluoroethylene patch (ePTFE, Gore-Tex) (31%). Postoperatively the mesh became infected in 8 patients (7%), a mean of 4.5 months (range 0.5-16) after hernia repair. All three infected ePTFE patches had to be removed whereas drainage was sufficient treatment for the infected polypropylene and polyester meshes.

CONCLUSION

Once a mesh infection is verified adequate drainage seems to be sufficient for polypropylene and polyester meshes but ePTFE patches should be removed.

[Gastrointestinal autonomic nerve tumor (GANT)--a rate tumor of the ileum]

The gastrointestinal autonomic nerve tumor (GANT) is an uncommon stromal tumor of the intestinal tract and retroperitoneum first described by Herrera and associates in 1984. GAN tumors, also termed "plexosarcomas", arise from autonomic nervous system plexuses of the gastrointestinal tract. We report a case of GAN tumor of the intestinal tract in a 63-year-old woman. The diagnosis is based on light microscopy and immunohistochemical analyses. The tumor stained positive for neuron-specific enolase (NSE) and S-100 protein and was negative for muscle markers. Pain and chronic and acute bleeding are the most frequent but not specific symptoms, and the diagnostic delay is reflected by a large diameter of these tumors. GAN tumors are fatal and must be considered malignant. They need radical surgical resection.

Mehrschicht-Spiral-CT des Abdomens bei onkologischen Patienten: Einfluss von Tischvorschub und Detektorkonfiguration auf Bildqualität und Strahlenexposition

PURPOSE

To evaluate the image quality and radiation exposure of different spiral CT scanning parameters for routine staging examination of the abdomen in oncologic patients using a multi-slice CT scanner.

METHODS/MATERIALS

Examination of 40 patients in 4 groups on a multi-slice CT scanner (Somatom VolumeZoom, Siemens AG, Forchheim). Functional detector width (4 x 2.5, 4 x 5 mm) and pitch (table feed in relation to collimated slice width) were varied (3 and 5). Tube voltage (120 kV), effective tube current (160 mAs), slice-thickness (6 mm), increment (4 mm), kernel (B 30), and contrast injection parameters were kept constant. Axial images were assessed by three radiologists regarding delineation of anatomic structures, artifacts, and overall image quality.

RESULTS

Significantly reduced image quality especially due to artifacts was observed using a 5 mm detector configuration with a pitch of 5 (scan time 9 sec). Image quality was rated best for a 2.5 mm detector configuration with a pitch of 3 and a scan time of 28 sec. The effective dose was independent of the pitch. However, the mean effective dose was 9% higher using the smaller detector configuration (9.9 mSv vs 10.9 mSv).

CONCLUSIONS

For routine staging CT of the abdomen use of a 4 x 2.5 mm detector configuration with a pitch between 3 and 5 is recommended. A 4 x 5 mm detector configuration using overlapping data acquisition can also be recommended, but additional thin slice reformations are not possible.

[Biomechanical study of angle-stable anterior atlanto-axial spondylodesis plate]

The optimum fixation method to achieve atlantoaxial fusion after odontoid resection is still subject to discussion. Isolated posterior surgical procedures for treatment of irreducible atlantoaxial kyphosis with spinal cord compression are associated with a high rate of morbidity and mortality. Transoral atlantoaxial plate fixation has been described by Harms as a fixation technique after odontoid resection. The purpose of this study was to compare biomechanically a new anterior atlantoaxial locking plate (AALP) with the Harms plate and the atlantoaxial transarticular screw fixation described by Magerl. Sixteen human cadaver craniocervical specimens were tested in flexion, extension, rotation, and bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Five different groups were examined: (1) control group (intact) (n = 16), (2) unstable group (after dissection of the atlantoaxial ligaments and odontoidectomy) (n = 16), (3) Harms group (transoral atlantoaxial plate fixation) (n = 8), (4) AALP group (anterior atlantoaxial locking plate fixation) (n = 8), and (5) Magerl group (transarticular atlantoaxial screw fixation) (n = 16). Stiffness in any direction was significantly higher in the AALP specimens and those fixated with the Magerl method than in the Harms, control, or unstable specimens. The difference in stiffness between the AALP and Magerl reconstruction groups was not statistically significant. Experimentally, the AALP was significantly stiffer than the Harms plate. The AALP provided stiffness equal to transarticular screw fixation according to Magerl. A question that cannot be answered by this in vitro study concerns the level of rigidity required to obtain long-term stability and fusion by atlantoaxial fixation methods. However, it may be assumed that the more spinal motion is eliminated the greater the chance of definite spinal fusion. Therefore, it seems reasonable that the most reliable and rigid fixation method would be the method of choice.

Central corneal thickness measurement with a retinal optical coherence tomography device versus standard ultrasonic pachymetry

PURPOSE

To demonstrate the capability of a standard, commercially available optical coherence tomography device (originally designed to measure retinal thickness) to image the human cornea in vivo and to measure central corneal thickness (CCT) in normal and edematous corneas. The intrapatient precision and interpatient variability of this novel application was compared to standard ultrasonic pachymetry. Also, the correlation of both methods was investigated.

