Centralization of Pancreaticoduodenectomy: A Systematic Review and Spline Regression Analysis to Recommend Minimum Volume for a Specialist Pancreas Service

OBJECTIVE

Through a systematic review and spline curve analysis, to better define the minimum volume threshold for hospitals to perform (pancreaticoduodenectomy) and the high volume centre (HVC).

SUMMARY BACKGROUND DATA

The pancreaticoduodenectomy (PD) is a resource intensive procedure, with high morbidity and long hospital stays resulting in centralization towards high-volume hospitals; the published definition of high-volume remains variable.

MATERIALS AND METHODS

Following a systematic review of studies comparing PD outcomes across volume groups, semiparametric regression modelling of morbidity (%), mortality (%), length of stay (days), lymph node harvest (number of nodes) and cost ($USD) as continuous variables was performed and fitted as a smoothed function of splines. If this showed a non-linear association, then a "zero-crossing" technique was used which produced "first and second derivatives" to identify volume thresholds.

RESULTS

Our analysis of 33 cohort studies (198,377 patients) showed 55 PDs/year and 43 PDs/year were the threshold value required to achieve lowest morbidity and highest lymph node harvest, with model estimated degrees of freedoms 5.154 (P<0.001) and 8.254 (P<0.001) respectively. The threshold value for mortality was approximately 45 PDs/year (model 9.219 (P <0.001)) with the lowest mortality value (the optimum value) at approximately 70 PDs/year (i.e. a high volume centre). No significant association was observed for cost (e.d.f=2, P=0.989), and length of stay (e.d.f=2.04, P=0.099).

CONCLUSIONS

There is a significant benefit from centralization of PD, with 55 PDs/year and 43 PDs/year the threshold value required to achieve lowest morbidity and highest lymph node harvest respectively. To achieve mortality benefit, the minimum procedure threshold is 45 PDs/year, with the lowest and optimum mortality value (i.e. a high volume center) at approximately 70 PDs/year.

An improved GBSO-TAENN-based EEG signal classification model for epileptic seizure detection

Detection and classification of epileptic seizures from the EEG signals have gained significant attention in recent decades. Among other signals, EEG signals are extensively used by medical experts for diagnosing purposes. So, most of the existing research works developed automated mechanisms for designing an EEG-based epileptic seizure detection system. Machine learning techniques are highly used for reduced time consumption, high accuracy, and optimal performance. Still, it limits by the issues of high complexity in algorithm design, increased error value, and reduced detection efficacy. Thus, the proposed work intends to develop an automated epileptic seizure detection system with an improved performance rate. Here, the Finite Linear Haar wavelet-based Filtering (FLHF) technique is used to filter the input signals and the relevant set of features are extracted from the normalized output with the help of Fractal Dimension (FD) analysis. Then, the Grasshopper Bio-Inspired Swarm Optimization (GBSO) technique is employed to select the optimal features by computing the best fitness value and the Temporal Activation Expansive Neural Network (TAENN) mechanism is used for classifying the EEG signals to determine whether normal or seizure affected. Numerous intelligence algorithms, such as preprocessing, optimization, and classification, are used in the literature to identify epileptic seizures based on EEG signals. The primary issues facing the majority of optimization approaches are reduced convergence rates and higher computational complexity. Furthermore, the problems with machine learning approaches include a significant method complexity, intricate mathematical calculations, and a decreased training speed. Therefore, the goal of the proposed work is to put into practice efficient algorithms for the recognition and categorization of epileptic seizures based on EEG signals. The combined effect of the proposed FLHF, FD, GBSO, and TAENN models might dramatically improve disease detection accuracy while decreasing complexity of system along with time consumption as compared to the prior techniques. By using the proposed methodology, the overall average epileptic seizure detection performance is increased to 99.6% with f-measure of 99% and G-mean of 98.9% values.

Surgical management of high-grade pancreatic injuries: Insights from a high-volume pancreaticobiliary specialty unit

BACKGROUND

The management of high-grade pancreatic trauma is controversial.

