Incidental lymphadenopathy in renal transplantation

INTRODUCTION

Iliac lymphadenectomy is performed to provide anastomotic access during the vascular implantation procedure in renal transplantation. Iliac lymph nodes (LNs) are often enlarged, but there are no standardised guidelines for the management of incidentally enlarged LNs during transplantation. We aimed to evaluate histological findings of LNs sent for examination at our unit.

METHODS

Patients were evaluated in two distinct date cycles. In the first cycle, lymphadenectomy and histological assessment were performed at the discretion of the transplanting surgeon. In the second cycle, all incidentally enlarged LNs were sent for histological assessment, regardless of size.

RESULTS

In the first cycle (n = 76), 11 patients (14.47%) had incidentally enlarged iliac LNs on lymphadenectomy and histology showed only reactive changes. In the second cycle (n = 165), eight patients (4.85%) had incidentally enlarged LNs on lymphadenectomy. One patient was found to have mature B cell chronic lymphocytic leukaemia. The patient was referred to haematology and a "watch and wait" approach was taken, with the patient still alive at last follow-up (511 days post-transplantation).

DISCUSSION

There are currently no published guidelines on the management of incidentally enlarged iliac LNs during transplantation. Current literature suggests that clinically significant lymphadenopathy needs to be investigated in all patients. Based on our centre's experience of a 5.26% (1 in 19) positive pathological LN sampling, we recommend that all incidental LNs with suspicious features and/or that are greater than 10mm in diameter should be considered for histological, microbiological and molecular assessment as appropriate.

562 Biopsy of Localised Renal Masses Offers High Diagnostic Yield and Low Complication Rate in Patients with Suspicious Renal Masses

Aim

Biopsy of localised renal masses is generally accurate at detecting benign or malignant histology but can cause complications. The aim of this study was to determine the detection rate and complication rate of renal mass biopsies.

Method

Patients undergoing a renal mass biopsy at a single tertiary centre between January 2015 and December 2019 were identified electronically using a prospective database. Details about their biopsies were recorded including tumour size, radiological guidance, number of cores, longest margin of biopsy, accuracy of biopsy, histology type, and complications.

Results

This study included 334 biopsies (Median age 68 years (IQR 60-72); 61.4% (n = 204) male). Median size of tumour was 30mm (IQR 25-50) and 79.9% (n = 267) were solid masses. The biopsies were done under ultrasound (78.4%) or computed tomography (21.6%) guidance. 91.9% had core biopsies (n = 307) with median biopsy margin of 14mm (IQR 9-21). Benign histology was observed in 18.9% (n = 63), malignant in 72.1% (n = 241) while biopsy was non-diagnostic in 9.0% (n = 30). 62.6% (n = 209) of the cases were renal cell carcinoma with clear cell subtype more commonly seen (72.2%, n = 151). Complications following biopsy included haematoma (n = 7, 2.1%), haemorrhage (n = 3, 0.9%), pneumothorax (n = 1, 0.3%) and vasovagal episode (n = 1, 0.3%), resulting in an overall complication rate of 3.6%.

Conclusions

Biopsy of localised renal masses in this study showed a detection rate of 91% and complication rate of 3.6%. This study suggests renal mass biopsies have high diagnostic yield and low complication rate.

Venae Comitantes Fistulae: An Option in Patients with Difficult Hemodialysis Access

Objectives

To evaluate the outcome of use of venae comitantes vessels in the formation of arterio-venous fistulae as vascular access for hemodialysis, in patients with limited venous anatomy.

Methods

Twenty patients who underwent arterio-venous anastomosis between brachial artery and venae comitantes were identified (2002 – 2005) and the notes reviewed.

Results

There was early failure in two (10%) patients (immediate postoperative period) and a further four (20%) failed late (mean 26 weeks, range 7–60). One patient developed a steal syndrome with radial nerve dysfunction requiring ligation of the fistula. Six (30%) patients utilised their fistulae for dialysis successfully without additional surgery and a further 6(30%) required surgical intervention to exteriorise the fistulae by the use of interposition grafts to allow successful use.

