Multivisceral Transplant in a Patient With Portopulmonary Hypertension: A Case Report

Portopulmonary hypertension, a type of pulmonary arterial hypertension in the setting of cirrhotic or noncirrhotic portal hypertension, is associated with elevated morbidity and mortality during and after transplantation. Uncontrolled portopulmonary hypertension may prevent or delay listing for transplant candidates, and the prognosis without treatment and ultimately transplant is extremely poor. We present a 29-year-old White woman, who had a post-liver transplant at infancy due to biliary atresia. Later on, she developed extensive portal vein thrombosis and portopulmonary hypertension and underwent a multivisceral transplant (liver, stomach, pancreaticoduodenal complex, and small and large intestine). Preoperative mean pulmonary artery pressure was <30 mm Hg with a pulmonary vascular resistance of <300 dynes^.s/cm⁵ on oral sildenafil and intravenous epoprostenol. Intraoperatively, management required comprehensive transfusion protocols, a careful balance between correcting blood loss and preventing thrombosis. Intravenous epoprostenol, sildenafil, milrinone, and inhaled nitric oxide were used to reduce elevated mean pulmonary artery pressure and right ventricular strain associated with vascular clamping, reperfusion, and massive fluid shifts. Nitric oxide and epoprostenol use unleashed antiplatelet effects on a patient already susceptible to coagulopathy. A multimodal and multidisciplinary approach continued throughout the surgery and in the postoperative period, which led to a successful outcome.

A Monte Carlo model of synchrotron radiotherapy shows good agreement with experimental dosimetry measurements: Data from the imaging and medical beamline at the Australian Synchrotron

Experimental measurement of Synchrotron Radiotherapy (SyncRT) doses is challenging, especially for Microbeam Radiotherapy (MRT), which is characterised by very high dynamic ranges with spatial resolutions on the micrometer scale. Monte Carlo (MC) simulation is considered a gold standard for accurate dose calculation in radiotherapy, and is therefore routinely relied upon to produce verification data. We present a MC model for Australian Synchrotron's Imaging and Medical Beamline (IMBL), which is capable of generating accurate dosimetry data to inform and/or verify SyncRT experiments. Our MC model showed excellent agreement with dosimetric measurement for Synchrotron Broadbeam Radiotherapy (SBBR). Our MC model is also the first to achieve validation for MRT, using two methods of dosimetry, to within clinical tolerances of 5% for a 20×20 mm² field size, except for surface measurements at 5 mm depth, which remained to within good agreement of 7.5%. Our experimental methodology has allowed us to control measurement uncertainties for MRT doses to within 5-6%, which has also not been previously achieved, and provides a confidence which until now has been lacking in MRT validation studies. The MC model is suitable for SyncRT dose calculation of clinically relevant field sizes at the IMBL, and can be extended to include medical beamlines at other Synchrotron facilities as well. The presented MC model will be used as a validation tool for treatment planning dose calculation algorithms, and is an important step towards veterinary SyncRT trials at the Australian Synchrotron.

Arteriovenous Fistulae vs. Arteriovenous Grafts: A Retrospective Review of 1,700 Consecutive Vascular access Cases

Objective

Vascular access (VA) procedures are rapidly becoming the most prevalent surgery in the United States. It is estimated that there will be over 500,000 VA procedures done this year. Previously, surgeons in the US were attempting many more non-autogenous grafts than autogenous fistulae. In recent years, there has been a great push called “Fistula First” to promote arteriovenous fistulae (AVF) as the first line of treatment vs. non-autogenous grafts. The goal of this investigation is to determine if too many fistulae are now being performed without attention to specific patient profiles.

Methods

A retrospective review of 1700 consecutive cases was performed by one surgeon at one institution between 1997 and 2005. Patients were categorized by demographics, co-morbidities, previous access procedures, access location, and type of graft. Patency was calculated. Kaplan-Meier, Cox regression and the Log Rank Test were used to analyze data. Access endpoints and complications were also documented.

Results

The study reviewed 1700 procedures. The median age was 52 (60.2% male) with 58.7% fistulae and 41.3% grafts. Median patency time was 10 months, with no statistically significant difference between access types. There was no significant difference in length of patency when comparing upper arm (70.1%), lower arm (24.5%) and thigh (5.4%). Graft infection rate was 9.5% and fistula infection rate was 0.9% (p<0.001). The overall infection rate was 4.5%, and decreased patency significantly (4 vs. 11 months). Thrombosis occurred in 24.7% of grafts and 9.0% of fistulae. Thrombosed grafts had better salvage rates (8 vs. 4 months, p<0.001). The data showed diabetes, HTN and HIV have no overall impact on patency.

