Prevalence and duration of postoperative pneumoperitoneum: sensitivity of CT vs left lateral decubitus radiography

Accuracy of radiographic diagnosis of pneumoperitoneum secondary to gastrointestinal perforation in dogs and cats

BACKGROUND

Radiography is commonly included in the diagnostic investigation of animals with suspected gastrointestinal perforation and resultant pneumoperitoneum. This study aimed to (1) identify the accuracy of radiographic diagnosis of pneumoperitoneum and (2) determine if observer experience affected accuracy.

METHODS

This was a retrospective case-controlled study evaluating abdominal radiographs of dogs and cats with surgical confirmation of gastrointestinal perforation or peritonitis without pneumoperitoneum. Radiographs were reviewed by a radiologist, an imaging resident, a general practitioner and a veterinary student.

RESULTS

Radiographs from 60 dogs and eight cats were evaluated; 34 animals had confirmed perforation. Accuracy was fair to excellent for all observers: student 61.8%, general practitioner 70.6%, resident 85.3% and radiologist 83.8%. There was no significant difference in sensitivity between observers (all 70.6%-85.3%); however, there was a significant difference in specificity between both the resident (91.2%) and radiologist (91.2%) compared to the student (52.9%) (p < 0.001) and the general practitioner (55.9%) (p = 0.002). Overall, there was slight to substantial agreement between observers (κ = 0.28-0.73), with the highest being between the radiologist and resident.

CONCLUSION

Abdominal radiography, when interpreted by veterinarians with differing experience, has variable accuracy for diagnosis of pneumoperitoneum for animals in this study. Further studies are needed to determine if these results are applicable for other populations of animals with pneumoperitoneum.

Accuracy of specific free air distributions in predicting the localization of gastrointestinal perforations

PURPOSE

To evaluate the role of specific distributions of free air in predicting the location of gastrointestinal (GI) tract perforation.

MATERIALS AND METHODS

One hundred and fifteen patients with surgically proven GI tract perforation between January 2015 and June 2019 were included in the study. The site of perforation was based on surgical findings in all cases. Two radiologists retrospectively interpreted the computed tomography (CT) images of these patients for extraluminal free air distribution. Perforation sites were demonstrated intraoperatively in all cases and were categorized as follows: stomach and duodenum, jejunum and ileum, proximal colon (cecum, ascending colon, and transverse colon), distal colon (descending colon and sigmoid colon), rectum, and appendix.

RESULTS

There were 79 male and 36 female patients with a mean age of 56.4 years. Periportal, perihepatic, and perigastric free air were statistically significant in predicting gastroduodenal perforation. Mesenteric free air was significant in predicting both small bowel and distal colon perforations. Pelvic free air was statistically significant in distal colon perforations. Periappendiceal free air was found to be a strong predictor of acute perforated appendicitis.

CONCLUSION

Specific free air distributions may help to predict the site of gastrointestinal perforation, which would change the treatment plan.

Correlation of gastrointestinal perforation location and amount of free air and ascites on CT imaging

PURPOSE

To analyze the amount of free abdominal gas and ascites on computed tomography (CT) images relative to the location of a perforation.

METHODS

We retrospectively included 172 consecutive patients (93:79 = m:f) with GIT perforation, who underwent abdominal surgery (ground truth for perforation location). The volume of free air and ascites were quantified on CT images by 4 radiologists and a semiautomated software. The relation of the perforation location (upper/lower GIT) and amount of free air and ascites was analyzed by the Mann-Whitney test. Furthermore, best volume cutoff for upper and lower GIT perforation, areas under the curve (AUC), and interreader volume agreement were assessed.

RESULTS

There was significantly more abdominal ascites with upper GIT perforation (333 ml, range 5 to 2000 ml) than with lower GIT perforation (100 ml, range 5 to 2000 ml, p = 0.022). The highest volume of free air was found with perforations of the stomach, descending colon and sigmoid colon. Significantly less free air was found with perforations of the small bowel and ascending colon compared to the aforementioned. An ascites volume > 333 ml was associated with an upper GIT perforation demonstrating an AUC of 0.63 ± 0.04.

CONCLUSION

Using a two-step process based on the volumes of free air and free fluid can help localizing the site of perforation to the upper, middle or lower GI tract.

A Deep Learning Method for Alerting Emergency Physicians about the Presence of Subphrenic Free Air on Chest Radiographs

Hollow organ perforation can precipitate a life-threatening emergency due to peritonitis followed by fulminant sepsis and fatal circulatory collapse. Pneumoperitoneum is typically detected as subphrenic free air on frontal chest X-ray images; however, treatment is reliant on accurate interpretation of radiographs in a timely manner. Unfortunately, it is not uncommon to have misdiagnoses made by emergency physicians who have insufficient experience or who are too busy and overloaded by multitasking. It is essential to develop an automated method for reviewing frontal chest X-ray images to alert emergency physicians in a timely manner about the life-threatening condition of hollow organ perforation that mandates an immediate second look. In this study, a deep learning-based approach making use of convolutional neural networks for the detection of subphrenic free air is proposed. A total of 667 chest X-ray images were collected at a local hospital, where 587 images (positive/negative: 267/400) were used for training and 80 images (40/40) for testing. This method achieved 0.875, 0.825, and 0.889 in sensitivity, specificity, and AUC score, respectively. It may provide a sensitive adjunctive screening tool to detect pneumoperitoneum on images read by emergency physicians who have insufficient clinical experience or who are too busy and overloaded by multitasking.

CT Abdominal Tomography Indications: Are We All Sticking to the Plan?

OBJECTIVE

Ultra-low radiation dose computed tomography (CT) abdominal tomography was introduced in our institution in 2016 to replace standard abdominal radiography in the investigation of emergency department patients. This project aims to ascertain whether investigation of emergency department patients using ultra-low radiation dose CT abdominal tomography complies with original indication guidelines and/or if there has been any "indication creep" 3 years after inception.

METHODS

Retrospective, quality assurance project with research ethics waiver. A review of 200 consecutive patients investigated with CT abdominal tomography between February and May 2017 was performed. This was compared with 200 consecutive patients investigated between February and May 2019. Data analyzed included patient demographics, indication for scan, as well as scan and patient outcomes.

RESULTS

In the 2017 group, 29/200 scans were noncompliant with approved indication guidelines. In the 2019 group, 30/200 scans were also noncompliant. There was no statistically significant difference between groups (P < .05) regarding the use of approved indications. Forty of 200 scans performed in 2017 revealed additional findings which are not specifically addressed on the reporting template. Forty-one of 200 scans in 2019 revealed these findings.

CONCLUSIONS

There has been no "indication creep" for CT abdominal tomography over time.

