Outcomes of elective and emergency surgical repair of incisional hernia: a comparative observational study

PURPOSE

Incisional hernia (IH) is a common complication following abdominal surgery. Surgical repair of IH is associated with the alleviation of symptoms and improvement of quality of life. Operative intervention can pose a significant burden to the patient and healthcare facilities. This study aims to describe and compare outcomes of elective and emergency surgical repair of IH.

METHODS

This study is a single-centre comparative retrospective study including patients who had repair of IH. Patients were divided into Group I (Emergency) and Group II (Elective), and a comparison was conducted between them.

RESULTS

Two hundred sixty-two patients were identified with a mean age of 61.8 ± 14.2 years, of which 152 (58%) were females. The mean BMI was 31.6 ± 7.2 kg/m2. More than 58% had at least one comorbidity. 169 (64.5%) patients had an elective repair, and 93 (35.5%) had an emergency repair. Patients undergoing emergency repair were significantly older and had higher BMI, p = 0.031 and p = 0.002, respectively. The significant complication rate (Clavien-Dindo III and IV) was 9.54%. 30 and 90-day mortality rates were 2.3% (n = 6) and 2.68% (n = 7), respectively. In the emergency group, the overall complications, 30-day and 90-day mortality rates were significantly higher than in the elective group, p ≤ 0.001, 0.002 and 0.001, respectively. Overall, 42 (16.1%) developed wound complications, 25 (9.6%) experienced a recurrence, and 41 (15.71%) were readmitted within 90 days, without significant differences between the two groups.

CONCLUSION

Patients who underwent emergency repair were significantly older and had a higher BMI than the elective cases. Emergency IH repair is associated with higher complication rates and mortality than elective repair.

198 Caveat Chirurgicus- Opioid Use Following Surgery

Introduction

Over the last 20-years there has been increasing opioid related deaths, in the context of a worldwide epidemic of misuse including addiction and overdose. Startlingly, opioid commencement is usually iatrogenic. Most published data is from the USA with little evidence from UK surgical practice.

Method

Retrospective analysis of surgical unit opioid prescriptions. Data included opioids prescribed on discharge, 1, 3- and 6-months post-discharge usage and milligrams-of-morphine equivalence(mgEq) used to compare regimes.

Results

One hundred cases reviewed. 35% of patients were opioid naïve on admission and of these 20%, 5.71% and 8.57% remained on opioids at 1, 3- and 6-months post discharge respectively.

Females more likely to remain on long-term opioids at 6 months at lower doses (42% v 30%).

Only 6% of discharge summaries recommended GP follow-up and assessment of opioid requirements. Furthermore, none were prescribed a tapering dosage regime on-discharge.

Patients receiving Acute Pain Team reviews, more likely to remain on long-term opioids, at lower doses (30.67mgEq, 29.25mgEq and 32.63mgEq at 1-, 3- and 6-months post-discharge) compared to those without (69.16mgEq, 74.25mgEq and 65.13mgEq).

Only 11% of patients with pre-existing opioid prescriptions were reviewed by the acute pain team.

Worryingly, there was no documented assessment of opioid misuse risk in patients.

Conclusions

Standardised assessments i.e., opioid Risk Assessment Tools and mgEq need to be documented and monitored in primary and tertiary care. Acute pain team services should be offered to more patients. Our study hopes to raise awareness of the need for effective opioid stewardship in surgical patients.

211 A Snapshot Audit of Time to Intervention for Gallstone Pancreatitis During the First Wave of COVID-19

Aim

We evaluated time to definitive treatment of Gallstone Pancreatitis (GSP) against the BSG guidelines during the first wave of COVID-19, comparing it to data of the same time period the previous year. Did the first wave of Covid-19 impact on time to intervention for patients diagnosed with GSP?

Method

Data were obtained retrospectively for 40 patients identified via the hospital coding department that presented with GSP between March 2019 - June 2019 and March 2020 – June 2020. Patient demographics, length of stay, time to intervention and re-admission awaiting intervention were recorded.

Results

Twenty-three patients were admitted during the non-COVID period. 30% (n = 7) of the non-COVID cohort had definitive management of GSP during index admission or within 2 weeks.

Seventeen patients were admitted during the first wave of Covid-19. 64.7% (n = 11) of the COVID-19 cohort had definitive management of GSP during the index admission or within 2 weeks.

Conclusions

Prior to COVID-19, we were not meeting guidelines for definitive management on index admission / within 2 weeks. During the first wave of COVID-19, more patients received definitive management of GSP during index admission / within 2 weeks than during the non-COVID period. A higher percentage of patients received surgical management within 2 weeks than in the non-COVID cohort. Those that did not receive management within 2 weeks, waited longer for intervention and had higher rates of re-admission than the non-COVID cohort. Despite anticipated future waves of COVID-19, prioritisation of urgent OP services is essential for those diagnosed with GSP to help reduce re-admission rates whilst awaiting intervention.

302 Metastatic: Benign Lymph Node Ratio (LNR) and Lymph Node Yield (LNY) as Predictors of Survival in Resected Colorectal Cancer (CRC)

Background

Lymphadenectomy is central to tumor prognosis. 12 LNY during CRC resection is a standard of good oncological resection, but 30–50 percent of resections do not achieve this. LNR was suggested to be a more accurate predictive factor.

Aim

To examine the prognostic significance of LNY and LNR on survival in patients with non-metastatic CRC.

Method

A retrospective study on patients with CRC treated at a DGH from January 2015 to February 2017. Outcome measures were Disease-Free (DFS) and Overall Survival (OS).

