Impact of Modified Frailty Index on Readmissions Following Surgery for NSCLC

BACKGROUND

 Analyzing the risk factors that predict readmissions can potentially lead to more individualized patient care. The 11-factor modified frailty index is a valuable tool for predicting postoperative outcomes following surgery. The objective of this study is to determine whether the frailty index can effectively predict readmissions within 90 days after lung resection surgery in cancer patients within a single health care institution.

METHODS

 Patients who underwent elective pulmonary resection for nonsmall cell lung cancer (NSCLC) between January 2012 and December 2020 were selected from the hospital's database. Patients who were readmitted after surgery were compared to those who were not, based on their data. Propensity score matching was employed to enhance sample homogeneity, and further analyses were conducted on this newly balanced sample.

RESULTS

 A total of 439 patients, with an age range of 68 to 77 and a mean age of 72, were identified. Among them, 55 patients (12.5%) experienced unplanned readmissions within 90 days, with an average hospital stay of 29.4 days. Respiratory failure, pneumonia, and cardiac issues accounted for approximately 67% of these readmissions. After propensity score matching, it was evident that frail patients had a significantly higher risk of readmission. Additionally, frail patients had a higher incidence of postoperative complications and exhibited poorer survival outcomes with statistical significance.

CONCLUSION

 The 11-item modified frailty index is a reliable predictor of readmissions following pulmonary resection in NSCLC patients. Furthermore, it is significantly associated with both survival and postoperative complications.

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

BACKGROUND

Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA.

METHODS

This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up.

RESULTS

564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections.

CONCLUSIONS

After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception.

Parallel pathways: A chronicle of evolution in rectal and breast cancer surgery

In this editorial, we have analyzed the historical evolution of rectal and breast cancer surgery, focusing on the progressive reduction of demolitive approaches and the increasing use of more conservative strategies, accompanied by a growing emphasis on perioperative treatments aimed at enhancing surgical outcomes. All of these changes have been made possible due to an increased awareness and understanding of oncological diseases and improved perioperative treatments.

Like a Rolling (Gall)Stone: Optimal Treatment of Gallstone Obstruction of the Sigmoid Colon

BACKGROUND

Sigmoid gallstone ileus is a rare complication of cholelithiasis, accounting for 1-4% of all cases of large-bowel obstruction. This is a highly morbid, and often fatal, condition due to its challenging diagnosis and late presentation.

CASE PRESENTATION

We report a case of a 90-year-old woman admitted to Emergency Department with abdominal pain and large-bowel obstruction due to a 6 cm gallstone lodged in a diverticulum of the proximal sigmoid colon as a consequence of a cholecysto-colonic fistula. Colonoscopy was deferred due to gallstone size carrying a high possibility of failure. The patient underwent urgent laparotomy with gallstone removal via colotomy. The cholecystocolonic fistula was left untreated. The post-operative course was uneventful; the patient was discharged on 6th post-operative day.

CONCLUSION

A multidisciplinary discussion between endoscopists and surgeons is often needed to choose the best therapeutic option, especially in high-risk patients.

Conservative management of an early abdominal complication during a Tullio percutaneous endoscopic excision of renal pelvis urothelial carcinoma: A case report

BACKGROUND

Upper tract urothelial carcinoma (UTUC) representing only a small fraction of all urothelial tumors. It predominantly affects the renal pelvis in men, often coexisting with bladder carcinoma. UTUC displays a more aggressive genetic profile compared to bladder neoplasms, with the majority of patients presenting with advanced disease. Histologically, about a quarter of UTUC cases exhibit high-grade subtypes, associated with a worse prognosis. Tobacco use and past exposure to aromatic amines are significant risk factors for UTUC. Imaging modalities such as Uro-computed tomography and magnetic resonance imaging play crucial roles in diagnosis. Ureterorenoscopy is vital for direct visualization and biopsy sampling, but its limited sampling capacity presents challenges in determining tumor depth and staging. Traditionally, nephroureterectomy with bladder cuff excision has been the gold-standard treatment for UTUC. Endoscopic conservative treatment has recently emerged as a viable option for selected patients, offering comparable oncological outcomes to radical surgery. Percutaneous access is also feasible for larger intrarenal tumors.

CASE SUMMARY

We present a case of an 84-year-old woman who underwent percutaneous endoscopic excision of a renal pelvis neoplasm using the Tullio laser. Despite successful tumor removal, the patient experienced a postoperative complication with abdominal fluid leakage. Conservative management effectively resolved the complication. Given the patient's age and refusal for radical surgery, the conservative approach proved to be a valid therapeutic choice.

CONCLUSION

Overall, UTUC remains a diagnostic and therapeutic challenge due to its rarity. However, advances in endoscopic and percutaneous techniques provide valuable alternatives for selected patients, warranting further exploration in this evolving field.

Incisional Hernia After Laparoscopic Right Colectomy for Colorectal Cancer: A Prospective Study with Retrospective Control on Intracorporeal Versus Extracorporeal Anastomosis

Background: Incisional hernias often occur after laparoscopic colorectal surgery, but the precise risk factors are not fully understood. This study's primary aim was to compare the incidence of incisional hernias following laparoscopic right colectomy with intracorporeal anastomotic reconstruction (ICA) versus extracorporeal anastomotic reconstruction (ECA). Materials and Methods: A cohort study compared two groups of patients who underwent elective laparoscopic right colectomy for colon cancer following a standardized perioperative enhanced recovery program (ERP): a prospective group underwent ICA from January 2018 to February 2020 and a retrospective group underwent ECA from January 2013 to December 2016. The presence of incisional hernias was assessed by reviewing patients' follow-up computed tomography scans or evaluating the patients by telephone interview or outpatient office visit and diagnostic imaging. Secondary objectives included the hospital length of stay, postoperative complications, 30-day readmission rate, reoperation, and mortality. Results: The study included 89 patients who had laparoscopic right colectomy for malignant colon neoplasms. Among these, 48 underwent ECA (ECA group), and 41 had ICA (ICA group). At a median follow-up of 36 months, incisional hernia was observed in 1 patient (2.4%) in the ICA group, in contrast to 11 (22.9%) confirmed cases in the ECA group (P = .010). The length of hospital stay was similar between the two groups (5 days versus 4 days; P = .064). The two groups showed similarities in terms of postoperative complications (P = .093), hospital readmission (P = .999), and the rate of reoperation within 30 days (P = .461). Conclusions: The ICA technique was associated with a reduced risk of incisional hernias compared with the ECA technique, with similar outcomes in short-term postoperative complications and overall patient recovery.

