High prevalence of pseudotumors in patients with a Birmingham Hip Resurfacing prosthesis: a prospective cohort study of one hundred and twenty-nine patients

BACKGROUND

Recently, concern has emerged about pseudotumors (lesions that are neither malignant nor infective in the soft tissues surrounding total hip arthroplasty components) after hip arthroplasties with metal-on-metal bearings. Patients treated in our hospital for degenerative arthritis of the hip with a Birmingham Hip Resurfacing (BHR) prosthesis were invited to return for follow-up evaluation. The prevalence and clinical relevance of pseudotumors were investigated. Risk factors for pseudotumor formation were sought.

METHODS

A single-center cross-sectional prospective cohort study was conducted and included all patients who received a BHR from 2005 to 2010 in Martini Hospital, Groningen, The Netherlands. Data were collected on patient and surgical characteristics, clinical hip outcome scores (Harris hip score and Oxford score), serum metal ion levels (cobalt and chromium), and radiographs. A computed tomographic scan (without metal suppression) was made. In patients who had a revision, tissue samples were histologically examined.

RESULTS

Originally, there were 129 patients with 149 BHRs. Four patients (six hips; 4%) were lost to follow-up. Our final cohort consisted of 125 patients (143 hips). From this final cohort, eleven patients (twelve hips) had a revision, and three of them (three hips) had the revision before the present study was conducted. Seven patients (eight hips; 5.6%) had a revision because of a symptomatic pseudotumor. Survival analysis showed an implant survival rate of 87.5% at five years (failure was defined as a revision for any reason). A pseudotumor was found on computed tomography in thirty-nine patients (forty hips; 28%). Of those patients, ten (eleven hips; 28%) had complaints involving groin pain and discomfort, a noticeable mass, or paresthesia. Symptomatic pseudotumors were significantly larger than asymptomatic pseudotumors (a mean volume of 53.3 cm3 compared with 16.3 cm3; p = 0.05). A serum cobalt level of >85 nmol/L was a predictor for pseudotumor formation (odds ratio, 4.9).

CONCLUSIONS

Pseudotumor formation occurred in 28% of hips after an average follow-up of forty-one months. Most pseudotumors (72.5%) were asymptomatic. Larger pseudotumors were associated with more complaints. Survival analysis showed an implant survival of 87.5% at five years. Failure occurred in 5.6% (eight) of 143 hips because of a symptomatic pseudotumor.

Effect of modified Davidson's fixative on examined number of lymph nodes and TNM-stage in colon carcinoma

AIMS

We evaluated the effect of modified Davidson's fixative (mDF) on the number of lymph nodes examined and staging in patients with colon carcinoma.

METHODS

The results of two different fixation methods used in the pathological preparation of the resection specimens were analyzed. A traditional formalin preparation with manual dissection of all nodes was performed in 117 colon specimens between January 2003 and July 2004. After July 2004, the resected specimens of 125 patients was fixated in mDF. Differences in the retrieval and number of nodes and size of suspected nodal metastases were measured. All lymph nodes were stained with conventional H&E methods.

RESULTS

The median number of examined nodes increased from 5 (0-17) to 13 (0-35) nodes after the introduction of mDF (p<0.001). The type of resection and the T-stage influenced the number of retrieved nodes significantly. The percentage of node-positive cases increased from 30% to 41% (p=0.077) with mDF, the median size of the retrieved lymph nodes decreased from 9 mm before to 6 mm after mDF (p<0.001) and more micrometastases were found (6% vs. 16%, p=0.03).

CONCLUSIONS

With mDF technique more lymph nodes were retrieved in the resected colon specimens. Smaller nodes and more micrometastases were found, leading to more node positive patients.

RT-PCR and immunohistochemical evaluation of sentinel lymph nodes after in vivo mapping with Patent Blue V in colon cancer patients

OBJECTIVE

Lymph node status is the most important predictive factor in the treatment of colorectal cancer. As sentinel lymph node (SLN) biopsy might upstage stage II colon cancer, it could have therapeutic consequences in the future. We investigated the feasibility of in vivo SLN detection with Patent Blue V dye and evaluated nodal microstaging and ultrastaging using cytokeratin immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR).