Conclusion

Venae Comitantes arterial fistulae offer an option in patients with limited venous anatomy for standard reconstruction. If access surgery utilizes such veins second stage procedures are often required with overall 70% use.

Survival of Arteriovenous Fistula for Dialysis at Different Centers in the North of England

Background

Renal failure patients rely on their vascular access for hemodialysis. Surgery for construction of arteriovenous fistulae is provided by a range of specialists. The aim of this review was to assess the survival of arteriovenous fistulae for hemodialysis patients in different centers of Northern England.

Methods

Data was collected on 473 hemodialysis patients in the North of England. Risk factors for failure were determined for each patient (age, sex, diabetes), together with their current mode of dialysis and history of surgical access procedures. This was expressed against their duration of dialysis. The dialysis units were then compared for fistula survival using the Kaplan Meier method.

Results

68.3% (323) patients were dialysed through via arteriovenous fistulae and 31.7% (150) via neck line. Overall fistula survival rates were 85.1% at 1 year, 82.5% at 2 years and 72.7% at 3 years. The best 1 year survival was 91.6% and worst 76.1%. These were 74.4% and 53.1% at 5 years and 74.4% and 29.5% at 10 years; these differences were highly statistically significant (p=0.0033).

Conclusion

Though graft survival is affected by many things, surgical training in access surgery is not mandatory and a review of surgical practice is urgently needed.

A case of a living-related kidney transplantation after ex-vivo repair of the donor renal artery aneurysm

BACKGROUND

Kidney transplantation is the definite surgical treatment for end-stage renal disease. Shortage of organs and the increasing number of patients with end-stage renal disease has led to an expansion of the selection criteria promoting the use of organs from marginal donors. Use of kidneys with renal artery aneurysm (RAA) is one such example. Description of the case: We report a case of living-related kidney transplantation from a 46-year-old female donor with unilateral RAA to her 68-year-old father. The pre-operative donor's assessment with a computed tomography angiogram revealed a saccular aneurysm of the left renal artery. The transplant team proceeded to the left nephrectomy, surgical ex vivo repair of the aneurysm and transplantation of this kidney to the recipient, with the total ischemic time of 130 minutes. At revascularization, there was no anastomotic leak with good perfusion of the organ and normal postoperative kidney function.

CONCLUSION

RAA is a rare renal anatomical abnormality with unproven clinical significance. Advanced microvascular surgical techniques can be used to repair the aneurysm with subsequent successful use for transplantation. Hippokratia 2016, 20(1): 90-92.

Practices and Results of Two Years Service from a single UK Renal Transplant Center

INTRODUCTION: End stage renal failure is a common condition requiring renal replacement therapy in the form of haemodialysis or peritoneal dialysis as a short-term measure with renal transplantation as a more definitive treatment option. The aim of this study was to evaluate the set up of arenal transplant unit in a developed country and compare its results with other centers of the world. METHODS: A retrospective observational study was conducted to see the results of two years activities of a well known renal transplant unit in the United Kingdom. A description of the setup of a renal transplant unit has been made and its results have been discussed. RESULTS: Of the total patients, who had transplants in the renal transplant unit in year 2006 and 2007, 209 were renal, 14 were simultaneous kidneypancreas and two were pancreas after kidney transplants. Our one year graft survival rate was 93%, delayed graft function was 15%, early rejection rate was 11% and mortality rate was 3% in one year follow up. CONCLUSIONS: To attain good results in renal transplantation surgery, a multi-disciplinary team approach is crucial. Our set up is an example where the results are comparable to published and unpublished data from other established units world-wide. Keywords: complications, immunosuppression, renal transplant.

Practices and results of two years service from a single U.K. renal transplant center

INTRODUCTION

End stage renal failure is a common condition requiring renal replacement therapy in the form of haemodialysis or peritoneal dialysis as a short-term measure with renal transplantation as a more definitive treatment option. The aim of this study was to evaluate the set up of a renal transplant unit in a developed country and compare its results with other centers of the world.

METHODS

A retrospective observational study was conducted to see the results of two years activities of a well known renal transplant unit in the United Kingdom. A description of the setup of a renal transplant unit has been made and its results have been discussed.