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

BACKGROUND

Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.

METHODS

This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.

RESULTS

The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (β coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.

CONCLUSION

Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely.

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Second-line treatment of diffuse large B-cell lymphoma: Evolution of options

In the era of immunochemotherapy, approximately 60%-70% of diffuse large B-cell lymphoma (DLBCL) patients achieve remission with first-line rituximab-based chemoimmunotherapy. However, 30%-40% relapse after initial response to first-line therapy and, out of them, 20%-50% are refractory or experience early relapse. The second-line therapy algorithm for DLBCL has recently evolved, thanks to the recent approval of new therapeutic agents or their combinations. The new guidelines suggest a stratification of relapsed/refractory (R/R) DLBCL based on the time to relapse. For transplant-eligible patients, autologous stem cell transplant remains the preferred option when the patient relapses after 12 months from diagnosis, while anti-CD19 CART-cell therapy is the current preferred choice for high-risk DLBCL, defined as primary refractory or relapse ≤12 months. For transplant-ineligible or CAR T-cell therapy-ineligible patients, the therapeutic arsenal historically lacked effective options. However, new therapeutic options, including polatuzumab vedotin combined with bendamustine-rituximab and tafasitamab with lenalidomide, have been recently approved, and novel agents such as loncastuximab tesirine, selinexor, anti-CD19 CAR T-cell therapy, and bispecific antibodies have shown promising efficacy and manageable safety in this setting offering new hope to patients in this challenging scenario.

Intracholecystic Papillary-tubular Neoplasm (ICPN) of the Gallbladder: A Case Report Focusing on an Unexpected Pathological Finding

BACKGROUND

Intracholecystic papillary neoplasms (ICPNs) represent a rare benign entity characterized by intraluminal polypoid lesions in the gallbladder. The incidence of ICPNs ranges from 0.4% to 0.61% in all gallbladder specimens.

CASE PRESENTATION

In this report, we present a case of a young Caucasian woman who underwent elective laparoscopic cholecystectomy due to gallbladder polyps. The histological examination revealed the presence of an intracholecystic papillary neoplasm (ICPN) with a tubulopapillary growth pattern, exhibiting gastric morphology and displaying both low and high-grade dysplasia. A thorough review of the existing literature was conducted, with a specific focus on the histological features.

CONCLUSION

A comprehensive understanding of neoplastic polyps of the gallbladder is still limited. Pathological examination of these lesions is crucial for identifying key features that can influence patient outcomes and survival.

Acute Esophageal Necrosis as a Rare Complication of Metabolic Acidosis in a Diabetic Patient: A Case Report

BACKGROUND Acute esophageal necrosis, or Gurvits syndrome, is a rare clinical process often secondary to a systemic low-flow state. It can be caused by several medical conditions, and it is thought to arise from a combination of impaired mucosal barrier and chemical and ischemic insults to the esophagus. Acute esophageal necrosis usually presents with severe complications due to delayed diagnosis and only rarely has surgical indications. We present a case of Gurvits syndrome, presumably triggered by metabolic acidosis in a diabetic patient. CASE REPORT A 61-year-old man with history of hypertension and type 2 diabetes mellitus treated with metformin, canagliflozin, glimepiride, and pioglitazone came to our attention with persistent vomiting, odynophagia, chest pain after each meal, and progressive weight loss. Arterial blood analysis showed mild metabolic acidosis, while the first esophagogastroduodenoscopy performed revealed a circumferential black appearance of the esophageal mucosa, as in concentric necrosis of the distal esophagus with possible fungal superinfection. Brushing cytology confirmed the infection by Candida spp. and the patient was treated with intravenous fluconazole. The second esophagogastroduodenoscopy, performed after 2 weeks, showed almost complete healing of the esophageal mucosa; in this case, biopsy confirmed mucosal ischemia and necrosis, without showing deep impairment of the mucosa by fungal agents. CONCLUSIONS Due to its high lethality, often caused by the underlying medical diseases, acute esophageal disease should be considered in the differential diagnosis of digestive symptoms, even without upper gastrointestinal bleeding. Prompt diagnosis and treatment of contextual collateral conditions can help clinicians to avoid the worst outcomes of the disease. Among the causative factors of metabolic acidosis leading to esophageal necrosis we recognized metformin and dapagliflozin.