Results

265 cases were identified. The mean age was (71.4±11.3) years with a median follow-up of 56 (range 0–72) months. Median LNY was 18 (range 0–66) nodes. 74.9% of the cases have> 12 LNY and only 25.1% of the cases have < 12 LN yielded in the specimen; however, 76.4% have LNR of 0-<0.25. Increasing LNR was associated with poorer OS and

DFS (p-value 0.0001). An LNR of (0.75–1) was associated with a very poor prognosis (p-value 0.0001); it showed 30 and 33 months less in median OS and DFS retrospectively than LNR

(0-<0.25). LNY did not show any statistically significant predictive factor in survival.

Multivariate analysis showed OS and DFS are affected (R2 = 27.3% and 26.1% retrospectively) mainly by LNR. It did not show statistical significance with the other variables, including TNM, LNY, and Dukes' stages.

Conclusions

Increasing LNR was a marker of poor survival; however, LNY was not a statistically significant predictive factor. LNR is better in predicting survival than TNM and Dukes' staging.

719 The Routine Use of Opioid Medication for Post-Operative Pain Relief Can Risk Long Term Dependence, In Patients Previously Opiate Naive

Introduction

Post-operative pain relief commonly involves opiates. Rising concerns about misuse has increased scrutiny of prescribing practices. In the UK, 12.5% of prescriptions are for opiates. In the US, the Department of Health and Human Services has declared an epidemic of opiate misuse. We aimed to evaluate opiate prescribing practices post-operatively, within a UK teaching hospital, and establish the risk of prolonged opiate use.

Method

A pan-speciality retrospective observational cohort study was performed. Patients who underwent surgery in the year 2018 were included. Patients were opiate naïve if their admission Medicine reconciliation and GP record described no opiates for the previous year. Endpoints: the proportion of patients discharged with opiates and the proportion of patients remaining on opiates at 1- and 2-years post admission.

Results

20526 operations were performed on 17524 patients, across pan-specialities. 8772 patients were discharged on opiates. 673 required further opiates from their GP after discharge, of which 331 were previously opiate naive. At 1 year post op, 180 previously naive patients remained on opiates.

Conclusions

Attention needs to be given to the risk of developing opiate dependence post-operatively. An evidence-based approach should support clinicians in preventing an opiate crisis in the UK.

90 Establishment and characterization of Day 30 equine chorionic girdle and allantochorion cell lines

Establishing cell lines is a good model for experimental applications to study molecular mechanisms and cell-specific gene expression. Equids have a diffuse epitheliochorial placenta, where the invasive trophoblast is represented by the chorionic girdle (CG) and the noninvasive trophoblast by the allantochorion (AC). Embryonic CG cells are unique to horses and have a crucial role in equine chorionic gonadotropin (eCG) production and maintenance of pregnancy during the first trimester. This study had three objectives: (1) establishing a stable cell line from Day 30 CG cells and AC using lentivirus encoding hTERT; (2) characterisation of Day 30 CG cells and AC cell morphology and expression of eCG α (eCGA) and β (eCGB) subunits, major histocompatibility complex class II (MHCII), and Kisspeptin receptor (KISS1R) in CG and AC cells; (3) investigating eCG protein production invitro from Day 30 CG and AC cells. Three mares (n=3) were used to collect Day 30 conceptuses by non-surgical uterine lavage on Day 30 of pregnancy. All 3 conceptuses were dissected for CG and AC cells then cultured invitro to confluency in cell culture plates. Second-generation lentiviral particles were generated using a three-vector system including transfer vector pLV-hTERT-IRES-hygro, and human telomerase reverse transcriptase (hTERT) lentivirus was utilised to establish stable hygromycin-resistant equine embryonic cell lines. Reverse-transcription PCR (RT-PCR) was used to study gene expression in cells and radioimmunoassay was used to investigate protein presence in the media. We established a hygromycin-resistant Day 30 CG and AC cell lines that express eCGA, eCGB, and hTERT and confirmed using RT-PCR yielding the predicted bands. The cell lines were maintained for 16 passages (7±2 days/passage), 10 of which were cultured after the lentiviral infection steps. Also, we characterised CG cells as fast-growing, large, binucleated, and epithelioid, and AC cells as rapid-growing showing smaller, squamous, mononucleate, epithelioid, and elongated fibroblastic cells. The RT-PCR results showed eCGA and eCGB subunits are expressed by both Day 30 CG and AC cells, but MHCII and KISS1R genes were not expressed in either of cells. Moreover, radioimmunoassay results showed that Day 30 CG cells did produce eCG protein (35.42ngmL−1) invitro earlier than what previous literature has shown. However, Day 30 AC cells did not produce eCG protein (0.042ngmL−1) invitro, and both CG and AC cell lines stopped secreting eCG in the media after the lentiviral infection. To conclude, establishing stable and hygromycin-resistant cell lines from Day 30 equine CG and AC cells using lentivirus encoding pLV-hTERT-IRES-hygro is attainable. Also, equine chorionic gonadotropin eCG protein is produced invitro as early as Day 30 from CG cells.

Impact of Introduction of a Clinical Pathway for the Management of Pyelonephritis on Obstetric Patients: a Quality Improvement Project

Aim To determine whether the introduction of a clinical pathway for the treatment of pyelonephritis in obstetric patients would improve outcomes. Methods This was a retrospective study conducted in a maternity hospital using quantitative analysis methods. Patients who met laboratory and clinical criteria for pyelonephritis during data collection were included. Results The study included analysis of 23 patients pre-intervention and 19 post-intervention. Baseline and patient characteristics were similar for both groups. A statistically significant difference was seen in 3 of 7 outcome measures. Increased use of gentamicin (13% Vs 52% p=0.006), Increased number of renal ultrasounds (17% Vs 47%, p=0.04) and increased use of prophylaxis (21% Vs 68%, p=0.003). The proportion of patients receiving ≥ 10 days of IV antimicrobials decreased from 48% to 21% post-intervention (p=0.07). Discussion This study has shown that the introduction of a pathway for the treatment of pyelonephritis in pregnancy had a positive impact on several important clinical outcomes.