MATERIAL AND METHODS

In 30 consecutive patients operated on for colon cancer, subserosal injection with Patent Blue dye was used for SLN detection in four different hospitals under the supervision of one regional coordinator. In searching for occult micrometastases, each SLN was examined at three levels. In tumor-negative SLNs at routine hematoxylin-eosin (H&E) examination (pN0) we performed CK8/CK18 immunohistochemistry (IHC) and RT-PCR for carcinoembryonic antigen (CEA).

RESULTS

The procedure was successful in 29 out of 30 patients (97%). The SLN was negative in 18 patients detected by H&E and IHC. In 16 patients the non-SLN was also negative, leading to a negative predictive value of 89% and an accuracy of 93%. Upstaging occurred in 10 patients (33%) - 7 by IHC and 3 by RT-PCR. Aberrant lymphatic drainage was seen in 3 patients (10%).

CONCLUSIONS

The SLN concept in colon carcinoma using Patent Blue V is feasible and accurate. It leads to upstaging of nodal status in 33% of patients when IHC and PCR techniques are combined. Therefore, the clinical value of SLN should be the subject of further studies.

Extra nodal growth as a prognostic factor in malignant melanoma

AIM

Extra nodal growth (ENG) in lymph-node metastases may be an additional indicator for poor prognosis and increased loco-regional recurrence in patients with a cutaneous malignant melanoma (CMM). Most studies analyzing prognostic factors lack a proper definition or description of the histological criteria for extra nodal growth. The objective of this study was to evaluate this factor.

METHODS

Retrospectively 94 patients with CMM and clinically lymph-node metastases were analysed. Metastatic lymph-nodes were evaluated for ENG and if present grouped in microscopic (<2 mm) or macroscopic (>2 mm) ENG. ENG was defined as metastatic tumour which clearly extends histologically through the nodal capsule into the perinodal fatty tissue or tumour involvement in the hilar region with interruption of the smooth outline of the (presumed) capsule.

RESULTS

Ninety-four patients, median age 52 (6-92) years with CMM, median Breslow thickness 2.8 (0.2-11.0) mm. In 50 patients ENG was present (macroscopic: 32, microscopic: 18). The median follow-up was 59 (range 5-325) months. The number of loco-regional recurrence was 10; 4 in the group with and 6 in the group without ENG (n.s.). Five years survival of patients with ENG was 42% and without ENG 50% (n.s.). There was no significant difference in survival or loco-regional recurrence between microscopic or macroscopic ENG.

CONCLUSION

ENG of lymph-node metastases of CMM is of no prognostic value and has no clinical impact.

Detection of micrometastatic breast cancer by means of real time quantitative RT-PCR and immunostaining in perioperative blood samples and sentinel nodes

The aim of our study was to detect micrometastatic breast cancer by epithelial glycoprotein-2 (EGP-2) and cytokeratin 19 (CK19), using immunostaining and real time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Fifty-eight breast cancer patients, 52 primary tumors, 75 sentinel nodes (SN) and 149 peripheral blood (PB) samples (from before, during and 4 days after operation) were examined. Immunostaining was performed with antibodies directed against EGP-2 and CK19. Detection limits were one Michigan Cancer Foundation-7 (MCF-7) breast cancer cell line cell/2.10(6) leukocytes (immunostaining) and one MCF-7 cell/10(6) leukocytes qRT-PCR. Control noncancer lymph nodes (n = 10) showed nonspecific CK19 staining, but were qRT-PCR negative; control healthy volunteer PB (n = 11) was always negative. Primary tumor samples, all positive with immunostaining, showed a wide variation of EGP-2 (>10(4) fold) and CK19 mRNA expression (>10(3) fold). SN (n = 19) from 16 patients were tumor-positive with routine haematoxylin-eosin (H&E) and/or immunostaining. SN tumor presence was positively correlated to qRT-PCR expression, but 3 tumor-positive SN were false negative with qRT-PCR. Three SN were qRT-PCR positive, while tumor negative with H&E and/or immunostaining. No immunostaining positive PB was observed, but 19 patients (33%) had one or more qRT-PCR positive PB samples. We concluded that primary tumors have varying expressions of EGP-2 and CK19 mRNA. Both markers can be used in qRT-PCR to obtain adequate sensitivity for single tumor cell detection. In SN, immunostaining appears more sensitive/specific than H&E or qRT-PCR for tumor detection. No immunostaining positivity was found in PB, while 33% of patients had qRT-PCR positive PB. The clinical value of these findings will have to be clarified.