Update on Classic and Novel Approaches in Metastatic Triple-Negative Breast Cancer Treatment: A Comprehensive Review

Triple-negative breast cancer (TNBC) accounts for almost 15% of all diagnosed breast cancers and often presents high rates of relapses and metastases, with generally poor prognosis despite multiple lines of treatment. Immunotherapy has radically changed the approach of clinicians towards TNBC in the last two to three years, even if targeted and specific therapeutic options are still missing; this unmet need is further justified by the extreme molecular and clinical heterogeneity of this subtype of breast cancer and by the weak response to both single-agent and combined therapies. In March 2023, the National Comprehensive Cancer Network (NCCN), the main association of cancer centers in the United States, released the last clinical practice guidelines, with an update on classic and novel approaches in the field of breast cancer. The purpose of this comprehensive review is to summarize the latest findings in the setting of metastatic TNBC treatment, focusing on each category of drugs approved by the Food and Drug Administration (FDA) and included in the NCCN guidelines. We also introduce part of the latest published studies, which have reported new and promising molecules able to specifically target some of the biomarkers involved in TNBC pathogenesis. We searched the PubMed and Scopus databases for free full texts reported in the literature of the last 5 years, using the words "triple-negative breast cancer" or "TNBC" or "basal-like". The articles were analyzed by the authors independently and double-blindly, and a total of 114 articles were included in the review.

Vascular injury during laparoscopic cholecystectomy: An often-overlooked complication

Laparoscopic cholecystectomy is one of the most frequently performed procedures in gastrointestinal surgery worldwide. Bleeding complications due to vascular injuries represent an important cause of morbidity and mortality, especially when facing major bleeding during laparoscopy, where bleeding control can be technically challenging in inexperienced hands. Interestingly, the reported incidence rate of conversion to open surgery due to vascular lesions is approximately 0%-1.9%, with a mortality rate of approximately 0.02%. The primary aim of this article was to perform an up-to-date overview regarding the incidence and surgical management of vascular injuries during laparoscopic cholecystectomy according to the available scientific evidence.

Prediction of morbidity and mortality after early cholecystectomy for acute calculous cholecystitis: results of the S.P.Ri.M.A.C.C. study

Background

Less invasive alternatives than early cholecystectomy (EC) for acute calculous cholecystitis (ACC) treatment have been spreading in recent years. We still lack a reliable tool to select high-risk patients who could benefit from these alternatives. Our study aimed to prospectively validate the Chole-risk score in predicting postoperative complications in patients undergoing EC for ACC compared with other preoperative risk prediction models.

Method

The S.P.Ri.M.A.C.C. study is a World Society of Emergency Surgery prospective multicenter observational study. From 1st September 2021 to 1st September 2022, 1253 consecutive patients admitted in 79 centers were included. The inclusion criteria were a diagnosis of ACC and to be a candidate for EC. A Cochran-Armitage test of the trend was run to determine whether a linear correlation existed between the Chole-risk score and a complicated postoperative course. To assess the accuracy of the analyzed prediction models—POSSUM Physiological Score (PS), modified Frailty Index, Charlson Comorbidity Index, American Society of Anesthesiologist score (ASA), APACHE II score, and ACC severity grade—receiver operating characteristic (ROC) curves were generated. The area under the ROC curve (AUC) was used to compare the diagnostic abilities.

Results

A 30-day major morbidity of 6.6% and 30-day mortality of 1.1% were found. Chole-risk was validated, but POSSUM PS was the best risk prediction model for a complicated course after EC for ACC (in-hospital mortality: AUC 0.94, p < 0.001; 30-day mortality: AUC 0.94, p < 0.001; in-hospital major morbidity: AUC 0.73, p < 0.001; 30-day major morbidity: AUC 0.70, p < 0.001). POSSUM PS with a cutoff of 25 (defined in our study as a ‘Chole-POSSUM’ score) was then validated in a separate cohort of patients. It showed a 100% sensitivity and a 100% negative predictive value for mortality and a 96–97% negative predictive value for major complications.

Conclusions

The Chole-risk score was externally validated, but the CHOLE-POSSUM stands as a more accurate prediction model. CHOLE-POSSUM is a reliable tool to stratify patients with ACC into a low-risk group that may represent a safe EC candidate, and a high-risk group, where new minimally invasive endoscopic techniques may find the most useful field of action.

Trial Registration: ClinicalTrial.gov NCT04995380.

Rapid Assessment of COVID-19 Mortality Risk with GASS Classifiers

Risk prediction models are fundamental to effectively triage incoming COVID-19 patients. However, current triaging methods often have poor predictive performance, are based on variables that are expensive to measure, and often lead to hard-to-interpret decisions. We introduce two new classification methods that can predict COVID-19 mortality risk from the automatic analysis of routine clinical variables with high accuracy and interpretability. SVM22-GASS and Clinical-GASS classifiers leverage machine learning methods and clinical expertise, respectively. Both were developed using a derivation cohort of 499 patients from the first wave of the pandemic and were validated with an independent validation cohort of 250 patients from the second pandemic phase. The Clinical-GASS classifier is a threshold-based classifier that leverages the General Assessment of SARS-CoV-2 Severity (GASS) score, a COVID-19-specific clinical score that recently showed its effectiveness in predicting the COVID-19 mortality risk. The SVM22-GASS model is a binary classifier that non-linearly processes clinical data using a Support Vector Machine (SVM). In this study, we show that SMV22-GASS was able to predict the mortality risk of the validation cohort with an AUC of 0.87 and an accuracy of 0.88, better than most scores previously developed. Similarly, the Clinical-GASS classifier predicted the mortality risk of the validation cohort with an AUC of 0.77 and an accuracy of 0.78, on par with other established and emerging machine-learning-based methods. Our results demonstrate the feasibility of accurate COVID-19 mortality risk prediction using only routine clinical variables, readily collected in the early stages of hospital admission.