AIM

To review our single-institution experience on the surgical management of blunt and penetrating pancreatic injuries.

METHODS

A retrospective review of records was performed on all patients undergoing surgical intervention for high-grade pancreatic injuries [American Association for the Surgery of Trauma (AAST) Grade III or greater] at the Royal North Shore Hospital in Sydney between January 2001 and December 2022. Morbidity and mortality outcomes were reviewed, and major diagnostic and operative challenges were identified.

RESULTS

Over a twenty-year period, 14 patients underwent pancreatic resection for high-grade injuries. Seven patients sustained AAST Grade III injuries and 7 were classified as Grades IV or V. Nine underwent distal pancreatectomy and 5 underwent pancreaticoduodenectomy (PD). Overall, there was a predominance of blunt aetiologies (11/14). Concomitant intra-abdominal injuries were observed in 11 patients and traumatic haemorrhage in 6 patients. Three patients developed clinically relevant pancreatic fistulas and there was one in-hospital mortality secondary to multi-organ failure. Among stable presentations, pancreatic ductal injuries were missed in two-thirds of cases (7/12) on initial computed tomography imaging and subsequently diagnosed on repeat imaging or endoscopic retrograde cholangiopancreatography. All patients who sustained complex pancreaticoduodenal trauma underwent PD without mortality. The management of pancreatic trauma is evolving. Our experience provides valuable and locally relevant insights into future management strategies.

CONCLUSION

We advocate that high-grade pancreatic trauma should be managed in high-volume hepato-pancreato-biliary specialty surgical units. Pancreatic resections including PD may be indicated and safely performed with appropriate specialist surgical, gastroenterology, and interventional radiology support in tertiary centres.

Practice variation in anastomotic leak after esophagectomy: Unravelling differences in failure to rescue

INTRODUCTION

Failure to rescue (FTR) is an important outcome measure after esophagectomy and reflects mortality after postoperative complications. Differences in FTR have been associated with hospital resection volume. However, insight into how centers manage complications and achieve their outcomes is lacking. Anastomotic leak (AL) is a main contributor to FTR. This study aimed to assess differences in FTR after AL between centers, and to identify factors that explain these differences.

METHODS

TENTACLE - Esophagus is a multicenter, retrospective cohort study, which included 1509 patients with AL after esophagectomy. Differences in FTR were assessed between low-volume (<20 resections), middle-volume (20-60 resections) and high-volume centers (≥60 resections). Mediation analysis was performed using logistic regression, including possible mediators for FTR: case-mix, hospital resources, leak severity and treatment.

RESULTS

FTR after AL was 11.7%. After adjustment for confounders, FTR was lower in high-volume vs. low-volume (OR 0.44, 95%CI 0.2-0.8), but not versus middle-volume centers (OR 0.67, 95%CI 0.5-1.0). After mediation analysis, differences in FTR were found to be explained by lower leak severity, lower secondary ICU readmission rate and higher availability of therapeutic modalities in high-volume centers. No statistically significant direct effect of hospital volume was found: high-volume vs. low-volume 0.86 (95%CI 0.4-1.7), high-volume vs. middle-volume OR 0.86 (95%CI 0.5-1.4).

CONCLUSION

Lower FTR in high-volume compared with low-volume centers was explained by lower leak severity, less secondary ICU readmissions and higher availability of therapeutic modalities. To reduce FTR after AL, future studies should investigate effective strategies to reduce leak severity and prevent secondary ICU readmission.

Meckel's diverticulectomy: a multi-centre 19-year retrospective study

BACKGROUND

Meckels diverticulum (MD) causes a number of acute surgical pathologies and can contain ectopic tissue with the surgical aim to resect all ectopic mucosa. This has traditionally implied a small bowel resection (BR); though contemporary literature has demonstrated Meckel's diverticulectomy to be safe. The aim of this study was to determine optimal resection strategy, and assess MD histopathological features and their relationship to outcomes.