The treatment of achalasia patients with esophageal varices: an international study

Background

Treatment options for achalasia include endoscopic and surgical techniques that carry the risk of esophageal bleeding and perforation. The rare coexistence of esophageal varices has only been anecdotally described and treatment is presumed to carry additional risk.

Methods

Experience from physicians/surgeons treating this rare combination of disorders was sought through the International Manometry Working Group.

Results

Fourteen patients with achalasia and varices from seven international centers were collected (mean age 61 ± 9 years). Five patients were treated with botulinum toxin injections (BTI), four had dilation, three received peroral endoscopic myotomy (POEM), one had POEM then dilation, and one patient underwent BTI followed by Heller's myotomy. Variceal eradication preceded achalasia treatment in three patients. All patients experienced a significant symptomatic improvement (median Eckardt score 7 vs 1; p < 0.0001) at 6 months follow-up, with treatment outcomes resembling those of 20 non-cirrhotic achalasia patients who underwent similar therapy. No patients had recorded complications of bleeding or perforation.

Conclusion

This study shows an excellent short-term symptomatic response in patients with esophageal achalasia and varices and demonstrates that the therapeutic outcomes and complications, other than transient encephalopathy in both patients who had a portosystemic shunt, did not differ to disease-matched patients without varices.

Artificial intelligence for the real-time classification of intrapapillary capillary loop patterns in the endoscopic diagnosis of early oesophageal squamous cell carcinoma: A proof-of-concept study

Background

Intrapapillary capillary loops (IPCLs) represent an endoscopically visible feature of early squamous cell neoplasia (ESCN) which correlate with invasion depth - an important factor in the success of curative endoscopic therapy. IPCLs visualised on magnification endoscopy with Narrow Band Imaging (ME-NBI) can be used to train convolutional neural networks (CNNs) to detect the presence and classify staging of ESCN lesions.

Methods

A total of 7046 sequential high-definition ME-NBI images from 17 patients (10 ESCN, 7 normal) were used to train a CNN. IPCL patterns were classified by three expert endoscopists according to the Japanese Endoscopic Society classification. Normal IPCLs were defined as type A, abnormal as B1-3. Matched histology was obtained for all imaged areas.

Results

This CNN differentiates abnormal from normal IPCL patterns with 93.7% accuracy (86.2% to 98.3%) and sensitivity and specificity for classifying abnormal IPCL patterns of 89.3% (78.1% to 100%) and 98% (92% to 99.7%), respectively. Our CNN operates in real time with diagnostic prediction times between 26.17 ms and 37.48 ms.

Conclusion

Our novel and proof-of-concept application of computer-aided endoscopic diagnosis shows that a CNN can accurately classify IPCL patterns as normal or abnormal. This system could be used as an in vivo, real-time clinical decision support tool for endoscopists assessing and directing local therapy of ESCN.

The role of the neutrophil:lymphocyte ratio (NLR) and the CRP:albumin ratio (CAR) in predicting mortality following emergency laparotomy in the over 80 age group

INTRODUCTION

Emergency laparotomy in the elderly is an increasingly common procedure which carries high morbidity and mortality. Risk prediction tools, although imperfect, can help guide management decisions. Novel markers of surgical outcomes may contribute to these scoring systems. The neutrophil:lymphocyte ratio (NLR) and CRP:albumin ratio (CAR) have been associated with outcomes in malignancy and sepsis. We assessed the use of ratio NLR and CAR as prognostic indicators in patients over the age of 80 undergoing emergency laparotomy.

METHODS

A retrospective analysis of all patients over the age of 80 who underwent emergency laparotomy during a 3 year period was conducted. Pre and post-operative NLR and CAR were assessed in relation to outcome measures including inpatient, 30-day and 90-day mortality. Statistical analysis was conducted with Mann-Whitney U, receiver operating characteristics, Spearmans rank correlation coefficient and chi-squared tests.

RESULTS

One hundred and thirty-six patients over the age of 80 underwent emergency laparotomy. Median age was 84 years (range 80-96 years). Overall inpatient mortality was 19.2%. Pre-operative and post-operative NLR and CAR were significantly raised in patients with sepsis v no sepsis (p < 0.05). Pre-operative NLR was significantly associated with inpatient (p = 0.046), 30-day (p = 0.02) and 90-day mortality (p = 0.01) in patients with visceral perforation. A pre-operative NLR value of greater than 8 was associated with significantly increased mortality (p = 0.016, AUC:0.78). CAR was not associated with mortality.

CONCLUSION

Pre-operative NLR is associated with mortality in patients with visceral perforation undergoing emergency laparotomy. NLR > 8 is associated with a poorer outcome in this group of patients. CAR was not associated with mortality in over-80s undergoing emergency laparotomy.

Bladder cancer in renal allograft recipients: risk factors and outcomes

BACKGROUND

Solid organ transplant recipients have an increased cancer risk owing to immunosuppression and oncogenic viral infections. We report on the incidence and types of bladder cancer in kidney transplant recipients in Ireland, describing possible additional risk factors and outcomes in these patients.

METHODS

We identified kidney transplant recipients diagnosed with de novo bladder cancer between January 1, 1994, and July 31, 2012, by integrating data from the Irish National Cancer Registry and National Renal Transplant Registry. We calculated the standardized incidence ratio (SIR) and examined patient and tumor characteristics and 1-year survival rate.

