Caregiver strain on informal caregivers when providing care for older patients undergoing major abdominal surgery: a longitudinal prospective cohort study

Background

Health-care systems nowadays rely on complementary patient care by informal caregivers. The need for, and burden on, informal caregivers will likely increase in the upcoming years. This study aimed to examine the burden on caregivers when providing care for elderly patients undergoing major abdominal surgery.

Methods

A single-centre longitudinal cohort study was conducted between November 2015 and June 2018 in the Amphia hospital in Breda, the Netherlands. Patients aged 70+ undergoing elective surgery for colorectal carcinoma (CRC) or an abdominal aortic aneurysm (AAA) were included in this study. Informal caregiver burden was assessed and compared over time using the Caregiver Strain Index (CSI) at the outpatient clinic visit, at discharge, 2 weeks post-discharge and after 6 and 12 months. The effects of patient- and caregiver-related factors on the experienced caregiver strain were examined.

Results

CSI scores of 248 caregivers were significantly increased at discharge (3.5 vs 2.6; p < 0.001) and 2 weeks post-discharge (3.3 vs 2.6; p < 0.001). After 12 months, scores dropped below baseline scores (1.8 vs 2.6; p = 0.012). The highest strain was observed 2 weeks post-discharge for AAA patients and at discharge for CRC patients. Older age, physical or cognitive impairment and burden of comorbidity were associated with an increased caregiver strain at baseline. Type of surgery was independently associated with the change in mean CSI scores over time; a bigger change in caregiver burden is observed after open surgery.

Conclusion

In the early postoperative period, perceived caregiver strain was significantly increased. Psychological support for caregivers may be advisable, with timing of this support depending on diagnosis and patient-related factors.

Trial registration

This manuscript was retrospectively registered on 05-04-2016 in the Netherlands Trial Register (NTR5932). http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5932

Chapter of Gastroenterologists professional guidance for management of patients with liver disease in Singapore during the COVID-19 pandemic

In this paper, we aim to provide professional guidance to clinicians who are managing patients with chronic liver disease during the current coronavirus disease 2019 (COVID-19) pandemic in Singapore. We reviewed and summarised the available relevant published data on liver disease in COVID-19 and the advisory statements that were issued by major professional bodies, such as the American Association for the Study of Liver Diseases and European Association for the Study of the Liver, contextualising the recommendations to our local situation.

Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Chapter of Gastroenterologists professional guidance on risk mitigation for gastrointestinal endoscopy during COVID-19 pandemic in Singapore

In this paper, we aimed to provide professional guidance to practising gastrointestinal (GI) endoscopists for the safe conduct of GI endoscopy procedures during the current coronavirus disease 2019 (COVID-19) pandemic and future outbreaks of similar severe respiratory tract infections in Singapore. It draws on the lessons learnt during the severe acute respiratory syndrome (SARS) epidemic and available published data concerning the COVID-19 pandemic. It addresses measures before, during and after endoscopy that must be considered for both non-infected and infected patients, and provides recommendations for practical implementation.

The Role of Delirium and Other Risk Factors on Mortality in Elderly Patients with Critical Limb Ischemia Undergoing Major Lower Limb Amputation

BACKGROUND

Delirium in patients with critical limb ischemia (CLI) is associated with increased mortality. The main goal of this study was to investigate the association between delirium and mortality in patients undergoing major lower limb amputation for CLI. In addition, other risk factors associated with mortality were analyzed.

METHODS

An observational cohort study was conducted including all patients aged ≥70 years with CLI undergoing a major lower limb amputation between January 2014 and July 2017. Delirium was scored using the Delirium Observation Screening Score in combination with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Risk factors for mortality were analyzed by calculating hazard ratios using a Cox proportional hazards model.

RESULTS

In total, 95 patients were included; of which, 29 (31%) patients developed a delirium during admission. Delirium was not associated with an increased risk of mortality (hazard ratio [HR] = 0.84; 95 % confidence interval [CI]: 0.51-1.73; P = 0.84). Variables independently associated with an increased risk of mortality were age (HR 1.1; 95% CI 1.0-1.1), cardiac history (HR 3.3; 95% CI 1.8-6.1), current smoking (HR 2.9; 95% CI 1.6-5.5), preoperative anemia (HR 2.8; 95% CI 1.1-7.2), and living in a nursing home (HR 2.2; 95% CI 1.1-4.4).

CONCLUSION

Delirium was not associated with an increased mortality risk in elderly patients with CLI undergoing a major lower limb amputation. Factors related to an increased mortality risk were age, cardiac history, current smoking, preoperative anemia, and living in a nursing home.

The Mollring Cutter™ Remote Endarterectomy: Preliminary Experience with a New Endovascular Technique for Treatment of Occlusive Superficial Femoral Artery Disease

Purpose:

To evaluate the feasibility and efficacy of the Mollring Cutter™ remote endarterectomy (EA) technique in the treatment of occlusive superficial femoral artery (SFA) disease.

Methods:

A new device was developed to perform remote EA of occluded SFAs through a single groin incision. The technique initially uses a conventional ring stripper, which is exchanged for a double-ring cutter that transects the distal atheroma core. The entire core and cutter are removed simultaneously, and a Palmaz stent is implanted to secure the distal intimal flap.

Results:

Twenty-six consecutive patients with disabling claudication or critical ischemia were treated for long segment occlusions (n = 23) and multiple stenoses (n = 3). Patients were evaluated on the intention-to-treat basis. Clinical and anatomic success was achieved in all 26 SFAs. Average length of the endarterectomized segments was 29.9 cm (range 23 to 41). Technical problems were encountered intraoperatively in four patients, including one who required a second incision at the distal SFA to retrieve a broken ring. Recovery was uneventful in all patients. At up to 6-month follow-up, one reocclusion has been seen at 5 months.

Conclusions:

Based on this early experience, remote EA with the Mollring Cutter appears to be a feasible and effective method for treating occlusive SFA disease. Obviating the need for a second incision at knee level, this technique offers a less invasive approach that should facilitate postoperative recovery and earlier discharge.

Review: Quality of life in lower limb peripheral vascular surgery

PURPOSE

Vascular intervention studies generally consider patency and limb salvage as primary outcomes. However, quality of life is increasingly considered an important patient-oriented outcome measurement of vascular interventions. Existing literature was analyzed to determine the effect of different treatments on quality of life for patients suffering from either claudication or critical limb ischemia.

BASIC METHODS

A review of the literature was undertaken in the Medline library. A search was performed on quality of life in peripheral arterial disease. Results were stratified according to treatment groups.

PRINCIPAL FINDINGS

Twenty-one articles described quality of life in approximately 4600 patients suffering from peripheral arterial disease. Invasive treatment generally results in better quality of life scores (at a maximum of 2 years of follow-up), compared with non-invasive treatment. In patients with critical limb ischemia, successful revascularization improves quality of life scores. Only one study reported long-term results.

CONCLUSIONS

Increase in quality of life scores can be found for any intervention performed for peripheral arterial disease. However, there is scarce information on long-term quality of life after vascular intervention.

Reinterventions following endovascular abdominal aortic aneurysm repair: the learning curve of time

AIM

The DREAM and EVAR-1 trial show a higher reintervention rate after endovascular aneurysm repair (EVAR) compared to open repair. Since the initiation of these trials, endovascular-graft design and the experiences with EVAR have evolved substantially. The aim of this study was to compare the need for reinterventions in our recent EVAR procedures with our early procedures.

METHODS

A retrospective review of our prospectively maintained database of all patients undergoing an elective EVAR for infrarenal abdominal aortic aneurysm (AAA) was performed. The 68 patients treated between 2000 and 2006 were defined as the "Early EVAR" group; the 41 patients treated between 2006 and 2008 were defined as the "Recent EVAR" group. The median follow-up was 63.3 (range 2-111) and 43.7 (range 1-61) months in the Early and Recent EVAR group respectively.

