Intraoperative liver deformation and organ motion caused by ventilation, laparotomy, and pneumoperitoneum in a porcine model for image-guided liver surgery.

BACKGROUND: Image-guidance promises to make complex situations in liver interventions safer. Clinical success is limited by intraoperative organ motion due to ventilation and surgical manipulation. The aim was to assess influence of different ventilatory and operative states on liver motion in an experimental model. METHODS: Liver motion due to ventilation (expiration, middle, and full inspiration) and operative state (native, laparotomy, and pneumoperitoneum) was assessed in a live porcine model (n = 10). Computed tomography (CT)-scans were taken for each pig for each possible combination of factors. Liver motion was measured by the vectors between predefined landmarks along the hepatic vein tree between CT scans after image segmentation. RESULTS: Liver position changed significantly with ventilation. Peripheral regions of the liver showed significantly higher motion (maximal Euclidean motion 17.9 ± 2.7 mm) than central regions (maximal Euclidean motion 12.6 ± 2.1 mm, p < 0.001) across all operative states. The total average motion measured 11.6 ± 0.7 mm (p < 0.001). Between the operative states, the position of the liver changed the most from native state to pneumoperitoneum (14.6 ± 0.9 mm, p < 0.001). From native state to laparotomy comparatively, the displacement averaged 9.8 ± 1.2 mm (p < 0.001). With pneumoperitoneum, the breath-dependent liver motion was significantly reduced when compared to other modalities. Liver motion due to ventilation was 7.7 ± 0.6 mm during pneumoperitoneum, 13.9 ± 1.1 mm with laparotomy, and 13.5 ± 1.4 mm in the native state (p < 0.001 in all cases). CONCLUSIONS: Ventilation and application of pneumoperitoneum caused significant changes in liver position. Liver motion was reduced but clearly measurable during pneumoperitoneum. Intraoperative guidance/navigation systems should therefore account for ventilation and intraoperative changes of liver position and peripheral deformation.

Yield of abdominal radiographs in children with suspected intussusception; rate of pneumoperitoneum and other abdominal pathology.

OBJECTIVES: Ultrasound is the criterion standard imaging modality for the diagnosis of intussusception. However, to our knowledge the utility of abdominal radiographs to concurrently screen for pneumoperitoneum or other abdominal pathology that could have a similar presentation has not been studied. Our institutional protocol requires the performance of AP supine and left lateral decubitus views of the abdomen prior to ultrasound evaluation for intussusception, providing an opportunity to examine the yield of abdominal radiographs in this setting. Our primary objective was to determine the rate of pneumoperitoneum on screening abdominal radiographs in children undergoing evaluation for intussusception. Our secondary objective was to determine the rate that other clinically significant pathology is found on these screening abdominal radiographs. METHODS: We performed a retrospective chart review of all patients under 6 years of age who had any imaging ordered in our large urban pediatric emergency department to evaluate for suspected intussusception during the calendar years 2018-2020. RESULTS: 1115 patient encounters met our inclusion criteria. Among 1090 who had screening abdominal radiographs, 82 (8%) had findings concerning for intussusception. Of those not concerning for intussusception, 635 (58%) were read as normal, 263 (24%) showed moderate to large stool burden, 107 (10%) showed generalized bowel distention, and 22 (2%) showed abnormal gastric distention. Individually the remainder of all other findings compromised <1% of encounters and included radiopaque foreign body (8), intraabdominal calcification (4), pneumonia/effusion (3), pneumatosis intestinalis, abdominal mass (2), diaphragmatic hernia (1), rib fracture (1), appendicolith (1), feeding tube malposition (1), and bowel wall thickening (1). In one encounter the patient had a bowel perforation with pneumoperitoneum present secondary to ingestion of multiple magnets. CONCLUSIONS: Our study indicates that radiograph-detected pneumoperitoneum is rare in children with suspected intussusception. Constipation is the most common abnormal finding on screening radiographs. Other findings occur in approximately 15% of total cases, some of which require further workup.

Point-of-care ultrasound evaluation of suspected necrotizing enterocolitis in the ED.