RESULTS

Fifteen patients were diagnosed with de novo bladder cancer during the study period, representing 0.48% of kidney transplant recipients. The SIR was 2.5 (95% CI, 1.4-4.2; P < .001). The mean interval between transplantation and diagnosis of bladder tumor was 8.6 years and mean age at time of diagnosis was 55.7 years. Sixty percent of patients were male. The tumor types were transitional cell carcinoma (9 patients), squamous cell carcinoma (3 patients), adenocarcinoma (1 patient), carcinoma in situ (1 patient), and diffuse large B-cell lymphoma (1 patient). Beside immunosuppression, risk factors associated with bladder cancer were urogenital disease (6 patients), cyclophosphamide exposure (2 patients), BK nephropathy (1 patient), analgesic nephropathy (1 patient), and extensive smoking (1 patient). Eight patients underwent radical cystectomy for invasive tumors, with resection of other pelvic organs in 7 patients. Mortality rate within the first year was 40%.

CONCLUSION

Bladder cancer occurred more commonly in kidney transplant recipients with a predominance of aggressive tumors and a high mortality. In patients with preexisting risk factors such as urologic abnormalities and cyclophosphamide exposure careful assessment before transplantation and vigilant monitoring posttransplantation with a low threshold for cystoscopy may improve outcomes.

Organ donation following the circulatory determination of death (DCD): an audit of donation and outcomes following renal transplantation

Organ Donation following the Circulatory determination of Death was introduced in Beaumont Hospital during 2011. The Intensive Care Society of Ireland formally endorsed a national DCD clinical practice guideline in 2012. This retrospective audit covers a 2-year period during which eleven patients were considered suitable for DCD and where consent was obtained. Nine patients died within the ninety-minute period following the withdrawal of life sustaining therapies and subsequently donated organs (82%). Eighteen kidneys were recovered and seventeen patients received renal transplants--one patient received a nephron-dosing dual renal transplant. Lungs were recovered on two occasions and one patient received a lung transplant. Heart valves were recovered on one occasion. To date sixteen of seventeen recipient patients have functioning renal transplants (94%). In conclusion, this model of deceased donation has proven acceptable to families, nursing and medical staff and the outcomes reported are consistent with international best practice.

Twenty-year survivors of kidney transplantation

There have been few studies of patients with renal allografts functioning for more than 20 years. We sought to identify clinical factors associated with ultra long-term (>20 year) renal allograft survival and to describe the clinical features of these patients. We performed a retrospective analysis of the Irish Renal Transplant Database and included 1174 transplants in 1002 patients. There were 255 (21.74%) patients with graft function for 20 years or more. Multivariate analysis identified recipient age (HR 1.01, CI 1.01-1.02), gender (male HR 1.25, CI 1.08-1.45), acute rejection (HR 1.26, CI 1.09-1.45) and transplant type (living related donor vs. deceased donor) (HR 0.52, CI 0.40-0.66) as significantly associated with long-term graft loss. Median serum creatinine was 115 μmol/L. The 5-year graft survival in 20-year survivors was 74.7%. The mean age at death was 62.7 years (±10.6). The most common causes of death were cardiovascular disease and malignancy. The two major causes of graft loss were death (with function) and interstitial fibrosis/tubular atrophy. Comorbidities included skin cancer (36.1%), coronary heart disease (17.3%) and other malignancies (14.5%). This study identifies factors associated with long-term allograft survival and a high rate of morbidity and early mortality in long-term transplant recipients.

Pleuroperitoneal leak complicating peritoneal dialysis: a case series

Pressure related complications such as abdominal wall hernias occur with relative frequency in patients on peritoneal dialysis. Less frequently, a transudative pleural effusion containing dialysate can develop. This phenomenon appears to be due to increased intra-abdominal pressure in the setting of congenital or acquired diaphragmatic defects. We report three cases of pleuroperitoneal leak that occurred within a nine-month period at our institution. We review the literature on this topic, and discuss management options. The pleural effusion resolved in one patient following drainage of the peritoneum and a switch to haemodialysis. One patient required emergency thoracocentesis. The third patient developed a complex effusion requiring surgical intervention. The three cases highlight the variability of this condition in terms of timing, symptoms and management. The diagnosis of a pleuroperitoneal leak is an important one as it is managed very differently to most transudative pleural effusions seen in this patient population. Surgical repair may be necessary in those patients who wish to resume peritoneal dialysis, or in those patients with complex effusions. Pleuroperitoneal leak should be considered in the differential diagnosis of a pleural effusion, particularly a right-sided effusion, in a patient on peritoneal dialysis.

An assessment of the long-term health outcome of renal transplant recipients in Ireland

BACKGROUND

Renal transplantation remains the preferred method of renal replacement therapy in terms of patient survival, quality of life and cost. However, patients have a high risk of complications ranging from rejection episodes, infection and cancer, amongst others.

AIMS AND METHODS

In this study, we sought to determine the long-term health outcomes and preventive health measures undertaken for the 1,536 living renal transplant patients in Ireland using a self-reported questionnaire. Outcomes were divided into categories, namely, general health information, allograft-related information, immunosuppression-related complications and preventive health measures.

RESULTS

The results demonstrate a high rate of cardiovascular, neoplastic and infectious complications in our transplant patients. Moreover, preventive health measures are often not undertaken by patients and lifestyle choices can be poor.

CONCLUSIONS

This study highlights the work needed by the transplantation community to improve patient education, adjust immunosuppression where necessary and aggressively manage patient risk factors.