METHODS

A 19-year retrospective review of patient medical records across seven hospitals was conducted with demographic, clinical and pathological data collected. Analysis was conducted using a student's t-test for continuous variables and chi-squared test for categorical variables. Univariate regression was performed to identify risk factors. P < 0.05 was considered statistically significant.

RESULTS

One hundred and sixty patients underwent resection of MD, 70 (44%) had Meckel's diverticulectomy and 90 (56%) had BR. No significant difference in length (P = 0.486), width (P = 0.238), or ratio (P = 0.188) of diverticulectomy compared to BR, with fewer complications in diverticulectomy. In all, 24 (15.3%) MD were perforated, of whom 5 had gastric mucosa, 2 had mixed ectopic mucosa and 1 carcinoid tissue. There were no cases of ectopic mucosa in the resection margin requiring re-operation, or causing base perforation. MD specimen with greater length: width ratio was a risk factor for perforation OR 1.437 P = 0.042 but not for malignancy P = 0.813 or ectopic tissue P = 0.185.

CONCLUSION

Meckel's diverticulectomy is safe via laparoscopic or open approach compared with BR. Despite higher perforation rates in MD with greater length: width ratio, no malignancy or ectopic risk was identified, supporting diverticulectomy as a safe operative approach.

The role of repeated imaging in detecting complications in the post-operative period following pancreaticoduodenectomy: Serial CT imaging post-pancreaticoduodenectomy

BACKGROUND

Post-pancreaticoduodenectomy haemorrhage is a potentially life-threatening complication. Delay in the detection and subsequent management of complications contribute significantly to post-operative mortality and morbidity associated with pancreaticoduodenectomy.

METHODS

All patients undergoing pancreaticoduodenectomy at an Australian-based tertiary referral center between 2017 and 2022 were reviewed retrospectively. We identified those patients who suffered a post-pancreaticoduodenectomy haemorrhage and further analysed those patients who had their post-pancreaticoduodenectomy haemorrhage identified on repeated CT imaging performed within 24 h of their previous CT scan.

RESULTS

A total of 232 pancreaticoduodenectomies were identified for analysis during the study period, of which 23 patients (9.9%) suffered a post-pancreaticoduodenectomy haemorrhage. We present four patients who had their post-pancreaticoduodenectomy haemorrhage identified on repeat CT scan in the setting of a recent (within 24 h) CT scan which showed no evidence of active haemorrhage or pseudoaneurysm formation. All patients received prompt and definitive endovascular management through stent insertion or coil embolization resulting in successful cessation of bleeding. Three patients made an uncomplicated recovery thereafter. Unfortunately, one patient died as a complication of the bleed despite early and definitive endovascular intervention.

CONCLUSION

Our study highlights the importance of having a low threshold for repeated CT imaging in the post-pancreaticoduodenectomy setting, particularly when there remains a high index of suspicion clinically for a post-operative complication, even in the context of previous benign imaging. Given the complexity of pancreaticoduodenectomy, we believe early detection with liberal imaging allows the best chance at successfully managing the morbidity and mortality associated in the post-pancreaticoduodenectomy setting.

Granular cell tumour of the pancreas: a case report and systematic review

PURPOSE

Granular cell tumours (GCTs) of the pancreas are mostly benign and exceptionally rare, with no unique identifying radiological features. Following a case discussion of a patient with GCT, a comprehensive review of available literature was conducted to identify the common diagnostic features associated with GCT.

METHODS

Following a case report identified in our institution, a systematic review was conducted by two authors in accordance with Preferred Reporting Items for Systematic review and Meta-Analysis protocols (PRISMA) guidelines. Databases MEDLINE, EMBASE, Scopus, World of Science, and grey literature were searched on August 2021. Inclusion criteria were histopathology diagnosed granular cell tumour of the pancreas.