METHODS

CCT measurements using optical coherence tomography (OCT) and ultrasonic pachymetry (PACH) were obtained in 36 normal eyes and 16 eyes with corneal edema.

RESULTS

Direct in vivo imaging of the cornea and measurements of CCT by OCT could be performed in all eyes. In normal subjects, CCT(OCT) was 530+/-32 microm and CCT(PACH) was 581+/-34 microm. The two methods showed a highly significant correlation with a standardized regression coefficient of 0.988. The difference between both methods was constant over the range of CCT (mean difference, 49.4+/-5.9 microm). The mean intrapatient SD of CCT measurements was 4.90 microm and 4.96 microm for OCT and PACH, respectively. In patients with corneal edema, mean CCT(OCT) was 601+/-59 microm, and mean CCT(PACH) was 667+/-68 microm. The difference between the two techniques increased slightly with increasing corneal edema (mean difference, 66.9+/-10.9 microm).

CONCLUSION

Imaging of the human cornea can be performed by a standard retinal OCT device, and OCT measurement of CCT shows excellent correlation to values obtained by PACH, giving similar readings separated by a constant difference. In corneal edema, the difference between the two methods is additionally increased, but continues to demonstrate excellent consistency.

The role of the transmembrane and of the intraviral domain of glycoproteins in membrane fusion of enveloped viruses

Fusion of enveloped viruses with their target membrane is mediated by viral integral glycoproteins. A conformational change of their ectodomain triggers membrane fusion. Several studies suggest that an extended, triple-stranded rod-shaped alpha-helical coiled coil resembles a common structural and functional motif of the ectodomain of fusion proteins. From that, it is believed that essential features of the fusion process are conserved among the various enveloped viruses. However, this has not been established so far for the highly conserved transmembrane and intraviral sequences of fusion proteins. The article will focus on the role of both sequences in the fusion process. Recent studies from various enveloped viruses strongly imply that a transmembrane domain with a minimum length is required for later steps of membrane fusion, i.e., the formation and enlargement of the aqueous fusion pore. Although no specific sequence of the TM is necessary for pore formation, distinct properties and motifs of the domain may be obligatory to ascertain full fusion activity. However, with some exceptions, the intraviral domain seems to be not required for fusion activity of viral fusion proteins.

Digital selenium radiography: detection of subtle pulmonary lesions on images acquired with and without an additional antiscatter grid

OBJECTIVE

the objective of this ROC-study was to evaluate the diagnostic efficacy of images acquired with a grid in digital selenium radiography compared to that on images obtained with the integrated air gap only.

MATERIALS AND METHODS

seven types of simulated lesions were superimposed onto an anthropomorphic chest phantom. Selenium radiography images were obtained either with or without an additional antiscatter grid. For images acquired with a grid either a similar or increased exposure level was used. Both normal and obese patients were simulated.

RESULTS

When a grid was used with an equivalent detector dose and a higher exposure, diagnostic performance was significantly improved as compared to images obtained with only the air gap. ROC curve areas for mediastinal nodules and catheters were substantially higher for images acquired with a grid and the same exposure level compared to images obtained without a grid. However, detection of linear, net-shaped and reticulonodular structures in peripheral lung regions was significantly worse when a grid was used with an equivalent exposure level. Concerning the interpretation of images obtained from the normal and obese phantom models, no substantial differences were observed.

CONCLUSION

a marked improvement in diagnostic performance could be achieved by means of the use of an additional antiscatter grid and an equivalent detector dose. However, when the same exposure was used, images acquired with the grid allowed a better detection of mediastinal structures although a worse performance was evident in radiolucent lung regions. Therefore, the routine use of a grid without increased exposure is not recommended.

Central corneal thickness determined with optical coherence tomography in various types of glaucoma

AIMS

To evaluate central corneal thickness determined by optical coherence tomography (OCT) in various types of glaucoma, and its influence on intraocular pressure (IOP) measurement.

METHODS

Central corneal thickness (CCT) was determined by using OCT in 167 subjects (167 eyes). 20 had primary open angle glaucoma (POAG), 42 had low tension glaucoma (LTG), 22 had ocular hypertension (OHT), 10 had primary angle closure glaucoma (AC), 24 had pseudoexfoliation glaucoma (PEX), 13 had pigmentary glaucoma (PIG), and 36 were normal.

RESULTS

CCT was significantly higher in ocular hypertensive subjects (593 (SD 35) microm, p <0.0001) than in the controls (530 (32) microm), whereas patients with LTG (482 (28) microm, p < 0. 0001), PEX (493 (33) microm, p <0.0001), and POAG (512 (30) microm, p <0.05) showed significantly lower readings. There was no statistically significant difference between the controls and patients with PIG (510 (39) microm) and AC (539 (37) microm).

CONCLUSIONS

Because of thinner CCT in patients with LTG, PEX, and POAG this may result in underestimation of IOP, whereas thicker corneas may lead to an overestimation of IOP in subjects with OH. By determining CCT with OCT, a new and precise technique to measure CCT, this study emphasises the need for a combined measurement of IOP and CCT in order to obtain exact IOP readings.