Radiographic Findings of Anastomotic Leaks

Although computed tomography (CT) scans play an important role in the diagnosis and management of anastomotic leaks (AL), there is no consensus on what radiographic findings are associated with AL. The purpose of this study is to identify the most common CT scan findings associated with AL and whether the amount of extraluminal air or the density of extraluminal fluid can be correlated with the presence of an AL. A retrospective chart review of 210 patients with anastomotic leaks from 2003 to 2010 at Mount Sinai Medical Center was performed. Eighty-six patients fit our criteria and were included. All CT scans were reread by an independent radiologist not involved with patient care. Our study included 59 per cent men and 41 per cent women with a mean age of 51 years. Diagnoses included inflammatory bowel disease (53%), malignancy (21%), and diverticulitis (12%). One hundred per cent of the patients had one of three findings: extraluminal air (92%), extraluminal fluid (88%), or extravasation of contrast (32%). Eighty-one per cent (70/86) had both fluid and air simultaneously. Extraluminal air was seen in 79 patients. The estimated amounts of extraluminal air were as follows: 0 to 25 mL (49%), 26 to 500 mL (41%), 500 to 1000 mL (5%), and more than 1000 mL (5%). The Hounsfield unit (HU) measurements of the fluid ranged from 3 to 633 HUs. The most common CT findings associated with AL are pneumoperitoneum and extraluminal fluid, including extravasation of contrast, which can be seen in up to 100 per cent of patients. The amount of estimated extraluminal air and density of fluid collection have no prognostic value in predicting AL.

Free abdominal gas on computed tomography in the emergency department: aetiologies and association between amount of free gas and mortality

INTRODUCTION

Free abdominal gas is an important finding with major clinical implications. However, data on the aetiologies and prognosis of patients with free gas are scarce. Our primary aim was to describe the sources of free abdominal gas on emergency department (ED) computed tomography (CT). The secondary aim was to evaluate the association between the amount of free gas and all-cause mortality.

METHODS

All patients who underwent CT in the ED between February 2012 and February 2019 with free abdominal gas were included in the study. A scoring system was used to assess the amount of free gas: small - gas bubbles; medium - any gas pocket ≤2cm in diameter; large - any gas pocket >2cm. Data were collected from laboratory and clinical assessment regarding the source of free gas and all-cause mortality.

RESULTS

A total of 372 patients had free abdominal gas. Colonic diverticulitis was the most common aetiology among those with a small or medium amount of free gas (81/250 [32.4%] and 12/71 [16.9%] respectively). For patients with a large amount of gas, peptic disease was the most common aetiology (11/51 [21.6%]). Three-quarters of the patients (280/372, 75.2%) had the source of free gas identified during ED admission. Ninety-day mortality rates were 7.2%, 9.9% and 21.6% for patients with small, medium and large amounts of gas respectively (p=0.007).

CONCLUSIONS

Colonic diverticulitis was the most common source of free abdominal gas and peptic disease was the most common cause of a large amount of free gas. Mortality rates correlated with the amount of gas and were significantly higher in patients with a large amount.

The left lateral projection is comparable to horizontal beam radiography for identifying experimental small volume pneumoperitoneum in the canine abdomen

Nontraumatic spontaneous pneumoperitoneum suggests the presence of gastrointestinal perforation; early detection can be lifesaving. Horizontal beam projections have been reported to be more sensitive than standard radiographic views for detecting small volumes of free peritoneal gas. This prospective, experimental, analytical study compared both left lateral (LL) and ventrodorsal (VD) standard views to horizontal beam projections for detecting small volumes of artificially induced pneumoperitoneum in live dogs. The effect of radiology training on accurate detection of small amounts of free peritoneal air was also assessed. Fourteen dogs had four radiographic projections taken after injection of 0, 2.5, 5, and 10 mL of cumulative air into their abdominal cavities. Radiographs were interpreted individually by three American College of Veterinary Radiology-certified radiologists and three small animal internship-trained veterinarians who were blinded to the air volume injected. At 2.5 and 10 mL of air injected, the LL projection had highest odds of an accurate response (odds ratio [OR] = 2.4 and 99.0 when compared to VD horizontal and VD projections, respectively). At 5 mL of air injected, the lateral horizontal (LH) projection had the highest odds of an accurate response (OR = 3.2 compared to VD horizontal). The LL projection was not significantly different from the LH projection at all volumes of air injected. Board certification led to higher odds of accurate responses at volumes of 5 (OR = 2.2) and 10 mL (OR = 3.6), as compared to nonspecialist veterinarians. Overall, LH and standard LL appeared to be the most useful radiographic projections for detection of small amounts of free peritoneal gas.

Radiographic Evidence of Soft-Tissue Gas 14 Days After Total Knee Arthroplasty Is Predictive of Early Prosthetic Joint Infection

OBJECTIVE. The diagnosis of early prosthetic joint infection (PJI)-defined as within 6 weeks after a total knee arthroplasty (TKA)-can be difficult because of expected postsurgical changes and elevated inflammatory markers. The role of radiographic evaluation in this situation carries unclear clinical significance. This study had three primary aims: first, to determine when soft-tissue gas is no longer an expected postoperative radiographic finding; second, to determine whether soft-tissue gas is predictive of early PJI; and, third, to determine whether the presence of soft-tissue gas correlates with specific patient characteristics and microbiology culture results. MATERIALS AND METHODS. This retrospective study was of patients who underwent TKA from 2008 to 2018 with available imaging between 5 days and 6 weeks after TKA and no interval intervention before imaging. All confirmed early PJIs were included (n = 24 cases; 15 patients). For comparison, patients who underwent TKA but did not have a PJI (n = 180 cases; 150 patients) were selected randomly. Radiographs were reviewed by two readers. A two-tailed p < 0.05 was considered significant. RESULTS. Soft-tissue gas was identified on postoperative radiography of 13 of 24 (54.2%) cases (mean ± standard error of the mean [SEM], 28.3 ± 2.3 days after TKA) with early PJI and four of 180 (2.2%) cases (mean ± SEM, 15.3 ± 7.3 days after TKA) without PJI (p < 0.0001; odds ratio, 52.0 [95% CI, 14.7-156.9]). The presence of soft-tissue gas on radiography 14 days after TKA had a sensitivity of 0.54 (95% CI, 0.35-0.72) and specificity of 0.99 (95% CI, 0.97-1.00) for early PJI. Staphylococcus species were the dominant organisms; cases with soft-tissue gas showed a wider variety of microbiology species (p < 0.01). CONCLUSION. Postoperative soft-tissue gas present on radiography performed 14 days or more after TKA is predictive of early PJI and is associated with a wider spectrum of microorganisms.