Predictive Factors of Recurrence After Laparoscopic Incisional Hernia Repair: A Retrospective Multicentre Cohort Study

Background: The main purpose of this study was to analyze patient-related factors that may influence the risk of hernia recurrence following laparoscopic incisional hernia repair (LIHR), including the potential role of chosen materials. Materials and Methods: A multicenter, retrospective cohort study was conducted on all patients who were aged >18 years and who underwent elective laparoscopic incisional hernia mesh repair at the Departments of Surgery of the S. Anna University Hospital in Ferrara and Sassuolo Hospital in Modena, Italy. Exclusion criteria were as follows: patients undergoing an open or emergency incisional hernia repair or with primary ventral hernia. All hernia and operative variables that may favor hernia recurrence were collected and analyzed. Follow-up was conducted through a standardized telephone interview, followed by an outpatient visit and diagnostic imaging if needed. Results: From September 2002 to September 2017, 312 consecutive patients underwent elective laparoscopic incisional hernia mesh repair. At a mean 22-month follow-up, 273 patients presented no recurrence of incisional hernia and 39 had relapsed. Intra- and postoperative complications were similar between groups. Unadjusted Cox regression analysis showed a statistically significant association between both the partially absorbable mesh (P < .0001) and absorbable tacks (P = .001) and recurrence, while after adjusting for potential confounders, only the partially absorbable mesh was significantly associated with recurrence (P = .007). Conclusions: The laparoscopic approach may be considered safe for incisional hernia mesh repair. In this multicenter, retrospective cohort study, the use of a partially absorbable mesh in LIHR was the only predictor of hernia recurrence. The partially absorbable mesh that was investigated, however, has been withdrawn from the market.

Long term Implications in Surgical re-Assisting (L.I.S.A. study) during the Covid-19 outbreak. A retrospective observational cohort study on a rural population

BACKGROUND

COVID-19 is having a worldwide impact on surgical treatment. Our aim was to investigate the impact of the pandemic in a rural hospital serving a low densely populated area.

METHODS

We investigated the volume and type of surgical performed operations during both the pandemic (March 2020 - February 2021) and pre-pandemic periods (March 2019 - February 2020) as well as during the first and second pandemic waves compared to the pre-pandemic period. We compared the volume and timing of emergency appendectomy and cholecystectomy performed during the pandemic with those of the pre-pandemic period, doing the same with the volume, timing and stages of elective gastric and colorectal resections for cancer.

RESULTS

In the pre-pandemic period a higher number of appendectomies (42 vs. 24) and urgent and elective cholecystectomies (174 vs. 126) was performed. The patients operated during the pandemic period (both for appendectomy and cholecystectomy) were on average older (58 vs. 52 years old, p=0.006), including for cholecystectomy (73 vs. 66 years old, p=0.01) and appendectomy (43 vs. 30 years old, p =0.04). The logistic regression analysis with regard to the cholecystectomies and appendectomies performed in emergency showed that male sex and age were associated with gangrenous type histology, both in the pandemic and pre-pandemic period. Finally, we found a reduction in the stage I and IIA colorectal cancers operated during the pandemic compared to those of the pre-pandemic period, with no increase of the advanced stages.

CONCLUSIONS

The reduction in services imposed by governments during the first months of total lock down could not justify the whole decrease in surgical interventions in the year of the pandemic. Data suggest that greater "non-operative management" for appendicitis and acute cholecystitis does not lead to an increase of cases operated over time, nor to an increase in the "gangrenous" pattern, this seems to depend on age advanced and male population.

KEY WORDS

COVID-19, Emergency Surgery, General Surgery, Pandemics.

Factors Associated with Early Discharge after Thoracoscopic Lobectomy: Results from the Italian VATS Group Registry

Objective. There are limited data for estimating the risk of early discharge following thoracoscopic lobectomy. The objective was to identify the factors associated with a short length of stay and verify the influence of these variables in uncomplicated patients. Methods. We reviewed all lobectomies reported to the Italian VATS Group between January 2014 and January 2020. Patients and perioperative characteristics were divided into two subgroups based on whether or not they met the target duration of stay (≤ or >4 days). The association between preoperative and intraoperative variables and postoperative length of stay (LOS) ≤4 days was assessed using a stepwise multivariable logistic regression analysis to identify factors independently associated with LOS and factors related to LOS in uncomplicated cases. Results. Among 10,240 cases who underwent thoracoscopic lobectomy, 37.6% had a hospital stay ≤4 days. Variables associated with LOS included age, hospital surgical volume, Diffusion Lung CO % (81 [69–94] vs. 85 [73–98]), Forced Expiratory Volume (FEV1) % (92 [79–106] vs. 96 [82–109]), operative time (180 [141–230] vs. 160 [125–195]), uniportal approach (571 [9%] vs. 713 [18.5%]), bioenergy sealer use, and pain control through intercostal block or opioids (p < 0.001). Except for FEV1 and blood loss, all other factors emerged significantly associated with LOS when the analysis was limited to uncomplicated patients. Conclusions. Demographic, clinical, and surgical variables are associated with early discharge after thoracoscopic lobectomy. This study indicates that these characteristics are associated with early discharge. This result can be used in association with clinical judgment to identify appropriate patients for fast-track protocols.

Short bowel disease after emergency surgery for massive intestinal infarction. A case report and review of the literature

Mesenteric ischemia is an infrequent diagnosis, although it carries substantial morbidity and mortality. In adults, the massive resection of small bowel leaving less than 150 cm of intestine results in malabsorption and diarrhoea and defines the short bowel syndrome (SBS). In this report, we present a case of emergency surgery with a near total enterectomy due to superior mesenteric ischemia with a long time of survival. KEY WORDS: Case report, General surgery, Mesenteric ischemia, Small intestine.

Diet and nutrition against inflammatory bowel disease: Trick or treat(ment)?

Even if the relationships between nutrition and inflammatory bowel disease (IBD) remain underexplored, the current literature is providing, day by day, much more evidence on the effects of various diets in both prevention and treatment of such illnesses. Wrong dietary habits, together with other environmental factors such as pollution, breastfeeding, smoke, and/or antibiotics, are among the theoretical pathogenetic causes of IBD, whose multifactorial aetiology has been already confirmed. While some of these risk factors are potentially reversible, some others cannot be avoided, and efficient treatments become necessary to prevent IBD spread or recurrence. Furthermore, the drugs currently available for treatment of such disease provide low-to-no effect against the symptoms, making the illnesses still strongly disabling. Whether nutrition and specific diets will prove to effectively interrupt the course of IBD has still to be clarified and, in this sense, further research concerning the applications of such dietary interventions is still needed.