RESULTS

Of the total patients, who had transplants in the renal transplant unit in year 2006 and 2007, 209 were renal, 14 were simultaneous kidney pancreas and two were pancreas after kidney transplants. Our one year graft survival rate was 93%, delayed graft function was 15%, early rejection rate was 11% and mortality rate was 3% in one year follow up.

CONCLUSIONS

To attain good results in renal transplantation surgery, a multi-disciplinary team approach is crucial. Our set up is an example where the results are comparable to published and unpublished data from other established units world-wide.

Survival of arteriovenous fistula for dialysis at different centers in the North of England

BACKGROUND

Renal failure patients rely on their vascular access for hemodialysis. Surgery for construction of arteriovenous fistulae is provided by a range of specialists. The aim of this review was to assess the survival of arteriovenous fistulae for hemodialysis patients in different centers of Northern England.

METHODS

Data was collected on 473 hemodialysis patients in the North of England. Risk factors for failure were determined for each patient (age, sex, diabetes), together with their current mode of dialysis and history of surgical access procedures. This was expressed against their duration of dialysis. The dialysis units were then compared for fistula survival using the Kaplan Meier method.

RESULTS

68.3% (323) patients were dialysed through via arteriovenous fistulae and 31.7% (150) via neck line. Overall fistula survival rates were 85.1% at 1 year, 82.5% at 2 years and 72.7% at 3 years. The best 1 year survival was 91.6% and worst 76.1%. These were 74.4% and 53.1% at 5 years and 74.4% and 29.5% at 10 years; these differences were highly statistically significant (p = 0.0033).

CONCLUSION

Though graft survival is affected by many things, surgical training in access surgery is not mandatory and a review of surgical practice is urgently needed.

Venae comitantes fistulae: an option in patients with difficult hemodialysis access

OBJECTIVES

To evaluate the outcome of use of venae comitantes vessels in the formation of arterio-venous fistulae as vascular access for hemodialysis, in patients with limited venous anatomy.

METHODS

Twenty patients who underwent arterio-venous anastomosis between brachial artery and venae comitantes were identified (2002 - 2005) and the notes reviewed.

RESULTS

There was early failure in two (10%) patients (immediate postoperative period) and a further four (20%) failed late (mean 26 weeks, range 7-60). One patient developed a steal syndrome with radial nerve dysfunction requiring ligation of the fistula. Six (30%) patients utilised their fistulae for dialysis successfully without additional surgery and a further 6(30%) required surgical intervention to exteriorise the fistulae by the use of interposition grafts to allow successful use.

CONCLUSION

Venae Comitantes arterial fistulae offer an option in patients with limited venous anatomy for standard reconstruction. If access surgery utilizes such veins second stage procedures are often required with overall 70% use.

Non-heart-beating kidney transplantation: 6-year outcomes

Non-heart-beating donor kidneys (NHBD) are being used to increase the donor pool due to the scarcity of cadaveric heart beating donors (HBD). We evaluated the long-term outcomes of renal transplantation using NHBD kidneys, comparing the first 100 NHBD kidneys transplanted at our facility to the next consecutive cadaveric HBD kidneys for graft survival, recipient survival, and quality of graft function. Recipient survival (P = .22) and graft survival (P = .19) at 6 years did not differ between recipients of NHBD (83%, 80%) and HBD (89%, 87%) kidneys. Quality of graft function using the mean glomular filtration rates were significantly lower in the NHBD group up to 3 months following discharge (41 +/- 2 vs 47 +/- 2, P = .007) but were then comparable up to 6 years following transplantation (43 +/- 5 vs 46 +/- 4, P = .55).

Diabetic donors as a source of non-heart-beating renal transplants

Due to the organ shortage, many renal transplantation centers attempt to increase the donor pool by using non-heart-beating donors (NHBDs). These kidneys are generally regarded as "marginal" grafts. Many centers do not consider transplantation from an NHBD with a history of diabetes as it is a more suboptimal donor. We began our NHBD program in 1998 and have performed 5 renal transplants from diabetic NHBDs. Viability testing identified kidneys suitable for single or dual transplantation. Although kidneys from brain stem dead donors with diabetes have been used successfully, our data suggested that kidneys from diabetic NHBDs can also be used although we still need long-term results.