Natural History of Pneumoperitoneum After Laparotomy: Findings on Multidetector-Row Computed Tomography

BACKGROUND

Postoperative pneumoperitoneum after abdominal surgery represents a diagnostic challenge. This study was designed to analyze the appearance of pneumoperitoneum on computed tomography after uncomplicated abdominal surgery through laparotomy.

METHODS

The database of the department of digestive surgery was retrospectively queried to identify all patients who underwent abdominal surgery through laparotomy during a 13-month period. This initial search retrieved a total of 384 consecutive patients. Criteria for inclusion in this study were: (a) the operation was performed in our institution, (b) the patient had computed tomography examination postoperatively, and (c) the patient had no postoperative grade ≥3 complication.

RESULTS

Postoperative pneumoperitoneum was visible in 38/80 patients (47.5 %), with a mean volume of 15 ± 22.8 (SD) cm³ and multiple locations in 32/38 patients (84 %). Postoperative pneumoperitoneum was observed in 22/26 patients (85 %) until day 5 postoperative, 14/34 patients (41 %) between day 6 and day 15 postoperative, and in 2/21 patients (9.5 %) after day 15 postoperative. Its volume decreased when the time interval between surgery and computed tomography increased. Results of multivariate analysis showed that the time interval between surgery and computed tomography was the single independent variable that was associated with the presence of postoperative pneumoperitoneum.

CONCLUSIONS

Postoperative pneumoperitoneum is a frequent finding on computed tomography in the early period following abdominal surgery and commonly with multiple locations. Although commonly observed before day 5 postoperative, its presence must be considered as an alarming finding after day 7 postoperative, if present in a single location with a volume >20 cm³.

Delayed Small Bowel Perforation with Findings of Severe Ischemia Following Blunt Abdominal Trauma

Background

Isolated small bowel perforation following blunt abdominal trauma (BAT) is an uncommon situation with high morbidity and mortality rates, and delayed small bowel perforation is even rarer. The pathophysiology of this condition is not clear in all cases. To the best of our knowledge, this is the first case report of delayed small bowel perforation following BAT with extensive portomesenteric vein gas.

Case Report

A 33-year-old male patient was admitted to the emergency department after a car accident. His initial abdominal CT showed no signs of posstraumatic injury. However, follow-up CT, performed after deterioration in his general condition, showed jejunal dilatation, intestinal intramural gas, portomesenteric vein gas, extensive intraperitoneal gas and intraabdominal free fluid. CT findings and emergent laparotomy findings were both compatible with small bowel ischemia-necrosis and perforation.

Conclusions

Delayed small bowel perforation following BAT is thought to occur secondary to mesenteric hematoma formation or mesenteric tear complications. Our patient did not have any mesenteric injury or hematoma on initial abdominal CT. We are not aware of any other case report of delayed small bowel perforation following BAT without signs of intraabdominal injury on initial imaging and extensive portomesenteric vein gas on follow-up imaging. Ischemic bowel necrosis was the main cause of portomesenteric vein gas in our case. Posttraumatic patients should be kept under medical observation and abdominal CT should be preferred for imaging in case of a deterioration in the general condition and laboratory findings or appearance of new abdominal complaints.

Conservative treatment of hepatic portal venous gas consecutive to a complicated diverticulitis: A case report and literature review

INTRODUCTION AND PRESENTATION OF CASE

Eight days after being diagnosed with multiple small strokes a 71year old male patient is readmitted with suspicion of a petit mal seizure also complained of diarrhoea and abdominal pain. The patient was stable, not febrile and neurologically intact with a slight tenderness in the left lower quadrant. An ultrasound revealed presence of air in the hepatic portal venous system and a suspicion for sigmoid diverticulitis. A CT-scan confirmed both diagnoses. We proceeded with a conservative regimen under close observation. The clinical course and laboratory results were unremarkable.

DISCUSSION

The review of the literature (PubMed database) triggered 685 items with only one clinical trial establishing a scoring system to detect adult individuals, which need operation.

CONCLUSION

A pneumoportogram (hepatic portal venous gas, HPVG) is a very rare and usually associated with bowel ischemia and from poor prognosis. The last decades saw the emergence of numerous other aetiologies (also benign) with a shift of paradigm from systematic emergency laparotomies to individual patient selection.

From esophagus to rectum: a comprehensive review of alimentary tract perforations at computed tomography

Gastrointestinal (GI) tract perforation is a life-threatening condition that can occur at any site along the alimentary tract. Early perforation detection and intervention significantly improves patient outcome. With a high sensitivity for pneumoperitoneum, computed tomography (CT) is widely accepted as the diagnostic modality of choice when a perforated hollow viscus is suspected. While confirming the presence of a perforation is critical, clinical management and surgical technique also depend on localizing the perforation site. CT is accurate in detecting the site of perforation, with segmental bowel wall thickening, focal bowel wall defect, or bubbles of extraluminal gas concentrated in close proximity to the bowel wall shown to be the most specific findings. In this article, we will present the causes for perforation at each site throughout the GI tract and review the patterns that can lead to prospective diagnosis and perforation site localization utilizing CT images of surgically proven cases.

Evaluating Patients with Left Upper Quadrant Pain

Imaging plays a major role in the evaluation of patients who present to the emergency department with acute left upper quadrant (LUQ) pain. Multidetector computed tomography is currently the primary modality used for imaging these patients. The peritoneal reflections, subperitoneal compartment, and peritoneal spaces of the LUQ are key anatomic features in understanding the imaging appearance of acute diseases in this area. Diseases of the stomach, spleen, pancreas, and splenic flexure are encountered in patients with acute LUQ pain. Optimization of the imaging protocol is vital for accurate diagnosis and characterization of these diseases in the acute setting.

Pneumoretroperitoneum Associated with "Dirty Mass": An Unusual Case of Rectal Perforation

Perforation of the rectum requires early recognition and treatment. The diagnosis of rectal perforation is sometimes difficult owing to non specific clinical presentation, especially in elderly patients, in whom, in case of acute abdomen, Computed Tomography (CT) is increasing used as first diagnostic procedure [1]. Several CT signs of gastrointestinal perforation have been described [2, 3]. Recently another CT finding related to colonic perforation called “ dirty mass” has been reported [4]. We present a case of extraperitoneal rectal perforation secondary to colonoscopy in which CT demonstrated the presence of a focal collection of extraluminal fecal matter (“dirty mass”) associated with pneumoretroperitoneum.

Is CT cystography an accurate study in the evaluation of spontaneous perforation of augmented bladder in children and adolescents?

BACKGROUND

Spontaneous bladder perforation (SBP) is a potentially fatal complication of augmented bladder. Imaging is often used for diagnosis. In this study we present our experience with CT cystography (CTC) in the diagnosis of SBP.

OBJECTIVE

To determine CTC accuracy in the evaluation of SBP in children with an augmented bladder.