Nephrogenic systemic fibrosis

Nephroaenic systemic fibrosis (NSF) is a potentiallv fatal dermatiological condition found exclusively in patients with advanced renal I failure. There is minimal literature regarding the epidemiology and outcomes of patients with NSF in Ireland. A retrospective chart review was performed for all patients with NSF in Ireland. Ireland's experience with the disease was examined in light of international reports. There have been three cases of NSF in Ireland; an area which serves 1915 dialysis patients--giving a point prevalence among Irish end-stage kidney disease patients of 0.002. There was a large variation in disease severity between the three patients. All three patients had significant exposure to gadolinium chelate. Caution with gadolinium administration must be exercised in patients with advanced renal failure.

The structure of the heterodimer reaction center from Rhodobacter sphaeroides at 2.55 å resolution

Crystals have been obtained of reaction centers of the heterodimer mutant that has significantly different properties than wild type due to the primary donor being formed from both a bacteriochlorophyll and bacteriopheophytin rather than two bacteriochlorophylls as found for wild type. The crystals belong to the trigonal space group P3(1)21 and the structure has been refined to a resolution limit of 2.55 A with an R factor of 19.0%. The electron density maps confirm that a primary donor does indeed contain a bacteriopheophytin due to the His to Leu substitution at M202 that coordinates the corresponding bacteriochlorophyll in wild-type. Other structural changes compared to wild type are relatively minor with the relative orientation and positioning of the two tetrapyrroles forming the primary donor being unchanged within the error. Compared to wild type, the only significant alterations are small shifts of residues M196 to M206, a rotation of the side chain of Ile M206, and the loss of a bound water molecule that in wild-type is hydrogen-bonded to both His M202 and the bacteriochlorophyll monomer on the active branch. Since hydrogen-bonding interactions strongly influence the energies of tetrapyrroles, the loss of the water molecule should result in changes in the energies of the bacteriochlorophyll monomer that contributes to the observed functional differences with wild-type.

UDP-glucose pyrophosphorylase: up-regulation in hypertrophic cartilage and role in hyaluronan synthesis

Previously, we have performed subtractive hybridization to identify genes up-regulated in hypertrophic chondrocytes of the avian epiphyseal growth plate. In the present study, we report the identification of one of the clones as UDP-glucose pyrophosphorylase (UDPG-PPase) and propose a possible function for this enzyme in regulating hyaluronan (HA) synthesis in hypertrophic cartilage. We have cloned the 2.6 kb full-length cDNA for avian UDPG-PPase and confirmed its up-regulation in hypertrophic versus non-hypertrophic cartilage by Northern-blot analysis. The 6-fold increase in mRNA was paralleled by an equivalent increase in enzymic activity. The enzyme catalyses the conversion of glucose 1-phosphate into UDP-glucose, which is used to synthesize a number of cellular components, including HA. Overexpression of enzymically active UDPG-PPase in non-hypertrophic chondrocytes resulted in a 2-3-fold increase in total HA, as determined by a competitive binding assay and immunohistochemistry. In the developing growth plate, HA synthesis was elevated in the hypertrophic zone along with the up-regulation of the HA synthase (HAS)-2 gene. Our data suggest that an increase in both activities, UDPG-PPase and HAS-2, is required for non-hypertrophic chondrocytes to synthesize an amount of HA comparable with that in hypertrophic chondrocytes. Therefore we conclude that HA synthesis during chondrocyte differentiation is regulated at the level of the substrate-provider gene, UDPG-PPase, as well as the HAS genes.

Is a 1-CM margin necessary during nephron-sparing surgery for renal cell carcinoma?

OBJECTIVES

To determine whether a 1-cm margin is necessary for cancer control during nephron-sparing surgery (NSS) for renal cell carcinoma (RCC).

METHODS

A retrospective review of 67 patients who underwent NSS for RCC between 1990 and 2000 was conducted. The data collected included patient demographics, tumor size and location, histologic type and grade, margin status (positive or negative), and the shortest distance of normal parenchyma (in millimeters) around the tumor in the final pathologic specimen. Recurrence was determined from the clinical follow-up, which included physical examination, ultrasonography or computed tomography, and various laboratory tests.

RESULTS

Fifty-five cases were performed open and 12 laparoscopically. The mean follow-up was 60 months (range 5 to 124). The mean tumor size was 3.0 cm (range 0.9 to 11.0). Seven patients were found to have a positive margin; 1 died of metastatic RCC, 1 was alive with systemic recurrence, and 5 had no evidence of disease. Of 11 patients with a negative margin distance of less than 1 mm, 9 were recurrence free, 1 had simultaneous local and pulmonary relapse, and the other had pulmonary recurrence only. The remainder of the study patients (n = 49) had negative margins greater than 1 mm, and all were alive without evidence of disease at the last follow-up.

CONCLUSIONS

This review questions the necessity of a 1-cm margin to prevent recurrence after NSS for RCC. Additional studies to determine the optimal margin distance should be conducted.

Pregnancy outcomes among U.S. Gulf War veterans: a population-based survey of 30,000 veterans

PURPOSE

We evaluated an association between veterans' Gulf War service and reported adverse pregnancy outcomes.

METHODS

We conducted a health survey in which selected reproductive outcomes of a population-based sample of 15,000 Gulf War veterans representing four military branches and three unit components (active, reserve, and National Guard) were compared to those of 15,000 non-Gulf veteran controls.

RESULTS

Male Gulf veterans, compared with their non-Gulf veteran controls, reported a significantly higher rate of miscarriage (odds ratio [OR] = 1.62; 95% confidence interval [CI] = 1.32-1.99). Female Gulf veterans also reported more miscarriages than their respective controls, although their excess was not statistically significant (OR= 1.35; CI = 0.97-1.89). Both men and women deployed to the Gulf theater reported significant excesses of birth defects among their liveborn infants. These excess rates also extended to the subset of "moderate to severe" birth defects [males: OR= 1.78 (CI = 1.19-2.66); females: OR = 2.80 (CI = 1.26-6.25)]. No statistically significant differences by deployment status were found among men or women for stillbirths, pre-term deliveries or infant mortality.