RESULTS

Treatment related mortality occurred in three (4.4%) patients in the Early EVAR group. No treatment related mortality occurred in the Recent EVAR group. In the Early EVAR group 16 reinterventions occurred in 13 patients (19.1%) and in the Recent EVAR group three reinterventions occurred in three patients (7.5%). This difference was statistically significant (P=0.039).

CONCLUSION

In our center, continued experiences with EVAR, improvement of graft design and a different management of complications have led to a significant decrease in reinterventions after EVAR. These findings and a review of the literature suggests that current need for reintervention after EVAR is substantially less than reported in the early trials.

Pathophysiology and treatment of edema following femoropopliteal bypass surgery

Substantial lower-limb edema affects the majority of patients who undergo peripheral bypass surgery. Edema has impairing effects on the microvascular and the macrovascular circulation, causes discomfort and might delay the rehabilitation process of the patient. However, the pathophysiology of this edema is not well understood. The Cochrane Library and Medline were used to retrieve literature on edema following peripheral bypass surgery. Factors other than local wound healing alone are suggested in the literature to play a role, given the severity and duration of this edema. Hyperemia, microvascular permeability, reperfusion-associated inflammation and lymphatic disruptions are likely to facilitate the development of edema. Preventive methods could be lymphatic-sparing surgery, intraoperative antioxidative therapy and postoperative elevation. Successful treatment strategies to reduce postoperative edema are based on lymph massage and external compression. In conclusion, the pathophysiology of edema following peripheral surgery is not fully understood, although reperfusion-associated inflammation and lymphatic disruptions are likely to play a crucial role. When future less-invasive techniques prove to be successful, postoperative edema might be minimized. Until then, a careful lymphatic-sparing dissection should be executed when performing a peripheral bypass reconstruction. Postoperatively, the use of compression stockings and leg elevation are currently the golden standards.

Quality of life in perspective to treatment of postoperative edema after peripheral bypass surgery

BACKGROUND

To examine the effects of peripheral bypass surgery on patients' quality of life (QoL) as well as to compare two treatment modalities to reduce postoperative edema with regard to patients' QoL.

METHODS

This was a randomized controlled trial set in the department of vascular surgery in a nonacademic teaching hospital. Ninety-three patients (mean age, 70 years; 33% Rutherford 5-6), enrolled between August 2006 and September 2009, who underwent peripheral bypass surgery (autologous 57, polytetrafluoroethylene 36). Patients were assigned to intermittent pneumatic compression (n = 46) or to compression stockings (n = 47). The main outcome measure was QoL, measured with the World Health Organization Quality of Life assessment instrument (short form: WHOQOL-BREF).

RESULTS

QoL improved on the domain of Physical Health by 7.18 points (P < 0.001 [range, 0-100]) after 2 weeks and by 10.03 points (P < 0.001) after 3 months. Patients who received a polytetrafluoroethylene bypass scored 0.45 points (P = 0.0008 [range, 1-5]) lower at baseline on Global QoL than patients who received an autologous bypass. Type of bypass or edema treatment method did not affect the improvements. Edema did not correlate with QoL.

CONCLUSION

Improvement in QoL on the domain Physical Health following femoropopliteal bypass surgery was found as soon as 2 weeks after surgery. Improvement in QoL domains was not influenced by the type of bypass reconstruction. No specific effects of edema on QoL were detected.

Midterm results of autologous saphenous vein and ePTFE pre-cuffed bypass surgery in peripheral arterial occlusive disease

INTRODUCTION

The graft of choice in lower limb bypass surgery is the autologous saphenous vein (ASV). However, a prosthetic graft is needed in the absence of an ASV. In such situations, we used an expanded polytetrafluoroethylene (ePTFE) pre-cuffed Dynaflo graft as supragenicular bypass or Distaflo graft as infragenicular or femorocrural bypass. In respect to the expanding possibilities of percutaneous transluminal angioplasty (PTA), the indication for bypass surgery moved toward patients with advanced stages of peripheral arterial occlusive disease. For this reason, this study analyzed the current performances of these ePTFE grafts and ASV grafts with special attention to limb salvage.

METHODS

In a retrospective study all patients who underwent peripheral bypass surgery between 2004 and 2008 were included. Kaplan-Meier curves were used to express primary patency, secondary patency, and limb salvage rates at 1 and 3 years. Log-rank tests were performed to compare graft types.

RESULTS

A total of 272 grafts (ePTFE/ASV: 110/162) were performed in lower limb bypass surgery. The mean follow-up was 20.3 months. The secondary 3-year patency rates were for (n=78) supragenicular grafts (ePTFE/ASV: 45%/94%)*, for (n=124) infragenicular grafts (24%/74%), and 70 for femorocrural grafts (26%/52%). Limb salvage after 3 years was 59% in the ePTFE group versus 78% in the ASV group (P < .05).

CONCLUSION

In the current population of vascular patients where no PTA is possible and a peripheral bypass is necessary, the ASV remains the graft of first choice. However, the pre-cuffed ePTFE graft is a good alternative, especially in cases of critical limb ischemia, in respect to an acceptable limb salvage rate.

Evaluation of A-V impulse technology as a treatment for oedema following polytetrafluoroethylene femoropopliteal surgery in a randomised controlled trial

OBJECTIVE

To investigate the efficacy of A-V impulse technology (A-V) for oedema prevention and treatment following PTFE femoropopliteal surgery.

DESIGN

Prospective randomized clinical trial.

MATERIALS

36 patients undergoing PTFE femoropopliteal bypass reconstructions, either being treated postoperatively with a compression stocking (CS) (Group-1, n = 19) or with A-V (Group-2, n = 17).

METHODS

Patients in treatment group-1 used a CS postoperatively during 1 week day and night, patients in group-2 were treated with A-V postoperatively at night during one week. The lower leg circumference was measured preoperatively and at five postoperative time points.

RESULTS

Limb circumference has increased postoperatively on day 1 (CS 1.5%/A-V 1.4%), on day 4 (5.7%/6.3%), on day 7 (6.6%/6.1%), on day 14 (7.9%/7.7%) and on day 90 (5.8%/5.2%). Differences between treatment groups were not significant. A re-operation gives a significant 3.9% increase in circumference as compared to a first operation (95% CI: 1.5-6.4%; p = 0.002).

CONCLUSION

No significant differences were found in the extent of developed edema between the groups following PTFE femoropopliteal bypass surgery. A redo peripheral bypass operation results in significantly more postoperative oedema than a first-time performed bypass operation.

Surgical removal of an infected aortic endoprosthesis using a wire cutter

The purpose of this study is to report a new method of removing an infected endoprosthesis from the abdominal aorta using a wire cutter. A 65-year-old man with a ruptured abdominal aortic aneurysm was admitted to our hospital. He was treated with an endovascular abdominal endoprosthesis and discharged one week later. Three months after placement, the patient returned with an infection of the aortic endoprosthesis. The endoprosthesis had been fixed with barbs and hooks above the renal arteries and was surgically explanted by using a wire cutter to cut the hooks. The bare suprarenal stent was left in place. The patient was discharged one month after stent removal, and was treated with oral antibiotics for another ten weeks. At one year follow-up the patient showed no clinical, biochemical, or radiological signs of infection. In conclusion, infected endoprostheses should be surgically removed according to the medical literature. We recognize that removing a Zenith endoprostheses requires a dangerous operation because the hooks of the bare stent are engaged into the supra-renal aorta. This case report documents a new technique to safely remove an infected endoprosthesis with the help of a wire cutter.