STUDY DESIGN

The institutional review board approved this HIPAA-compliant study; informed consent was waived. All patients under 20 years old, who underwent CTC for SBP evaluation from 2003 to 2013, were identified. Two radiologists independently reviewed CTC studies for contrast extravasation, ascites, and pneumoperitoneum. Ascites was graded: small - confined to the rectovesical pouch (RVP); moderate - beyond the RVP; large - beyond the pelvis.

RESULTS

Eighty-nine patients (47 males, age 4.2-19.8 years) had 132 CTCs. SBP was diagnosed in 14% (19/132). Both radiologists found contrast extravasation in 74% (14/19) of patients with SBP; two patients had only pneumoperitoneum, and three had only ascites (large = 2, moderate = 1) (Fig.). SBP was found in 1% of CTCs with no ascites or small ascites (1 of 98 and 92; radiologists 1 and 2, respectively). Findings of extraluminal extravasation, unexplained pneumoperitoneum, or large ascites, yielded a detection rate of 95% for SBP by each radiologist. In eight patients, small bowel obstruction was diagnosed.

DISCUSSION

Contrast extravasation was detected in only 74% of patients with SBP. The use of indirect signs of perforation (unexplained pneumoperitoneum and large ascites) in addition to contrast extravasation, increased the detection rate of SBP to 95%. US screening for SBP and selection of patients with moderate or large ascites for CTC, may eliminate the need for most CT scans. In the absence of SBP, other abdominal abnormalities should be evaluated. Bowel obstruction was the most common non-urological emergency detected in this series. The main limitations of the study are: the small number of SBP cases; the diagnosis of SBP not based on surgical findings in three patients; and inability to completely exclude occult SBP in patients not explored surgically.

CONCLUSION

Extraluminal contrast was seen on CTC in most cases of SBP, but some patients with sealed bladder perforation had only pneumoperitoneum or moderate/large ascites. Therefore, SBP should be suspected in any patient with moderate/large volumes of pelvic fluid or unexplained pneumoperitoneum, even when there is no evidence of contrast extravasation. Patients with no ascites, or small volumes, are unlikely to have SBP; therefore, US can be used to screen low risk patients.

Postoperative pneumoperitoneum: is it normal or pathologic?

BACKGROUND

Pneumoperitoneum on computed tomography (CT) after abdominal surgery is common, but its incidence, duration, and clinical significance is widely debated.

MATERIALS AND METHODS

A retrospective, cohort study of patients who underwent abdominal CT within 30 days of abdominal surgery.

RESULTS

Among 344 patients, pneumoperitoneum was found in 39% (135/344) of patients on postoperative days 0-6 in 53%, 7-13 in 41%, 14-20 in 23%, 21-27 in 13%, and 28-30 in 0%. Pneumoperitoneum was associated with the presence of a drain (P = 0.014) but not with age, gender, body mass index, smoking history, lung disease, or open versus laparoscopic surgery (P > 0.05 for all variables). Eight patients required intervention (6%), most commonly for anastomotic leak (4 patients, 50%).

CONCLUSIONS

Postoperative pneumoperitoneum on abdominal CT can be seen in up to 23% of patients 3-weeks postoperatively; however, only 6% of the patients required intervention emphasizing the typically benign consequences of postoperative free air.

Postoperative pneumoperitoneum on computed tomography: is the operation to blame?

BACKGROUND

Postoperative radiographs demonstrating pneumoperitoneum are a vexing problem for surgeons. This dilemma stems from uncertainty regarding the length of time for resolution of gas introduced operatively via either an open or a laparoscopic approach. We attempted to quantify the duration of pneumoperitoneum after both laparoscopic and open surgery in an animal model.

METHODS

A prospective study using 2 groups of 10 pigs (Sus scrofa) was performed. The animals were assigned to undergo either an exploratory laparoscopy or an open abdominal exploration. Postoperatively, sequential computed tomography (CT) scans were performed to assess for the presence of pneumoperitoneum.

RESULTS

Pneumoperitoneum resolution occurred sooner than average on CT scan in the laparoscopic group when compared to open group (1.79 days vs 4.73 days respectively; P value of .02).

CONCLUSIONS

Postoperative pneumoperitoneum resolves more quickly after laparoscopy when compared to open surgery in the porcine model. This information may aid in evaluating postoperative CT scans demonstrating pneumoperitoneum.

Accuracy of sonographic diagnosis of pneumoperitoneum using the enhanced peritoneal stripe sign in Beagle dogs

The objective of this study was to evaluate the feasibility and accuracy of estimating the smallest amount of abdominal free gas detectible in a large population of Beagles by ultrasonography. Healthy dogs were randomly divided into three groups: group A that received 0.1 mL of air injected into the peritoneal cavity, group B that received 0.2 mL of air injected into the peritoneal cavity, and group C that received 0.5 mL of intraperitoneal air. Randomly, some dogs in each group did not receive air injection for the negative control. All ultrasonographic procedures were performed by individuals blinded to group assignments and the presence of intraperitoneal air. The minimum volume of consistently detectable air with good accuracy and reliability was 0.2 mL. Results of the study demonstrated that the enhanced peritoneal stripe sign (EPSS) can verify cases of pneumoperitoneum if more than 0.2 mL of intra-abdominal free gas is present The EPSS is a reliable and specific ultrasonographic characteristic for diagnosing pneumoperitoneum in dogs.

Non-surgical pneumoperitoneum after oro-genital intercourse

INTRODUCTION

In many cases, a pneumoperitoneum is due to air escaping from a perforated hollow viscus or surgical intervention but there are increasing reports of non-surgical causes.

PRESENTATION OF CASE

We report a case where a pneumoperitoneum was identified after oro-genital sexual intercourse.

DISCUSSION

There were nineteen reported cases of non-surgical pneumoperitoneum from gynaecologic causes up to May 2013. We report an additional case four hours after oro-genital intercourse. Close clinical observation and symptomatic treatment are usually all that is required but operative interventions should be considered if the patient develops abdominal pain, peritoneal signs, fever or leukocytosis during observation.

CONCLUSION

This adds to the world literature on non-surgical pneumoperitoneum from oro-genital intercourse. Clinicians should be aware of this condition and focus on medical-sexual history as this information could prevent a patient from being exposed to expensive diagnostics and invasive operative treatments. Patients should also be educated about the mechanisms to avoid future possible diagnostic dilemmas.

Diagnostic value of abdominal free air detection on a plain chest radiograph in the early postoperative period: a prospective study in 648 consecutive patients who have undergone abdominal surgery

BACKGROUND

To the best of our knowledge, this is the first study to evaluate the predictive value of free air (on a plain radiograph) for bowel perforation in a large prospective cohort of surgical patients.