Swab test in biological fluids as predictor of COVID-19 transmission risk during surgery: a prospective cross-sectional study from an Italian COVID center

BACKGROUND

The contamination of body fluids by Severe Acute Respiratory Syndrome Coronavirus 2 during surgery is current matter of debate in the scientific literature concerning CoronaVIrus Disease 2019. Surgical guidelines were published during the first wave of the COVID-19 pandemic and recommended to avoid laparoscopic surgery as much as possible, in fear that the chimney effect of high flow intraperitoneal gas escape during, and after, the procedure would increase the risk of viral transmission.

AIM

The aim of this study was to evaluate the possibility of SARS-CoV-2 transmission during surgery by searching for viral RNA in serial samplings of biological liquids.

METHODS

This is a single center prospective cross-sectional study. We used a real-time reverse transcriptase (RT) polymerase chain reaction (PCR) test to perform swab tests for the qualitative detection of nucleic acid from SARS-CoV-2 in abdominal fluids, during emergency surgery and on the first post-operative day. In the case of thoracic surgery, we performed a swab test of pleural fluids during chest drainage placement as well as on the first post-operative day.

RESULTS

A total of 20 samples were obtained: 5 from pleural fluids, 13 from peritoneal fluids and two from biliary fluid. All 20 swabs performed from biological fluids resulted negative for SARS-CoV-2 RNA detection.

CONCLUSION

To date, there is no scientific evidence of possible contagion by laparoscopic aerosolization of SARS-CoV-2, neither is certain whether the virus is effectively present in biological fluids.

COVID-19: identifying the main outcome predictors. A retrospective cohort study in Northern Italy

OBJECTIVE

The need for efficient drugs and early treatment of patients with SARS-CoV-2 infection developing COVID-19 symptoms is of primary importance in daily clinical practice and it is certainly among the most difficult medical challenges in the current century. Recognizing those patients who will need stronger clinical efforts could effectively help doctors anticipate the eventual need for intensification of care (IoC) and choose the best treatment in order to avoid worse outcomes.

PATIENTS AND METHODS

We enrolled 501 patients, consecutively admitted to our two COVID hospitals, and collected their clinical, anamnestic and laboratory data on admission. The aim of this retrospective study was to identify those data that are strictly associated with COVID-19 outcomes (IoC and in-hospital death) and that could somehow be intended as predictors of these outcomes. This allowed us to provide a "sketch" of the patient who undergoes, more often than others, an intensification of care and/or in-hospital death.

RESULTS

Males were found to have a double risk of needing an IoC (OR=2.11) and a significant role was played by both the PaO2/FiO2 ratio on admission (OR=0.99) and serum LDH (OR=1.01). The main predictors of in-hospital death were age (OR=1.08) and the PaO2/FiO2 ratio on admission (OR=0.99).

CONCLUSIONS

Male patients with high serum LDH on admission are those who undergo more often an intensification of care among COVID-19 inpatients. Both age and respiratory performances on admission modify the prognosis within the hospitalization period.

The Berne-Donovan technique for diverticulization of a severe lateral non-traumatic duodenal fistula

BACKGROUND

The duodenal «diverticulization» is a surgical technique described by Berne and colleagues in 1968 for the treatment of combined duodenal pancreatic injuries. It consisted of closure of the duodenal injury by suture and tube duodenostomy, gastric antrectomy with end-to-side isoperistaltic Billroth II gastrojejunostomy, and abdominal drainage. As evidenced from the literature in few reports, this technique has also been adopted for lateral duodenal lacerations in non traumatic conditions. Most biliary disease may be responsible for duodenal injury.

CASE PRESENTATION

Herein, we describe the application of this emergency technique for the treatment of a wide lateral duodenal laceration discovered intra-operatively during laparoscopic cholecystectomy for acute cholecystitis. A comprehensive critical review of the different surgical methods proposed for duodenal protection in case of severe duodenal lesions has been performed and discussed.

CONCLUSION

Duodenal injuries represent a challenging condition, especially for surgeons with limited experience in this field. The key-message of this report is to consider emergency surgical techniques in difficult unexpected intra-operative situations which may occur during routine surgical practice.

KEY WORDS

Duodenal diverticulization, Duodenal fistula, Laparoscopic cholecystectomy, Surgical repair.

Fluorescent cholangiography: An up-to-date overview twelve years after the first clinical application

Laparoscopic cholecystectomy (LC) is one of the most frequently performed gastrointestinal surgeries worldwide. Bile duct injury (BDI) represents the most serious complication of LC, with an incidence of 0.3%-0.7%, resulting in significant perioperative morbidity and mortality, impaired quality of life, and high rates of subsequent medico-legal litigation. In most cases, the primary cause of BDI is the misinterpretation of biliary anatomy, leading to unexpected biliary lesions. Near-infrared fluorescent cholangiography is widely spreading in clinical practice to delineate biliary anatomy during LC in elective and emergency settings. The primary aim of this article was to perform an up-to-date overview of the evolution of this method 12 years after the first clinical application in 2009 and to highlight all advantages and current limitations according to the available scientific evidence.