Donor risk factors for renal graft thrombosis

Graft thrombosis is one of the most devastating complications of transplantation. In obtaining consent prior to transplant, it is useful to share potential risk factors with the recipient. In order to do this, we explored the impact of different risk factors that could contribute to this complication. Using multivariate analysis we found that neither multiple vessels nor vascular injury had a bearing on the risk of graft thrombosis but atheroma did (P < .02).

Donation after cardiac death kidneys with low severity pre-arrest acute renal failure

The widening gap between supply and demand for renal transplantation has prompted many centers to use donors after cardiac death. Some of these donors exhibit signs of acute renal failure (ARF) prior to cardiac arrest. Concern has been expressed about poor quality of graft function from such donors. In response to this perception, we reviewed 49 single renal transplant recipients from category III donors after cardiac death between 1998 and 2005, at our center. All kidneys but one had hypothermic machine perfusion and viability testing prior to transplantation. According to the RIFLE criteria, nine recipients had kidneys from donors with "low severity pre-arrest ARF". The remainder of the recipients were used as control group. There was no statistical significant difference in delayed graft function and rejection rates between these two groups. Recipients GFR at 12 months was 44.4 +/- 17.1 and 45.2 +/- 14.7 (mL/min/1.73m(2)) from donors with ARF and without ARF, respectively (p = 0.96). In conclusion, low severity ARF in kidneys from controlled after cardiac death donors can be a reversible condition after transplantation. Short-term results are comparable to the kidneys from same category donors without renal failure, providing that some form of viability assessment is implemented prior to transplantation.

Renal transplants from category III non-heart-beating donors with evidence of pre-arrest acute renal failure

Kidneys transplanted from non-heart-beating donors (NHBDs) have been exposed to varying degrees of ischemic damage after death. Category III donors have invariably been managed, treated, and investigated in a hospital setting prior to arrest and death. Some therefore exhibit evidence of renal dysfunction and even acute renal failure (ARF) before death. Many surgeons would regard a NHBD with pre-arrest evidence of ARF as too marginal for renal transplantation. This retrospective study examines five Maastricht category III NHBD donors with evidence of pre-arrest ARF. We compare 3- and 12-month GFR outcome data from the nine resulting transplants with 40 category III NHBD transplants with normal pre-arrest renal function. The mean GFR at 3 months was 45.4 and 43.8 for the ARF and normal group, respectively. At 12 months the GFR was 42.2 and 44.7 in the ARF and normal groups, respectively. Thus evidence of ARF pre-arrest does not preclude successful category III NHBD renal transplantation.

Dual renal transplantation for kidneys from marginal non-heart-beating donors

Kidneys transplanted from non-heart-beating donors (NHBD) are generally regarded as marginal or extended criteria grafts due to the associated period of warm ischemia. The most prolonged periods occurring in the category II (uncontrolled) donor. This potential for injury can adversely affect the glomular filtration rate (GFR), which in severe cases results in primary nonfunction. Viability testing can identify a group of kidneys that, although unsuitable for solitary transplantation, may be considered for dual transplant. This retrospective study examined a series of 11 dual renal transplants, comparing 3- and 12-month GFR outcome data with 81 single NHBD transplants. The mean GFR at 3 months in the dual group was 47.6 and at 12 months was 48.6. In the single group the GFR at 3 months was 40.6 and at 12 months was 41.9. Thus using viability testing to identify NHBD kidneys suitable for dual transplant appears reliable and predictable.

Agonal period in potential non-heart-beating donors

The shortage of donor kidneys for renal transplantation is becoming more severe as the gap between the number of patients waiting for renal transplantation and the number of cadaveric organs available continues to widen. Therefore, many centres have started using non-heart-beating (NHB) donors. There was no clear plan for maximal duration of agonal period in Maastricht category NHB donors after withdrawal of treatment in Newcastle. This withdrawal has been audited in retrospect. Our current wait time is now a maximum of 5 hours; however, previously there have been some considerably longer periods. Concern has always been expressed about poor quality with protracted periods. Nonuse in this review of 58 kidneys can be expressed against time: 0 to 2 hours 13%, 2 to 5 hours 33%, and >5 hours 45%. Therefore, though the nonuse rate was significantly different between 0 to 2 hours and >5 hours (P < .05, chi-square), there were 16 transplants performed with kidneys >2 hours and 12 transplanted >5 hours. In conclusion, although good usable kidneys can still be used with protracted withdrawal, there are considerable logistical difficulties with our 5-hour cut-off, which means that one third of potential kidneys will not be utilized.