Therapy evaluation of laryngeal carcinomas by tyrosine-pet

INTRODUCTION

One of the major problems in head and neck oncology is determination of tumor status after radiotherapy. Physical examination and conventional imaging by CT and MRI do not always accurately differentiate between residual or recurrent tumor and posttreatment inflammation, fibrosis, edema, or scarring. The feasibility of positron emission tomography (PET) with L-[1-(11)C]-tyrosine (TYR) for therapy evaluation of laryngeal squamous cell carcinomas by identification of residual or recurrent disease after radiotherapy was investigated.

PATIENTS AND METHODS

Nineteen patients with laryngeal carcinomas had standard workups with endoscopy and conventional imaging. All subjects underwent a TYR PET scan (PET1) before definitive treatment. For determination of tumor status, a second TYR PET scan (PET2) was performed 3 months after radiotherapy. At the time of scanning, seven patients were clinically suspected of having residual disease, and in these cases, additional CT imaging and biopsies during endoscopy were performed. During the minimal follow-up period of 29 months, six patients had clinical suspicion of recurrent disease. In these six cases, a third TYR PET (PET3), CT imaging, and biopsy were performed.

RESULTS

All pretreatment tumors were depicted by TYR PET (PET1). Three months after radiotherapy, sensitivity and specificity of TYR PET (PET2) for discrimination between residual tumor and benign posttreatment tissue changes were both 100%, and for CT, 50% and 67%, respectively. For detection of recurrent tumor during follow-up, sensitivity and specificity of TYR PET (PET3) were also 100%, and CT, 75% and 50%, respectively.

CONCLUSIONS

Dynamic TYR PET is an accurate imaging modality for therapy evaluation in detection of residual and recurrent disease with higher sensitivity (100%) and specificity (100%) for discrimination of tumor status by TYR PET compared with conventional imaging.

Vena Cava Filter Behavior and Endovascular Response: An Experimental In Vivo Study

PURPOSE

To evaluate the behavior and endovascular response of a new nitinol permanent vena cava filter, the TrapEase.

METHODS

Percutaneous implantation of the filter was performed in six goats, with inferior vena cava (IVC) diameter close to that of man. Radiologic data concerning the IVC, filter diameter, patency and stability were collected. At 2, 4, 20 and 26 weeks post-implantation, histopathologic analysis of the IVC wall was performed at the site of filter distension, and distal and proximal to the filter.

RESULTS

All filters remained patent. There was no migration and no signs of biological incompatibility. Signs of neointimalization were seen at 2 weeks, with well-developed neointima at 4 weeks. No acute vessel wall perforation was detected by cavography at implantation. During follow-up histologic analysis at 26 weeks, perforation of some of the small fixation barbs was seen, causing minimal damage to the vessel wall and adjacent organ tissue without impairing organ function. These events were well tolerated, probably due to the gradual nature of the penetration of fixation barbs allowing reactive fibrous tissue development. At 26 weeks the parallel filter struts were well covered with neointima and did not perforate the vessel wall. There were no complications associated with the filter implantation.

CONCLUSIONS

The TrapEase vena cava filter was well tolerated and is suitable for incorporation into the IVC wall of healthy animals without any apparent deleterious reaction due to biological incompatibility.