RESULTS

A 37-year-old male presented with 1 month of abdominal pain and an MRI demonstrating a dilated main pancreatic duct, distal parenchymal atrophy, but no focal lesion. Repeat MRI at 6 months re-demonstrated similar findings and subsequent endoscopic ultrasound was suspicious for main duct IPMN. Following multidisciplinary team discussion, a spleen-preserving distal pancreatectomy was performed. Histopathology demonstrated granular cell tumour with cells diffusely positive for S100 and no malignant transformation. 11 case reports were identified in the literature with diagnosis confirmed on tissue histopathology based on positive immunohistochemical staining for S-100 protein. Eight patients presented with gastrointestinal symptoms with abdominal pain the main presenting complaint (50%). 10 patients underwent CT with portal venous contrast and all underwent endoscopic examination. Imaging findings were similar in five studies for EUS which demonstrated a hypoechoic lesion with homogenous appearance. On non-contrast CT GCT was iso-enhancing, and with portal venous contrast demonstrated hypo-enhancement that gradually enhanced on late phases. Pre-operative diagnosis of pancreatic carcinoma was described in six cases based on imaging and biopsy, resulting in progression to surgical resection. Nine patients were managed surgically and no complications identified on follow-up (6-52 months).

CONCLUSION

The currently proposed management pathway includes EUS with biopsy and CT, and surgical resection recommended due to malignancy risk. Improved sample collection with EUS-FNA and microscopic assessment utilising S-100 immunohistochemistry may improve pre-operative diagnosis. Limitations include rare numbers in reported literature and short follow-up not allowing an assessment of GCT's natural history and malignancy risk. Additional cases would expand the current dataset of GCTs of the pancreas, so that surgical resection may be avoided in the future.

Transition from open to robotic distal pancreatectomy in a low volume pancreatic surgery country: a single Australian centre experience

BACKGROUND

Advances in technology and techniques have allowed for robotic distal pancreatectomies to be readily performed in patients at high volume centres. This study describes the experience of a single surgeon during the learning curve and transition from open to robotic distal pancreatectomy in Australia, a traditionally low volume pancreatic surgery country.

METHODS

All patients undergoing distal pancreatectomy at an Australian-based tertiary referral centre between 2010 and 2021 were reviewed retrospectively. Demographic, clinicopathologic and survival data were analysed to compare perioperative and oncological outcomes between patients who underwent open, laparoscopic and robotic distal pancreatectomies.

RESULTS

A total of 178 distal pancreatectomies were identified for analysis during the study period. Ninety-one open distal pancreatectomies (ODP), 48 laparoscopic distal pancreatectomies (LDP), and 39 robotic distal pancreatectomies (RDP) were performed. Robotic distal pancreatectomy was non-inferior with respect to perioperative outcomes and yielded statistically non-significant advantages over LDP and ODP.

CONCLUSION

RDP is feasible and can be performed safely in well-selected patients during the learning phase at large pancreatic centres in a traditionally low-volume country like Australia. Referral to large pancreatic centres where access to the robotic platform and surgeon experience is not a barrier, and where a robust multidisciplinary team meeting can take place, remains pivotal in the introduction and transition toward the robotic approach for management of patients with pancreatic body or tail lesions.

Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

Association between neutrophil-lymphocyte ratio and lymph node metastasis in gastric cancer: A meta-analysis

INTRODUCTION AND AIM

The prognostic role of neutrophil to lymphocyte ratio (NLR) has been explored extensively in the literature. The aim of this meta-analysis was to evaluate the link between NLR and lymph node metastasis in gastric cancer. A method for increasing specificity and sensitivity of pre-treatment staging has implications on treatment algorithms and survival.

SEARCH STRATEGY

The relevant databases were searched as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart. After selection, 12 full text articles that met the inclusion criteria were included for quantitative analysis. 2 × 2 squares were generated using lymph node positive/negative, and NLR high/low data. The effect size for each study was calculated using the DerSimonian-Laird random effects model. P values were calculated using the chi-square method. Finally publication bias was evaluated. All statistics were calculated using R Studio.