Sterilization of elastic ligatures for intraoperative mandibulomaxillary immobilization

Sterilization can influence the mechanical properties of elastic ligatures used for mandibulomaxillary immobilization. The aim of this study was to compare different sterilization protocols (ethylene oxide, autoclave, irradiation, plasma sterilization, povidone-iodine for 24 hours and 70% isopropyl alcohol for 24 hours) of three elastomers (natural rubber, silicone rubber, and polyurethane). Three mechanical variables were assessed in a testing machine: breaking strength, tensile strength and tensile strength after a 24-hour load (material fatigue). Natural rubber was most susceptible to mechanical alteration by sterilization and lost 46% of its breaking strength and 43% of its tensile strength after autoclaving. Polyurethane was more resistant (multiple comparison, Tukey-Kramer), but polyurethane ligatures stuck together after autoclaving. The protocols for low-temperature sterilization, ethylene oxide, irradiation, and plasma were superior to autoclaving and the disinfecting solutions. These data suggest that polyurethane sterilized with ethylene oxide is the material of choice.

Unfavorable response to cyclophosphamide in steroid-dependent nephrotic syndrome

Development of steroid dependency represents a significant therapeutic challenge in steroid-sensitive nephrotic syndrome. Previous studies have shown conflicting results concerning the benefit of a 12-week treatment with cyclophosphamide (CPO), with 24%-67% of patients achieving long-term remission. We therefore analyzed the clinical response of 20 consecutive children with steroid-dependent nephrotic syndrome (SDNS) (12 male, median age at start of treatment 5.9 years, range 3.2-14.7 years) treated at our institution with CPO (2 mg/kg per day) for 12 weeks since 1989. Median duration of follow-up was 5.8 (range 1.1-9.25) years. Only 6 of 20 children (30%) showed a long-term remission of >2 years, while 14 of 20 (70%) developed relapses again. Of these, 12 patients (86%) again developed steroid dependency, requiring further alternative treatment. Our data show that a 12-week course of CPO leads to unfavorable results in the majority of patients with SDNS. We therefore conclude that there is a need for further optimization of therapy in SDNS.

Efficacy of botulinum toxin A for treatment of upper esophageal sphincter dysfunction

OBJECTIVES

To investigate the efficacy of botulinum toxin A (BTA)-induced chemodenervation of the upper esophageal sphincter (UES) in patients with dysphagia and UES dysfunction.

STUDY DESIGN

Prospective clinical trial in 10 selected patients with pure UES dysfunction.

METHODS

In each patient 30 units of BTA were injected into the UES under brief general anesthesia. Videofluoroscopic swallowing study (VSS) was done and a clinical symptom score was determined before and after treatment.

RESULTS

On VSS relative opening of the UES improved in all patients (mean +/- SD: 47 +/- 14% before versus 71 +/- 24% after treatment; P < .01). Hypopharyngeal retention or laryngeal penetration of barium was significantly reduced in four of seven patients. Clinical symptom scores improved in all patients. One patient was free of symptoms, mild dysphagia persisted in six patients, and moderate dysphagia persisted in three patients.

CONCLUSIONS

Our results support the use of BTA in selected patients with pure UES dysfunction. Its efficacy is limited by the possibility of a persistent structural stenosis of the UES and the risk of BTA diffusion into the larynx or hypopharynx.

Bilateral anterior lenticonus: Scheimpflug imaging system documentation and ultrastructural confirmation of Alport syndrome in the lens capsule

BACKGROUND

Alport syndrome is a combination of proteinuria, hematuria, and neurosensory high-frequency deafness. Bilateral anterior lenticonus may be a late sign. Diagnosis relies on characteristic electron microscopy changes of glomerular basement membranes in renal biopsy specimens.

PATIENT

A 38-year-old man was seen for progressive visual acuity loss (20/400 OU; best-corrected visual acuity, 20/60 OD and 20/50 OS). Findings from slitlamp examination included bilateral anterior lenticonus and central posterior subcapsular cataract, documented using a modified Scheimpflug imaging system. Retinal pathology was not present. On detailed questioning, a history of microhematuria and proteinuria since childhood and progressive high-frequency deafness for years were discovered. The family history was negative for nephropathies, deafness, or eye diseases. Cataract extraction rehabilitated the patient's vision.

RESULTS

Electron microscopy of a fragile capsulorhexis specimen showed typical thinned basal lamina with basement membrane disruptions.

CONCLUSIONS

Anterior lenticonus is a rare bilateral progressive developmental anomaly. More than 90% of cases are associated with Alport syndrome. For diagnosis of Alport syndrome, the presence of 3 of 4 criteria is required: family history positive for Alport syndrome, progressive intra-auricular deafness, characteristic eye anomalies, and positive findings from glomerular ultrastructural examination. We believe that ultrastructural proof of anterior lenticonus may also be provided in the lens capsule. Arch Ophthalmol. 2000;118:895-897