Conclusions

AVF and grafts are both useful in providing VA for patients requiring hemodialysis. Our data shows that grafts are equivalent in long-term patency. Therefore, it is apparent in those patients who are not candidates for an AV fistula; an AV graft for VA should be placed.

New Graft for Low Friction Tunneling in Vascular Access Surgery

Purpose

Prosthetic accesses of the upper extremity have been in use for more than 25 years. Many different conduits have been employed; investigators have continually searched for a graft with superior properties.

Methods

We describe a prospective randomized study comparing the new Slider Graft (Atrium) with the Hybrid PTFE Graft (Atrium); the latter has been used for a number of years. The Slider Graft is also made of PTFE. For this study, both grafts were 6 mm in diameter and 40 cm in length. The Slider Graft has a low friction polyethylene sheath over its entire length. This sheath expedites the passage of the graft through the tunnel. At one end, the graft and the polyethylene sheath are attached to a metal tip. This tip has male threads, which may be inserted firmly into a Kelly Wyck, Atrium, or any standard non-sheath tunneling system. This alleviates graft separation, turning, and slipping during tunneling. The primary objective of this trial was to determine the safety and efficacy of the Slider Graft as compared to the Hybrid Graft in vascular access surgery. The secondary objective was to evaluate how tunneling effects graft performance. We randomized 60 subjects for this study with two equal arms. During surgery we measured various parameters including ease of tunneling, tunnel bleeding, anastomotic bleeding, graft sweating, and immediate patency. To assess arm edema we measured circumference 7.5 cm and 20 cm above the wrist, prior to surgery and in follow-up visits at 1 week, 1 month, and 3 months. Primary patency was also assessed at these visits and at 6, 9, and 12 months.

Results

Our results show tunneling with the Slider Graft is easier to accomplish (p = 0.0001) with reduced tunnel bleeding (p = 0.0047) and anastomotic bleeding (p = 0.042). Further, the Slider Graft virtually eliminated the complication of graft sweating and seroma development (p = 0.0005). This may be due to reduced stretching and graft wetting during insertion. At 180 days the Slider Graft demonstrated improved primary patency, which was statistically significant (p = 0.047). At 360 and 720 days the Slider Graft continued to demonstrate a trend toward improved primary patency (p = 0.160).

Conclusions

This study suggests the Slider Graft has significant advantages when compared to the Hybrid Graft and highlights the importance of tunneling in creating prosthetic accesses.

Computer hexapod-assisted orthopaedic surgery provides a predictable and safe method of femoral deformity correction

Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

Patients and Methods

The medical records and radiographs of all patients who underwent CHAOS for femoral deformity at our institution between 2005 and 2011 were retrospectively reviewed. Records were available for all 55 consecutive procedures undertaken in 49 patients with a mean age of 35.6 years (10.9 to 75.3) at the time of surgery.

Results

Patients were assessed at a mean interval of 44 months (6 to 90) following surgery. The indications were broad; the most common were vitamin D resistant rickets (n = 10), growth plate arrest (n = 6) and post-traumatic deformity (n = 20). Multi-planar correction was required in 33 cases. A single level osteotomy was performed in 43 cases. Locking plates were used to stabilise the osteotomy in 33 cases and intramedullary nails in the remainder. Complications included two nonunions, one death, one below-knee deep vein thrombosis, one deep infection and one revision procedure due to initial under-correction. There were no neurovascular injuries or incidence of compartment syndrome.

Conclusion

This is the largest reported series of femoral deformity corrections using the CHAOS technique. This series demonstrates that precise intra-operative realignment is possible with a hexapod external fixator prior to definitive stabilisation with contemporary internal fixation. This combination allows reproducible correction of complex femoral deformity from a wide variety of diagnoses and age range with a low complication rate. Cite this article: Bone Joint J 2017;99-B:283–8.