METHODS

All consecutive patients undergoing abdominal surgery between January 2011 and June 2012 were screened for this study. We performed an upright chest radiograph on the second and third postoperative day. Thereafter, additional radiographic evaluations were performed every 2 days until the disappearance of abdominal free air.

RESULTS

Of the 648 subjects enrolled in our study, free abdominal air was found in 65 subjects on the first radiographic evaluation (2 days after surgery), 51 on the second (3 days after surgery), three on the third (5 days after surgery), and none on the fourth (7 days after surgery). The presence of free abdominal air was associated with an increased risk of gastrointestinal perforation. The presence of free air was associated with a hazard ratio (HR) of 21.54 (95% CI 9.66-48.01, p<0.001) and a HR of 23.87 (95% CI 10.68-53.34, p<0.001) at 2 and 3 days after surgery, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value were 70, 93, 33, and 98%, respectively, at 2 days after surgery, and similar results were confirmed at 3 days after surgery.

CONCLUSION

We believe that the presence of free air at 3 days after surgery should not be considered a common finding. Here, we demonstrate that the detection of free air has a remarkable predictive value for gastrointestinal perforation, which has been overestimated in previous experience.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

The etiology of pneumoperitoneum in the 21st century

BACKGROUND

We sought to determine the origin of free intraperitoneal air in this era of diminishing prevalence of peptic ulcer disease and imaging studies. In addition, we attempted to stratify the origin of free air by the size of the air collection.

METHODS

We queried our hospital database for "pneumoperitoneum" from 2005 to 2007 and for proven gastrointestinal perforation from 2000 to 2007. Massive amount of free air was defined as any air pocket greater than 10.0 cm.

RESULTS

Among patients with free air, the predominant causes were perforated viscus (41%) and postoperative (<8 days) residual air (37%). For patients with visceral perforation, only 45% had free air on imaging studies, and for these patients, the predominant cause was peptic ulcer (16%), diverticulitis (16%), trauma (14%), malignancy (14%), bowel ischemia (10%), appendicitis (6%), and endoscopy (4%). The likelihood that free air was identified on an imaging study by lesion was 72% for perforated peptic ulcer, 57% for perforated diverticulitis, but only 8% for perforated appendicitis. The origin of massive free air was equally likely to be gastroduodenal, small bowel, or colonic perforation.

CONCLUSION

The cause of free air when surgical pathology is the source has substantially changed from previous reports.

LEVEL OF EVIDENCE

Epidemiologic study, level IV.

Laparoscopic approach to acute abdomen from the Consensus Development Conference of the Società Italiana di Chirurgia Endoscopica e nuove tecnologie (SICE), Associazione Chirurghi Ospedalieri Italiani (ACOI), Società Italiana di Chirurgia (SIC), Società Italiana di Chirurgia d'Urgenza e del Trauma (SICUT), Società Italiana di Chirurgia nell'Ospedalità Privata (SICOP), and the European Association for Endoscopic Surgery (EAES)

BACKGROUND

In January 2010, the SICE (Italian Society of Endoscopic Surgery), under the auspices of the EAES, decided to revisit the clinical recommendations for the role of laparoscopy in abdominal emergencies in adults, with the primary intent being to update the 2006 EAES indications and supplement the existing guidelines on specific diseases.

METHODS

Other Italian surgical societies were invited into the Consensus to form a panel of 12 expert surgeons. In order to get a multidisciplinary panel, other stakeholders involved in abdominal emergencies were invited along with a patient's association. In November 2010, the panel met in Rome to discuss each chapter according to the Delphi method, producing key statements with a grade of recommendations followed by commentary to explain the rationale and the level of evidence behind the statements. Thereafter, the statements were presented to the Annual Congress of the EAES in June 2011.

RESULTS

A thorough literature review was necessary to assess whether the recommendations issued in 2006 are still current. In many cases new studies allowed us to better clarify some issues (such as for diverticulitis, small bowel obstruction, pancreatitis, hernias, trauma), to confirm the key role of laparoscopy (such as for cholecystitis, gynecological disorders, nonspecific abdominal pain, appendicitis), but occasionally previous strong recommendations have to be challenged after review of recent research (such as for perforated peptic ulcer).

CONCLUSIONS

Every surgeon has to develop his or her own approach, taking into account the clinical situation, her/his proficiency (and the experience of the team) with the various techniques, and the specific organizational setting in which she/he is working. This guideline has been developed bearing in mind that every surgeon could use the data reported to support her/his judgment.

Postoperative pneumoperitoneum after colorectal surgery: Expectant vs surgical management

Postoperative pneumoperitoneum poses a clinical dilemma. Depending on the cause, its management includes a spectrum from simple observation and supportive care to surgical exploration. The aim of this paper is to present four clinical cases and propose an algorithm for the management of postoperative pneumoperitoneum based on available literature. The causes, diagnosis and possible complications arising from pneumoperitoneum will also be discussed. Three of the four cases presented were successfully managed conservatively and one had an exploratory laparotomy with negative findings. In such scenarios, it is important to consider the nonsurgical causes of pneumoperitoneum, which include pseudopneumoperitoneum, thoracic, abdominal, gynecological and idiopathic. These causes do not always require emergent exploratory laparotomy. The surgical team needs to consider the history, physical exam and diagnostic workup of the patient. If a patient presents with peritoneal signs, then exploratory laparotomy is a must. Since 10% of the cases of pneumoperitoneum are caused by nonsurgical entities, managed expectantly, a negative exploratory laparotomy and its associated risks are avoided.

Postoperative pneumoperitoneum: guilty or not guilty?

Purpose

The aim of this study was to determine the incidence and duration of postoperative pneumoperitoneum on plain radiographs and to identify the radiologic findings associated with anastomotic leakage.

Methods

A retrospective analysis was conducted on plain radiographs of 384 patients who underwent intra-abdominal anastomoses between March 2005 and December 2008.

Results

Of the 384 patients, 93 patients (24.2%) had postoperative pneumoperitoneums. Of the 93 patients, 86 patients (92.5%) had physiologic pneumoperitoneums and 7 patients (7.5%) had pneumoperitoneums associated with anastomotic leakage. The initial air height was significantly greater in the leakage group than the physiologic air group (12.16 ± 7.65 mm vs. 7.71 ± 5.08 mm, P = 0.04). The area under the receiver operating characteristic curve of the initial height of free air for anastomotic leakage was 0.69 (95% confidence interval, 0.59 to 0.78). The best cut-off point was 11.7 mm. The height of the pneumoperitoneum increased with time in the leakage group. Ileus was significantly more prevalent in the leakage group than the physiologic air group (P < 0.01).

