Laparoscopic Versus Open Surgery for Colorectal Cancers: Clinical and Pathological Outcomes from a Single Institution in Bahrain.

INTRODUCTION: Colorectal carcinoma is commonly diagnosed and accounts for an important cause of cancerrelated mortality worldwide. Despite that literature has shown the superiority of laparoscopic surgery, with improved short-term clinical benefits and equivalent oncological outcomes compared with open surgery for colorectal cancer, most cases are operated by open approach. The purpose of this study was to compare the clinical and pathological outcomes between laparoscopic and open colorectal cancer surgery at our institution. METHODOLOGY: 126 patients who had operations for colorectal cancers were identified. Patients ' clinical data, surgery type and details, postoperative early clinical outcomes and histology reports were retrieved from the database and retrospectively reviewed. Statistical analysis was used to assess the differences between laparoscopy and open approach in terms of clinical and oncological outcomes. RESULTS: Significant advantages were associated with minimally invasive colorectal surgery, with shorter postoperative hospital stay, less incidence of medical complications and improved survival. There were no statistically significant differences between both groups in pathological parameters, namely, number of retrieved lymph nodes and margins. DISCUSSION: In the hands of skilled trained surgeons, laparoscopic surgery for colorectal cancer is oncologically safe as it showed adequate dissection and appropriate number of resected lymph nodes, and is associated with reduction in postoperative morbidity and mortality. Conversion to open surgery is a risk associated with minimally invasive surgery. However, it is reported that conversion and postoperative complications are decreasing with increased surgical experience. CONCLUSION: In accordance with the current worldwide practice, our study indicates that minimally invasive surgery for colorectal cancer has the benefits of laparoscopy in terms of short-term clinical outcomes but show similar pathological outcomes in comparison to open approach. With increased surgical expertise, laparoscopic surgery is becoming the standard approach to treat colorectal cancer in our centre.

Risk Factors for Positive Margins in Breast-Conserving Surgery.

Introduction Breast-conserving surgery (BCS) followed by adjuvant radiotherapy has similar overall survival compared to mastectomy but is associated with higher rates of local recurrence. Positive surgical margins in BCS are the most important predictor of local recurrence. The aim of our study was to assess the risk factors associated with positive margins in women undergoing BCS for breast cancer in order to inform our clinical practice and minimize re-operation rates. Methods Patients with a diagnosis of breast cancer who underwent BCS from January 2013 to January 2021 were identified from our pathology database and included in the study. All patients underwent a lumpectomy with the removal of additional shaved cavity margins. Statistical analysis was used to assess the effect of patient clinical and pathological risk factors on the rate of positive margins. Results One hundred and twenty patients underwent BCS for breast cancer. Twenty-four percent of patients had positive margins. Of the 29 patients that underwent subsequent re-excisions, only 13 (45%) had residual disease in the re-excision specimen. In younger patients, tumors localized in lower quadrants and the presence of extensive intraductal component within invasive breast cancer increased the risk of positive margins. In addition, positive margins were encountered more significantly in patients with ductal carcinoma in situ (DCIS) compared to invasive tumors. Multivariate analysis showed that DCIS and young age were the only factors independently associated with positive margins. Conclusion DCIS and younger patients have a higher rate of positive margins during BCS than invasive breast cancer. For such patients at higher risk of positive margins, excision of cavity shave margins and intraoperative inking may be done to lower positive margin rates. Preoperative review of breast imaging, core biopsies, and counseling of patients about the likelihood of positive margins is important.

De-escalation of Sentinel Lymph Node Biopsy in Patients With Ductal Carcinoma In Situ.

Introduction Current guidelines recommend that sentinel lymph node biopsy (SLNB) be performed in patients with ductal carcinoma in situ (DCIS) undergoing mastectomy, in patients for whom the location of excision may compromise future SLNB, or if there is a high suspicion or risk of upstaging to invasive cancer on final pathology. Whether axillary surgery should be performed in patients with DCIS remains controversial. Our study aimed to examine the factors associated with the upgrade of DCIS to invasive cancer on final pathology and sentinel lymph node (SLN) metastases to evaluate whether axillary surgery may be safely omitted in DCIS. Methods Patients with a diagnosis of DCIS on core biopsy who underwent surgery with axillary staging between 2016 and 2022 were identified from our pathology database and retrospectively reviewed. Patients who underwent surgical management of DCIS without axillary staging and those treated for local recurrence were excluded. Results Out of 65 patients, 35.3% of patients were upstaged to the invasive disease on final pathology. 9.23% of cases had a positive SLNB. Predictive factors associated with upstaging to invasive cancer included palpable mass on clinical examination (P = 0.013), presence of a mass on preoperative imaging (P = 0.040), and estrogen receptor status (P = 0.036). Conclusion Our results support ongoing opportunities for the de-escalation of axillary surgery in patients with DCIS. In a subset of patients undergoing surgery for DCIS, SLNB may be omitted as the risk of upstaging to invasive cancer is low. Patients with a mass on clinical examination or imaging and negative estrogen receptor (ER) lesions have a higher risk of upstaging to invasive cancer, where a sentinel lymph node biopsy should be performed.