RESULTS

Meta-analysis showed a 1.90 times (odds ratio, with 95% CI 1.52-2.38) increase in risk of positive lymph node status with high neutrophil to lymphocyte ratio. This has significant implications for cancer screening and staging, as NLR is a highly reproducible, cost-effective, and widely available prognostic factor for gastric cancer patients. Additionally, high or low NLR values may have implications for management pathways. Patients with lymph node metastasis can be offered neoadjuvant chemotherapy, avoiding salvage therapy in the form of adjuvant chemoradiotherapy, which is poorly tolerated.

CONCLUSION

This meta-analysis shows an association between NLR and positive lymph node status in gastric cancer patients with implications for staging, as well as preoperative personalisation of therapy.

Clinical suspicion of pancreatic cancer despite negative endoscopic ultrasound-guided fine-needle aspiration biopsy

BACKGROUND

The early and accurate diagnosis of pancreatic ductal adenocarcinoma is vital for improving the efficacy of therapeutic interventions and to provide patients with the best chance of survival. While endoscopic ultrasound-fine needle aspiration (EUS-FNA) has been demonstrated to be a reliable and accurate diagnostic tool for solid pancreatic neoplasms, the ongoing management of patients with a high clinical suspicion for malignancy but with a negative EUS-FNA biopsy result can prove a challenge.

METHODS

We describe five patients from a single centre who presented for further work-up of a pancreatic mass and/or imaging features concerning for a periampullary malignancy.

RESULTS

All patients had at least one EUS-FNA biopsy performed which returned no malignant cells on cytology. Despite these negative cytology results, all patients underwent further invasive investigation through upfront resection (pancreaticoduodenectomy) or extra-pancreatic biopsy (laparoscopic biopsy of peritoneal nodule) due to worrisome features on imaging, biochemical factors and clinical presentation culminating in a high degree of suspicion for malignancy. The final tissue histopathological diagnosis in all patients was pancreatic ductal adenocarcinoma.

CONCLUSION

This case series highlights the important clinical findings, imaging and biochemical features which need to be considered in patients who have high suspicion for malignancy despite having a negative EUS-FNA cytology result. In these patients with a high index of suspicion, surgical intervention through an upfront resection or further invasive investigation should not be delayed.

Pancreatic solid pseudopapillary neoplasm: a single-institution study

BACKGROUNDS

Solid pseudopapillary neoplasms (SPNs) are a distinct but rare form of low-grade pancreatic neoplasia, accounting for 0.3%-2.7% of all pancreatic tumours. They are most common in young females. Local recurrence and distant metastasis are reported but extremely rare, and are usually resectable with curative intent. We report the clinicopathological features and long-term outcomes of SPNs following surgical resection from a single institution.

METHODS

A total of 1296 patients undergoing pancreatic resection during the 30 years period from 1991 to 2020 were retrospectively reviewed, and those with a confirmed pathological diagnosis of pancreatic SPN on review were included.

RESULTS

Twenty-two patients (1.7% of all patients undergoing resection), were identified. Twenty patients (91%) were female. Unlike previous studies, most patients (91%) were symptomatic at diagnosis. On diagnostic CT, cystic components were visible in 16 patients (73%), calcifications were found in two patients (9%), haemorrhage in one patient (5%) and a defined capsule was seen in four patients (18%). Surgical resection was undertaken on all cases, with distal pancreatectomy the most commonly performed (n = 11, 50%). One patient (4.7%) had nodal involvement, nine patients had an incomplete tumour capsule (41%) and seven patients (32%) had tumour extension into the pancreatic parenchyma. Despite this, no patients had disease recurrence at 10 years. One patient died within 5 years of heart failure unrelated to the SPN process; no patients died within 10 years of the disease.

CONCLUSION

We confirm a high proportion of female patients. Interestingly, a high proportion of our cohort was investigated for symptomatic disease. Despite a high proportion of tumours with an incomplete capsule, and extension into the pancreatic parenchyma, our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.