Tuberculosis of the chest wall: unusual presentation as a breast lump

A 33-year-old woman presented with a painless right breast lump of four weeks' duration. There were no symptoms such as fever or night sweats. Mammogram revealed an elliptical lesion in the retromammary region. Ultrasonography showed a hypoechoeic collection deep in the right breast. As the lesion was localised to the chest wall, computed tomography of the thorax was performed. This confirmed a fluid collection in the right anterior chest wall and also bilateral upper lobe consolidations, suggestive of pulmonary tuberculosis with an abscess in the anterior chest wall. Ultrasound-guided core needle biopsy confirmed a Mycobacterium tuberculosis infection. It is unusual for a tuberculous abscess of the chest wall to present as a painless breast lump. We also present a companion case of tuberculous mastitis to illustrate their distinct imaging features.

Endovascular aneurysm repair with Zenith graft. Complications caused by leg extensions

AIM

A large amount of Zenith endovascular stent complications is due to problems with the leg extensions. This kind of complication has never been reported in literature. The aim of this study was to monitor the complications of endovascular abdominal aneurysm repair (EVAR) performed with the Zenith endovascular graft occurred in the Amphia Ziekenhuis in Breda to see how many recurrences were due to leg extension.

METHODS

The study enrolled all patients (N.=66) treated with the Zenith endograft in the period between October 2000 and September 2006. Mortality, complications and the number of reinterventions were analysed. Average age of the patients was 73.4 years, average follow-up was 24.5 months and average aneurysm size was 61.5 mm. Radiologic follow-up was performed by computed tomography scans and X-rays.

RESULTS

Postoperative mortality rate was 0%. The overall mortality rate during follow-up was 3%. Ten patients required a total number of 12 reinterventions (15%). The average time for reintervention was 10 months after the primary operation. Mortality, complication and reintervention rates were comparable with those reported in the literature, but 75% of these reinterventions were related to the leg extensions.

CONCLUSION

Authors observed that nine out of 12 complications which required reintervention were due to problems with one of the leg extensions. This is the first study that specifies clearly the percentage of problems with leg extensions in EVAR (75%). When placing a Zenith endovascular graft extra attention should be paid to optimal placement of the leg extensions.

Effects of temperature and pH on adsorption of basic brown 1 by the bacterial biopolymer poly(gamma-glutamic acid)

Poly(gamma-glutamic acid) (gamma-PGA), an extracellular polymeric substance (EPS) synthesized by Bacillus species, was explored to study its interaction with the basic brown 1 dye by conducting a systematic batch adsorption study as affected by two critical parameters, temperature and pH. Adsorption isotherms were closely predicted by Temkin equation among the eight isotherm models tested. The rate of adsorption was very rapid attaining equilibrium within 60 min and the kinetics were well described by both modified second-order and pseudo second-order models. Boyd's ion exchange model, which assumes exchanges of ions to be a chemical phenomenon, also fitted the kinetic data precisely. The adsorption rate increased with increasing solution temperature, however, a reversed trend was observed for the adsorption capacity. Changes in enthalpy, entropy and free energy values revealed dye adsorption by gamma-PGA to be an exothermic and spontaneous process involving no structural modification in gamma-PGA, whereas the activation energy of 37.21 kJ/mol indicated dye adsorption to be reaction-controlled. Following a rise in solution pH, the dye adsorption increased and reached a plateau at pH 5, while the maximum release of dye from spent gamma-PGA occurred at pH 1.5, suggesting a possible ion exchange mechanism. Ion exchange adsorption of basic dyes by gamma-PGA was further proved by the presence of two new IR bands at approximately 1600 and 1405.72 cm(-1), representing asymmetric and symmetric stretching vibration of carboxylate anion, for dye-treated gamma-PGA.

Encapsulation of lycopene extract from tomato pulp waste with gelatin and poly(gamma-glutamic acid) as carrier

Tomato pulp waste, a byproduct obtained during the processing of tomato juice, has been shown to be a rich source of lycopene. The objectives of this study were to use gelatin and poly(gamma-glutamic acid) (gamma-PGA) as coating materials for the encapsulation of lycopene extract from tomato pulp waste. Initially, lycopene was extracted with supercritical carbon dioxide, followed by microencapsulation using an emulsion system consisting of 4.5% gelatin, 10% gamma-PGA, and 4.8% lycopene extract. Analysis of differential scanning calorimetry revealed that the thermal stability of the coating material could be up to 120 degrees C, with a mean particle size of 38.7 microm based on Coulter counter analysis. The total weight of microencapsulated powder was 617 microg with the yield of lycopene being 76.5%, indicating a 23.5% loss during freeze drying. During storage of microencapsulated powder, the concentrations of cis-, trans-, and total lycopene decreased along with increasing time and temperature. A fast release of lycopene in the powder occurred at pH 5.5 and 7.0, while no lycopene was released at pH 2.0 and 3.5.

Clinical outcome after re-occlusion of initially successful remote endarterectomy of the superficial femoral artery

AIM

The clinical consequences of re-occlusion after initially successful arterial revascularization procedures might be as important as patency when it comes to procedure selection. This study evaluates the clinical consequences of re-occlusion after initially successful remote superficial femoral artery endarterectomy (RSFAE), in particular the recurrence and severity of symptoms and the need for re-intervention or amputation.

METHODS

A total of 239 successful RSFAEs were performed with a mean endarterectomized segment of 30 cm (10 to 45 cm) between March 1994 and December 2003 in 214 patients (144 males, 163 procedures) with a median age of 63 years (39 to 89 years). Indications for operation were Rutherford category 3 in 174 procedures (73%), Rutherford category 4 in 27 procedures (11%), and Rutherford category 5 in 38 procedures (16%). The incidence and time interval of re-occlusion with the presenting symptoms were recorded as well as the therapeutic consequences.

RESULTS

A total of 79 (33%) re-occlusions occurred (40 males, 41 procedures; 34 females, 38 procedures). Eighty percent of patients still had improved or unchanged symptoms following re-occlusion compared to the initial indication for operation, 18% had become worse and 2% were unknown. The mean time between RSFAE and re-occlusion was 17 months (1 day to 88 months). A total of 36 re-interventions were performed: 7 percutaneous recanalisations (one followed by thrombolysis), 5 percutaneous thrombolyses, 1 thrombectomy, 21 venous and 2 prosthetic femoropopliteal bypasses. A further three venous bypasses were planned. Five (14%) of these re-interventions were acute with an overall median time interval between re-occlusion and re-intervention of 41 days (0 to 68 months). Two below-knee amputations were performed: one the same day of re-occlusion, 44 months after RSFAE and one 11 days after re-occlusion, 30 days after RSFAE.

CONCLUSION

The clinical consequences of re-occlusion after remote endarterectomy for long occlusive disease of the superfricial femoral artery, from a mixed patient population with 27% ischemic rest pain and gangrene, were mild with 31 elective and only five acute re-interventions and two below-knee amputations.

Removal of cationic dyes from aqueous solution using an anionic poly-gamma-glutamic acid-based adsorbent

Natural polymeric materials are gaining interest for application as adsorbents in wastewater treatment due to their biodegradable and non-toxic nature. In this study, a biopolymer, poly-gamma-glutamic acid (gamma-PGA) derived from bacterial sources (Bacillus species) was evaluated for its efficiency in removing basic dyes from aqueous solution. Sorption studies under batch mode were conducted using C.I. Basic blue 9 (BB9) and C.I. Basic green 4 (BG4) as test dyes. Equilibrium process conformed well with the Redlich-Peterson isotherm equation and the monolayer sorption capacity obtained from the Langmuir model was 352.76 and 293.32mg/g for BB9 and BG4 dyes, respectively. The kinetic studies of dye sorption on gamma-PGA gave high coefficients of determination (>0.98) for a pseudo second-order equation. An ion-exchange model, which assumes adsorption as a chemical phenomenon, was also found to fit the kinetic data precisely. The dye sorption largely depended on the initial pH of the solution with maximum uptake occurring at pH above 5. About 98% of the dye adsorbed on gamma-PGA could be recovered at pH 1, which facilitates the reuse of spent gamma-PGA.