COVID-19 and blood groups: A six-months observational study in Ferrara, Italy

The current literature still gives a little information about the relationships between the ABO blood group system and the immune response to the virus or the different disease outcomes. Hypothesizing the presence of a predisposition by some blood groups to COVID-19, we searched for differences between patients towards the different outcomes of disease.We enrolled 330 inpatients with a diagnosis of COVID-19, determining both their ABO blood group system and Rh factor, collecting demographic, clinical and laboratory data. We searched for relationships with COVID-19 outcomes within an observation period of 180 days (Intensification of Care - IoC, Inhospital death, 180-days mortality). The most frequent ABO blood group was A (45.8%); a minor part was represented by group O (38.8%), B (11.5%), AB (3.9%). As for the Rh factor, 86.7% of patients were Rh-positive. There were no significant differences between blood groups and Rh factors as for age, length of hospital stays (LoS), or Charlson Comorbidity Index (CCI), nor we found significant relationships between the ABO groups and COVID-19 outcomes. A significant relation was found between AB group and IoC (p=0.03) while as for the Rh factor, the patients with Rh factor positive died with less frequency during the stay (p=0.03). Cox regression analyses showed substantial differences in the survival functions concerning the Rh factors. The Rh factor seems to be involved in the 180-day prognosis. The survival functions of patients with Rh factor positive show, in fact, significantly better curves when compared to those with Rh factor negative.

COVID-19 inpatients with gastrointestinal onset: sex and care needs' differences in the district of Ferrara, Italy

Background

COVID-19 is characterized by interstitial pneumonia, but a presentation of the disease with digestive symptoms only may occur.

This work was aimed at evaluating: (1) the prevalence of presentation with digestive symptoms only in our cohort of COVID-19 inpatients; (2) differences between patients with and without gastrointestinal onset; (3) differences among males and females with gastrointestinal presentation; (4) outcomes of the groups of subjects with and without gastrointestinal onset.

Method

We retrospectively divided the patients hospitalized with COVID-19 into two groups: (1) the one with digestive symptoms (DSG) and (2) the other without digestive symptoms (NDSG). We compared the subjects of DSG with those of NDSG and males with females in the DSG group only, in terms of demographics (age, sex), inflammation and organ damage indexes, length of stay, in-hospital and 100-day mortality.

Results

The prevalence of gastrointestinal symptoms at presentation was 12.5%. The DSG group showed a prevalence of females, and these tended to a shorter hospital stay; DSG patients were younger and with a higher load of comorbidities, but no differences concerning inflammation and organ damage indexes, need for intensification of care, in-hospital and 100-day mortality were detected. Among DSG patients, males were younger than females, more comorbid, with higher serum CRP and showed a longer length of hospital stay. Survival functions of DSG patients, in general, are more favourable than those of NDSG if adjusted for sex, age and comorbidities.

Conclusions

(1) The prevalence of gastrointestinal presentation among hospitalized COVID-19 patients was 12.5%; (2) DSG patients were on average younger, more comorbid and with a prevalence of females, with a shorter hospital stay; (3) in the DSG group, males had a higher Charlson Comorbidity Score and needed a longer hospital stay; (4) DSG subjects seem to survive longer than those of the NDSG group.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06476-y.

Impact of Covid-19 on surgical activities and personnel: lessons for the future

BACKGROUND

Covid-19 pandemic has impacted professional, economic and social activities. In the surgical field, it has brought changes to operating activities, the organization of workforces, the protection measures for patients and personnel against possible intraoperative transmissions as well as training young surgeons. This study intends to assess the extent of this impact in our institution.

METHODS

The patients operated on in nine Operating Units(OUs) in the period February 1 - March 31 2020 with follow-ups on April 30 2020 were evaluated both retrospectively and prospectively. Organizational, clinical and impact parameters on staff were evaluated.

RESULTS

Of the 833 consecutive admitted patients, 742 were operated on ,705 of whom were recruited for the study. Compared to the same period in 2019 there was a decrease in the number of operations (742 compared to 1187), similar use of intensive care unit (ICU), a diagnostic activity only for symptomatic patients, heterogeneity in organizational behaviors, an impact on staff who highlighted concerns about getting sick or passing the infection on to others (87.64%) or their family members (75.14%).

CONCLUSIONS

The study made it possible to detect the need to make significant changes in the clinical, organizational and teaching fields, for which some operational proposals are suggested.

SARS-CoV-2 infection and H1N1 vaccination: does a relationship between the two factors really exist? A retrospective analysis of a territorial cohort in Ferrara, Italy

OBJECTIVE

SARS-CoV-2 has been compared with other strains of coronaviruses, SARS-CoV and MERS-CoV, and with the flu viruses: all of them manifest themselves with respiratory symptoms and, although their genetic patterns are similar, the spread of SARS-CoV-2 infection has quickly reached global dimensions, demonstrating that SARS-CoV-2 is a virus with greater spreading capacity, albeit less lethal. Compared with influenza viruses, coronaviruses have a longer incubation period and the patients with coronaviruses' syndromes develop more severe diseases requiring frequent hospitalizations and intensive care admissions. The aim was to explore the relationships between seasonal influenza vaccination and coronavirus infection and to understand whether this hypothetic role by the flu vaccines modifies SARS-CoV-2 infection's outcomes.

PATIENTS AND METHODS

In this retrospective, multicenter study, we enrolled 952 patients diagnosed with SARS-CoV-2 infection; 448 were admitted to our two main hospitals in Ferrara territory, while the remaining 504 were isolated at home. We compared the group of patients who had been vaccinated for influenza in the previous 12 months to that of unvaccinated patients.

RESULTS

Significant differences were found for both the need for hospitalization and 30-day mortality between vaccinated and unvaccinated patients. We found age to be the only independent risk factor for a worse 30-day prognosis, while gender, influenza vaccinations and age itself were independent risk factors for undergoing hospitalization.

CONCLUSIONS

In our groups of patients, we found a relationship between seasonal influenza vaccinations and SARS-CoV-2 infection. Age seems to be the main risk factor for short-term mortality in COVID-19 inpatients, while the influenza vaccination is, together with gender and age itself, a determining factor in predicting the need for hospitalization.