Absorbed dose determination in kilovoltage X-ray synchrotron radiation using alanine dosimeters

Alanine dosimeters from the National Physical Laboratory (NPL) in the UK were irradiated using kilovoltage synchrotron radiation at the imaging and medical beam line (IMBL) at the Australian Synchrotron. A 20 × 20 mm² area was irradiated by scanning the phantom containing the alanine through the 1 mm × 20 mm beam at a constant velocity. The polychromatic beam had an average energy of 95 keV and nominal absorbed dose to water rate of 250 Gy/s. The absorbed dose to water in the solid water phantom was first determined using a PTW Model 31014 PinPoint ionization chamber traceable to a graphite calorimeter. The alanine was read out at NPL using correction factors determined for ⁶⁰Co, traceable to NPL standards, and a published energy correction was applied to correct for the effect of the synchrotron beam quality. The ratio of the doses determined by alanine at NPL and those determined at the synchrotron was 0.975 (standard uncertainty 0.042) when alanine energy correction factors published by Waldeland et al. (Waldeland E, Hole E O, Sagstuen E and Malinen E, Med. Phys. 2010, 37, 3569) were used, and 0.996 (standard uncertainty 0.031) when factors by Anton et al. (Anton M, Büermann L., Phys Med Biol. 2015 60 6113-29) were used. The results provide additional verification of the IMBL dosimetry.

Routes of early enteral nutrition following oesophagectomy

Introduction Oesophagectomy for cancer is a challenging procedure with a five-year overall survival rate of 15-20%. Early enteral nutrition following oesophagectomy is a crucial component of the postoperative recovery and carries a significant impact on the outcome. Different methods of enteral feeding were conducted in our unit. The aim of this study was to examine the efficacy and safety of nasojejunal tube (NJT), jejunostomy tube (JT) and pharyngostomy tube (PT) feeding after oesophagectomy. Methods A retrospective review was carried out of prospectively collected data on patients with oesophageal cancer who underwent an oesophagectomy between 2011 and 2014. The primary outcome was feeding tube related complications such as occlusion, dislocation and leak. The secondary outcomes were length of stay and 30-day morbidity. Results A total of 90 oesophagectomies were included in the study. A NJT was inserted in 41 patients (45.6%), a JT was used in 14 patients (15.5%) and a PT was the route for enteral nutrition in 35 patients (38.9%). In total, five patients (5.5%) developed tube related complications. There were no tube related complications in the NJT group but one JT patient (7.1%) developed tube related cellulitis (p=0.189) and four PT patients (11.4%) developed tube related haemorrhage (p=0.544), tube dislocation (p=0.544) or cellulitis (p=0.189). The median length of stay and 30-day postoperative morbidity were similar between the groups. Conclusions NJT feeding is a less invasive, feasible route for early enteral nutrition following oesophagectomy. A randomised controlled trial is recommended to verify these findings.

High spatial resolution dosimetric response maps for radiotherapy ionization chambers measured using kilovoltage synchrotron radiation

Small circular beams of synchrotron radiation (0.1 mm and 0.4 mm in diameter) were used to irradiate ionization chambers of the types commonly used in radiotherapy. By scanning the chamber through the beam and measuring the ionization current, a spatial map of the dosimetric response of the chamber was recorded. The technique is able to distinguish contributions to the large-field ionization current from the chamber walls, central electrode and chamber stem. Scans were recorded for the NE 2571 Farmer chamber, the PTW 30013, IBA FC65-G Farmer-type chambers, the NE 2611A and IBA CC13 thimble chambers, the PTW 31006 and 31014 pinpoint chambers, the PTW Roos and Advanced Markus plane-parallel chambers, and the PTW 23342 thin-window soft x-ray chamber. In all cases, large contributions to the response arise from areas where the incident beam grazes the cavity surfaces. Quantitative as well as qualitative information about the relative chamber response was extracted from the maps, including the relative contribution of the central electrode. Line scans using monochromatic beams show the effect of the photon energy on the chamber response. For Farmer-type chambers, a simple Monte Carlo model was in good agreement with the measured response.

Alpha particle and proton relative thermoluminescence efficiencies in LiF:Mg,Cu,P:is track structure theory up to the task?