The effect of socioeconomic deprivation on presentation stage and long-term outcomes in patients undergoing colorectal cancer resection in Western Sydney

BACKGROUND

While socioeconomic deprivation has been shown to affect survival in colorectal cancer, other factors such as global region of birth and ethnicity also exert an effect. We wished to ascertain the influence of socioeconomic deprivation on stage of presentation and cancer survival in an ethnically diverse Australian population.

METHODS

Cases from a database of resections in Western Sydney (n = 1596) were stratified into cohorts of socioeconomic quintiles. Univariate analysis was used to compare demographics, AJCC stage and histopathological details between the least and most socioeconomically deprived groups. Kaplan-Meier analysis and log-rank testing were used to compare cancer-specific and all-cause 5-year survival between the most deprived quintile and all others, after case-control matching for age and overseas birth.

RESULTS

A total of 322 (20.2%) patients from the most socioeconomically deprived centile, and 275 (17.2%) from the least were compared. The most deprived were significantly more likely to be aged under 70 (54.1% vs. 44.4%, p = 0.019), born overseas (54.3% vs. 38.6%, p = 0.003), present with stage III disease (37.4% vs. 26.7%, p = 0.005), perforated (12.5% vs. 5.3%, p = 0.005) or circumferential tumours (37% vs. 24.3%, p = 0.043). There was no significant difference in proportions presenting with metastatic disease, or 5-year survival between the most deprived quintile and all others after correction for age and foreign birth.

CONCLUSIONS

Socioeconomic deprivation is associated with unfavourable colorectal cancer presentation stage but not poorer 5-year survival in our Western Sydney population. The reasons for this are unclear and demand further attention.

The Robotic Spleen Preserving Distal Pancreatectomy Under Temporary Splenic Artery Occlusion: the Royal North Shore Technique

There are numerous advantages of splenic vessel preservation in performing the minimally invasive spleen preserving distal pancreatectomy. Dissection along the splenic artery, and a medial to lateral dissection of the splenic vein, is associated with high risk of injury and bleeding. Proximal control of the splenic artery with vessel loops, which require tightening or adjustment with the advent of distal bleeding, is inefficient. Instead, a modified technique (the Royal North Shore Technique), whereby a vascular clamp is placed on the splenic artery, reduces splenic artery inflow and indirectly, splenic vein returns. This allows for more accurate and injury-free dissection of the now non-distended splenic vein and the associated tributaries, and maintains a relatively bloodless field in the event of arterial injury.

Safety and Efficacy of Pancreaticoduodenectomy in Octogenarians

Backgrounds: Pancreaticoduodenectomy (PD) remains the only hope of a cure in selected patients with pancreatic adenocarcinoma (PAC). With an aging population, there will be an increasing number of very elderly patients being diagnosed with PAC of whom a selected proportion would be suitable for PD. However, the literature on outcomes of elderly patients after PD remains ambiguous. Therefore, the aim of this study was to examine the safety and efficacy of PD in octogenarians with PAC.

Methods: A retrospective analysis of 304 patients with PAC undergoing PD. Patients were divided into two age groups using age of 80 years old as the cut-off.

Results: Overall mortality and major morbidity rates were 0.5 and 18.5%, respectively. The octogenarian group had a higher rate of mortality (6.3%, n = 1, p < 0.001), a higher rate of major morbidity (37.5%, n = 6, p = 0.042) and a longer hospital stay (p = 0.035). However, median survival of octogenarians was 15.6 months. Multivariate analysis showed age was not identified as a prognostic factor for major morbidity and overall survival.

Conclusion: Age alone should not be an exclusion criterion for consideration of PD. With careful selection, PD can be safely performed in octogenarians. Elderly patients should be referred to a specialized unit for an objective assessment to determine the suitability for this aggressive but potential curative approach.