Renal Graft Function After Prolonged Agonal Time in Non–Heart-Beating Donors

To deal with the increasing gap between organ demand and supply for kidney transplantation, many centers have started to use non-heart-beating (NHB) donors. When we initiated our program to utilize kidneys from such donors in 1998, we had no protocol for the maximal agonal period. This however was audited in retrospect. Our current wait time is now a maximum of 5 hours. Concern has been expressed in the past about possible deterioration in the quality of the organs with a protracted agonal time. We aimed in this study to examine the effect of prolonging agonal period on the quality of kidneys retrieved from Maastricht category III donors: A total of 40 kidneys were transplanted from 29 category III donors between 1998 and 2004. Eleven kidneys had donor agonal times of >5 hours; the remainder, agonal times <5 hours. Both groups were matched for donor and recipient factors. The mean glomerular filtration rates at 12 months for <5 hours versus >5 hours agonal time were 43.8 +/- 4.4 versus 49.8 +/- 5.8, respectively (P = .24) and at 24 months, 46.83 +/- 8.99 versus 37.67 +/- 3.85, respectively (P = .24). In conclusion, intermediate graft function is comparable to ones with shorter agonal time, although we await long-term results.

Variation in organ donation in northeastern England 1986 to 2003

Renal transplantation is established as the best form of renal replacement therapy, but demand for kidneys exceeds supply from cadaveric donations. It is therefore important to make the best use of the pool of potential cadaveric organ donors. Donation rates are to a large extent dependent on public opinions, which may be influenced by external events. In northeast England from 1986 to 2003, there was a potential pool of 1170 brain stem-dead donors, of whom 190 (16%) could not be retrieved due to relatives' objections. From 1998 to 2003 we were referred 90 potential non-heart-beating donors, of whom relatives refused donation in 10 (11%). A major reason for not retrieving organs from a potential donor has been lack of consent from the relatives. Refusals appear to vary year by year and are consistently lower for non-heart-beating donors. This therefore raises the possibility that negative or positive media publicity plays a role in this variation.

A simple cardiovascular risk score can predict poor outcome in NHBD renal transplantation

A simple cardiovascular risk score used in our center to plan cardiovascular workup for renal transplantation can predict outcome in non-heart-beating donor (NHBD) renal transplantation. Patients in the higher risk group, with a score of >12 out of a maximum of 36 are likely to have a longer duration of delayed graft function, poorer glomerular filtration rate at 6 months, and inferior graft and patient survival, together with an relative rate of graft loss within 60 days of >4 (P = .053). Although a high cardiovascular risk score should not be regarded as a contraindication to NHBD transplantation, the score can be used to facilitate recipient selection.

Ischemia-reperfusion injury in cadaveric nonheart beating, cadaveric heart beating and live donor renal transplants

PURPOSE

Ischemia-reperfusion injury is gaining importance in transplantation as being responsible for allograft dysfunction. Ischemia occurs during kidney procurement, which is shortest in LDs, and prolonged in cadaveric HBDs and NHBDs.

MATERIALS AND METHODS

Renal transplants from 17 LDs, 15 HBDs and 19 NHBDs were assessed during reperfusion for biochemical markers of ischemia-reperfusion injury and assessed clinically. Central venous blood sampling was assayed for free radicals using electron spin resonance and tissue injury biomarkers, namely lactate dehydrogenase, fatty acid binding protein, alanine aminopeptidase, lactate and total antioxidants.