Low-energy alpha particle and proton heavy charged particle (HCP) relative thermoluminescence (TL) efficiencies are calculated for the major dosimetric glow peak in LiF:Mg,Cu,P (MCP-N) in the framework of track structure theory (TST). The calculations employ previously published TRIPOS-E Monte Carlo track segment values of the radial dose in condensed phase LiF calculated at the Instituto National de Investigaciones Nucleares (Mexico) and experimentally measured normalised (60)Co gamma-induced TL dose-response functions, f(D), carried out at the Institute of Nuclear Physics (Poland). The motivation for the calculations is to test the validity of TST in a TL system in which f(D) is not supralinear (f(D) >1) and is not significantly dependent on photon energy contrary to the behaviour of the dose-response of composite peak 5 in the glow curve of LiF:Mg,Ti (TLD-100). The calculated HCP relative efficiencies in LiF:MCP-N are 23-87% lower than the experimentally measured values, indicating a weakness in the major premise of TST which exclusively relates HCP effects to the radiation action of the secondary electrons liberated by the HCP slowing down. However, an analysis of the uncertainties involved in the TST calculations and experiments (i.e. experimental measurement of f(D) at high levels of dose, sample light self-absorption and accuracy in the estimation of D(r), especially towards the end of the HCP track) indicate that these may be too large to enable a definite conclusion. More accurate estimation of sample light self-absorption, improved measurements of f(D) and full-track Monte Carlo calculations of D(r) incorporating improvements of the low-energy electron transport are indicated in order to reduce uncertainties and enable a final conclusion.

Mysteries of LiF TLD response following high ionisation density irradiation: nanodosimetry and track structure theory, dose response and glow curve shapes

Three outstanding effects of ionisation density on the thermoluminescence (TL) mechanisms giving rise to the glow peaks of LiF:Mg,Ti (TLD-100) are currently under investigation: (1) the dependence of the heavy charged particle (HCP) relative efficiency with increasing ionisation density and the effectiveness of its modelling by track structure theory (TST), (2) the behaviour of the TL efficiency, f(D), as a function of photon energy and dose. These studies are intended to promote the development of a firm theoretical basis for the evaluation of relative TL efficiencies to assist in their application in mixed radiation fields. And (3) the shape of composite peak 5 in the glow curve for various HCP types and energies and following high-dose electron irradiation, i.e. the ratio of the intensity of peak 5a to peak 5. Peak 5a is a low-temperature satellite of peak 5 arising from electron-hole capture in a spatially correlated trapping centre/luminescent centre (TC/LC) complex that has been suggested to possess a potential as a solid-state nanodosemeter due to the preferential electron/hole population of the TC/LC at high ionisation density. It is concluded that (1) the predictions of TST are very strongly dependent on the choice of photon energy used in the determination of f(D); (2) modified TST employing calculated values of f(D) at 2 keV is in agreement with 5-MeV alpha particle experimental results for composite peak 5 but underestimates the 1.5-MeV proton relative efficiencies. Both the proton and alpha particle relative TL efficiencies of the high-temperature TL (HTTL) peaks 7 and 8 are underestimated by an order of magnitude suggesting that the HTTL efficiencies are affected by other factors in addition to radial electron dose; (3) the dose-response supralinearity of peaks 7 and 8 change rapidly with photon energy: this behaviour is explained in the framework of the unified interaction model as due to a very strong dependence on photon energy of the relative intensity of localised recombination and (4) the increased width and decrease in T(max) of composite peak 5 as a function of ionisation density is due to the greater relative intensity of peak 5a (a low-temperature component of peak 5 arising from two-energy transfer events, which leads to localised recombination).

Experimental investigation of the 100 keV X-ray dose response of the high-temperature thermoluminescence in LiF:Mg,Ti (TLD-100): theoretical interpretation using the unified interaction model

The dose response of LiF:Mg,Ti (TLD-100) chips was measured from 1 to 50,000 Gy using 100 keV X rays at the European Synchroton Radiation Facility. Glow curves were deconvoluted into component glow peaks using a computerised glow curve deconvolution (CGCD) code based on first-order kinetics. The normalised dose response, f(D), of glow peaks 4 and 5 and 5b (the major components of composite peak 5), as well as peaks 7 and 8 (two of the major components of the high-temperature thermoluminescence (HTTL) at high levels of dose) was separately determined and theoretically interpreted using the unified interaction model (UNIM). The UNIM is a nine-parameter model encompassing both the irradiation/absorption stage and the thermally induced relaxation/recombination stage with an admixture of both localised and delocalised recombination mechanisms. The effects of radiation damage are included in the present modelling via the exponential removal of luminescent centres (LCs) at high dose levels. The main features of the experimentally measured dose response are: (i) increase in f(D)(max) with glow peak temperature, (ii) increase in D(max) (the dose level at which f(D)(max) occurs) with increasing glow peak temperature, and (iii) decreased effects of radiation damage with increasing glow peak temperature. The UNIM interpretation of this behaviour requires both strongly decreasing values of ks (the relative contribution of localised recombination) as a function of glow peak temperature and, as well, significantly different values of the dose-filling constants of the trapping centre (TC) and LC for peaks 7 and 8 than those used for peaks 4 and 5. This suggests that different TC/LC configurations are responsible for HTTL. The relative intensity of peak 5a (a low-temperature satellite of peak 5 arising from localised recombination) was found to significantly increase at higher dose levels due to preferential electron and hole population of the trapping/recombination complex giving rise to composite glow peak 5. It is also demonstrated that possible changes in the trapping cross section of the LC and the competitive centres due to increasing sample/glow peak temperature do not significantly influence these observations/conclusions.