Necrotizing enterocolitis (NEC) is a rare but life-threatening diagnosis in infants presenting with bilious emesis, abdominal distension, or bloody stools. Ultrasonography has been advocated as an alternative initial imaging modality to abdominal radiography, and may be superior in the evaluation of NEC. We describe the use of point-of-care ultrasound (PoCUS) in the evaluation of suspected NEC in the emergency department (ED) when the ability to obtain immediate abdominal x-ray (AXR) was delayed due to pandemic conditions. A pre-term infant with history of bowel resection presented with non-bilious emesis, bloody stools, and slight abdominal distension. Evaluation with PoCUS identified pneumatosis intestinalis and pneumoperitoneum, which were confirmed on subsequent AXR. Pneumatosis intestinalis in a neonate is highly suggestive of NEC, but seen by itself, can be associated with milk protein allergy and Food Protein Induced Enterocolitis syndrome (FPIES). Pneumoperitoneum is considered an indication for operative intervention for NEC. The infant was re-admitted to the NICU for suspected NEC. NEC is a rare, but potentially surgical diagnosis in infants as can be FPIES, but not milk protein allergy. NEC can be identifiable using PoCUS to search for a constellation of findings that include pneumatosis intestinalis, pneumoperitoneum, free peritoneal fluid, and portal venous gas. These findings have been previously described in the PoCUS literature for other diseases, but not for a case of suspected NEC presenting to the ED.

Pneumomediastinum, pneumatosis intestinalis and pneumoperitoneum in a patient with polymyositis: case-based review.

Pneumomediastinum (PnM), pneumatosis intestinalis (PI), and pneumoperitoneum (PP) are rare complications of inflammatory myositis. We present a 59-year-old polymyositis (PM) patient who experienced all three complications simultaneously. The patient who presented with proximal muscle weakness, dysphagia, and weight loss was diagnosed with PM due to elevated muscle enzymes and consistent electromyography and muscle biopsy with inflammatory myopathy. On the 45th day of her immunosuppressive treatment, PnM, PI, and PP were detected incidentally in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan performed for severe weight loss and treatment-resistant severe disease. Since the patient had no symptoms or signs of PnM and PP, no additional intervention was applied to the current treatment, and spontaneous regression was observed in the follow-up. In addition to this case, we reviewed patients with PM who developed PBM, PP, and PI in the literature.

Urinary excretion of low-osmolar contrast media during small-bowel follow-through studies in infants is not definitive evidence of bowel perforation.

BACKGROUND: Presence of contrast agent in the urinary system in infants after small-bowel follow-through study with low-osmolar contrast media has been described as a sign of bowel perforation. OBJECTIVE: To evaluate how often the presence of contrast agent in the bladder after small-bowel follow-through is a reliable sign of bowel perforation or necrosis. MATERIALS AND METHODS: From the radiology information system, we retrieved imaging reports of infants evaluated with small-bowel follow-through and findings of contrast agent in the bladder. We retrieved demographic and clinical information from the medical records. Presence of bladder contrast medium was considered true-positive evidence of bowel perforation or necrosis if confirmed by pneumoperitoneum, extraluminal contrast agent, surgery or pathology within 3 days of the small-bowel follow-through. False-positives for bowel perforation or necrosis were based on surgical findings or clinical follow-up. RESULTS: Of the 207 infants who had small-bowel follow-through, 18 infants (12 boys; mean age 50 days, range 14 days to 8.5 months) had contrast medium in the bladder after the small-bowel follow-through. Fifteen of the 18 (83.3%) had a history of prematurity and 11 had prior abdominal surgery. Four of the 18 (22.2%) had bowel perforation or necrosis at surgery or pathology performed more than 3 days after the small-bowel follow-through and were considered indeterminate and excluded. Eight of the remaining 14 infants (57.1%) had bowel perforation or necrosis based on surgical evidence of perforation or pathology confirmation of necrosis (n=6), pneumoperitoneum (n=1) or contrast agent leakage from enterocutaneous fistula (n=1). Six of the 14 (42.9%) were false-positives, without evidence of bowel perforation or necrosis based on clinical follow-up (n=4) or surgery (n=2). CONCLUSION: Demonstration of urinary contrast agent post small-bowel follow-through with low-osmolar contrast medium in newborns/infants with complex medical problems is not a definitive indication of bowel perforation or necrosis. More than one-third of our patients with contrast medium in the bladder did not have bowel perforation or necrosis.

[Pneumobilia, pneumoperitoneum and pneumowirsung of traumatic etiology: Case report and review of the literature]. / Neumobilia, neumoperitoneo y neumowirsung de etiología traum ática: Reporte de caso y revisión de la literatura.