Involvement of renal ACE activity in proteinuria-associated renal damage in untreated and treated adriamycin nephrotic rats

Proteinuria is assumed to play a pathogenetic role in progressive renal damage. Angiotensin-converting enzyme (ACE) inhibition reduces proteinuria and provides renoprotection. This suggests that ACE activity might play a pathogenetic role in the development of proteinuria-induced renal structural damage. We investigated this hypothesis in untreated and treated established adriamycin nephrosis, a model of proteinuria-induced renal damage. In a time-course experiment, the development of renal structural damage in untreated adriamycin nephrotic rats was paralleled by a significant rise in renal ACE activity. Moreover, on cross-sectional analysis, a consistent positive correlation between renal, but not plasma, ACE activity and proteinuria, focal glomerulosclerosis and interstitial injury was present. Notably, these associations were present, not only in the untreated condition, but also during intervention with either ACE inhibition or AT(1)-receptor antagonism. Interestingly, we found that higher renal ACE activity is associated with more severe renal damage for a given amount of proteinuria, suggesting that renal ACE activity may be either a permissive or a promoting factor in the processes by which proteinuria eventually leads to renal structural damage. This relationship was abolished by renin-angiotensin system (RAS)-blockade, suggesting that RAS-mediated effects are involved in the relationship between renal ACE activity and proteinuria-induced renal damage. In conclusion, in untreated as well as treated adriamycin nephrotic rats, renal ACE activity is closely associated with renal outcome. This association appears to be independent of the specific mode of blockade of the RAS. Renal ACE activity is a consistent marker of individual differences in proteinuria-associated renal damage: further studies are needed to investigate a possible pathogenetic role in renal damage.

Clinical relevance of immunohistochemical staining for ecto-AMPase and ecto-ATPase in chronic allograft nephropathy (CAN)

INTRODUCTION

Chronic allograft nephropathy (CAN) is a major cause of deterioration of kidney function in transplanted patients. It is thought that glomerular ischaemia may contribute to glomerular dysfunction and proteinuria in these subjects. As reduced expression of glomerular ecto-ATPase concurrent with upregulation of glomerular ecto-AMPase activity is associated with local ischaemia, we compared the expression of these glomerular ecto-enzymes in kidney biopsies from subjects with CAN or with acute rejection vs normal human kidney tissue.

METHODS

Kidney biopsies in comparison with normal kidney tissue samples (n = 10) were studied from subjects with CAN (n = 6), acute interstitial rejection (n = 13), acute vascular rejection (n = 3), or subjects whose biopsies were histologically difficult to classify (n = 8). Cryostat sections (4 micro m) were stained for ecto-ATPase using standard procedures. For the demonstration of ecto-AMPase activity, conventional enzyme histochemistry was used. Reaction product of individual sections was quantified using computerized image analysis.

RESULTS

The results clearly show decreased expression of glomerular ecto-ATPase in combination with increased glomerular ecto-AMPase in all biopsies from subjects with CAN vs normal kidney tissue (P < 0.001). Although to a lesser extent, this staining pattern was also observed in patients with vascular rejection as well as in subjects whose biopsies were histologically difficult to classify (P < 0.01), while biopsies from subjects with interstitial rejection and normal control tissue stained negative for glomerular ecto-AMPase.

CONCLUSION

In CAN diminished glomerular ecto-ATPase expression occurs in association with significantly enhanced activity of glomerular ecto-AMPase. This is a strong indication for ischaemic injury of the glomerular microvasculature. As positive staining for ecto-AMPase in acute rejection episodes may be an important sign for long-term prognosis, we feel that screening of biopsies from individual subjects for glomerular ecto-AMPase activity should be considered.

New diagnostic techniques in staging in the surgical treatment of cutaneous malignant melanoma

The emphasis of the research on the surgical treatment of melanoma has been on the resection margins, the role of elective lymph node dissection in high risk patients and the value of adjuvant regional treatment with hyperthermic isolated lymph perfusion with melphalan. Parallel to this research, new diagnostic techniques, such as Positron Emission Tomography and the introduction of the sentinel lymph node biopsy with advanced laboratory methods such as immuno-histochemical markers, and reverse transcriptase polymerase chain reaction, have been developed to facilitate early detection of metastatic melanoma. The role of these new techniques on the staging and surgical treatment of melanoma is discussed in this paper.