Regionally acquired intestinal failure data suggest an underestimate in national service requirements

OBJECTIVES, SETTING AND PATIENTS: With complete case referral for prolonged parenteral nutrition (PN) beyond term equivalent, serving a stable population of 1.25 million people, we describe the long-term outcome and survival of patients referred to an intestinal failure (IF) nutrition support team over the first 8 years of existence at a regional paediatric centre, and extrapolate to potential numbers of national home parenteral nutrition (HPN) cases and intestinal transplantation data.

DESIGN AND OUTCOME MEASURES

Retrospective analysis detailing patient demographics, interventions, use of HPN, occurrence of intestinal failure-associated liver disease (IFALD), and outcomes of enteral adaptation, survival, and referral for and receipt of organ transplantation.

RESULTS

23 patients were referred over 8 years, 20 being PN dependent within the neonatal period. Diagnoses included short bowel syndrome (SBS) (18), neuromuscular abnormalities (4) and congenital enterocyte disorder (1). 12 696 days of PN were delivered with 314 confirmed episodes of sepsis at a median of 12 episodes per patient. 144 central venous catheters (CVCs) were required at a median of four per patient. IFALD occurred in 17 (73%) patients, with 10 (44%) referred for transplant assessment. Thirteen (56%) children received HPN. Overall mortality was 44%. A significant predictor for survival in the SBS group was residual bowel >40 cm (82% vs 28%, p = 0.049).

CONCLUSIONS

Survival for IF at 56% was lower than reported from non-UK supra-regional centres, and nationally collected data, possibly reflecting pre-selected referral populations. Data from regional centres with complete ascertainment may be important both when counselling parents and when planning regional and national HPN and IF specialist services.

Arteriovenous fistulae vs. arteriovenous grafts: a retrospective review of 1,700 consecutive vascular access cases

OBJECTIVE

Vascular access (VA) procedures are rapidly becoming the most prevalent surgery in the United States. It is estimated that there will be over 500,000 VA procedures done this year. Previously, surgeons in the US were attempting many more non-autogenous grafts than autogenous fistulae. In recent years, there has been a great push called 'Fistula First' to promote arteriovenous fistulae (AVF) as the first line of treatment vs. nonautogenous grafts. The goal of this investigation is to determine if too many fistulae are now being performed without attention to specific patient profiles.

METHODS

A retrospective review of 1700 consecutive cases was performed by one surgeon at one institution between 1997 and 2005. Patients were categorized by demographics, co-morbidities, previous access procedures, access location, and type of graft. Patency was calculated. Kaplan-Meier, Cox regression and the Log Rank Test were used to analyze data. Access endpoints and complications were also documented.

RESULTS

The study reviewed 1700 procedures. The median age was 52 (60.2% male) with 58.7% fistulae and 41.3% grafts. Median patency time was 10 months, with no statistically significant difference between access types. There was no significant difference in length of patency when comparing upper arm (70.1%), lower arm (24.5%) and thigh (5.4%). Graft infection rate was 9.5% and fistula infection rate was 0.9% (p<0.001). The overall infection rate was 4.5%, and decreased patency significantly (4 vs. 11 months). Thrombosis occurred in 24.7% of grafts and 9.0% of fistulae. Thrombosed grafts had better salvage rates (8 vs. 4 months, p<0.001). The data showed diabetes, HTN and HIV have no overall impact on patency.

CONCLUSIONS

AVF and grafts are both useful in providing VA for patients requiring hemodialysis. Our data shows that grafts are equivalent in long-term patency. Therefore, it is apparent in those patients who are not candidates for an AV fistula; an AV graft for VA should be placed.