Pneumobilia is a phenomenon associated with the presence of a biliary-enteric fistula or manipulation of the bile duct during procedures or surgical interventions that cause dysfunction of the sphincter of Oddi. A known, but infrequently reported event, is the increase in intraabdominal pressure after closed abdominal trauma, which causes pneumobilia due to a mechanism of retrograde air leakage towards the bile duct. Depending on the general compromise of each patient, the prognosis can vary from a benign condition that only requires conservative management, to being life threatening. We present the case of a 75-year-old male patient who, after suffering a closed thoraco-abdominal trauma, presented with rib fracture and, in addition, gallbladder wall rupture, pneumoperitoneum, pneumobilia, and pneumowirsung, having a favorable clinical course after receiving conservative management.

Pneumatosis cystoides intestinalis as a rare cause of non-surgical pneumoperitoneum.

Pneumoperitoneum as a finding on imaging examinations is not always a sign of acute abdomen due to gastrointestinal perforation. These findings must be viewed in connection with the clinical condition and personal history of each patient because they may also indicate a non-surgical or spontaneous pneumoperitoneum. This condition is repeatedly described but very often neglected. This paper presents the case report of a patient with non-surgical pneumoperitoneum where, despite proceeding according to the guidelines, no expected intra-abdominal pathology explaining the patient's problems was found.

Postmortem computed tomography differentiation between intraperitoneal decomposition gas and pneumoperitoneum.

PURPOSE: The aim of this study is to investigate the ability of postmortem computed tomography (PMCT) to distinguish intraperitoneal decomposition gas from pneumoperitoneum due to intestinal perforation. METHODS: This retrospective study investigated the factors affecting intraperitoneal gas in two groups of 14 decedents as detected by postmortem CT performed in the Department of Legal Medicine of Hamburg University. The first group died with a cause of death associated with intestinal perforation, and the second group with other different natural causes of death. These factors include postmortem interval, gas volume, gas distribution, radiology alteration index (RAI), and pneumoperitoneum-associated pathology. RESULTS: The findings of this study showed the appearance of specific gas distribution patterns and a significant increase in gas volumes in the cases of intestinal perforation. Moreover, postmortem interval and the pneumoperitoneum-associated pathology could help distinguish postmortem-generated gas from pneumoperitoneum. CONCLUSION: Based on the findings of this study, we propose that these findings can improve the proper detection of intestinal perforation cases in the future.

Atypical image of pneumoperitoneum secondary to colon perforation.

The case was a 66-year-old female with a diagnosis of bilateral ovarian carcinoma with peritoneal carcinomatosis and liver metastases. She had only undergone one cycle of chemotherapy and could not be given other cycles because of her poor general condition. She was admitted due to intermittent vomiting for a week and severe heartburn, with the last stool passed two days before, presenting abdominal distension and lower abdominal pain, without signs of peritonism and no peristaltic sounds. After performing several complementary tests a computed tomography scan showed a large amount of intra-abdominal air, which was thought to be a possible transverse colon volvulus, that caused extrinsic compression on the stomach. A colonoscopy was performed in an attempt to devolvulate, which was unsuccessful.

Gastric perforation in a 5-day-old infant: A case report.

Gastric perforation in a new-born signifies a surgical emergency requiring immediate attention. Therefore, early diagnosis is expected to lead to a better prognosis. Any infant presenting with sudden and severe abdominal distention should be suspected of gastric perforation. Diagnosis is confirmed by pneumoperitoneum in the plain abdominal X-ray, including anteroposterior and lateral views. In this study, we report a case of a 5-day-old neonate, who was diagnosed with gastric perforation and accordingly proceeded with primary surgical repair.

Delayed Tension Symptomatic Pneumoperitoneum After POEM Requiring Needle Decompression.

INTRODUCTION: Per-oral endoscopic myotomy (POEM) is an effective modality for the management of achalasia. Tension pneumoperitoneum is a significant complication that causes hemodynamic instability, generally within the periprocedural period. METHODS: Here, we report 2 cases of delayed tension pneumoperitoneum that was recognized and treated several hours after uncomplicated POEM. RESULTS: These cases illustrate the importance of continued vigilance for this complication outside of the immediate periprocedural period as well as the utility of computed tomography-guided aspiration in managing it. DISCUSSION: When discharging patients after POEM, caregivers should be aware of this rare complication and alert patients to return for immediate care when it happens.