Left-Sided Acute Appendicitis in a Patient With Situs Inversus Totalis.

Acute appendicitis is one of the most common reasons for presentation to the emergency department that requires an emergency appendectomy. Clinical presentation with abdominal pain in the left lower quadrant is very uncommon but can occur with a congenital left-sided appendix or right-sided long appendix. We report a rare case of a 65-year-old man with incidental finding of situs inversus totalis who presented with left lower quadrant abdominal pain. A CT scan of the abdomen confirmed the diagnosis of left-sided acute appendicitis, and the patient underwent laparoscopic appendectomy with an uneventful postoperative course.

Photochemical alterations of natural and anthropogenic dissolved organic nitrogen in the York River.

In the following study, we addressed the effects of photoirradiation on the turnover of dissolved organic nitrogen (DON) from both natural and anthropogenic sources at the molecular level. Analysis of long-term photoirradiated samples via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) identified both the photolabile and the photoproduced DON from both natural and anthropogenic sources. Although photoproduction of DON was prominent with natural dissolved organic matter (DOM) sources, even in a low nitrogen environment, the anthropogenic source shows a shift from photobleaching to photohumification denoted by an increase in the average molecular weight (MW) and the double bound equivalent (DBE) after 25 days of a continuous exposure to UV light, implying condensation of low MW molecules (LMW) to form high MW (HMW) molecules. Furthermore, the sharp increase in N/C molar ratio, in the anthropogenic source, substantiates the photoinduced dissolved inorganic nitrogen (DIN) incorporation hypothesis. Hence, our findings suggest that anthropogenic input will drive substantial variation in riverine DOM and, thus, estuarine optics and photochemistry and bioavailability. Furthermore, we validate that photochemistry is one of the main processes that shapes the DON quality in aquatic systems regardless of its original source.

Estimating hydroxyl radical photochemical formation rates in natural waters during long-term laboratory irradiation experiments.

In this study it was observed that, during long-term irradiations (>1 day) of natural waters, the methods for measuring hydroxyl radical (˙OH) formation rates based upon sequentially determined cumulative concentrations of photoproducts from probes significantly underestimate actual ˙OH formation rates. Performing a correction using the photodegradation rates of the probe products improves the ˙OH estimation for short term irradiations (<1 day), but not long term irradiations. Only the 'instantaneous' formation rates, which were obtained by adding probes to aliquots at each time point and irradiating these sub-samples for a short time (≤2 h), were found appropriate for accurately estimating ˙OH photochemical formation rates during long-term laboratory irradiation experiments. Our results also showed that in iron- and dissolved organic matter (DOM)-rich water samples, ˙OH appears to be mainly produced from the Fenton reaction initially, but subsequently from other sources possibly from DOM photoreactions. Pathways of ˙OH formation in long-term irradiations in relation to H2O2 and iron concentrations are discussed.

Two dimensional correlation analysis of Fourier transform ion cyclotron resonance mass spectra of dissolved organic matter: a new graphical analysis of trends.

Two-dimensional (2D) correlation analysis was applied to 20 Fourier transform ion cyclotron resonance mass spectra (FTICR-MS) of ultrafiltered dissolved organic matter samples from a salinity transect of the lower Chesapeake Bay. We were able to investigate the chemical changes in the dissolved organic matter pool at the molecular level and classify the individual peaks based on their biogeochemical reactivity. The power of this technique is its ability to be used on either the presence/absence of the individual peaks or their normalized magnitudes. The presence or absence of the peaks are utilized to identify the reactivity and correlation between peaks that plot in different regions of the van Krevelen diagram, whereas the normalized magnitudes are used to correlate the changes among individual peaks. One of the promising advantages of 2D correlation of FTICR-MS data is the ability to associate the variations of the individual peaks with the changes in the functional groups that are measured by other spectroscopic techniques. This approach takes us one step further from identifying molecular formulas to proposing chemical structures.

Using two-dimensional correlations of ¹³C NMR and FTIR to investigate changes in the chemical composition of dissolved organic matter along an estuarine transect.

Applying two-dimensional correlation spectroscopy to (13)C NMR and FTIR spectra of the high molecular-weight dissolved organic matter (HMW-DOM) isolated along an Elizabeth River/Chesapeake Bay salinity transect shows that HMW-DOM consists of three major components that have different biogeochemical reactivities. The first appears to be a heteropolysaccharide (HPS) component and its contribution to carbon increases as we approach the marine offshore. The second appears to be composed of carboxyl-rich compounds (CRC); its carbon percentage decreases. The third component contains the major functional group of amide/amino sugar (AMS) and its carbon percentage stays almost constant along the salinity transect. It seems that the HPS and CRC are present in many aquatic environments at different relative ratios. The 2D-correlation maps reveal that each of these components is composed of dynamic mixtures of compounds that share similar backbone structures but have significant functional group differences. Two-dimensional (2D) correlation spectroscopy is a powerful new biogeochemical tool to track the changes in complex organic matter as a function of space, time, or environmental effects.