Reproducibility of the Gartland classification for supracondylar humeral fractures in children

PURPOSE

To evaluate the intra- and inter-observer reproducibility of the Gartland radiographic classification for supracondylar humeral fractures in children.

METHODS

Anteroposterior and lateral radiographs of 50 supracondylar humeral fractures in children were graded on 2 separate occasions by 4 orthopaedic surgeons according to the Wilkins modification of the Gartland classification. Data were analysed by calculating the Kappa values for intra- and inter-observer agreement to indicate the reproducibility of the classification.

RESULTS

There was moderate inter-observer agreement, except for poor agreement over type I fractures. Type II fractures only showed fair to moderate agreement. Type III fractures and the flexion group showed good to very good agreement. Intra-observer agreement was good to very good.

CONCLUSION

Surgeons should treat paediatric supracondylar humeral fractures based on an assessment of the degree of displacement rather than by employing the Gartland classification.

Combined surgery and chemoradiation as a treatment for the Buschke-Löwenstein tumour

BACKGROUND

The Buschke-Löwenstein tumour (BLT) or giant condyloma acuminata is a rare disease which affects the anogenital region. Although histologically benign, it behaves in a malignant fashion, infiltrating the surrounding tissues. The morbidity and mortality from this tumour is high, as is the risk of recurrence following treatment. It lies on the continuum between the benign condylomata acuminata and squamous cell carcinoma. The human papillomavirus is implicated in its aetiology. Treatment is controversial, with topical chemotherapy, radiotherapy, immunotherapy and radical surgery all having been employed. Chemoradiation remains the mainstay of treatment for anal cancers but has not been routinely employed in the management of the BLT without squamous cell carcinoma transformation.

METHODS

Two cases of extensive perineal BLT treated with chemoradiation and subsequent surgical excision are presented.

RESULTS

The first patient had a good symptomatic response to the chemoradiation but unfortunately died of recurrent disease following surgery. The second patient had a macroscopically complete response to chemoradiation and remains well following abdominoperineal excision.

CONCLUSION

Pre-operative chemoradiation has proved to be useful in management for histologically proven benign BLT

Latis™ Catheter: New Technology for Thrombectomy of Vascular access Grafts

Purpose

The most common complication of vascular access surgery is thrombosis. This study compared the gold standard Fogarty Thrombectomy Catheter, to the new latis Catheter with an advanced monofilament matrix.

Methods

30 patients with thrombosed access grafts were randomly assigned to undergo thrombectomy with the Fogarty or latis catheter. An angioscope measured remaining graft thrombi.

Results

Twenty-nine of 30 subjects were successfully thrombectomized. No statistical differences in age, gender, race, or extension graft requirements were found. Catheter use in the latis group was: 1 in 14 procedures, and 2 in 1 procedure; Fogarty group: 1 in 10 procedures, 2 in 3 procedures, and 3 in 2 procedures. The average number of catheter passes was: latis 3.06 (1–6 passes) and Fogarty 4.13 (1–9 passes). A trend in favor of the latis catheter was demonstrated; however, statistical significance was not reached (p = 0.067). The overall 6-month primary patency rates were latis (40%) and Fogarty (30%). The estimated patency at the 50th percentile for latis is 120 days and Fogarty 108 days. Statistical significance was not reached with a p-value of the Log-Rank statistic of 0.68 and a p-value of the Wilcoxon statistic of 0.78.

Conclusions

The latis and Fogarty catheters are very similar. However, the latis balloon is more rugged with fewer catheters used and reduced number of passes. A difference in primary patency could not be demonstrated. The angioscope identified significant residual thrombus despite no returning thrombus from the catheter. Consequently, our protocol is modified to include the angioscope.

LatisTM catheter: New technology for thrombectomy of vascular access grafts

PURPOSE

The most common complication of vascular access surgery is thrombosis. This study compared the gold standard Fogarty Thrombectomy Catheter, to the new latis Catheter with an advanced monofilament matrix.

METHODS

30 patients with thrombosed access grafts were randomly assigned to undergo thrombectomy with the Fogarty or latis catheter. An angioscope measured remaining graft thrombi.