RESULTS

The return to stable renal function was more rapid in LD renal transplants, while recovery continued from 3 months after hospital discharge in NHBD renal transplants. Injury markers, such as lactate dehydrogenase, fatty acid binding protein, alanine aminopeptidase and lactate, were raised at the time of reperfusion, especially in NHBD renal transplants. Free radical release measured by electron spin resonance showed 2 phase release, that is early (0 to 10-minute) and late (20 to 40-minute) release. In NHBD, HBD and LD renal transplants the index of free radical release in the early phase was 1.43, 1.36 and 1.20, and in the late phase it was 1.43, 1.38 and 0.97, respectively (each ANOVA p <0.05).

CONCLUSIONS

NHBD renal transplants were accompanied by a greater release of free radicals at reperfusion (NHBD > HBD > LD), which was associated with an increase in tissue injury markers at reperfusion. This was reflected in a slower return to stable renal function in NHBD compared to HBD and LD renal transplants.

Does Donor Cardiopulmonary Resuscitation Time Affect Outcome in Uncontrolled Non–Heart-Beating Donor Renal Transplants?

Uncontrolled non-heart-beating donors offer the opportunity to significantly expand the potential pool of kidney donors but are associated with a variable duration of cardiopulmonary resuscitation (CPR), where cardiac output is only 30% to 40% of normal. We were concerned that prolonged CPR would adversely affect the function of transplanted kidneys. In our series of 46 uncontrolled donors the mean duration of CPR was 60 minutes, which also represents a realistic cutoff point for CPR duration. Taking a cutoff point of 60 minutes, we found no differences in kidney discard rates following viability assessment, primary nonfunction rate, or duration of delayed graft function. We therefore conclude that if formal viability assessment is performed, kidneys may be retrieved from uncontrolled non-heart-beating donors irrespective of duration of CPR.

A Simple Cardiovascular Risk Score Can Predict Poor Outcome in Non–Heart-Beating Donor Renal Transplantation

A simple cardiovascular risk score used in our centre to plan cardiovascular work-up for renal transplantation can predict outcome in non-heart-beating donor (NHBD) renal transplantation. Patients in the higher-risk group, with a score of >12 of a maximum of 36 are likely to have a longer duration of delayed graft function, poorer glomerular filtration rate at 6 months, and inferior graft and patient survival, together with a relative rate of graft loss within 60 days of 4.514 (P = .019) and within 1 year of 3.511 (P = .036). Although a high cardiovascular risk score should not be regarded as a contraindication to NHBD transplantation, the score can be used to facilitate recipient selection.

Factors predicting duration of delayed graft function in non-heart-beating donor kidney transplantation

Non-heart-beating donors (NHBDs) are an important potential source of donor organs, but kidneys from such donors are prone to delayed graft function (DGF) and primary nonfunction, which are multifactorial in origin but believed to be mainly due to warm ischemic injury. This retrospective study examined a series of 88 transplants from Maastricht category II and III NHBDs to examine the role of factors to predict the duration of DGF. The main factors affecting duration of DGF were total warm ischemic time, cold ischemic time, product of perfusate GST concentration and donor age, quality of postoperative graft perfusion, incidence of acute rejection, recipient cardiovascular risk score, maximum pressure on machine perfusion, and weight gain during machine perfusion. Primary nonfunction was not accurately predicted from these factors for kidneys that had passed the viability assessment.

Anaesthesia for laparoscopic urological surgery

Laparoscopy for urological surgery is a relatively recent surgical innovation. Some centres have substantial experience of single operations, but very few have experience with a comprehensive range. Our programme began with nephrectomy and pyeloplasty, and has expanded to provide for a living related kidney donor programme and for other procedures usually conducted open. Recently, it has included prostate and bladder cancer surgery. The learning curve and implications for anaesthesia are described on the basis of the experience of one anaesthetist with 124 patients. Perioperative care issues, in common with other abdominal laparoscopic procedures, relate to operating positions, the consequences of carbon dioxide under pressure in the abdomen and postoperative analgesia. There is only a small requirement for regional anaesthesia supplementation and invasive analgesia. The corporate laparoscopic cholecystectomy experience was used as the foundation for anaesthesia and to delineate specific organ system issues and any interventions. Significant differences were found in the spectrum of the urological patient population and comorbidity, notably renal function or dysfunction, and complications.