Conclusion

Postoperative pneumoperitoneum is a common phenomenon after abdominal surgery. An initial air height >11.7 mm, increasing air height over time, and the presence of ileus on plain radiographs suggest a high likelihood of anastomotic leakage.

Pneumoperitoneum post-fluoroscopic percutaneous gastrojejunostomy insertion: computed tomography and clinical evaluation

INTRODUCTION

To assess the incidence and clinical significance of pneumoperitoneum after radiologic percutaneous gastrojejunostomy (PGJ) tube insertion.

METHODS

Sixteen subjects were prospectively assessed after imaging-guided PGJ tube insertion to discern the incidence of pneumoperitoneum related to specific clinical signs and symptoms. Computed tomography of the abdomen and the pelvis was performed immediately after PGJ insertion. A clinical evaluation, including history, general and abdominal physical examination, temperature, complete blood cell count, abdominal pain, and abdominal tension, was performed on days 1 and 3, and at the discretion of the nutritional support team on day 7 after PGJ insertion.

RESULTS

Fifteen of the 16 subjects demonstrated imaging findings of pneumoperitoneum after the PGJ-tube insertion. Only a small amount of pneumoperitoneum was demonstrated in 10 of the subjects, whereas a large volume of gas was detected in 2 of the subjects. The only altered clinical findings encountered were increased white blood cell count and fever. These abnormal clinical data were most frequently seen immediately after feeding-tube placement.

DISCUSSION

Pneumoperitoneum was a common finding after PGJ-tube placement in our study population. There were no statistically significant abnormal clinical parameters, in the presence or absence of pneumoperitoneum, for any of the subjects after PGJ-tube insertion. Conservative management of pneumoperitoneum after PGJ is warranted.

Effectiveness of plain radiography in diagnosing hollow viscus perforation: study of 1,723 patients of perforation peritonitis

Gastrointestinal perforations remain the most common cause of surgical pneumoperitoneum since time immemorial. The aim of this study was to find out the effectiveness of plain radiography in diagnosing hollow viscous perforation. A prospective analysis of a total of 1,723 patients of perforation peritonitis between January 2009 and June 2011, confirmed by exploratory laparotomy, was worked out in the study. All these patients had undergone either an upright chest or erect abdominal or both radiographs before undergoing operative procedure. Pneumoperitoneum was evaluated, and the findings were compared with that of exploratory laparotomy. Out of the 1,723 patients of documented perforation on intraoperative finding, 1,537 patients showed pneumoperitoneum on preoperative plain radiography. The overall positivity rate of plain radiography in detecting pneumoperitoneum was 89.20%. The positivity rate was highest for stomach and duodenal perforation (94.19%) and the least for appendicular perforation (7.69%) with highly significant difference (p value, <0.001). In developing world, where there is limited availability of resources and overburden of patients, imposing a limitation in adapting advanced radiological technique as a first line of investigation, plain radiography may be considered as a valuable screening tool in detecting pneumoperitoneum with high positivity rate.

Can low-dose abdominal CT replace abdominal plain film in evaluation of acute abdominal pain?

BACKGROUND

Non-contrast computed tomography (NCT) has become an important diagnostic tool in acute abdominal pain, but the drawback is the increased radiation dose compared to abdominal plain film (APF).

PURPOSE

To evaluate whether NCT, including low-dose computed tomography (LDCT, using 50 mAs), provides more diagnostic information than APF in patients presenting with acute non-traumatic abdominal pain and if the use of CT can reduce the total number of additional radiograms. A second aim was to compare the diagnostic outcome between standard-dose computed tomography (SDCT) and LDCT.

MATERIAL AND METHODS

During 2000, 2002, and 2004 a total of 222 patients were retrospectively reviewed, and 86 patients had APF, 60 had SDCT, and 76 had LDCT. The radiological report of each patient was compared with the final diagnosis obtained from the medical record within 30 days. Additional radiograms were registered, and a total radiation dose excluding or including APF or NCT was calculated.

RESULTS

NCT gave a correct diagnosis in 50%, compared to 20% with APF (P < 0.001). The total number of additional radiograms was substantially lower in the computed tomography (CT) group compared to the APF group (P < 0.001), and the average sum of radiation dose was similar for APF and LDCT.

CONCLUSION

NCT was found to be significantly better at providing diagnostic information than APF in patients presenting with acute abdominal pain. It reduced the number of additional radiograms, but the total patient dose remained somewhat higher in the CT group even when using LDCT with 50 mAs.

CT colonography after metallic stent placement for acute malignant colonic obstruction

PURPOSE

To evaluate the feasibility of using computed tomographic (CT) colonography for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by colorectal cancer.

MATERIALS AND METHODS

Institutional review board approval was obtained, and patient informed consent was waived. Fifty patients (mean age +/- standard deviation, 58.5 years +/- 11.7), who demonstrated no postprocedural complication after successful placement of self-expandable metallic stents to treat acute colon obstruction caused by cancer, underwent CT colonography 1-43 days (median, 5 days) after stent placement. CT colonography was performed after cathartic preparation by using magnesium citrate (n = 20) or sodium phosphate (n = 3), combined with oral bisacodyl, or by using polyethylene glycol (n = 27). Fecal/fluid tagging was achieved by using 100 mL of meglumine diatrizoate. The colon was distended by means of pressure-monitored CO(2) insufflation. The sensitivity and specificity of CT colonography in evaluating the colon proximal to the stent and CT colonography-related complications were assessed. The 95% confidence intervals (CIs) were calculated for proportional data.

RESULTS

Per-lesion and per-patient sensitivities of CT colonography for lesions 6 mm or larger in diameter in the colon proximal to the stent were 85.7% (12 of 14 lesions; 95% CI: 58.8%, 97.2%) and 90% (nine of 10 patients; 95% CI: 57.4%, 99.9%), respectively. CT colonography depicted all synchronous cancers (two lesions) and advanced adenomas (five lesions). Per-patient specificity for lesions 6 mm and larger in the proximal colon was 85.7% (18 of 21 patients; 95% CI: 64.5%, 95.9%). CT colonography did not generate any false diagnosis of synchronous cancer. False-positive findings at CT colonography did not result in a change in surgical plan for any patients. No CT colonography-associated stent dislodgment/migration or colonic perforation occurred in any patient (95% CI: 0%, 6.2%).

CONCLUSION

CT colonography is a safe and useful method for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by cancer. (c) RSNA, 2010.