Effect of pH on binding of mutagenic heterocyclic amines by the natural biopolymer poly(gamma-glutamic acid)

Poly(gamma-glutamic acid) (gamma-PGA), a nontoxic and biodegradable macropolymer, was evaluated for its efficiency in binding three mutagenic heterocyclic amines (HAs), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-p-2), as affected by pH in a batch mode. The maximum HA sorption was attained for pH 3-7 and decreased sharply for pH less than 3. Binding isotherms obtained at pH 2.5 and 5.5 showed different isotherm shapes that belong to S and L types, respectively. The isotherm data at pH 2.5 were well described by a linear form of the Langmuir equation, while at pH 5.5 it showed two distinct curves, which were precisely fitted as multiple Langmuir curves. The deviation of linearity in Scatchard plot proved the multisite HA sorption. The Brunauer-Emmett-Teller equation also fitted better to isotherm data at pH 5.5, suggesting a multisite sorption caused by multimolecular HA layers on gamma-PGA. High HA sorption levels of 1250, 667, and 1429 mg/g at pH 2.5 and 1429, 909, and 1667 mg/g at pH 5.5 were observed for MeIQ, 4,8-DiMeIQx, and Trp-p-2, respectively. Among the HAs studied, the sorption capacity correlated directly with hydrophobicity of HAs and inversely with the number of methyl groups in HA molecules. The plausible binding mechanism of HAs on gamma-PGA may include a combination of hydrophobic, hydrogen-bonding, ionic, and dipole-dipole interactions.

Outcome After Occlusion of Infrainguinal Bypasses in the Dutch BOA Study: Comparison of Amputation Rate in Venous and Prosthetic Grafts

OBJECTIVE

To compare the consequences of occlusion of infrainguinal venous and prosthetic grafts.

METHODS

In total, 2690 patients were included in the Dutch BOA study, a multicenter randomised trial that compared the effectiveness of oral anticoagulants with aspirin in the prevention of infrainguinal bypass graft occlusion. Two thousand four hundred and four patients received a femoropopliteal or femorodistal bypass with a venous (64%) or prosthetic (36%) graft. The incidence of occlusion and amputation was calculated according to graft material and the incidence of amputation after occlusion was compared with Cox regression to adjust for differences in prognostic factors.

RESULTS

The indication for operation was claudication in 51%, rest pain in 20% and tissue loss in 28% of patients. The mean follow up was 21 months. After venous bypass grafting 171 (15%) femoropopliteal and 96 (24%) femorodistal grafts occluded. After prosthetic bypass grafting 234 (30%) femoropopliteal and 25 (38%) femorodistal grafts occluded. Patients with occlusions in the venous group had more severe ischemia, less runoff vessels and were older than the patients with prosthetic grafts. In the venous occlusion group 54 (20%) amputations were performed compared to 42 (16%) in the prosthetic occlusion group; crude hazard ratio 1.17 (95% CI 0.78-1.75). After adjustment for above mentioned differences in patient characteristics the hazard ratio was 0.86 (95% CI 0.56-1.32).

CONCLUSION

The need for amputation after occlusion is not influenced by graft material in infrainguinal bypass surgery.

Founder mutation in the BRCA1 gene in Malay breast cancer patients from Singapore

The mutation spectrum of the BRCA1 gene among ethnic groups from Asia has not been well studied. We investigated the frequency of mutations in the BRCA1 gene among Malay breast cancer patients from Singapore, independent of family history. By using the protein truncation test (PTT) and direct sequencing, BRCA1 mutations were detected in 6 of 49 (12.2%) unrelated patients. Four novel missense mutations in exon 11, T557A (1788A>G), T582A (1863A>G), N656S (2086A>G) and P684S (2169C>T) were identified in one patient. Two patients had missense mutations in exon 23, V1809A (5545T>C), which has been previously detected in individuals from Central and Eastern Europe. Three unrelated patients had the deleterious 2846insA frameshift mutation in exon 11. Methylation specific PCR (MSP) of the promoter region of the BRCA1 gene detected hypermethylation of tumor DNA in an additional 2 patients. Haplotype analysis using the microsatellite markers D17S855, D17S1323 and D17S1325 revealed a common haplotype for the three unrelated patients and their three relatives with the 2846insA mutation. These findings strongly suggest that the 2846insA mutation, the most common deleterious mutation in this study, may possibly be a founder mutation in breast cancer patients of Malay ethnic background.

Remote endarterectomy: first choice in surgical treatment of long segmental SFA occlusive disease?

OBJECTIVES

to report the long term results of remote superficial femoral artery endarterectomy (RSFAE) with the MollRing Cutter for the treatment of long segmental SFA occlusive disease.

DESIGN

retrospective open study.

PATIENTS AND METHODS

from March 1994 to August 2000 183 RSFAEs were performed in 164 selected patients (105 males, 120 procedures) with a median age of 63 years (43-84 years). Indications for operation were disabling intermittent claudication in 129 procedures (70%), rest pain in 20 procedures (11%), and limb salvage in 34 procedures (19%). Follow up consisted of clinical evaluation, ankle-brachial index measurements and duplex scanning.

RESULTS

the mean follow-up time was 29.3 months. The mean length of the endarterectomised SFAs was 31 cm (range, 17-45cm). The five year cumulative primary patency rate by means of life table analysis was 37.8+/-6.67% (SE). Percutaneous transluminal balloon angioplasty and surgical re-intervention were performed in twenty-nine and four patients respectively resulting in a primary assisted patency rate of 47.9+/-6.27%. Limb salvage was achieved in 30 of the 34 patients. Females had a statistically significant lower primary patency rate, i.e., 26 vs 45% (p -value=0.01).

CONCLUSIONS

the long term results of remote SFA endarterectomy show that it is a safe, effective and durable, minimally invasive procedure. It also leaves open all other options for conventional bypass procedures. The five-year primary patency rate is at least similar to prosthetic above-knee bypass surgery.

Molecular analysis of the INK4A and INK4B gene loci in human breast cancer cell lines and primary carcinomas

The INK4A and INK4B loci are located at 9p21 and have been implicated in the tumorigenesis of various human malignancies. The INK4A gene encodes two cell cycle regulators, p16(INK4A) and ARF, while INK4B encodes p15(INK4B). Previously, we have shown that the p16(INK4) tumor suppressor was not mutated or deleted in primary breast carcinomas. However, primary and metastatic breast carcinomas exhibited a relative hypomethylation of p16(INK4A), which is associated with expression, compared to normal breast tissue. The present study was conducted to determine if inactivation of p15(INK4B) and INK4A exon 1beta (ARF) are common events in breast carcinoma. Mutational analysis was performed by PCR-SSCP, and mRNA expression was evaluated by RT-PCR. Methylation-specific PCR was used to determine the methylation status of the p15(INK4B) promoter. Our results demonstrate that the p15(INK4B) gene was altered in 3 (21%) of the 14 breast cell lines; one had a silent mutation and two had homozygous deletion of the gene. None of the cell lines showed methylation of p15(INK4B). Two (14%) cell lines had homozygous deletion of INK4A exon 1beta. All normal and malignant breast tissue samples were wild-type and non-methylated for p15(INK4B) and wild-type for exon 1beta. Our results show that these structurally and functionally related genes are not invariably affected together, and the most frequently observed alteration at the INK4A and INK4B loci in breast carcinoma appears to be p16(INK4A) hypomethylation.

