Rectal Biopsy for Hirschsprung's Disease: A Multicentre Study Involving Biopsy Technique, Pathology and Complications.

BACKGROUND: The heterogeneity of rectal biopsy techniques has encouraged us to search for a surgical and pathological standardisation of this diagnostic technique to exclude Hirschsprung's disease. The different amounts of information on the anatomopathology report prompted us to compile a template for the anatomopathology report for diagnostic rectal biopsies for surgical colleagues and pathologists working on Hirschsprung's disease. METHODS: We gathered the anonymous biopsy information and its pathology information from five hospitals for all patients in which rectal biopsies were taken to diagnose Hirschsprung's disease over two years (2020-2021). RESULTS: Of the 82 biopsies, 20 suction (24.4%), 31 punch (37.8%) and 31 open biopsies (37.8%) were taken. Of all biopsies, 69 were conclusive (84.2%), 13 were not (15.8%). In the suction biopsy group, 60% were conclusive and 40% were not; for punch biopsy, the values were 87% and 13%, respectively and for open biopsy, 97% and 3%. Inconclusive results were due to insufficient submucosa in 6/8 suction biopsies, 4/4 punch biopsies and 0/1 open biopsies. An insufficient amount of submucosa was the reason for an inconclusive result in 6/20 cases (30%) after suction biopsy, 4/31 (12.9%) cases after punch biopsy and 0 cases (0%) after open biopsy. We had one case with major postoperative bleeding post suction biopsy; there were no further adverse effects after biopsy. CONCLUSIONS: Diagnostic rectal biopsies in children are safe. Non-surgical biopsies are more likely to give inconclusive results due to smaller amounts of submucosa present in the specimen. Open biopsies are especially useful when previous non-surgical biopsies are inconclusive. An experienced pathologist is a key factor for the result. The anatomopathology report should specify the different layers present in the specimen, the presence of ganglion cells and hypertrophic nerve fibres, their description and a conclusion.

Peripheral precocious puberty in Li-Fraumeni syndrome: a case report and literature review of pure androgen-secreting adrenocortical tumors.

INTRODUCTION: Pure androgen-secreting adrenocortical tumors are a rare but important cause of peripheral precocious puberty. CASE PRESENTATION: Here, we report a pure androgen-secreting adrenocortical tumor in a 2.5-year-old boy presenting with penile enlargement, pubic hair, frequent erections, and rapid linear growth. We confirmed the diagnosis through laboratory tests, medical imaging, and histology. Furthermore, genetic testing detected a pathogenic germline variant in the TP53 gene, molecularly confirming underlying Li-Fraumeni syndrome. DISCUSSION: Only 15 well-documented cases of pure androgen-secreting adrenocortical tumors have been reported so far. No clinical or imaging signs were identified to differentiate adenomas from carcinomas, and no other cases of Li-Fraumeni syndrome were diagnosed in the four patients that underwent genetic testing. However, diagnosing Li-Fraumeni syndrome is important as it implies a need for intensive tumor surveillance and avoidance of ionizing radiation. CONCLUSION: In this article, we emphasize the need to screen for TP53 gene variants in children with androgen-producing adrenal adenomas and report an association with arterial hypertension.

Effect of the feed injection method on band broadening in analytical supercritical fluid chromatography.

The behavior of a novel type of SFC injector, the feed injector, was investigated. In SFC, the sample compounds are usually diluted in a solvent which has a higher elution strength than the mobile phase, which leads to solvent mismatch upon injection and evidently band broadening. The feed injector differs from standard injectors as the sample, contained in the sample needle or loop, is not switched in line with the mobile phase flow, but directly injected/added to the mobile phase flow (F). The subsequent mixing of sample and mobile phase flows inherently results in a dilution of the sample, thus reducing the solvent mismatch. However, for a given injection/feed flow rate Ffeed, the total volume in which the sample is contained increases with a factor (Ffeed + F)/Ffeed. In addition, to ensure that all of the loaded sample is injected on the column, an additional overfeed volume (Vov) needs to be injected after the sample plug. To better understand the effect of these operating parameters, a wide range of injection conditions was investigated by varying the Ffeed/F-ratio, Vov, overfeed solvent etc. under SFC conditions. It was found that an optimal Ffeed/F exists which is independent of F and decreases with increasing solvent strength dependency of the sample compound. Decreasing Vov has a beneficial effect on peak dispersion but can only be varied over a certain range to ensure the full injection of the loaded sample. On the other hand, it was found that a much larger gain could be made by switching the overfeed solvent to one more compatible with the CO2-based mobile phase. Further reduction of the band broadening could be achieved by applying partial sample injections.

Detailed efficiency analysis of columns with a different packing quality and confirmation via total pore blocking.