Gas-forming bacterial peritonitis mimics hollow organ perforation

Acute abdomen is an emergent condition in the emergency department, and it is mandatory to evaluate it immediately and treat it without delay. Pneumoperitoneum is usually attributed to perforation of the gastrointestinal tract. However, intra-abdominal, gynecologic, urologic, and miscellaneous pathogenesis not related to a perforated gastrointestinal tract had never been described in the past. Approximately 10% of pneumoperitoneum is not associated with hollow organ perforation. There are many imitators of pneumoperitoneum including subphrenic abscess, colon volvulus, Chilaiditi syndrome, and so on. In our case, the gas-forming bacterial peritonitis accounted for the pneumoperitoneum. We presented an 85-year-old man who received laparotomy due to peritonitis, and radiographic subphrenic free air was seen. However, a large amount of ascites was found rather than perforated bowels during the surgical exploration, and the culture of ascites was positive for Pseudomonas aeruginosa.

Prolonged postlaparoscopy carbon dioxide pneumoperitoneum

In this article we report what is to our knowledge the longest published duration of postlaparoscopy CO2 pneumoperitoneum, and discuss factors that may contribute to the duration of postoperative pneumoperitoneum.

Automated carbon dioxide insufflation for CT colonography: effectiveness of colonic distention in cancer patients with severe luminal narrowing

OBJECTIVE

The objective of our study was to determine the effectiveness of automated CO2 insufflation in colonic distention for CT colonography (CTC) in patients with severe luminal narrowing by colorectal cancer and preliminarily evaluate its safety performed shortly after colonoscopic polypectomy or biopsy.

MATERIALS AND METHODS

Seventy-four patients were examined with colonoscopy and subsequent CTC (time interval, 0-8 days) using automated CO2 insufflation. Thirty-six patients whose colonoscopy was incomplete due to severe luminal narrowing by cancer that prevented colonoscope passage constituted the stenotic group. The remaining 38 patients constituted the nonstenotic group. Colonic distention was graded by two experienced readers from 1 (worst) to 4 (best) and compared between the two groups. Clinical data and CT images were analyzed for the occurrence of colonic perforation.

RESULTS

Distention was not significantly different between the stenotic and nonstenotic groups in any colonic segments in both supine and prone positions. The mean distention grade +/- SD of the colonic segments proximal to the luminal narrowing in the stenotic group (n = 143 segments) was 3.7 +/- 0.7 and 3.8 +/- 0.7 for the supine and prone positions, respectively. Colonic perforation was not noted in any of the 74 patients, including 65 patients who underwent CTC within 24 hours after colonoscopy (62 snare polypectomies, two polypectomies using biopsy forceps, 63 routine mucosal biopsies).

CONCLUSION

Automated pressure-controlled CO2 insufflation is as efficient in colonic distention for CTC in colorectal cancer patients with severe luminal narrowing as it is in patients without severe luminal narrowing.

Sonographic diagnosis of pneumoperitoneum using the ‘enhancement of the peritoneal stripe sign.’ A prospective study

The objective of this study was to validate the Enhanced Peritoneal Stripe Sign (EPSS) in diagnosing pneumoperitoneum in patients presenting with acute abdomen. The EPSS was described as a specific sonographic sign of pneumoperitoneum in an animal model and few patients who had undergone laparoscopy (Muradali et al. in Am J Roentgenol 173(5): 1257-1262, 1999). This is the first large-scale study in patients to detect the efficacy of EPSS. Six hundred consecutive patients with acute abdominal pain presenting to the author over a period of 3 months in the emergency ultrasonography department were prospectively studied for the presence of the EPSS. As part of their clinical work up, patients also underwent plain radiographs and/or a computed tomography (CT) of the abdomen. The author was unaware of the results of other imaging studies at the time of the sonographic examination. In all cases, the final diagnosis was based on the intra-operative findings, results of other imaging techniques and clinical follow-up. Based on the final diagnosis, 21 out of 600 patients had pneumoperitoneum. The EPSS was found to be positive in all 21 of these patients. Another three patients were found to have the sign false positive. There were no false negatives in this study. The EPSS thus had a sensitivity of 100%, a specificity of 99%, a positive predictive value of 87.5% and a negative predictive value of 100%. The EPSS is a reliable and accurate sonographic sign for the diagnosis of pneumoperitoneum. It should be looked for in all patients presenting with acute abdominal pain.

CT assessment of anastomotic bowel leak

AIM

To evaluate the predictors of clinically important gastrointestinal anastomotic leaks using multidetector computed tomography (CT).

SUBJECTS AND METHODS

Ninety-nine patients, 73 with clinical suspicion of anastomotic bowel leak and 26 non-bowel surgery controls underwent CT to investigate postoperative sepsis. Fifty patients had undergone large bowel and 23 small bowel anastomoses. The time interval from surgery was 3-30 days (mean 10+/-5.9 SD) for the anastomotic group and 3-40 days (mean 14+/-11 SD) for the control group (p=0.3). Two radiologists blinded to the final results reviewed the CT examinations in consensus and recorded the presence of peri-anastomotic air, fluid or combination of the two; distant loculated fluid or combination of fluid and air; free air or fluid; and intestinal contrast leak. Final diagnosis of clinically important anastomotic leak (CIAL) was confirmed at surgery or by chart review of predetermined clinical and laboratory criteria.

RESULTS

The prevalence of CIAL in the group undergoing CT was 31.5% (23/73). The CT examinations with documented leak were performed 5-28 (mean; 11.4+/-6 SD) days after surgery. Nine patients required repeat operation, 10 percutaneous abscess drainage, two percutaneous drainage followed by surgery, and two prolonged antibiotic treatment and total parenteral nutrition (TPN). Of the CT features examined, only peri-anastomotic loculated fluid containing air was more frequently seen in the CIAL group as opposed to the no leak group (p=0.04). There was no intestinal contrast leakage in this cohort. Free air was present up to 9 days and loculated air up to 26 days without CIAL.

CONCLUSION

Most postoperative CT features overlap between patients with and without CIAL. The only feature seen statistically more frequently with CIAL is peri-anastomotic loculated fluid containing air.

Accuracy of MDCT in predicting site of gastrointestinal tract perforation

OBJECTIVE

The purpose of this study was to prospectively evaluate the accuracy of MDCT for preoperative determination of the site of surgically proven gastrointestinal tract perforations and to determine the most predictive findings in this diagnosis.

SUBJECTS AND METHODS

We prospectively studied 85 consecutive patients with extraluminal air on MDCT who had surgically proven gastrointestinal tract perforations. All patients underwent surgery within 12 hours after MDCT was performed. Two experienced radiologists, blinded to the surgical diagnosis, reached a consensus prediction of the site of the perforation using the following eight MDCT findings: concentration of extraluminal air bubbles adjacent to the bowel wall, free air in supramesocolic or inframesocolic compartments, extraluminal air in both abdomen and pelvis, focal defect in the bowel wall, segmental bowel-wall thickening, perivisceral fat stranding, abscess, and extraluminal fluid. MDCT imaging results were compared with surgical and pathologic findings. Logistic regression analyses were performed to assess the significance of the different radiologic criteria.