CONCLUSION

The risk of veterans reporting birth defects among their children was significantly associated with veteran's military service in the Gulf War. This observation needs to be confirmed by a review of medical records to rule out possible reporting bias.

Focal hepatic ablation using interstitial photon radiation energy

BACKGROUND

Intratumoral ablative therapy is being used increasingly for the treatment of primary and secondary hepatic malignancies. The interstitial point-source photon radiosurgery system (PRS) is a novel ablative technique that uses radiation therapy similar in dosimetry to interstitial brachytherapy.

STUDY DESIGN

To determine the feasibility, toxicity, and local tissue destructive capabilities of the PRS in the liver, preliminary studies in a nontumor-bearing canine model were examined. A 6-month survival study was conducted. Each animal received three radiation treatments, in the right, central, and left hepatic regions. Three low-dose treatments were delivered to each of six animals (group A), generating a 2.0-cm-diameter radiated sphere with a dose of 20 Gy at the lesion edge. Three high-dose treatments were delivered to each of six animals (group B), generating a 3.0-cm-diameter radiated sphere with 20 Gy at the lesion edge.

RESULTS

The treatment reproducibly generated sharply demarcated hepatic ablative lesions proportional to the administered dose. Mean lesion diameter at 1 month was 1.6+/-0.2 cm in group A and 3.4+/-1.0 cm in group B. Lesion size was independent of intrahepatic location, including near vascular structures. PRS therapy, when applied to portal structures, resulted in hilar damage. Hilar damage appeared to be associated with arteriolar thrombosis and bile duct injury. Treatment of regions adjacent to large hepatic veins and the IVC was not associated with vessel thrombosis or stricture.

CONCLUSIONS

PRS ablation is a generally well-tolerated method that results in consistent, well-demarcated, symmetric lesions of complete necrosis with minimal adjacent parenchymal injury. Application of such an approach for the treatment of liver tumors is promising.

Percutaneous deployment of a valved bovine jugular vein in the swine venous system: a potential treatment for venous insufficiency

PURPOSE

To develop a system for potential use in the treatment of chronic venous insufficiency by using percutaneous techniques.

MATERIALS AND METHODS

A segment of a glutaraldehyde-fixed bovine external jugular vein with valves was trimmed and sutured to a nitinol stent. Animals were premedicated and anesthetized (n = 11). Venography of the right external jugular vein, inferior vena cava (IVC), and common iliac vein was performed. Deployment was accomplished via a sheath (12-24 F) with use of fluoroscopic guidance. Eleven bioprostheses were deployed in 11 animals. Bioprostheses were deployed in the IVC (n = 3) or right external iliac vein (n = 6). Animals were killed immediately after deployment (n = 7) at 1 week (n = 1) or at 2 weeks (n = 2). One animal was found dead in the cage. At necropsy, each bioprosthesis (n = 4) was explanted and histopathologic analysis was performed.

RESULTS

Deployments of the bioprostheses were successful in nine of 11 swine. Two deployments were unsuccessful (one accidental deployment in the right renal vein, one deployment in the IVC caused rupture of the vein). Postdeployment venography (n = 9) confirmed no reflux (in the recumbent position of the swine) of the valve leaflets and patency of the vein inferior to the level of the bioprostheses. in the first group of animals (n = 5), valve leaflets were normal and competent. In the survival animal group (n = 4), the bioprostheses remained patent without evidence of thrombus formation by ascending and descending venography. Gross inspection of the explanted bioprostheses (n = 4) demonstrated grossly normal valves that fully occluded the lumen. Complications included hemarthrosis (n = 1), death (n = 1), and bioprosthesis thrombosis immediately after deployment (n = 1). Histopathologic analysis showed endothelial cells covering the luminal surfaces. The wall of the bioprostheses had granulomatous response and foreign body reaction. Bacterial contamination was noted in one bioprosthesis.

CONCLUSIONS

Deployment of a glutaraldehyde-fixed bovine vein sutured to a self-expanding nitinol stent in the swine iliac vein or IVC is technically feasible. Development of a venous bioprosthesis that can be placed percutaneously may have important clinical applications as an endovascular treatment for chronic venous insufficiency when it is due to valvular incompetence.

Feasibility of ablating normal renal parenchyma by interstitial photon radiation energy: study in a canine model

BACKGROUND AND PURPOSE

A miniature photon radiosurgery system (PRS) has been described as an alternative to surgical resection and external-beam radiation for tumors and may now offer an alternative for ablation of renal lesions. We evaluated the feasibility of ablation by PRS in a normal parenchyma canine model.

MATERIALS AND METHODS

Twelve mongrel dogs were used in this survival study. In the left and right kidneys of each animal, a peripheral lesion and central-hilar lesion, respectively, were induced with PRS. The probes were placed in the renal parenchyma, and local radiation of 15 Gy at a radius of 1.3 cm was delivered over 10 minutes. Serum electrolytes were measured serially. Computed tomography scans were obtained, and the animals were sacrificed for pathologic correlation. In a separate study, the liver received three additional treatments of 10 to 20 minutes of radiation.

RESULTS

Eleven dogs survived this 6-month study and were sacrificed as scheduled. One animal expired after 2 weeks from radiation-induced fulminant hepatic failure with normal renal function. No other complications were observed. The average lesion size was 2.5 cm in diameter. Histologic analysis confirmed coagulative necrosis with sharp demarcation from the surrounding parenchyma.

CONCLUSION

Preliminary studies demonstrate the feasibility of PRS ablation of the renal parenchyma. Further tumor model testing will be important to determine the ultimate efficacy of local photon radiation energy.