Oncological cases and complications in Urology

This collection of cases describes some unusual urological tumors and complications related to urological tumors and their treatment. Case 1: A case of left hydronephrosis referred four years after a right radical mastectomy for lobular breast carcinoma was described. Computed tomography scan revealed a left hydronephrosis with dilated ureter up to the proximal third. An exploratory laparoscopy was performed and the definitive histopathology examination showed a recurrence of the carcinoma with a right tubal metastasis and peritoneal carcinosis. Case 2: A rare case of an extensive penile squamous cell carcinoma in a young man. The patient was treated with radical surgery and modified inguinal lymphadenectomy. No recurrence was noticed so far. Case 3: A rare case of left sided Inferior Vena Cava (IVC) in a patient diagnosed with renal cell cancer who underwent open left partial nephrectomy. Case 4: A case of urethrorrhagia, caused by a recent trauma from an urinary catheter placed in a patient submitted to gastric resection due to a neoplastic pathology. Urethrorrhagia only temporarily responded to conservative treatment and ultimately resolved by coagulation with an endoscopic approach.

Mechanical hepaticojejunostomy: can we use a circular stapler as a viable and safe alternative? -a retrospective study of a single center

Background

Since the first years of the 1980s, some authors described the use of mechanical stapler for the creation of anastomosis in biliary surgery. However, the use of these devices has not spread during the following decades, and nowadays most centers usually craft hand-sewn anastomosis.

Methods

We retrospectively collected data from medical records, surgical registries and computerized databases about the use of mechanical circular staplers for the creation of hepaticojejunostomy at our institution.

Results

From 2012 to 2020, 11 stapled hepaticojejunostomy for both neoplastic and non-neoplastic diseases were performed at our institution. The mean age of the patient was 74, with a sex distribution of 5 men and 6 women. The mean preoperative common bile duct diameter was 19 mm. Preoperative blood samples showed mean total bilirubin of 6.95 mg/dL. No intraoperative complications were reported. Two patients (18%) had minor postoperative complications (1 wound dehiscence and 1 episode of melena that required blood transfusions), while no major complications occurred. No patients developed biliary fistula or anastomotic dehiscence. No one dies within 30 days from surgery. The mean postoperative length of stay was 13 days.

Conclusions

According to our limited experience, stapled hepaticojejunostomy seems to be a safe and effective technique in selected patients.

Voluminous abdominal gastrointestinal stromal tumor of unknown origin manifested with bleeding in a young man: synchronous management of the emergency and oncological approach-case report

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract, which cover about 1-2% of gastrointestinal neoplasms with an unadjusted incidence of around 1/100,000/year. They are also the most common non-epithelial neoplasms of the gastrointestinal tract and they are associated with a high rate of malignant transformation. They are more common in the stomach (40-60%) while a minor part repeatedly involves jejunum/ileus (25-30%), duodenum (5%), colorectal (5-15%) and esophagus (<1%). There are also much rarer extragastrointestinal stromal tumor (EGIST): these tumors have immunohistochemical and molecular characteristics similar to GISTs and for this reason, they are called this way, EGIST can involve retroperitoneum, mesentery, and omentum, without affecting the gastrointestinal tract. The clinical presentation depends on the primary localization of the neoplasm, however in 18% it is asymptomatic, and it is accidentally discovered during endoscopies, radiological examinations or surgical operations performed for other reasons, especially if it is small in size. More often, they are associated with non-specific symptoms such as early satiety, nausea or vomiting. Gastrointestinal bleeding is the most dangerous complication, often necessitating emergency surgery. The purpose of this case report is to describe our experience in the management of a young patient with gastrointestinal bleeding caused by an unknown voluminous retroperitoneal GIST with metastatic progression using a combined endovascular embolization and debulking-surgery approach for emergency and imatinib therapy combined with radiofrequency for the oncological approach. GIST requires multidisciplinary management, which improves both prognosis and quality of life.

Use of electrochemotherapy in a voluminous chest wall recurrence of triple-negative breast cancer: case report

Breast cancer is the most common cause of chest wall recurrence, skin, and subcutaneous tissue metastases which mainly occur as multiple nodes in the skin and subcutaneous tissue. When it occurs, surgery (re-excision or totalization) is the treatment of choice. Unfortunately, it is not possible in rare cases for example after multiple plastic reconstructions and particular anatomical sites not eligible for resection. Moreover, in some cases where radiation therapy has already been used, and systemic therapy is ineffective or contraindicated, electrochemotherapy could represent a choice of palliation treatment. The principle of electrochemotherapy is based on a physical approach to permeabilize cells in the tissue exposed to electric pulses with increased cellular uptake of hydrophilic chemotherapeutics as bleomycin. We present a case of a 62-year-old woman suffering from chest wall recurrence of triple-negative breast cancer, previously treated with chemotherapy, surgery, and radiotherapy. The persistence of the tumor disease with abundant losses of blood serum material led the patient to a progressive decay of the general physical conditions. For this reason, we performed an electrochemotherapy session with an improvement in pain management and partial necrosis of the tumor tissue and devascularization that reduced bleeding and serum production leading to a better quality of life.

Emergency surgery in COVID-19 outbreak: Has anything changed? Single center experience

BACKGROUND

The current coronavirus disease 19 (COVID-19) pandemic is changing the organization of health care and has had a direct impact on the management of surgical patients.At the General Surgery Department of Sant’Anna University Hospital in Ferrara, Italy, surgical activities were progressively reduced during the peak of the COVID-19 outbreak in Italy. During this period, only one operating room was available for elective cancer surgeries and another for emergency surgeries. Moreover, the number of beds for surgical patients had to be reduced to provide beds and personnel for the new COVID-19 wards.