CT-Guided Percutaneous Drainage of Pneumoperitoneum Presenting as Acute Abdomen.

PURPOSE: To evaluate the feasibility and effectiveness of computed tomography (CT)-guided percutaneous drainage (PD) in patients with iatrogenic pneumoperitoneum presenting as acute abdomen. MATERIALS AND METHODS: In this retrospective, single-center cohort study, 16 consecutive patients (9 males, 7 females; median age, 67.5 [51-85] years) undergoing PD for managing acute abdomen caused by iatrogenic pneumoperitoneum between 2013 and 2019 were analyzed. Inclusion criteria were clinical signs of acute abdomen that was unresponsive to conservative management and pneumoperitoneum due to an iatrogenic cause after PD, observed using CT imaging. Volumetry of pneumoperitoneum was performed using computer-aided image segmentation. To evaluate the clinical outcome, the paired t-test was performed to analyze the course of pain intensity on the numerical pain rating scale (NPRS, 0-10). Patient records were reviewed to determine PD-related adverse events and median drain duration. RESULTS: The median pneumoperitoneum volume was 891.1 (127.7-3,677.0) mL. All PD procedures were successfully performed, with symptom relief and immediate abdominal decompression (mean segmental volume reduction, 79.8% ± 13.5). Acute abdomen symptoms were resolved, with significant improvement in pain intensity between the day of the PD procedure and the first day after the procdure (mean NPRS scores, 3.3 ± 1.9 vs 0.8 ± 1.0; P < .001). The median drain duration was 2 (1-3) days. No PD-associated adverse events were observed. After PD, 14 patients required only conservative management, whereas 2 patients with anastomotic leakage required additional surgery as they showed signs of persisting sepsis and generalized peritonitis. CONCLUSIONS: PD is a safe and suitable procedure for the management of symptoms in patients with iatrogenic pneumoperitoneum presenting as acute abdomen.

A study of generalization and compatibility performance of 3D U-Net segmentation on multiple heterogeneous liver CT datasets.

BACKGROUND: Most existing algorithms have been focused on the segmentation from several public Liver CT datasets scanned regularly (no pneumoperitoneum and horizontal supine position). This study primarily segmented datasets with unconventional liver shapes and intensities deduced by contrast phases, irregular scanning conditions, different scanning objects of pigs and patients with large pathological tumors, which formed the multiple heterogeneity of datasets used in this study. METHODS: The multiple heterogeneous datasets used in this paper includes: (1) One public contrast-enhanced CT dataset and one public non-contrast CT dataset; (2) A contrast-enhanced dataset that has abnormal liver shape with very long left liver lobes and large-sized liver tumors with abnormal presets deduced by microvascular invasion; (3) One artificial pneumoperitoneum dataset under the pneumoperitoneum and three scanning profiles (horizontal/left/right recumbent position); (4) Two porcine datasets of Bama type and domestic type that contains pneumoperitoneum cases but with large anatomy discrepancy with humans. The study aimed to investigate the segmentation performances of 3D U-Net in: (1) generalization ability between multiple heterogeneous datasets by cross-testing experiments; (2) the compatibility when hybrid training all datasets in different sampling and encoder layer sharing schema. We further investigated the compatibility of encoder level by setting separate level for each dataset (i.e., dataset-wise convolutions) while sharing the decoder. RESULTS: Model trained on different datasets has different segmentation performance. The prediction accuracy between LiTS dataset and Zhujiang dataset was about 0.955 and 0.958 which shows their good generalization ability due to that they were all contrast-enhanced clinical patient datasets scanned regularly. For the datasets scanned under pneumoperitoneum, their corresponding datasets scanned without pneumoperitoneum showed good generalization ability. Dataset-wise convolution module in high-level can improve the dataset unbalance problem. The experimental results will facilitate researchers making solutions when segmenting those special datasets. CONCLUSIONS: (1) Regularly scanned datasets is well generalized to irregularly ones. (2) The hybrid training is beneficial but the dataset imbalance problem always exits due to the multi-domain homogeneity. The higher levels encoded more domain specific information than lower levels and thus were less compatible in terms of our datasets.

Family medicine residents' skill levels in emergency chest X-ray interpretation.