RESULTS

Analysis of MDCT images was predictive of the site of gastrointestinal tract perforation in 73 (86%) of 85 patients. Logistic regression showed that concentration of extraluminal air bubbles (p < 0.001), segmental bowel wall thickening (p < 0.001), and focal defect of the bowel wall (p = 0.007) were strong predictors of the site of bowel perforation.

CONCLUSION

MDCT is highly accurate for predicting the site of gastrointestinal tract perforations. Three of eight CT findings significantly correlate with surgical diagnosis.

Pneumoperitoneum after percutaneous endoscopic gastrostomy: A case report and review

A complication of percutaneous endoscopic gastrostomy (PEG) is perforation of a hollow viscus. This is typically detected by finding of pneumoperitoneum (PP) on radiographs. However, PP can occasionally be a benign finding. A review of the literature shows many causes for a benign PP, and it has been noted to occur frequently after PEG placement. In the absence of signs or symptoms of peritoneal inflammation, PP usually requires no further investigation or treatment.

Twenty-five simple ways to increase insufflation performance and patient safety in laparoscopy

Technical aspects of laparoscopic insufflation technique and interaction among patient, technique, and physician can affect the performance of laparoscopy and patient safety. A variety of laparoscopic equipment was evaluated regarding insufflation performance in laboratory measurements and/or in an intraoperative computer-based data-acquisition model for intraabdominal pressure, gas flow, and temperature. In this article, we present 25 suggestions for improving insufflation performance and increasing patient safety. These tips may help avoid and solve insufflation problems and malfunction, over- and under-pressure peaks, laparoscopic hypothermia, and gas embolism, and shorten operation room and anesthesia time, thereby saving time, money, and physician stress.

Gastro-duodenal perforations: conventional plain film, US and CT findings in 166 consecutive patients

INTRODUCTION

Gastro-duodenal perforations may be suspected in patients with history of ulceration, who present with acute pain and abdominal wall rigidity, but radiological findings in these cases may be unable to confirm a clinical diagnosis. The aim of our study was to report our experience in the diagnosis of gastro-duodenal perforation by conventional radiography, US and CT examinations.

MATERIAL AND METHODS

We retrospectively reviewed medical records of 166 consecutive patients who presented in the last 2 years to our institutions with symptoms of acute abdomen and submitted to surgery at the Emergency Unit of the "A.Cardarelli" Hospital of Naples with a surgical finding of perforated gastro-duodenal ulcer. The evidence of free intraperitoneal air on abdominal plain film was considered as a direct or suggestive finding of perforation. Evidence of intraperitoneal free fluid and/or reduced intestinal peristalsis at sonographic examination were considered indirect signs of gastro-duodenal perforation. Evidence of free peritoneal gas at CT was considered as a direct evidence of gastro-duodenal perforation.

RESULTS

Twenty patients underwent immediate surgery with no preoperative imaging evaluation, in 10 of them the site of perforation was found in a juxta-pyloric region and in the others at level of duodenum. In 146 patients submitted to serial radiological investigations before surgery, the site of perforation was in 56 (38.3%) duodenal, in 52 (35.6%) juxta-pyloric, in 28 (19.1%) gastric and in 10 (6.8%) pyloric. The cause of perforation was in all cases gastric or duodenal ulceration, in seven cases involving pancreatic parenchyma. In 110 (75.4%) patients with direct findings of perforation, in 94 cases (85.5%) the correct diagnosis was established on abdominal plain film, in two (1.8%) with radiographic and sonographic examinations and in 14 (12.7%) on CT findings. In 36 (24,6%) patients with no direct findings of perforation, only 24 (16,4%) of them showed indirect findings of perforation. In other 12 patients no direct or indirect finding of free peritoneal air was detected.

CONCLUSIONS

Our experience documents that in 146 gastroduodenal perforations the free peritoneal air was not evident in 12 cases and in 66% of these patients the presence of intraperitoneal fluid could be the only sign of perforation. If free peritoneal air was detected with conventional radiography, other investigations were not indicated. In the absence of direct or indirect findings of pneumoperitoneum, US examination could help to confirm intestinal paresis and the evidence of intraperitoneal free fluid. Helical CT examination was useless before at least 6h from the onset of symptomatology, because in the absence of direct or indirect findings of penumoperitoneum at abdominal plain film and sonograpy, CT could not demonstrate any additional diagnostic information.

Postoperative pneumoperitoneum: prevalence, duration, and possible significance

Free intraperitoneal air after abdominal surgery is a confounding finding with uncertain significance. A diagnostic dilemma often arises as to its origin: does it merely represent residual postoperative pneumoperitoneum (PP), which will need no intervention, or does it indicate a complication such as an anastomotic leak or a perforation of the gastrointestinal tract. Residual PP is usually well tolerated, as it will be absorbed over time and requires no therapy. On the other hand, air escaping through a gastrointestinal tract perforation or leak usually represents an intra-abdominal catastrophe requiring urgent intervention. This intriguing subject has been dealt with quite extensively based on plain film radiography findings in the past 50 years, and has lately also been studied on CT. This review discusses factors influencing the prevalence of PP and its range of duration.

Ultrasonography is superior to plain radiography in the diagnosis of pneumoperitoneum

BACKGROUND

The aim of this study was to compare plain radiography with abdominal ultrasonography in the detection of pneumoperitoneum.

METHODS

A total of 188 patients with suspected hollow organ perforation were studied. All patients had abdominal ultrasonography, upright chest radiography and left lateral decubitus abdominal radiography examinations. The sensitivity, specificity, positive and negative predictive value, and accuracy of chest and abdominal radiography were compared with that of abdominal ultrasonography.

RESULTS

One hundred and seventy-eight patients underwent laparotomy; 170 patients had hollow organ perforation, five patients had perforated appendicitis and three had acute cholecystitis. In the diagnosis of pneumoperitoneum, ultrasonography had improved sensitivity (92 versus 78 per cent), negative predictive value (39 versus 20 per cent) and accuracy (88 versus 76 per cent), and similar specificity (both 53 per cent) and positive predictive value (95 versus 94 per cent) compared with plain radiography.

CONCLUSION

Ultrasonography is more sensitive than plain radiography in the diagnosis of pneumoperitoneum.

Blunt abdominal trauma resulting in Pneumatosis intestinalis in an infant

We report a case of pnuematosis intestinalis in a 2-year-old boy after blunt abdominal trauma. In the setting of blunt trauma, the hypothesized mechanism of pneumatosis intestinalis is mechanical disruption of the intestinal mucosa with extravasation of luminal gas within the intestinal wall. Although the presence of intraluminal gas may imply intestinal necrosis and the need for an invasive procedure, this case report suggests that management without surgery can lead to successful outcome in selected cases.