AIM

To compare 2 different period (from March 9 to April 9 2019 and from March 9 to April 9 2020), searching differences in terms of number and type of interventions in emergency surgery of a main University Hospital in Ferrara, a city in Emilia Romagna region, North of Italy.

METHODS

This retrospective study was carried out at the General Surgery Department of Sant’Anna University Hospital in Ferrara, Italy. We examined the number of emergency surgeries performed and patient outcomes during the peak of the COVID-19 outbreak in Italy and subsequent total lockdown. We then drew a comparison with the number of surgeries performed and their outcomes during the same period in 2019. The study examined all adult patients who underwent emergency surgery from March 9 to April 9, 2019 (n = 46), and those who underwent surgery during the first month of the lockdown, from March 9 to April 9, 2020 (n = 27). Analyses were adjusted for age, gender, American Society of Anesthesiologists classification scores and types of surgery.

RESULTS

A total of 27 patients underwent emergency surgery at Sant’Anna University Hospital in Ferrara during the first month of the lockdown. This represents a 41.3% reduction in the number of patients who were hospitalized and underwent emergency surgery compared to the same period in 2019. The complication rate during the pandemic period was substantially higher than it was during the analogous period in 2019: 15 out of 27 cases from March 9 to April 9, 2020 (55) vs 17 out of 46 cases from March 9 to April 9, 2019 (36.9). Of the 27 patients who underwent emergency surgery during the pandemic, 10 were screened for COVID-19 using both thorax high resolution computerized tomography and a naso-pharyngeal swab, while 9 only underwent thorax high resolution computerized tomography. Only 1 patient tested positive for SARS-CoV-2 and died following surgery.

CONCLUSION

There was a significant reduction in emergency surgeries at our center during the COVID-19 pandemic, and it is plausible that there were analogous reductions at other centers across Italy.

Risks of COVID-19 transmission in blood and serum during surgery A prospective cross-sectional study from a single dedicated COVID-19 center

The present pandemic caused by the SARS COV-2 coronavirus is still ongoing, although it is registered a slowdown in the spread for new cases. The main environmental route of transmission of SARS-CoV-2 is through droplets and fomites or surfaces, but there is a potential risk of virus spread also in smaller aerosols during various medical procedures causing airborne transmission. To date, no information is available on the risk of contagion from the peritoneal fluid with which surgeons can come into contact during the abdominal surgery on COVID-19 patients. We have investigated the presence of SARS-CoV-2 RNA in the peritoneal cavity of patients affected by COVID-19, intraoperatively and postoperatively. KEY WORDS: Covid-19, Laparotomy, Surgery.

Surgical excision of a tufted angioma of the hand in an adult-a rare case report with a review of literature

Tufted Angiomas, also known as angioblastomas/Angioblastoma of Nagakawa, are rare vascular neoplasms of both sexes localised to the skin and subcutaneous tissues with the upper trunk and neck being the most common sites. They are more common in children but a few cases in juveniles and adults have been reported. Typically, Tufted Angioma remains stable or can show rarely a spontaneous regression. This article wants to evaluate the efficacy of current treatment modalities for tufted angioma (TA). A review was performed using PubMed database (Medline) for clinical studies. We report our case, a 29-year-old female who presented with a second finger of the left hand, painful, slowly progressive, firm swelling diagnosed as Tufted Angioma on histopathology and immunohistochemistry after complete surgical excision.

A rare case of intralobar pulmonary sequestration: combined endovascular and video-assisted thoracoscopic approach

Pulmonary sequestration is a congenital malformation characterized by cystic, non-functioning embryonic lung tissue supplied by an abnormal systemic artery. It's a rare disease widely variable in clinical presentation and severity, depending mostly on the degree of lung involvement and location in the thoracic cavity. Most patients have recurrent infections and inflammatory conditions in the affected lobe. Surgical resection continues to be the gold standard of therapy and in this context anatomical resection is the procedure of choice and yields excellent long-term results. There are few studies reporting the use of combined endovascular and thoracoscopic approaches for pulmonary sequestration. We describe a case of intralobar pulmonary sequestration located in the lower lobe of the right lung, which was treated with video-assisted thoracoscopic surgery (VATS) after endovascular embolization of systemic artery arising from celiac trunk.

Laparoscopic resection of a jejunal mesenteric pseudocyst: case report

Mesenteric cysts are rare and can occur at any age. They can manifest with abdominal pain or compressive mass effect. The exact etiology is unknown. Ultrasonography, computed tomography and laparoscopy are used in diagnosing mesenteric cysts. Laparoscopic excision of a mesenteric cyst is possible and should be considered as the treatment of choice. We present a case of mesenteric pseudocyst of small bowel treated by laparoscopic excision.

Totally laparoscopic resection of a very large gastric GIST

Laparoscopic approach was safely performed for the diagnosis and treatment of the submucosal tumors of the stomach because it is associated with low morbidity, mortality, and sound oncologic outcomes. However, no report on the long-term safety and efficacy of this surgery for large sized gastric GISTs has been published to date. We present a 63-year-old female case of a large gastric GIST of 19 cm removed by laparoscopic wedge resection.

Quasiparticle dynamics in a bose insulator probed by interband bragg spectroscopy

We investigate experimentally and theoretically the dynamical properties of a Mott insulator in decoupled one-dimensional chains. Using a theoretical analysis of the Bragg excitation scheme, we show that the spectrum of interband transitions holds information on the single-particle Green's function of the insulator. In particular, the existence of particle-hole coherence due to quantum fluctuations in the Mott state is clearly seen in the Bragg spectra and quantified. Finally, we propose a scheme to directly measure the full, momentum-resolved spectral function as obtained in the angle-resolved photoemission spectroscopy of solids.