BACKGROUND: Family medicine physicians may encounter a wide variety of conditions, including acute and urgent cases. Considering the limited access to diagnostic investigations in primary care practice, chest X-ray remains the imaging modality of choice. The current study assessed the competency of family medicine residents in the interpretation of chest X-rays for emergency conditions and to compare it with that of diagnostic radiology residents, general practitioners, and medical interns. METHODS: An online survey was distributed to 600 physicians, including family medicine residents, medical interns, general practitioners, and diagnostic radiology residents. The study included some background information such as gender, years in practice, training type, interest in pulmonary medicine and diagnostic radiology, and having adequate training on the interpretation of chest X-rays. The survey had 10 chest X-ray cases with brief clinical information. Participants were asked to choose the most likely diagnosis and to rate their degree of confidence in the interpretation of the chest X-ray for each case. RESULTS: The survey was completed by 205 physicians (response rate = 34.2%). The overall diagnostic accuracy was 63.1% with a significant difference between family medicine and radiology residents (58.0% vs. 90.5%; P < 0.001). The COVID-19 pneumonia (85.4%) and pneumoperitoneum (80.5%) cases had the highest diagnostic accuracy scores. There was a significant correlation between the diagnostic confidence and accuracy (rs = 0.39; P < 0.001). Multivariable regression analysis revealed that being diagnostic radiology residents (odds ratio [OR]: 13.0; 95% confidence interval [CI]: 2.5-67.7) and having higher diagnostic confidence (OR: 2.2; 95% CI: 1.3-3.8) were the only independent predictors of achieving high diagnostic accuracy. CONCLUSION: The competency of family medicine residents in the interpretation of chest X-ray for emergency conditions was far from optimal. The introduction of radiology training courses on emergency conditions seems imperative. Alternatively, the use of tele-radiology in primary healthcare centers should be considered.

Assessment of Perioperative Atelectasis Using Lung Ultrasonography in Patients Undergoing Pneumoperitoneum Surgery in the Trendelenburg Position: Aspects of Differences according to Ventilatory Mode.

BACKGROUND: During robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position, aeration loss leads to perioperative atelectasis. Recently developed ventilator mode pressure-controlled ventilation volume-guaranteed (PCV-VG) mode could provide adequate ventilation with lower inspiratory pressure compared to volume-controlled ventilation (VCV); we hypothesized that PCV-VG mode may be beneficial in reducing perioperative atelectasis via low tidal volume (VT) of 6 mL/kg ventilation during robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position. We applied lung ultrasound score (LUS) for detecting perioperative atelectasis. We aimed to compare perioperative atelectasis between VCV and PCV-VG with a low VT of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position using LUS. METHODS: Patients scheduled for robotic gynecologic surgery were randomly allocated to the VCV (n = 41) or PCV-VG group (n = 41). LUS, ventilatory, and hemodynamic parameters were evaluated at T1 (before induction), T2 (10 minutes after induction in the supine position), T3 (10 minutes after desufflation of CO2 in the supine position), and T4 (30 minutes after emergence from anesthesia in the recovery room). RESULTS: Eighty patients (40 with PCV-VG and 40 with VCV) were included. Demographic data showed no significant differences between the groups. The total LUS has changed from baseline to T4, 0.63 (95% confidence interval [CI], 0.32, 0.94) to 1.77 (95% CI, 1.42, 2.21) in the VCV group and 0.86 (95% CI, 0.56, 1.16) to 1.43 (95% CI, 1.08, 1.78) in the PCV-VG group (P = 0.170). In both groups, total LUS increased significantly compared to the baseline values. CONCLUSION: Using a low VT of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position, our study showed no evidence that PCV-VG ventilation was superior to VCV in terms of perioperative atelectasis. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0006404.

Ultra-low dose CT abdomen and pelvis for the detection of acute abdominal pathology in the emergency room: initial experience from an academic hospital.