Is sentinel node biopsy beneficial in melanoma patients? A report on 200 patients with cutaneous melanoma

AIM

The aim of this study was to evaluate the reliability and clinical impact of sentinel node biopsy, including preoperative lymphoscintigraphy and intraoperative lymphatic mapping in patients with cutaneous melanoma of the head, neck, trunk or extremities.

METHODS

Two hundred patients (103 women, 97 men), median age 57 (range 21-86) years with cutaneous melanoma > or =1.0mm Breslow thickness and clinically negative lymph nodes participated in a single institutional prospective study from May 1995 to January 2000. Primary melanoma sites included: 22 head and neck (11%), 67 trunk (34%), 29 upper extremity (14%) and 82 lower extremity (41%). The median Breslow thickness was 2.5 (range 1.0-20.0)mm. Preoperative dynamic and static lymphoscintigraphy, intraoperative blue dye and a gamma detection probe were used. If histological examination with HE or IHC showed metastases, therapeutic lymph node dissection (TLND) was performed.

RESULTS

Sentinel node(s) could be identified in 197 patients (99%); 393 sentinel nodes (mean: 2.0 per patient, range 1-7) were removed from 241 basins. Three procedures failed in the head and neck region. In 167 patients, the sentinel nodes were both blue and radioactive (85%); in 26 patients, they were only radioactive (13%) and in four patients only blue (2%). In total, 150 patients had tumour-negative sentinel nodes (76%). During a median follow-up of 47 (range 24-79) months, nodal recurrence in a negative mapped basin was documented in six patients of which isolated recurrence was in two patients and recurrence together with locoregional recurrence in four patients (false negative rate 6/54=11%). Estimated three-year recurrence-free survival in the node-negative patients and node-positive patients was 83 and 66% respectively (P<0.05). The overall survival at three years was 92 and 73% respectively (P<0.05).

CONCLUSION

Sentinel node biopsy provides accurate staging and important prognostic information. The final place of sentinel node biopsy is still undefined, and therefore sentinel node biopsy is still considered as an experimental surgical staging procedure.

Carbon-11 tyrosine PET for visualization and protein synthesis rate assessment of laryngeal and hypopharyngeal carcinomas

Accurate assessment of tumour extent and lymph node involvement in squamous cell carcinomas of the head and neck region is essential for therapy planning. Unfortunately, conventional diagnostic examination and imaging techniques, which monitor tumours on the basis of anatomical parameters, have drawbacks in clinical practice. The aim of this study was to investigate the feasibility of L-[1-(11)C]-tyrosine (TYR) positron emission tomography (PET) for visualisation of squamous cell carcinoma of the larynx and hypopharynx and quantification of tumour activity by assessment of protein synthesis rate (PSR). Dynamic TYR PET was performed on 31 patients with T1-T4 laryngeal or hypopharyngeal carcinoma before therapy. Plasma activity of TYR, (11)CO(2) and (11)C-protein levels were measured, and PSRs were calculated for primary malignancies. All 31 laryngeal and hypopharyngeal tumours were visualised as a hotspot (sensitivity 100%). The median PSR of the tumours (2.06 nmol ml(-1) min(-1); range 0.72-6.96) was significantly higher ( P<0.001) than that of non-tumour (background) tissue (0.51 nmol ml(-1) min(-1); range 0.22-0.89). L-[1-(11)C]-Tyrosine PET appears to be a potential method for visualisation of primary laryngeal and hypopharyngeal tumours. In vivo quantification of tumour activity by assessment of PSR is possible and may have a future role in the therapy planning and therapy evaluation of laryngeal and hypopharyngeal tumours.