Expression of E2F-1 and E2F-4 is reduced in primary and metastatic breast carcinomas

The E2F family of transcription factors can induce both cell proliferation and apoptosis. Whether they function as oncogenes or tumor suppressors appears to be tissue specific. Their role in breast carcinogenesis remains unclear. We found a decreased expression of E2F-1 and E2F-4 in 70% (7/10) of primary breast carcinomas and in all (10/10) metastatic nodal tissues when compared with the corresponding normal breast tissue. No tumor-specific mutation was detected, but polymorphisms were identified in E2F-1 exon 5 and in the polyserine tract of E2F-4. The presence of polymorphisms did not correlate with E2F expression. Among the 12 human breast cancer cell lines, one contained a missense mutation in E2F-1 exon 2. Five (42%) cell lines overexpressed E2F-1, while three (25%) expressed low levels of the protein. Our results suggest that not only are the E2Fs likely to function as tumor suppressors in breast cancer, but also that their down-regulation may be important in the development of metastases.

Genetic alterations of the p14ARF -hdm2-p53 regulatory pathway in breast carcinoma

TP53 is the most commonly mutated tumor suppressor gene in human cancers. The amplification and overexpression of HDM2 plays a role in tumorigenesis via inactivation of p53-dependent cell cycle arrest. p14ARF, an alternate transcript of the INK4A tumor suppressor locus, prevents hdm2-induced transcriptional silencing of p53 by binding hdm2. The role of this p14ARF-hdm2-p53 regulatory pathway in breast carcinoma is unknown. We hypothesized that p14ARF mutations and HDM2 gene amplification may be alternative mechanisms of p53 inactivation in breast cancer. Mutational analysis of TP53 (exons 5-9) and exon 1beta of pl4ARF was performed by PCR-SSCP and putative mutations were confirmed by sequencing. p14ARF mRNA expression was evaluated by RT-PCR and the presence of HDM2 gene amplification by differential PCR. Among the cell lines, 7/14 (50%) harbored TP53 mutations and 2/14 (14%) had a deletion ofp14ARF exon 1beta with no detectable p14ARF mRNA. None demonstrated HDM2 gene amplification. TP53 mutations were identified in 7/36 (19%) breast tumors and HDM2 amplification in 2/30 (7%) tumors. All the tumors contained an intact p14ARF exon 1beta with corresponding expression of the mRNA. Alterations in the various components of this regulatory pathway were identified in nine (64%) cell lines and 25% of the 36 breast cancers with TP53 mutation being the predominant aberration. Although p14ARF mutations and HDM2 gene amplification appear to be uncommon events in breast carcinoma, deregulation of this pathway may occur via alternative mechanisms in breast carcinogenesis.

In microdissected ductal carcinoma in situ, HER-2/neu amplification, but not p53 mutation, is associated with high nuclear grade and comedo histology

BACKGROUND

HER-2/neu and p53 are two molecular markers that have been the focus of investigation in patients with invasive breast carcinoma. However, most of the published data have relied on immunohistochemical detection of the proteins as a surrogate marker of the underlying genetic alterations, a detection method that often gives variable results due to technical factors. In addition, there are limited data documenting HER-2/neu amplification and p53 mutations in the various histologic subtypes of ductal carcinoma in situ (DCIS). The authors evaluated a series of microdissected, pure DCIS lesions comprising a spectrum of morphologic subtypes (comedo, micropapillary, papillary, cribriform, and solid) and their corresponding normal breast tissue for genetic aberrations in HER-2/neu and p53.

METHODS

HER-2/neu amplification was determined by differential polymerase chain reaction, and p53 mutations were identified by single-strand conformation polymorphism analysis.

RESULTS

HER-2/neu amplification was identified in 12 of 30 DCIS samples (40%), and p53 mutations were identified in 6 of 30 DCIS samples (20%). The genetic alterations were not present in any of the normal breast tissue samples. HER-2/neu amplification occurred predominantly in the comedo subtype (69% vs. 18% of the noncomedo subtype; P = 0.008) and in lesions of high nuclear grade (63% vs. 14% of low grade; P = 0.01). There was no difference in the frequency of p53 mutations among the subtypes or between low grade and high grade lesions. No correlation between the presence of the two genetic alterations was observed.

CONCLUSIONS

The presence of HER-2/neu amplification, but not p53 mutations, correlates with histologic subtype and nuclear grade. The relatively frequent occurrence of HER-2/neu amplification and p53 mutations in DCIS tissue and their absence in normal breast tissue suggest that these genetic aberrations are important early in breast duct carcinogenesis.

Novel germline BRCA1 mutations detected in women in singapore who developed breast carcinoma before the age of 36 years

BACKGROUND

In recent years, although BRCA1 has been extensively investigated, the contribution of inherited BRCA1 mutations to breast carcinoma in Asian populations is largely unknown. The authors undertook this study to determine the prevalence and spectrum of germline BRCA1 mutations among women in Singapore with early onset breast carcinoma.

METHODS

Forty-three of 72 eligible patients whose breast carcinoma was diagnosed before the age of 36 years were studied, independent of family history. DNA samples from 50 unrelated individuals randomly selected from the National Thalassemia Registry served as controls. Mutational screening was performed by single-strand conformation polymorphism analysis and protein truncation test, and alterations were confirmed by sequencing. First-degree relatives of patients with definite BRCA1 mutations were offered screening.

RESULTS

A total of 6 novel alterations in BRCA1 were identified, including 2 frameshift mutations in exon 11 (2846insA and 2885delA), 3 rare sequence variants, and 1 polymorphism. Three women (7%) carried deleterious mutations, and the mutation was present in at least 1 unaffected first-degree relative of the proband. The same mutation (2846insA) was identified in 2 of the 7 unrelated subjects of Malay ethnicity. One mutation and three rare variants were identified in four women with no family history of breast or ovarian carcinoma whereas all women with affected first-degree relatives did not harbor BRCA1 mutations. No mutation was identified in the controls.

CONCLUSIONS

The spectrum of germline BRCA1 mutations among the patients in this study was distinct from that in Caucasian populations although a similar prevalence was observed. Larger studies are necessary to clarify the significance of the mutation 2846insA in the Malay community and the penetrance of specific mutations in the Singapore population.

Spectrum of abnormal mammographic findings and their predictive value for malignancy in Singaporean women from a population screening trial

INTRODUCTION

The ability to categorise mammographic features according to their likelihood of malignancy would be valuable in the management of women with abnormal mammograms. The aim of our study was to correlate abnormal mammographic features in a screened population with their histology to identify those features which are predictive of malignancy. The study also examined the spectrum of mammographic features in an Asian population.

MATERIALS AND METHOD

This prospective study involved 28,231 women who were randomly selected from a population registry and underwent two-view screening mammography without physical examination. Women with suspicious lesions were recalled for further mammographic views or to a joint assessment clinic prior to biopsy. Mammographic abnormalities and their corresponding histology were assessed.

RESULTS

The spectrum of mammographic abnormalities was similar to that in Caucasian populations. The positive predictive value for malignancy was 44.1% of all biopsied cases. Mammographic features could be broadly classified into low-, moderate- and high-risk categories for malignancy. Those features which correspond to high malignancy rates (9.8% to 16.0%) include multiple abnormalities or parenchymal lesions with microcalcifications. The presence of microcalcifications was a good predictor of ductal carcinoma-in-situ (DCIS): 46% of lesions in which the microcalcifications were the sole abnormality were DCIS only. Further, 71% of cancers with any microcalcification on the mammogram had a focus of DCIS on histology.

CONCLUSION

Mammographic abnormalities can be segregated into three risk groups for malignancy, and this in turn can improve the selection criteria for breast biopsy, hence reducing unnecessary intervention. Furthermore, the presence of microcalcifications denotes the presence of DCIS, and would be an important determinant of the extent of surgical excision.

The importance of revision of early restenosis after endovascular remote endarterectomy in SFA occlusive disease

OBJECTIVES

to investigate the results of revision of recurrent stenoses after superficial femoral artery (SFA) remote endarterectomy.

DESIGN

prospective, non-open, study.