RESULTS

Twenty-nine of 30 subjects were successfully thrombectomized. No statistical differences in age, gender, race, or extension graft requirements were found. Catheter use in the latis group was: 1 in 14 procedures, and 2 in 1 procedure; Fogarty group: 1 in 10 procedures, 2 in 3 procedures, and 3 in 2 procedures. The average number of catheter passes was: latis 3.06 (1-6 passes) and Fogarty 4.13 (1-9 passes). A trend in favor of the latis catheter was demonstrated; however, statistical significance was not reached (p = 0.067). The overall 6-month primary patency rates were latis (40%) and Fogarty (30%). The estimated patency at the 50th percentile for latis is 120 days and Fogarty 108 days. Statistical significance was not reached with a p-value of the Log-Rank statistic of 0.68 and a p-value of the Wilcoxon statistic of 0.78.

CONCLUSIONS

The latis and Fogarty catheters are very similar. However, the latis balloon is more rugged with fewer catheters used and reduced number of passes. A difference in primary patency could not be demonstrated. The angioscope identified significant residual thrombus despite no returning thrombus from the catheter. Consequently, our protocol is modified to include the angioscope.

Eosinophilic cholecystitis as a possible late manifestation of the eosinophilia-myalgia syndrome

We describe a case of acute acalculous cholecystitis occurring in a 43-year-old woman with a history of the eosinophilia-myalgia syndrome, associated with the ingestion of 1-tryptophan. The patient underwent a laparoscopic cholecystectomy and subsequent histological examination of the gallbladder revealed an infiltrate predominantly of eosinophils, suggesting a possible relationship to the underlying condition. This may represent a late complication of the eosinophilia-myalgia syndrome--such an association has not previously been reported in the literature. The gastrointestinal and hepatic complications of this syndrome are discussed.

Fractures of the tuberosity of the calcaneus

We describe 24 fractures of the tuberosity of the calcaneus in 22 patients. Three were similar to the type of avulsion fracture which has been well-defined but the remainder represent a group which has been unrecognised previously. Using CT and operative findings we have defined the different patterns of fracture of the calcaneal tuberosity. Ten fractures extended into the subtalar joint, but did not fit the pattern of the common intra-articular fracture as described classically. We have defined a new pattern which consists of a fracture of the medial calcaneal process with a further fracture which separates the upper part of the tuberosity in the semicoronal plane. Non-operative treatment of displaced fractures resulted in a mis-shapen heel and a poor functional outcome. Open reduction and internal fixation with either a plate or compression screw did not give satisfactory fixation. We prefer to use an oblique lateral tension-band wire. This technique gave excellent fixation and we recommend it for the treatment of displaced fractures of the tuberosity of the calcaneus.

Aicardi-Goutières syndrome displays genetic heterogeneity with one locus (AGS1) on chromosome 3p21

We have studied 23 children from 13 families with a clinical diagnosis of Aicardi-Goutières syndrome. Affected individuals had developed an early-onset progressive encephalopathy that was characterized by a normal head circumference at birth, basal ganglia calcification, negative viral studies, and abnormalities of cerebrospinal fluid comprising either raised white cell counts and/or raised levels of interferon-alpha. By means of genomewide linkage analysis, a maximum-heterogeneity LOD score of 5.28 was reached at marker D3S3563, with alpha=.48, where alpha is the proportion of families showing linkage. Our data suggest the existence of locus heterogeneity in Aicardi-Goutières syndrome and highlight potential difficulties in the differentiation of this condition from pseudo-TORCH (toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus types 1 and 2) syndrome.

Multiple cysteine proteinases of the pathogenic protozoon Tritrichomonas foetus: identification of seven diverse and differentially expressed genes

The cattle protozoan parasite Tritrichomonas foetus has multiple forms of cysteine proteinases. To investigate their diversity, PCR and reverse transcriptase PCR were used to isolate genomic DNA and cDNA fragments, respectively, encoding different cysteine proteinases. Seven genes have been identified, TFCP3-6 from amplification of genomic DNA and TFCP7-9 from amplification of cDNA. Comparison of the predicted amino acid sequences indicates that the T. foetus enzymes are cathepsin-L-like rather than cathepsin-B-like in structure. However, there is considerable diversity among the proteinases. TFCP7 and TFCP8 are most similar to one another (78% identity), while TFCP3 and TFCP9 are the least closely related (30% identity). All but one of the genes are single-copy, the exception being TFCP3, which was present in multiple copies in one of the three isolates examined. Single transcripts were detected for each of the seven genes. TFCP8 was expressed at the highest levels, while transcripts for TFCP4 were only just detectable. In T. foetus F2, the strain from which the genomic DNA and mRNA were isolated, transcripts of the five other genes were present at intermediate levels. When two other isolates were compared with F2, differences in the expression of individual genes were apparent, with either one or two of them not expressed. In spite of these differences the major cysteine proteinases detected in the three isolates using substrate-SDS-PAGE appeared identical. The data show that the multiplicity of cysteine proteinases in T. foetus is due, in part at least, to the presence of multiple genes and that some of the genes encode cysteine proteinases which are not among the high-activity enzymes detected previously.