TIPS placement in swine, guided by electromagnetic real-time needle tip localization displayed on previously acquired 3-D CT

PURPOSE

To determine the feasibility of guiding a transjugular intrahepatic portosystemic shunt (TIPS) procedure with an electromagnetic real-time needle tip position sensor coupled to previously acquired 3-dimensional (3-D) computed tomography (CT) images.

METHODS

An electromagnetic position sensor was placed at the tip of a Colapinto needle. The real-time position and orientation of the needle tip was then displayed on previously acquired 3-D CT images which were registered with the five swine. Portal vein puncture was then attempted in all animals.

RESULTS

The computer calculated accuracy of the position sensor was on average 3 mm. Four of five portal vein punctures were successful. In the successes, only one or two attempts were necessary and success was achieved in minutes.

CONCLUSION

A real-time position sensor attached to the tip of a Colapinto needle and coupled to previously acquired 3-D CT images may potentially aid in entering the portal vein during the TIPS procedure.

Cellular and humoral mechanisms of vascularized allograft rejection induced by indirect recognition of donor MHC allopeptides

INTRODUCTION

To investigate the role and mechanisms of indirect allorecognition in allograft rejection, we studied whether priming T cells with donor-derived MHC allopeptides could accelerate rejection in a vascularized allograft model.

METHODS

Lewis recipients of fully mismatched Wistar Furth cardiac allografts were immunized before transplantation with donor MHC allopeptides.

RESULTS

Animals immunized with immunogenic class II MHC allopeptides rejected their grafts in a significantly accelerated fashion compared with controls. Additional studies demonstrated that a single immunodominant RT1.D (HLA-DR like) allopeptide was responsible for accelerating the rejection process. Histological analysis of rejected allografts revealed marked vascular rejection in the accelerated, although not the control, group as well as severe cellular rejection. Peak production of IgM and IgG donor-specific alloantibodies was detected by flow cytometry 1 week earlier in the sera of the accelerated group compared with the control group. Immunohistological analysis of grafts from the accelerated compared with the control group showed increased endothelial deposition of IgG2b, C3, and fibrin, and up-regulation of class II MHC molecule expression. Increased intragraft expression of interferon-y and the interferon-gamma-induced chemokines, inducible protein-10 and Mig, and infiltration by activated mononuclear cells expressing CXCR3, the receptor for inducible protein-10 and Mig, was also seen.

CONCLUSION

These novel data provide evidence of a definitive link between indirect allorecognition of donor-derived MHC class II peptides and the cellular and humoral mechanisms of vascularized allograft rejection.

Immunomodulatory functions of low-molecular weight hyaluronate in an acute rat renal allograft rejection model

Low molecular weight hyaluronate (LMW-HA) blocks interactions between T lymphocyte CD44 and hyaluronate (HA), a heteropolysaccharide that is expressed on the surface of endothelial cells and ubiquitously in the extracellular matrix. This study was undertaken to assess the ability of LMW-HA to modify the course of experimental acute renal allograft rejection. Lewis (LEW) rats were bilaterally nephrectomized and received an orthotopic, fully MHC-mismatched, Wistar-Furth (WF) kidney transplant. Animals received either no treatment, low doses of cyclosporin A (CsA) on days 0 to 5, LMW-HA on days 0 to 5, or CsA plus LMW-HA on days 0 to 5 after transplantation. With no treatment, CsA monotherapy, or HA monotherapy, animals rejected their allografts at a median of 15, 13, and 7.5 d, respectively (P = NS). In contrast, combined CsA plus LMW-HA therapy prevented acute rejection and significantly prolonged graft survival (P = 0.008) to a median of 49.0 d. CsA/LMW-HA-treated grafts also demonstrated better preservation of renal function at day 30 (serum creatinine level, 1.38+/-0.8 mg/dl), compared with surviving animals treated with CsA alone (2.9+/-0.55 mg/dl, P<0.05). Histologic graft analysis of CsA/LMW-HA-treated animals at day 7 after transplantation showed minimal rejection and leukocyte infiltration, compared with all other groups. Intragraft gene expression analysis, using semiquantitative reverse transcription-PCR, at the same time point showed reductions of CD4, CD8, and interferon-gamma transcript levels in the combined-treatment group. This is the first study demonstrating the immunomodulatory functions of LMW-HA in vivo in the setting of organ transplantation. Defining the exact mechanisms that underlie this immunomodulation may provide the rationale to develop novel strategies for use in clinical transplantation.

Immunomodulatory functions of hyaluronate in the LEW-to-F344 model of chronic cardiac allograft rejection

BACKGROUND

CD44 is an important leukocyte cell surface glycoprotein with diverse functions including cell adhesion, homing, migration, and activation.

METHODS

Because administration of the principal ligand of CD44, hyaluronate (HA), in soluble form, can inhibit CD44-HA interaction, we tested the effects of HA in vivo in an established model of chronic allograft rejection. Control F344 recipients of LEW hearts received either no treatment or low-dose cyclosporine (CsA) for 30 days from the day of transplantation. Experimental animals received 30 days of CsA in combination with 30 or 90 days of low molecular weight HA (LMW-HA).