Reperfusion injury in renal transplantation: comparison of LD, HBD and NHBD renal transplants

Comparison of reperfusion injury in kidneys transplanted from LD, HBD or NHBD donors is presented in the paper. Central venous blood samples (taken during perioperative period) was assessed for free radicals, total antioxidant activity and various markers of tissue injury. There was demonstrable ischemia reperfusion injury occurring at the time of revascularization, which was particularly notable in kidneys transplanted from NHBD donors.

Noninvasive measurement of bladder pressure by controlled inflation of a penile cuff

PURPOSE

A noninvasive test providing reliable objective quantification of bladder pressure during the voiding cycle would make an important contribution to the management of lower urinary tract symptoms. We developed a new noninvasive test to measure bladder pressure in males based on controlled inflation of a penile cuff during voiding. We compared the new technique with simultaneous invasive bladder pressure measurement.

MATERIALS AND METHODS

We evaluated 7 volunteers and 32 patients. A conventional pressure flow study was performed first. The bladder was refilled, a penile cuff was fitted and after voiding commenced the cuff was inflated in steps of 10 cm. water every 0.75 seconds until urine flow was interrupted. The cuff was rapidly deflated, allowing flow to resume, and the cycle was repeated until the end of voiding. The flow rate was graphed against cuff pressure for each interruption cycle to determine the pressure at which flow was interrupted. This pressure was compared with simultaneous invasive isovolumetric bladder pressure.

RESULTS

Invasive and noninvasive pressure measurements agreed well. Average cuff pressure at interruption of flow exceeded mean simultaneous isovolumetric bladder pressure plus or minus standard deviation by 14.5 +/- 14.0 cm. water.

CONCLUSIONS

The new method provides noninvasive quantitative information on voiding bladder pressure in males. Further study is required to assess whether the technique can contribute to the management of lower urinary tract symptoms.

A comparison of fluoride release by resin-modified GIC and polyacid-modified composite resin

The objective of this study was to compare the fluoride release of 2 fluoride-containing orthodontic adhesives from bracketed teeth and adhesive disks, a resin-modified glass ionomer cement (Fuji Ortho LC, encapsulated; GC America Corp, Aslip, Ill) and a polyacid-modified composite resin (Assure; Reliance Orthodontic Products, Itasca, Ill). A composite resin without fluoride (Transbond XT; 3M Unitek, Monrovia, Calif) was used as a reference control. Metal brackets were bonded to the buccal surfaces of 120 human premolars (40 teeth per adhesive), and disks were made from each adhesive. The deionized storage water was changed, and fluoride release was measured at specified intervals up to 28 days for the bracketed teeth and up to 150 days for the disks. Fuji Ortho LC released 75% more accumulated fluoride than Assure (6.61 microg/bracket vs 3.77 microg/bracket) from bracketed teeth over the 28-day observation period. Assure released more fluoride per day than did Fuji Ortho LC from the disks during the first 3 months. For the rest of the 150-day period, Fuji Ortho LC released more fluoride per day than did Assure. The amount of fluoride released by these materials varied dramatically with different water-changing protocols. The large discrepancy between fluoride released from disks compared with that released from bracketed teeth suggests that caution must be used in extrapolating fluoride-release levels of adhesive disks to in vivo treatment conditions.

Comparison of bond strength of three adhesives: composite resin, hybrid GIC, and glass-filled GIC