Antenatal screening for cystic fibrosis: a trial of the couple model

OBJECTIVE

To assess the delivery and acceptability of antenatal couple screening for cystic fibrosis. Carrier status was notified only when both members of a partnership had cystic fibrosis alleles and therefore a one in four risk of having an affected child.

DESIGN

Mouthwash samples were tested when both partners participated. Results were returned only to positive couples.

SETTING

Two large maternity hospitals in Edinburgh.

SUBJECTS

Screening was offered to all couples who booked at one of the two hospitals.

MAIN OUTCOME MEASURES

(a) The take up of screening, carriers and carrier couples identified, take up of prenatal diagnosis, and numbers of affected fetuses detected; (b) questionnaire measures of patient satisfaction and stress.

RESULTS

Screening was offered to 8536 couples. 714 (8.4%) were regarded as ineligible, usually because of late booking or absence of a partner. 1900 (24.3%) of the remainder declined screening. Among the 5922 screened couples, four tested positive--that is, both partners were cystic fibrosis heterozygotes. All four elected to have prenatal diagnosis. There were three terminations of pregnancy because of an affected fetus, one couple having two successive pregnancies with affected fetuses. The participation rate was 76% for eligible couples (5922/7822) and 69% for all couples (5922/8536). Only 89 screened couples (1.5%) requested information on individual carrier status. No anxiety was detected among a cohort of the screened population, and 99% of questioned participants expressed satisfaction with the concept of couple screening.

CONCLUSIONS

Antenatal couple screening is a satisfactory and acceptable way of screening for cystic fibrosis and has been adopted as routine in the two trial hospitals.

A preliminary trial of couple screening for cystic fibrosis: designing an appropriate information leaflet

An information leaflet, inviting participation in an antenatal screening trial for cystic fibrosis, was sent to 388 couples together with the pregnant woman's first clinic appointment. The leaflet pointed out that couples would be treated as a unit and that further action would be taken only if both partners were found to carry mutant alleles. Participants and non-participants were also asked to fill in a questionnaire eliciting their views on the leaflet. Three hundred and twelve (80%) questionnaires were returned and 253 (65%) couples elected to be screened. More than 90% of respondents found the leaflet easy to understand, although about 10% wanted more information on cystic fibrosis. The main reason for entering the trial was to avoid the birth of an affected child, and the main reason for non-entry was opposition to termination of pregnancy. There was little anxiety about the prospect of being screened. However, more than a third of couples mis-identified their risk of both carrying a CF gene, despite the figure of 1 in 600 being explicitly stated in the leaflet.

An exclusion map for pre-eclampsia: assuming autosomal recessive inheritance

Pre-eclampsia is a common complication of the second half of pregnancy that is associated with substantial fetal and maternal morbidity. Although the genetic basis of the disorder is unclear, epidemiological studies suggest that it occurs predominantly in the first pregnancies of women who are homozygous for a relatively common susceptibility gene. Using this epidemiological model, we have begun to construct an exclusion map by using both candidate genes and random DNA markers on a panel of two-generation families in which pre-eclampsia was rigorously defined. No evidence was found for linkage to the HLA region or to several genes implicated in the pathogenesis of hypertension.

Association between susceptibility to pre-eclampsia within families and HLA DR4

56 women who had had proteinuric pre-eclampsia and who had parous sisters were studied. In first pregnancy, proteinuric pre-eclampsia was more common in the sisters than in the maternity hospital population (8/71 [11%] vs 41/1978 [2%]); the relative risk was 6.0. The frequency of HLA DR4 was higher in sisters with pregnancy-induced hypertension than in sisters with normotensive pregnancies (8/18 [44%] vs 10/54 [19%]) and more of them shared HLA DR4 with their spouses (4/14 [29%] vs 0/29). Genetic susceptibility to pre-eclampsia is associated with HLA DR4; it may be conferred by fetomaternal sharing of a single recessive HLA-linked gene.