MATERIALS

eighty-eight consecutive patients with long segmental SFA occlusive disease underwent 101 remote end-arterectomy procedures. All patients had chronic lower extremity ischaemia necessitating surgical intervention.

METHODS

clinical, haemodynamic, and duplex examinations were performed postoperatively at regular intervals, identifying 46 recurrent stenosed (PSV ratio >2.5) limbs, which formed the cohort for this study. The median follow-up was 25 months. Secondary revision was performed in 23 limbs, based on recurrent symptoms and individual preference of the attending vascular surgeon. Cumulative primary and primary assisted-patency rates were compared using the log-rank test of significance.

RESULTS

univariate analysis did not show any significant differences for other demographic and lesion characteristics apart from recurrent symptoms (all revised). Multivariate analysis revealed that revision "adjusted for time-of-onset" predicted reocclusion (p=0.007; HR 0. 21; 95% CI 0.06, 0.66). Among subjects in whom restenoses developed within 1 year, revision of recurrent stenoses improved primary patency rates from 47% to 77% at 30 months.

CONCLUSIONS

revision of early (<1 year) recurrent stenoses improves the mid-term patency rates of SFA remote endarterectomy.

Endovascular femoropopliteal bypass combined with remote endarterectomy in SFA occlusive disease: initial experience

OBJECTIVES

to evaluate the feasibility of endovascular femoropopliteal bypass in combination with remote endarterectomy of the superficial femoral artery (SFA).

DESIGN

prospective, open study.

MATERIALS

thirteen patients with chronic lower-leg ischaemia due to femoropopliteal occlusive disease underwent 14 SFA remote endarterectomy procedures followed by endovascular ePTFE femoropopliteal bypass. Primary endografting was performed in seven cases. The indication for endograft insertion was vessel-wall perforation during endarterectomy in the remaining seven cases.

METHODS

pre- and postoperative clinicl and haemodynamic data were collected and compared. Technical problems and procedure-related complications were noted.

RESULTS

initial technical success was achieved in all 14 limbs. However, four early reocclusions occurred after 1, 4, 6 and 10 weeks postoperatively. Two late reocclusions were detected after 16 and 22 months without any preceding symptoms or haemodynamic changes. Primary and secondary patency rates were 61% and 70% at two years, probably due to graft-related factors, such as lack of radial force, graft folding or kinking, and possibly altered mechanical or thrombogenetic properties after dilatation of the ePTFE graft.

CONCLUSIONS

endovascular femoropopliteal endo-bypass after SFA remote endarterectomy is a feasible procedure. Further technical improvements are necessary to avoid procedure- and graft-related early failures.

Deformation of self-expanding stent-grafts complicating endovascular peripheral aneurysm repair

PURPOSE

To demonstrate the deformation of self-expandable stents after endovascular repair of peripheral aneurysms.

METHODS AND RESULTS

The Corvita Endoluminal Graft was used to treat a traumatic false aneurysm of the right subclavian artery and a common iliac artery aneurysm in 2 patients. In the subclavian case, the stent-graft showed a "cigar-shaped" deformation with hemodynamically significant stenoses at the proximal and distal ends at 3 months. In the second case, the same type of deformity was noted only 1 day after implantation. Two months later, the stent-graft occluded, necessitating surgical repair.

CONCLUSIONS

Both cases demonstrate the possibility of stent deformation of self-expanding stent-grafts implanted at arterial sites not subject to external compression.

Incidence, time-of-onset, and anatomical distribution of recurrent stenoses after remote endarterectomy in superficial femoral artery occlusive disease

PURPOSE

The incidence, time-of-onset, and anatomical distribution of recurrent stenoses after remote endarterectomy in superficial femoral artery (SFA) occlusive disease were studied.

METHODS

Patients undergoing SFA remote endarterectomy procedures were examined with duplex surveillance. Patients were examined at 6 weeks, 3, 6, 9, and 12 months, and then annually. Recurrent stenosis was defined as a peak systolic velocity ratio of 2.5 or higher. Duplex results were also compared with clinical and hemodynamic changes.

RESULTS

Restenoses were identified in 46 of 101 (46%) limbs treated after a mean interval of 5.8 months (range, 1 to 18 months). These 46 limbs formed the base of this study. The median follow-up period was 25 months. Thirty-eight (83%) of all restenoses were detected within 1 year. The lesions were located within the entire SFA and were not specifically related to the adductor canal or distal stented region only. Multiple stenoses were found in 21 limbs. Only 10 (22%) restenoses were correlated with worsening of clinical symptoms, change of ankle-brachial index, or both. Ten of 23 cases (43%) of nonrevised restenoses progressed to occlusion. These 10 occlusions occurred in all patients with restenosis that developed within the first year. Nonrevised late restenoses (more than 1 year) were not associated with any reocclusion.

CONCLUSION

Recurrent stenoses after SFA remote endarterectomy were noticed in 46 of 101 (46%) limbs. Most restenoses (83%) developed within the first year. In the nonrevised group, time-of-onset restenosis (less than 1 year) was correlated with a higher risk for occlusion ( P =.02). The location of restenoses were found without any anatomical site of preference along the entire endarterectomized SFA segment.

Endarterectomy of the superficial femoral artery

Semiclosed endarterectomy of the SFA belongs in the armamentarium of the vascular surgeon. New technology offers the possibility of performing this less invasive operation so that only a single incision is needed to obtain access to the artery and perform remote disobliteration. Strong indications show that the anticipated restenosis of long, segmental, closed endarterectomies can be reduced remarkably by expanded PTFE endolining.

Progestins inhibit the growth of MDA-MB-231 cells transfected with progesterone receptor complementary DNA

Because progesterone exerts its effects mainly via estrogen-dependent progesterone receptor (PgR), the expression of progesterone's effects may be overshadowed by the priming effect of estrogen. PgR expression vectors were transfected into estrogen receptor (ER)-alpha and PgR-negative breast cancer cells MDA-MB-231; thus the functions of progesterone could be studied independent of estrogens and ERs. Eight stable transfectant clones expressing both PgR isoform A and B were studied for their growth response to progesterone and its analogues. Although progesterone had no effect on growth in the control transfectant, the hormone markedly inhibited DNA synthesis and cell growth in all of the PgR-transfectants dose-dependently from 10(-12)-10(-6) M. This growth inhibition was associated with an arrest of cells in the G0/G1 phase of the cell cycle. Progestins medroxyprogesterone acetate, Org2058, and R5020 also strongly inhibited DNA synthesis, and their doses required for maximal inhibition of 60-70% were 10(-17) M, 10(-13) M, and 10(-7) M, respectively. Antiprogestin ZK98299 alone had no effect, but the compound was capable of counteracting the inhibitory effect of progesterone. In contrast, RU486 inhibited DNA synthesis, and it showed no further effects when it was used concurrently with progesterone. These results indicate that progestins are per se antiproliferative via a PgR-mediated mechanism in breast cancer cells. More importantly, we have shown that progestins may exert effective inhibitory control over the cell growth if the PgR expression is reactivated in ER- and PgR-negative breast cancer cells.

Serum IGF-binding protein-6 and prostate specific antigen in breast cancer

OBJECTIVE

Recent studies have demonstrated the presence of the IGF-binding proteins (IGFBPs) and prostate specific antigen (PSA), an IGFBP protease. in human breast tissue. We sought to investigate the differences in serum IGFs, IGFBP-1, -3 and -6, and PSA between patients with surgically proven breast cancer and patients with benign breast disease.

DESIGN AND METHODS

Concentrations of IGFs, IGFBP-1, -3 and -6, and PSA were determined in the sera from 57 patients with breast cancer (CA), and 46 women with benign breast disease (BBD) using immunoassays for IGFs and IGFBPs and an ultrasensitive ELISA for PSA.