Expression of inducible and endothelial nitric oxide synthases, formation of peroxynitrite and reactive oxygen species in human chronic renal transplant failure

Nitric oxide (NO.) is produced by NO synthases (NOS) and can interact with reactive oxygen species (ROS) to form peroxynitrite, which induces protein damage by formation of nitrotyrosine. NO. has a promotional effect on acute rejection. To investigate the role of NO. during chronic renal transplant failure (CRTF), we studied the expression of eNOS and iNOS in conjunction with H2O2 production and the formation of nitrotyrosines. Nephrectomy material from 10 patients and 10 control kidneys was used in this study. Expression of iNOS, eNOS, nitrotyrosine and the presence of ROS-producing cells and macrophages were determined using immunohistochemistry. INOS expression in nonsclerosed glomeruli and interstitium was significantly increased in patients with CRTF (p < 0.05). Glomerular eNOS expression was decreased in patients with CRTF compared with glomeruli of control kidneys (p < 0.01). Nitrotyrosine and ROS positive cells were significantly increased in CRTF in the interstitium (p < 0.05), but not in glomeruli. In summary, we found a marked interstitial increase in iNOS protein expression together with a decrease in glomerular eNOS expression in CRTF patients, associated with a significant increment in ROS and nitrotyrosine-positive cells in the interstitium. Our results suggest that loss of NO. production by glomerular eNOS in conjunction with an increased NO. production by interstitial iNOS, together with the formation of ROS and nitrotyrosine, is involved in the pathogenesis of CRTF.

Addition of AT1 blocker fails to overcome resistance to ACE inhibition in adriamycin nephrosis

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors provide renoprotection, but there is considerable interindividual variability in therapeutic efficacy, with residual proteinuria and progressive renal function loss in many individuals. This requires additional strategies to optimize therapy response, particularly for individuals with a poor response to ACE inhibition. We studied whether co-treatment with an angiotensin II subtype 1 (AT1) receptor antagonist (AII-A) improves the individual antiproteinuric response of maximal ACE inhibition in established adriamycin nephrosis.

METHODS

Rats were instituted on lisinopril (75 mg/L) six weeks after disease induction. After two weeks rats were re-stratified for residual proteinuria to continue this regimen, to a higher dose of lisinopril (150 mg/L) or to co-treatment with the AII-A L 158,809 for another four weeks. Groups on monotherapy AII-A and vehicle served as controls (all groups N=15).

RESULTS

Lisinopril lowered proteinuria by 63% from 741 to 246 g/day (range of percentage change -90 to +2%). Neither increasing the dose of the ACE inhibitor nor addition of AII-A to ACE inhibition improved the antiproteinuric efficacy on a group or individual level: non-responders remained non-responders. All drug categories reduced hard end-points of focal glomerulosclerosis to a similar degree.

CONCLUSIONS

ACE inhibition has variable renal protective efficacy in the adriamycin model. Neither increasing the dose of the ACE inhibitor beyond the optimal level nor co-treatment with AII-A overcome the individual therapy resistance. Thus, in established adriamycin nephrosis, blockade of the renin-angiotensin system at two different levels offers no additional benefit over ACE inhibition alone, either on the group or individual level.

Vessel wall reaction after vena cava filter placement

PURPOSE

To evaluate the interaction between the Cordis Keeper vena caval filter and vessel wall in a porcine model.

METHODS

Implantation of the filter was performed in five pigs. Radiologic data concerning inferior vena cava (IVC) diameter and filter patency, filter leg span, and stability were collected. At 2 or 6 months post-implantation, histopathologic analysis of the IVC wall was performed.

RESULTS

All filters remained patent with no evidence of migration. However, at 6 months follow-up, two legs of one filter penetrated the vessel wall and were adherent to the liver. These preliminary results suggest that with the observed gradual increase in the filter span, the risk of caval wall penetration increases with time, especially in a relatively small IVC (average diameter 16 mm).

CONCLUSION

The Cordis Keeper filter was well tolerated, but seems to be prone to caval wall penetration in the long term.