The objective of this study was to compare 3 orthodontic adhesives in the areas of shear-peel bond strength, location of adhesive failure, and extent of enamel cracking before bonding and after debonding of orthodontic brackets. The adhesives included a composite resin control (Transbond XT; 3M/Unitek, St Paul, Minn), a resin-modified glass ionomer cement (Fuji Ortho LC; GC America Corp, Alsip, Ill), and a polyacid-modified composite resin under dry and saliva-contaminated conditions (Assure; Reliance Orthodontic Products Inc, Itasca, Ill). Metal brackets were bonded to the buccal surfaces of 160 (4 groups of 40) human premolars. The bonded teeth were stored in deionized water at 37 degrees C for 30 days and thermocycled for 24 hours before debonding with a Universal Instron (Instron Corp, Canton, Mass) testing machine. The extent of cracking in the buccal surfaces was evaluated under 16x magnification before bonding and after debonding. Although the bond strength of the composite resin control (20.19 MPa) was significantly greater (P <.05) than that of the adhesives in the other groups, clinically acceptable shear-peel bond strengths were found for all adhesives (Fuji Ortho LC = 13.57 MPa, Assure-dry = 10.74 MPa, Assure-wet = 10.99 MPa). The bond strength for the Assure adhesive was not significantly affected by saliva contamination. The sample of extracted premolars used in this study displayed a greater frequency of buccal surface enamel cracking (46.7%) than that reported in the literature for in vivo premolars (7.8%-10.2%), which was possibly due to the extraction process. The frequency of enamel cracking in a subset of this sample (n = 34) increased from 46.4% at prebonding to 62.4% at postdebonding as a result of the forces of debonding.

A comparison of shear-peel band strengths of 5 orthodontic cements

The objective of this study was to compare the shear-peel band strength of 5 orthodontic cements using both factory and in-office micro-etched bands. The 5 orthodontic cements evaluated were a zinc phosphate (Fleck's Cement), 2 resin-modified glass ionomer cements (RMGI)(3M Multicure glass ionomer and Optiband), and 2 polyacid-modified composite resin cements (PMCR)(Transbond Plus and Ultra Band Lok). Salivary contamination was examined with a polyacid-modified composite resin (Transbond Plus). Two hundred and eighty extracted human molar teeth were embedded in resin blocks and each was randomly assigned to the following 7 groups: 6 groups with factory etched bands, 5 cement groups and salivary contaminated group, and 1 in-office micro-etched group. The cemented teeth were put in deionized water at 37 degrees C for 30 days and thermocycled for 24 hours. The force required to break the cement bond was used as a measure of shear-peel band retention. With the use of an Instron testing machine, a shear-peel load was applied to each cemented band. Data were analyzed with a one-way analysis of variance (ANOVA) with a Tukey test for the multiple comparisons. The RMGIs and PMCRs demonstrated significantly greater shear-peel band strengths compared to the zinc phosphate cement. No statistically significant differences were noted between the RMGI cement and PMCR cements and within the RMGI groups, however, there was a statistically significant difference within the PMCR groups. Significantly lower band strengths were noted with the saliva contaminated PMCR cement group (Transbond Plus) and the inpractice sandblasted PMCR group. Both RMGIs and PMCRs were found to demonstrate favorable banding qualities. The lower band strength with saliva-contaminated bands suggests that moisture control is critical when using a PMCR. The variability noted in the in-office micro-etched bands might be technique related.

"En bloc" paediatric renal donors into adult recipients -- the Newcastle technique

Whilst debate still continues about the best use of kidneys from small donors, the techniques used have been varied because of the high vascular thromboses rates and ureteric leak rates. The method described here employs a vessel transposition as described by two German series, but it is combined with an extraperitoneal approach. It is now the method of choice in our unit for such en bloc transplants.

Long-term adult renal graft outcome after ureteric drainage into an augmented bladder or ileal conduit

Patients with an augmented or diverted urinary system are considered higher risk recipients in view of increased technical problems and infective complications. We studied the long-term renal graft function and survival in patients with a pretransplant ileal conduit or ileal/caecocystoplasty. Between 1986 and 1997, 14 of 1253 (1.1%) renal transplant recipients had their transplant ureters anastomosed into an abnormal urinary tract. These consisted of ten ileal conduits and four ileal/caecocystoplasties. Median follow up was 42 months (range 1-156). All ten ileal conduits were discharged with a functioning graft. There was one graft loss chronic rejection and one cardiac death. The median creatinine level was 130 mmol/l and 50% have a urinary infection. All the patients with an ileal/caecocystoplasty were discharged with a functioning graft and these are still functioning; median creatinine of 132 mmol/l and 75% have a urinary infection. One- and 3-year graft survival was 93% and 86%. We conclude that the long-term outcome of renal transplantation in carefully assessed patients with an abnormal urinary tract is satisfactory despite a high incidence of urinary infection.