Human platelet antigen (HPA)-specific immunoglobulin M antibodies in neonatal alloimmune thrombocytopenia can inhibit the binding of HPA-specific immunoglobulin G antibodies

BACKGROUND

A term baby with unexplained thrombocytopenia and a platelet (PLT) count of 14 × 10⁹ /L (maternal PLT count was 200 × 10⁹ /L) was investigated for neonatal alloimmune thrombocytopenia.

STUDY DESIGN AND METHODS

Serologic investigations were performed using the PLT immunofluorescence test (PIFT), monoclonal antibody immobilization of PLT antigens (MAIPA), and a bead-based assay (BBA) with maternal sera taken up to 56 days postdelivery. One serum sample was also separated into "immunoglobulin (Ig)M-rich" and "IgM-depleted" fractions and tested for PLT-specific antibodies. The family was genotyped for HPA.

RESULTS

HPA-3a-specific IgM antibodies were detected in the PIFT and confirmed in the BBA. PLT-specific IgG HPA-3a antibodies were not detected in the MAIPA assay and BBA in the initial sample but were detected in both techniques in subsequent serum samples. Testing of IgM-rich and IgM-depleted fractions in the MAIPA assay revealed that IgG antibody binding of the IgM-depleted fraction was inhibited by approximately 50% when it was reconstituted with the IgM-rich fraction suggesting that the IgM antibodies blocked the binding of the IgG antibodies. This effect was not observed when the IgM-depleted fraction or untreated serum was diluted with elution buffer. Incompatibility for HPA-3 was identified between the mother and the infant. The infant received one HPA-1a, -5b negative neonatal PLT transfusion, and one random PLT transfusion, with satisfactory outcomes. Both units were later found to be HPA-3b3b.

CONCLUSION

HPA-3a IgM antibodies can inhibit PLT-specific HPA-3a IgG antibodies in the MAIPA assay.

Serotonin inhibits luteinizing hormone release via 5-HT1A receptors in the zona incerta of ovariectomised, anaesthetised rats primed with steroids

The zona incerta (ZI), an area in the dorsal hypothalamus, contains neuronal systems that appear to control gonadotropin release. Previous findings show that there is an inverse relationship between serotonin (5-HT) activity in the ZI and plasma luteinizing hormone (LH) levels, indicating that the 5-HT system in this area has an inhibitory effect on LH release. Employing anaesthetised, ovariectomised rats primed with 5 microg oestradiol benzoate followed at 48 h by 0.5 mg progesterone, we have shown that 2 microg/side 5-HT in the ZI inhibits the LH surge that normally occurs 4 h after the progesterone treatment. This effect was mimicked by 2 microg/side 8-OH-DPAT, a 5-HT1A agonist, but not by DOI, a 5-HT2 agonist, BMY7378, a presynaptic 5-HT1A agonist or MCPP, a 2B & 2C agonist. The inhibitory effect of 5-HT and 8-OH-DPAT was prevented by pretreatment, 1 h before, with either 2 mg/kg i.p. WAY100135, a 5-HT1A antagonist or 0.25 mg/kg i.p. ritanserin, a 5-HT2 antagonist. These results indicate that 5-HT in the ZI exerts its inhibitory effect on LH release via 5-HT1A receptors but that another 5-HT subtype may also be involved.

Cervical disease in women referred to colposcopy following inadequate smears

The aim of this audit was to determine if inadequate cervical smears are associated with significant cervical pathology. Case records for 52 women with three consecutive inadequate smears referred for colposcopy to the Leicester Royal Infirmary (LRI) were retrieved. Sixteen women underwent large loop excision of the transformation zone (LLETZ) and cervical intraepithelial neoplasia (CIN) was identified in six cases. There were no cases of inadequate smears initiating the diagnosis in 100 consecutive women with invasive cervical cancer. Inadequate smears are associated with high rates of treatment for a low yield of CIN. To reduce morbidity associated with colposcopy it may be acceptable to repeat an inadequate smear after 6 months rather than arranging immediate recall.