We report on a systematic study involving columns with a clearly different efficiency (4 distinct quality groups) obtained by packing the columns that were C18 bonded and endcapped with a different carbon loading. Using B-term analysis (via peak parking) and theoretical models to estimate the magnitude of the Cm- and Cs-term contributions, it could be concluded that the difference in efficiency among the groups was entirely due to a difference in eddy dispersion. As such, the columns provided an ideal testing ground to verify how well the total pore blocking (TPB)-method can be used to probe differences in packing heterogeneity. In agreement with earlier literature observations, it turns out the TPB-method is much more sensitive to packing heterogeneities than the eddy dispersion (Heddy)-contribution measured under open-pore conditions via B- and C- term subtraction. Typically, differences in Heddy on the order of 0.1-0.5µm translate into a difference on the order of 0.5-2µm in the TPB mode. This confirms the TPB as a powerful technique to make very sensitive measurements of the homogeneity of packed beds.

On-tubing fluorescence measurements of the band broadening of contemporary injectors in ultra-high performance liquid chromatography.

We report on a detailed study of the injection contribution to band broadening in contemporary UHPLC-instruments, using either flow-through needle or fixed loop injection (full loop). Using on-tubing fluorescence measurements at the outlet of the injector valve, very localized and undisturbed measurements were obtained. Varying both the flow rate and the injected volume allowed to split the injection variance (σV2,inj) in a volumetric component (related to the amount injected) and a hydrodynamic component (related to the flow rate). For the flow-through needle injector and for the small injection volumes (<2 µL) typically used in UHPLC, it was found that the volumetric contribution (i.e. the part of σV2,inj, that increases with increasing injection volume) is given by a value of σV2,inj,vol = 0.8 to 1·Vinj2 rather than by the value of 0.125 to 0.2·Vinj2 that is normally assumed in literature. For the hydrodynamic contribution to σV2,inj, (i..e, the part which remains present even for very small injection volumes), a clear increase in dispersion with flow rate is found, reaching a plateau around 0.8ml/min of 0.6 µL² or 1.2 µL² for the 75 µm and 120 µm needle seat capillaries respectively. The difference between both shows the clear advantage of using a low dispersion 75 µm injection needle seat capillary. For a loop-type injector operated in a full-loop mode, the increase in peak variance with the injection volume is much less pronounced, leading to a total injector variance given by σV2,inj = 0.34 µL²â€¯+ 0.12·Vinj2 over the entire range of investigated injection volumes of 1.1 µL up to 4.5 µL when using 120 µm or narrower ID loops. This expression was nearly completely independent of the flow rate. For larger ID sample loops, a clear increase of peak variance with flow rate at fixed injection volume was observed (σV2,inj increases with 20% for a 170 µm ID loop and with 70% for a 220 µm ID loop from 0.3 to 1 ml/min).

Problems involving the determination of the column-only band broadening in columns producing narrow and tailed peaks.

We have investigated which of the different existing peak variance read-out methods (including the effect of a deconvolution pre-treatment method) are most suited to eliminate the system contribution from the total observed band broadening observed in LC systems. Emphasis is put on the most demanding case, i.e., the measurement of non-retained component peaks, which typically are very narrow and tailed. The problem with such peaks is that the method that is generally considered to be the only mathematically correct method (i.e., the method of moments) leads to peak variance values that are so strongly dominated by the tail of the peak that they become highly exaggerated and practically meaningless (i.e., they are dominated by the peak width at 10 or 12σt, which corresponds to resolutions and peak purities that are so high they are never pursued in practice). Interestingly, filtering away the extra-column contribution from the entire peak shape using peak deconvolution (wherein not only the second order moment is corrected but also all other moments) produces corrected 4σt- and half height peak widths that are physically meaningful, i.e., the corrected values allow to make sufficiently accurate predictions of how the peak width at 4σt and at half height changes when the column length changes. This result now allows to navigate away from the classical method of moments to define the column plate height, and resort to plate heights based on the practically much more relevant 4σt- and 5σt-widths, provided theses are corrected via peak deconvolution.

Effect of pre- and post-column band broadening on the performance of high-speed chromatography columns under isocratic and gradient conditions.