RESULTS

The mean (+/- S.E.M.) serum IGFBP-6 level in the CA group, 127 (16) ng/ml, was statistically significantly lower than in the BBD group, 157 (10) ng/ml (P = 0.016). Patients with CA had an elevated geometric mean serum PSA level of 0.018 (range: 0.0015-0.107) ng/ml, compared with 0.007 (range: 0.0015-0.019) ng/ml in women with BBD (P = 0.025). Mean serum IGFBP-1 concentrations were significantly lower in the CA group, 16 (2) ng/ml, versus 37 (4) ng/ml in the BBD group (P = 0.001). Mean serum IGFBP-3 concentrations were also lower in the CA group versus the BBD group, at 1981 (65) ng/ml, versus 2603 (140) ng/ml (P = 0.002) respectively. In the CA group, statistically significant correlations between PSA and IGFBP-6 (r = 0.413; P = 0.001), and between PSA and IGFBP-1 (r = -0.329; P = 0.021) were seen. Differences in IGF-I and -II between the two groups were not statistically significant.

CONCLUSION

Lower serum concentrations of IGFBP-6, -3 and -1, but higher PSA concentrations were seen in the breast cancer group, and collectively these would suggest that there is an increase in bioavailable IGF-I in breast cancer.

Cystic tumours of the pancreas: a diagnostic dilemma

BACKGROUND

Cystic neoplasm of the pancreas is an uncommon entity that encompasses a range of tumours with varying potential for malignancy. These tumours are frequently misdiagnosed as pseudocysts and are inappropriately managed.

METHODS

A retrospective review was undertaken of 18 cases of cystic tumours of the pancreas over an 8-year period in two large hospitals in Singapore.

RESULTS

All patients were Asian, with a younger age group (mean 43.5 years) and a lesser degree of female predominance (3.5:1 ratio) compared to other series. Pain was the most common symptom. Pre-operative diagnosis using ultrasound and computed tomography was not diagnostic in half of the cases and misdiagnosed as pseudocyst in a sixth. There were five serous cystadenomas, four mucinous cystadenomas, two mucinous cystadenocarcinomas, one mucinous cystadenocarcinoma with cystic degeneration in a ductal adenocarcinoma, three Frantz tumours, one acinar cell tumour, one glucagonoma, and one benign epithelial cyst. Two-thirds of tumours were malignant or had the potential to become malignant. Resection was curative in all cases, and no recurrence was noted at a mean follow-up of 34.5 months.

CONCLUSIONS

The difficulties with pre-operative diagnosis, the high incidence of tumours with potential malignancy, and the good outcome with resection, suggest that all suspected cystic tumours of the pancreas should be resected.

Remote endarterectomy in SFA occlusive disease

The authors present a new modified endarterectomy technique for the treatment of artherosclerotic occlusive disease of the superficial femoral artery (SFA). The SFA remote endarterectomy procedure can be performed through a single groin incision using a ring strip cutter and stenting the distal endpoint. Complete disobliteration of lengthy occlusions was accomplished in more than 100 cases with a cumulative 2-year primary and assisted primary patency rate of 71 and 86%. The mean length of the removed intima core was 33 (10-45) cm. The endovascular remote endarterectomy technique is explained and depicted in detail and some important questions and controversies are discussed.

Tamoxifen alters levels of serum insulin-like growth factors and binding proteins in postmenopausal breast cancer patients: a prospective paired cohort study

BACKGROUND

Recent data suggest that tamoxifen may act by altering serum levels of insulin-like growth factors (IGFs) and their binding proteins (BPs). This prospective paired cohort study evaluated the influence of tamoxifen on serum levels of IGFs and BPs in postmenopausal patients with breast cancer.

METHODS

Blood was collected from 32 postmenopausal patients with breast cancer before and during tamoxifen therapy for at least 6 months. All patients had undergone primary surgery. Serum concentrations of IGF-I, IGF-II, BP-1, and BP-3 were determined by immunoradiometric assays, and Western ligand blots provided a semiquantitative measurement of BP-2, BP-3, and BP-4. Statistical analysis was performed by paired Student's t-test.

RESULTS

Mean serum IGF-1 level was significantly lower after tamoxifen treatment (pretreatment: 116.2 ng/mL+/-13.6 [SEM] vs. posttreatment: 77.5 ng/mL+/-7.8; P=.003). In contrast, mean IGF-II levels increased from 651.5+/-62.2 ng/mL to 812.5+/-35.1 ng/mL during treatment (P=.006). Posttreatment levels of BP-1 (92.9 ng/mL+/-7.5) were significantly higher compared to the pretreatment values (28.1 ng/mL+/-4.7; P <.001). Serum concentration of BP-3 also was elevated (pretreatment: 2228.1 ng/mL+/-145.2 vs. posttreatment: 3539.1 ng/mL+/-172.3; P <.001). Densitometric measurements showed a similar significant increase in BP-3 (P <.001) as well as BP-4 (P=.017) after hormonal therapy. Levels of BP-2 were not influenced by tamoxifen treatment.

CONCLUSIONS

These significant alterations in serum concentrations of IGFs and BPs with tamoxifen therapy suggest that the IGF system is a potential mechanism by which tamoxifen exerts its growth inhibitory effect on breast carcinomas.

[Compartment syndrome in both lower legs after prolonged surgery in the lithotomy position]

A 35-year-old man developed bilateral compartment syndrome in the lower legs after prolonged colorectal surgery in the lithotomy position. This complication of a prolonged non-physiological operation position is a rare event and the diagnosis is therefore often delayed, with sometimes serious irreversible neuromuscular damage. In this case the complication was successfully treated by four-compartment fasciotomy and forced diuresis (to prevent renal insufficiency caused by myoglobin nephrosis).

Results of intermediate measures from a population-based, randomized trial of mammographic screening prevalence and detection of breast carcinoma among Asian women: the Singapore Breast Screening Project

BACKGROUND

Although increasing rates of breast carcinoma incidence have been observed in Asian countries, appropriate strategies for detecting early stage breast carcinoma in such communities have been difficult to formulate, particularly because no large population screening trial specifically involving Asian women has been reported. The objective of this study was to evaluate the effectiveness and quality of mammography as a screening technique for Singaporean women, who are predominantly Chinese.

METHODS

In this prospective study, 166,600 women in Singapore ages 50-64 years were randomized to either 2-view mammography without physical examination (67,656) or observation (97,294, controls) over 2 years.

RESULTS

Of these women, 28,231 (41.7%) responded and were screened; they were more likely to be married, have more formal education, be working, be Chinese, and be in a higher socioeconomic group (P < 0.001 for all variables). To assess for response bias that could affect outcome, results were also evaluated for nonrespondents (n = 39,425). The incidence rate of cancers among nonrespondents (1 per 1000 woman-years) was less than the 1.3 in women not invited to have screening (P = 0.03, relative risk [RR], 1.3; 95% confidence interval [CI], 1.0-1.7). However, cancers arising from nonrespondents did not differ significantly in stage distribution when compared with cancers within the control group. For every 1000 women screened, 4.8 cancers were detected. The prevalence ratio (the number of cancers detected per 1000 women at first screening divided by the corresponding incidence rate in controls per year) was 3.6 for screened women and 2.4 for women invited to have screening. The majority of cancers detected through screening were early stage, with 64% as either ductal carcinoma in situ (26%) or Stage I disease (38%) and was significantly more than the corresponding 26% in women not invited to have screening (P < 0.001). When only invasive cancers were considered, screened women still had more early cancers, with 65% having no lymph node involvement, compared with 47% in the group not invited to have screening (P = 0.001; RR, 1.4; 95% CI, 1.2-1.7). Women who were screened had half the risk of having Stage II or later cancers (P < 0.0001; RR, 0.5; 95% CI, 0.4-0.7) when compared with women not invited to have screening. This higher detection rate of early cancers through screening was accomplished with acceptable recall rates of 8% for further mammographic films or physical examination and a biopsy rate of 1.0% (10 per 1000 women screened). The interval cancer rate was 2.1 per 10,000 women screened in the first year of follow-up.