PURPOSE: The aim of this study is to describe our initial experience using ULDCT performed in the emergency room in the evaluation of acute abdominal pathology. METHODS: Data from consecutive patients who underwent ULDCT for assessment of bowel obstruction, free intraperitoneal air, unexplained abdominal pain, or fecal loading for constipation between June 1, 2016 and March 31, 2017 was retrospectively assessed. Demographic data, radiation dose, CT findings, and clinical outcomes including performance of full dose contrast-enhanced CT (CECT), hospitalization, and surgery was collected. Concordance of ULDCT to CECT was calculated. RESULTS: ULDCT was performed in 325 patients (188 women and 137 men; mean age, 65.1 years). ULDCT detected acute abdominal pathology in 134/325 (41.2%), and in 89/134 (66.4%) it was concordant with the clinical working diagnosis. The average dose length product (DLP) was 101.6 mGy cm (range 51.7-614; median, 82.6). CECT was performed in 44/325 patients (13.5%). In 7/44 (15.9%), CECT identified discordant findings which likely impacted management. A greater proportion of patients were admitted to hospital after a positive ULDCT 99/137 (72.3%), compared to those with a negative study 81/188 (43.1%); p < 0.0001(Chi2, 27.30). Of those admitted to hospital, 11/99 (11.1%) with positive ULDCT had surgery compared to 1/81 (1.2%) with a negative ULDCT; p < 0.008 (Chi2, 6.98). CONCLUSION: With its high clinical yield and similar radiation dose, ULDCT appears as a suitable alternative to abdominal radiography for the detection of select acute abdominal pathology in the emergency room.

Spontaneous emphysematous splenitis: Radiographic and ultrasonographic findings in three Golden Retriever dogs.

Spontaneous emphysematous splenitis is a life-threatening condition reported rarely in humans; however, published reports in dogs are currently lacking. The aim of this multicentric, retrospective, case series design study was to describe radiographic and ultrasonographic imaging findings in Golden Retriever dogs diagnosed with spontaneous emphysematous splenitis. A total of three dogs were sampled. All dogs had a history of lethargy, diarrhea, and weight loss. Radiographic findings in all dogs included a mass effect with focal or multifocal coalescing "vesicular-like" gas pattern in the splenic region and focal loss of serosal detail. Ultrasonographic findings in all dogs included focal or multifocal irregularly shaped, hypoechoic areas containing a mixture of hyperechoic fluid and gas within the splenic parenchyma, hyperechoic abdominal free fluid, and generalized hyperechoic mesenteric fat without evidence of splenic torsion. Pneumoperitoneum was detected ultrasonographically and radiographically in two dogs. All three dogs underwent splenectomy and splenic torsion was definitively ruled out at surgery. One dog died three days after surgery, whereas the other two dogs recovered uneventfully. Culture of the splenic tissue and free abdominal fluid was positive for Clostridium spp. in all three cases. Findings supported inclusion of spontaneous emphysematous splenitis and septic peritonitis as differential diagnoses for dogs with this combination of clinical and imaging characteristics.

Pneumatosis intestinalis as an incidental finding in a patient with COVID-19 infection.

In reference to the article by Láinez Ramos-Bossini AJ et al., recently published in your Journal, we would like to provide our experience regarding a probable causal association between pneumoperitoneum and pneumatosis intestinalis in patients affected by COVID-19 (1).

Pneumoperitoneum and COVID-19. A causal association?

We read with great interest the letter from Pérez Naranjo et al. regarding the case we recently published in this journal. We believe that the case presented by the authors is undoubtedly useful as it contributes to the scarce existing casuistry on the relationship between COVID-19 and the development of pneumatosis/pneumoperitoneum. We would like to emphasize the difficulty of determining the causality of this association due to the frequent co-occurrence of other causes that could justify the presence of pneumatosis/pneumoperitoneum.

Perforation of the excluded segment without pneumoperitoneum following Roux-en-Y gastric bypass surgery: case report and literature review.

BACKGROUND: Because of the increasing prevalence of obesity and bariatric surgery (Roux-en-Y gastric bypass (RYGB) as the gold standard), there is a still growing population of people with altered post-operative anatomy. Although the most common early and late complications following RYGB are well known, they can still be difficult to diagnose. The altered anatomy after RYGB can create a real diagnostic and therapeutic challenge since routine examinations can be negative. CASE REPORT: We present a rare case of a 38-year-old woman with acute abdominal pain and a history of RYGB who proved to have a duodenal perforation in the absence of free air on radiologic examination. The perforation was closed laparoscopically and proton pump inhibitors were administered. CONCLUSIONS: Perforations of the excluded segment in RYGB patients are rare and represent a diagnostic challenge, as pneumoperitoneum is usually absent and the excluded segment is difficult to access. Despite negative diagnostic findings, laparoscopic exploration should always be considered.