RESULTS

CsA therapy alone resulted in approximately 40% long-term (>100 days) graft survival, whereas CsA + LMW-HA (30-day and 90-day protocols) significantly increased long-term graft survival to 60% and 92%, respectively. Light microscopy and immunohistology of CsA-treated and CsA + LMW-HA-treated grafts harvested at day 30 after transplantation demonstrated that LMW-HA + CsA therapy decreased mononuclear cell infiltration and afforded better preservation of myocardial architecture. In addition, LMW-HA + CsA-treated grafts exhibited decreased expression of interferon-gamma and the growth factors transforming growth factor-beta, platelet-derived growth factor, and fibrogenic growth factor-beta. Long-term surviving grafts were assessed for arteriosclerosis, the sine qua non of chronic rejection in this model. Using a standardized scoring system, significantly less arteriosclerosis was seen in grafts from LMW-HA + CsA-treated animals at 120 days after transplantation compared with CsA alone-treated grafts. This difference was not significant, however, in grafts harvested at >150 days.

CONCLUSION

This is the first report indicating that CD44-HA interactions play an important role in chronic allograft rejection.

Paternal exposures and cardiovascular malformations. The Baltimore-Washington Infant Study Group

Possible associations between paternal exposures and cardiovascular malformations were evaluated in the Baltimore-Washington Infant Study, a population based case-control investigation of congenital heart disease and environmental factors. Home interviews of case and control parents elicited information on parental home and occupational exposures. Analysis focused on twelve cardiac diagnostic groups and paternal exposures incurred during the six months preceding the pregnancy. Associations were identified between jewelry making and atrial septal defect (Odds ratio: 12.6; 95% confidence interval: 2.3-68.6) and membranous ventricular septal defect (8.1; 2.0-33.3), welding and endocardial cushion defect with Down syndrome (1.8; 1.1-3.0), lead soldering and pulmonary atresia (2.3; 1.1-4.9) and ionizing radiation and endocardial cushion defect without Down syndrome (4.7; 1.7-12.6). Ionizing radiation was found to be associated with endocardial cushion defect with Down syndrome only when father was present at interview (5.6; 1.7-17.9); a similar effect of father at interview was noted for paint stripping in relation to coarctation of the aorta (3.5; 1.5-8.0) and muscular ventricular septal defect (3.5; 1.5-8.5). Also, paint stripping was associated with hypoplastic left heart only in the presence of family history of cardiac defects (11.9; 2.4-60.0). This large study on cardiac diagnostic groups and specific preconceptional exposures provides new leads for further assessment of the role of paternal exposures on adverse pregnancy outcome.

Clostridium difficile colitis associated with chronic renal failure

BACKGROUND

Clostridium difficile-associated diarrhoea (CDAD) is a potentially life-threatening illness which has been shown to be more common and more severe in patients with chronic renal failure (CRF) than in other groups. A review of CDAD in our nephrology unit was carried out.

METHODS

A review of microbiology and histology records identified 32 cases of CDAD in the nephrology unit over a 24-month period. Patient notes were reviewed to identify risk factors, clinical features and outcome. Available isolates of C. difficile underwent 16S ribosomal RNA typing.

RESULTS

The incidence of CDAD in the nephrology unit was 10.7 per 1000 admissions, compared to 2.7 per 1000 in other areas of the hospital (P<0.0001). CDAD was considered the sole or principal cause of death in six (19%) and was considered a contributing factor in a further seven (22%). Mortality was significantly higher among patients with established CRF (P=0.04). Seven cases occurred as a cluster, over a 1-month period. Isolates from this cluster, along with comparative strains from other areas of the hospital, were found to be PCR type 1. Diarrhoea occurred in 28 (89%) of cases, pyrexia in 17 (53%) and ileus or abdominal pain in 14 (44%). Six patients responded to discontinuation of antibiotics alone and 22 required metronidazole and/or vancomycin. Three patients had colectomy and one caecostomy because of toxic megacolon. Four patients died before specific therapy could be given and in two of these cases the diagnosis was made at autopsy. Twenty-six patients had a record of recent antibiotic therapy. Of these, 15 had at least one agent considered to be inappropriate (excessively broad spectrum agent in 11, excessive duration of therapy in four). Nine patients had only received antibiotics prior to admission.

CONCLUSIONS

CDAD carries a high mortality in nephrology patients, especially those with established CRF. The diagnosis may be missed if a careful antibiotic history is not taken, including agents received prior to admission. Rational antibiotic prescribing and adherence to infection control measures are vital to reduce the incidence of this serious condition.

Plasma transglutaminase in hypertrophic chondrocytes: expression and cell-specific intracellular activation produce cell death and externalization

We previously used subtractive hybridization to isolate cDNAs for genes upregulated in chick hypertrophic chondrocytes (Nurminskaya, M. , and T.F. Linsenmayer. 1996. Dev. Dyn. 206:260-271). Certain of these showed homology with the "A" subunit of human plasma transglutaminase (factor XIIIA), a member of a family of enzymes that cross-link a variety of intracellular and matrix molecules. We now have isolated a full-length cDNA for this molecule, and confirmed that it is avian factor XIIIA. Northern and enzymatic analyses confirm that the molecule is upregulated in hypertrophic chondrocytes (as much as eightfold). The enzymatic analyses also show that appreciable transglutaminase activity in the hypertrophic zone becomes externalized into the extracellular matrix. This externalization most likely is effected by cell death and subsequent lysis-effected by the transglutaminase itself. When hypertrophic chondrocytes are transfected with a cDNA construct encoding the zymogen of factor XIIIA, the cells convert the translated protein to a lower molecular weight form, and they initiate cell death, become permeable to macromolecules and eventually undergo lysis. Non-hypertrophic cells transfected with the same construct do not show these degenerative changes. These results suggest that hypertrophic chondrocytes have a novel, tissue-specific cascade of mechanisms that upregulate the synthesis of plasma transglutaminase and activate its zymogen. This produces autocatalytic cell death, externalization of the enzyme, and presumably cross-linking of components within the hypertrophic matrix. These changes may in turn regulate the removal and/or calcification of this hypertrophic matrix, which are its ultimate fates.