CONCLUSIONS

These positive results of intermediate measures suggest that, in Asian communities, screening mammography could be an important modality for detecting early stage breast carcinoma. However, the low compliance rates suggest that health education efforts must focus on issues related to acceptability if such programs are to succeed.

Urinary 2/16 alpha-hydroxyestrone ratio: correlation with serum insulin-like growth factor binding protein-3 and a potential biomarker of breast cancer risk

Metabolism of estradiol occurs via two mutually exclusive hydroxylative pathways, yielding metabolites of divergent biological properties. 2-hydroxyestrone (2OHE1) is anti-estrogenic while 16 alpha-hydroxyestrone (16 alpha OHE1) is a potent estrogen. The ratio of 2OHE1 to 16 alpha OHE1 (2/16 alpha-OHE1 ratio) represents the net in vivo estrogenic activity. In this study, we sought to determine if the urinary 2/16 alpha-OHE1 ratio could be a predictor of breast cancer risk and the factors which influence this ratio. Variables analysed included age at diagnosis, menopausal status, parity, use of oral contraceptives, body mass index, serum levels of insulin-like growth factor-I (IGF-I), IGF binding proteins (BPs) and the presence of breast cancer. Serum and urine were collected from 65 breast cancer patients and 36 controls after an overnight fast. Urinary estrogen metabolites were measured by enzyme immunoassays while serum levels of IGF-I, BP-1 and BP-3 were determined by immunoradiometric assays. 2OHE1 levels and 2/16 alpha-OHE1 ratios were significantly lower (P < 0.05) while 16 alpha OHE1 levels were higher (P < 0.01) in cancer patients. Multiple linear regression analysis showed that levels of urinary metabolites were influenced by parity and breast carcinoma. 2/16 alpha-OHE1 ratio correlated positively with serum BP-3 level (P = 0.03). By multiple logistic regression, 2/16 alpha-OHE1 ratio was the most significant factor predictive of breast cancer. The odds ratio for women with higher 2/16 alpha-OHE1 ratios was 0.10 (0.03-0.38, 95% confidence interval). In conclusion, the profile of urinary estradiol metabolites was distinctly altered in breast cancer patients. In addition, BP-3 may be a potential mechanism by which estradiol metabolites influence breast cancer progression. As 16 alpha OHE1 has been shown to initiate neoplastic transformation of mammary epithelial cells, the 2/16 alpha-OHE1 ratio may serve as a biomarker of increased risk of breast cancer.

Risk factors for breast carcinoma in Singaporean Chinese women: the role of central obesity

BACKGROUND

The incidence of breast carcinoma in Singapore has nearly doubled over the past 25 years. This prospective case-control study involving 1086 women (204 cases and 882 controls) was conducted to determine significant factors associated with the risk of breast carcinoma among Chinese women in Singapore ages 45 to 69 years.

METHODS

A forward stepwise logistic regression model adjusted for confounding variables of age, age at menarche, menopausal status, parity, age at first and last delivery, use of oral contraceptives, hormone replacement therapy, family history of breast carcinoma, history of benign breast biopsy, smoking history, height, weight, body mass index, and waist to hip ratio was used.

RESULTS

Central obesity as indicated by women with a larger waist to hip ratio was associated with highest risk for breast carcinoma (odds ratio [OR]: 9.18; 95% confidence interval [CI],4.8-17.5 comparing last and first quintile; P < 0.0001, chi-square test for trend). Significant trends were also noted for increasing height and breast carcinoma risk (P = 0.003, chi-square test). Women who were taller than 159 cm (OR: 2.3; 95% CI, 1.4-3.9) had approximately twice the risk of women shorter than 150 cm. Body mass index as a measure of generalized obesity did not significantly predict risk for breast carcinoma. Reproductive and menstrual factors significantly related to risk for breast carcinoma were number of deliveries (OR: 0.81; 95% CI, 0.7-0.9; P < 0.001), age at last delivery (P = 0.03), and use of hormone replacement therapy (OR: 0.54; 95% CI, 0.3-0.9; P = 0.01). Previous breast biopsy for benign disease was also associated with a higher risk for breast carcinoma (OR: 3.5; 95% CI, 2.1-5.7; P < 0.001).

CONCLUSIONS

The authors conclude that the risk of breast carcinoma is strongly associated with changes in lifestyle related to caloric intake (central obesity and height) and reproductive or menstrual factors (number of deliveries, age at last delivery, age at menopause, and breast feeding). Better and excess nutrition in early and later years of life and fewer births (related to rapid urbanization) may explain in part the increasing incidence of breast carcinoma occurring in Singapore.

Closed superficial femoral artery endarterectomy: a 2-year follow-up

Closed superficial femoral artery endarterectomy is a minimal invasive technique. Through a single groin incision the occluded intima is remotely removed by a newly modified ring stripper. This device has a double ring which acts like remote scissors and enables the surgeon to recanalize long segmental femoral popliteal occlusive disease. The device was used in 103 limbs in 90 patients. The cumulative assisted primary and secondary patency was 86%. This technique is an alternative to bypass grafting when vein is not available.

Percutaneous nephrolithotomy--results and clinical experience

Percutaneous nephrolithotomy (PCNL) and extracorporeal shockwave lithotripsy (ESWL) have largely replaced open surgical intervention for the management of upper urinary tract calculi. ESWL is the preferred treatment modality for calculi less than or equal to 2 cm in diameter as morbidity is lower than PCNL and success rates are comparable. However, the morbidity of ESWL rises substantially for stones greater than 2 cm in diameter while stone-free rate is less when compared to PCNL, suggesting that PCNL is the preferred treatment modality for most larger stones. PCNL was performed on 86 patients with 87 renal calculi. The indication for this approach was either high stone burden as in 72 patients (83%) or failed previous ESWL as in 15 patients (17%). The success rate was 74.7% and this was associated with minimal morbidity which included; symptomatic urinary tract infection (9.2%), pleural effusion (2.3%) and the formation of a pseudo-aneurysm (2.3%). Blood transfusion was required in one patient (1.1%) and we had one postoperative death due to massive pulmonary embolism (1.1%). PCNL is the preferred approach to patient with difficult renal calculi at our institution.

Percutaneous transluminal angioplasty of the infrarenal aorta: initial outcome and long-term clinical and angiographic results

OBJECTIVE

Report of 1-8 year follow-up of patients treated by percutaneous transluminal angioplasty (PTA) for obstructive atherosclerosis of the infrarenal aorta.

DESIGN

Cohort study.

MATERIALS

Thirty-eight patients aged 26-81 years (mean 50 years) were submitted to undergo percutaneous transluminal angioplasty of the infrarenal aorta. All patients had symptomatic isolated stenotic lesions of the aorta located below the renal arteries and above the bifurcation. Stenoses at bifurcation-level and the iliac arteries were excluded.

METHODS

PTA of the aorta was performed under local anaethesia in the radiological department. Clinical symptoms and ankle/brachial indices were registered before, directly after the procedure and at follow-up. Angiography was performed in all patients pre- and post-procedure, and at follow-up. All patients received angiography in March 1995. Clinical data were analysed based on intention-to-treat.

RESULTS

Initial clinical and angiographic success was achieved in 36 patients (94%). Mean follow-up was 34 months (range 1-92). Recurrent stenosis was seen in seven patients (19%) at follow-up. Only five (13%) of these had recurrent symptoms and were treated successfully with a second PTA. No major complications were seen.

CONCLUSION

These results show PTA to be a safe, minimally-invasive and effective alternative to surgery in case of symptomatic stenosis of the infrarenal abdominal aorta.