We report on the results of an experimental and theoretical study of the effect of the extra-column band broadening (ECBB) on the performance of narrow-bore columns filled with the smallest particles that are currently commercially available. Emphasis is on the difference between the effect of ECBB under gradient and isocratic conditions, as well as on the ability to model and predict the ECBB effects using well-established band broadening expressions available from the theory of chromatography. The fine details and assumptions that need to be taken into account when using these expressions are discussed. The experiments showed that, the steeper the gradient, the more pronounced the extra-column band broadening losses become. Whereas the pre-column band broadening can in both isocratic and gradient elution be avoided by playing on the possibilities to focus the analytes on top of the column (e.g. by using the POISe injection method when running isocratic separations), the post-column extra-column band broadening is inescapable in both cases. Inducing extra-column band broadening by changing the inner diameter of the post-column tubing from 65 to 250 µm, we found that all peaks in the chromatogram are strongly affected (around a factor of 1.9 increase in relative peak width) when running steep gradients, while usually only the first eluting peak was affected in the isocratic mode or when running shallow gradients (factor 1.6-1.8 increase in relative peak width for the first eluting analyte).

Enhanced selectivity and search speed for method development using one-segment-per-component optimization strategies.

Linear gradient programs are very frequently used in reversed phase liquid chromatography to enhance the selectivity compared to isocratic separations. Multi-linear gradient programs on the other hand are only scarcely used, despite their intrinsically larger separation power. Because the gradient-conformity of the latest generation of instruments has greatly improved, a renewed interest in more complex multi-segment gradient liquid chromatography can be expected in the future, raising the need for better performing gradient design algorithms. We explored the possibilities of a new type of multi-segment gradient optimization algorithm, the so-called "one-segment-per-group-of-components" optimization strategy. In this gradient design strategy, the slope is adjusted after the elution of each individual component of the sample, letting the retention properties of the different analytes auto-guide the course of the gradient profile. Applying this method experimentally to four randomly selected test samples, the separation time could on average be reduced with about 40% compared to the best single linear gradient. Moreover, the newly proposed approach performed equally well or better than the multi-segment optimization mode of a commercial software package. Carrying out an extensive in silico study, the experimentally observed advantage could also be generalized over a statistically significant amount of different 10 and 20 component samples. In addition, the newly proposed gradient optimization approach enables much faster searches than the traditional multi-step gradient design methods.

Early experience with single-incision laparoscopic surgery for the placement of a gastrostomy in a 10-year-old girl: a case report.

INTRODUCTION: Access procedures for alimentation have been performed both endoscopically and surgically. In patients in whom endoscopic gastrostomy feeding tubes cannot be placed, single-incision laparoscopic surgery gastrostomy is an alternative method. This minimally invasive approach is a new technique performed through a single umbilical incision and without the need for additional laparoscopic ports. CASE PRESENTATION: In this article we present a case of single-incision laparoscopic surgery gastrostomy performed with conventional laparoscopic instruments in a 10-year-old girl of Caucasian ethnicity who was not a candidate for a percutaneous endoscopic gastrostomy tube because of esophageal varices due to her advanced-stage cystic fibrosis with liver cirrhosis and portal hypertension. She also had an umbilical hernia, which was repaired during the same procedure through the same incision. Access and pneumoperitoneum were obtained through the umbilicus with the single-incision laparoscopic surgery port. The selected site for the feeding tube in the stomach was exteriorized through this incision and a feeding tube was placed. The stomach was returned into the abdomen. The fascial defect, and thus also the hernia, was repaired, and the 2cm umbilical incision was closed with endocutaneous sutures. The total operative time was 25 minutes. Our patient's intra-operative and post-operative course was uneventful. We were able to use the feeding tube on the first post-operative day with good intestinal function. Our patient and her parents were pleased with the cosmetic result. CONCLUSIONS: The single-incision laparoscopic surgery procedure seems to be a less invasive alternative to open placement of gastrostomy. This approach has the possible advantages of reduced post-operative pain, faster return to normal function, reduced port site complications, improved cosmesis and better patient satisfaction.

Long-term disease-free survival following dendritic cell therapy and resection of small bowel melanoma metastases - a case report.

BACKGROUND: Although the resection of solitary visceral melanoma metastases is indicated when possible, further progression of metastatic disease is seen in the vast majority of patients. New modalities of immunotherapy can offer durable disease control in a significant proportion of melanoma patients. CASE REPORT: A 28-year-old man was diagnosed with stage III melanoma in 2003 and was treated with autologous dendritic cells in the adjuvant setting. Five years later melanoma metastases causing small bowel obstruction were surgically removed and he was retreated with dendritic cells. Following 5 months without disease manifestations, the patient presented with intermittent abdominal discomfort. Following the visualization of a hot spot at the level of the jejunum on 18F-fluorodeoxyglucose position-emission tomography, the patient underwent a laparotomy, during which a solitary melanoma metastasis of the small bowel causing intussusception was resected. The patient has so far remained disease-free, more than one year after the latest surgical intervention. CONCLUSION: Combined modality treatment with surgery and immunotherapy may result in an improved long-term outcome for patients with metastatic melanoma.