Diagnosis of inguinal hernia by prone- vs. supine-position computed tomography

Evaluation of overexposure risk when there is a space between the subject and the couch in computed tomography: a phantom study

The purpose of this study was to investigate the risk of overexposure associated with automatic tube current modulation (ATCM) and automatic couch height positioning compensation mechanism (AHC) in computed tomography (CT) systems, particularly in scenarios involving a gap between the subject and the couch. Results revealed that when AHC was enabled, CT dose index volume (CTDIvol) increased by approximately 10% at 2.5 cm, 20% at 5.0 cm, and 40% at 10.0 cm gaps compared to close contact conditions. While the AHC function ensures consistent exposure doses and image quality regardless of subject positioning relative to the CT gantry isocenter, the study highlights a potential risk of overexposure when a gap exists between the subject and the couch. These findings offer valuable insights for optimizing CT imaging protocols and underscore the importance of carefully considering subject positioning in clinical practice.

Muscular groin hernias: an anatomical variation as a cause of recurrence

PURPOSE

The objective of this study was to understand our center's experience with the rare entity of muscular groin hernias. Specifically, to determine this hernia's incidence and characteristics and provide valuable information to surgeons that can be utilized at the time of a hernia repair regardless of modality used.

METHODS

This was a retrospective chart review between 2005 and 2019. Patients who had a primary or recurrent groin hernia operation for an atypically located hernia (other than direct, indirect, or femoral) were included. Descriptive statistics were utilized to present the hernia and patient data as median (interquartile range, range).

RESULTS

There were 152 patients with 155 muscular hernias identified in primary operations and 41 patients with 41 muscular hernias identified in recurrent operations. In both primary and recurrent groups there were more males, and the males were on average younger with a higher body mass index (BMI) than females. Most muscular hernias were located lateral (76) or lateral/superior (33) to the internal ring with a median distance between 2 and 3 cm (1, 0.3-5; 2.8,2-5) from the internal ring. A concurrent ipsilateral inguinal hernia was found and repaired in 42.3% of left and 46.8% of right sided primary muscular hernia operations. A concurrent ipsilateral inguinal hernia was noted in 5% of left and 14.3% of right sided recurrent muscular operations. In left sided recurrent operations for a muscular hernia, 68.9% had a previous ipsilateral inguinal hernia repair and in right sided recurrent operations, 67.7% had a previous ipsilateral inguinal hernia repair.

CONCLUSION

This study describes a previously unidentified groin muscular hernia in both primary and recurrent hernia operations as a potential cause of hernia recurrence and identifies muscular hernia locations. This information can be utilized at the time of surgery to identify and subsequently repair these defects, leading to improved patient and hernia outcomes.

Diagnostic performance of CT with Valsalva maneuver for the diagnosis and characterization of inguinal hernias

PURPOSE

Inguinal hernias are mainly diagnosed clinically, but imaging can aid in equivocal cases or for treatment planning. The purpose of this study was to evaluate the diagnostic performance of CT with Valsalva maneuver for the diagnosis and characterization of inguinal hernias.

METHODS

This single-center retrospective study reviewed all consecutive Valsalva-CT studies between 2018 and 2019. A composite clinical reference standard including surgery was used. Three blinded, independent readers (readers 1-3) reviewed the CT images and scored the presence and type of inguinal hernia. A fourth reader measured hernia size. Interreader agreement was quantified with Krippendorff's α coefficients. Sensitivity, specificity, and accuracy of Valsalva-CT for the detection of inguinal hernias was computed for each reader.

RESULTS

The final study population included 351 patients (99 women) with median age 52.2 years (interquartile range (IQR), 47.2, 68.9). A total of 381 inguinal hernias were present in 221 patients. Sensitivity, specificity, and accuracy were 85.8%, 98.1%, and 91.5% for reader 1, 72.7%, 92.5%, and 81.8% for reader 2, and 68.2%, 96.3%, and 81.1% for reader 3. Hernia neck size was significantly larger in cases correctly detected by all three readers (19.0 mm, IQR 13, 25), compared to those missed by all readers (7.0 mm, IQR, 5, 9; p < 0.001). Interreader agreement was substantial (α = 0.723) for the diagnosis of hernia and moderate (α = 0.522) for the type of hernia.

CONCLUSION

Valsalva-CT shows very high specificity and high accuracy for the diagnosis of inguinal hernia. Sensitivity is only moderate which is associated with missed smaller hernias.

Diagnostic Accuracy of Imaging Modalities on Occult Groin Hernias According to Hernia type and a Surgeon-centered Individualized Groin Hernia Management Algorithm

BACKGROUND

The purpose of this study is to evaluate the diagnostic performance of imaging techniques for the identification of groin hernias based on the type of hernia and to demonstrate the efficacy of an algorithm based on the surgeon and surgical technique.

MATERIALS AND METHODS

Medical records of 561 patients who were operated on for groin hernia were retrospectively analyzed. A total of 102 patients who had both pelvic computed tomography (CT) and ultrasonography (USG) recordings preoperatively and underwent transabdominal preperitoneal repair were included in the study.

RESULTS

A contralateral asymptomatic occult groin hernia was detected in 25.5% of all patients. The overall sensitivity of USG and CT on contralateral asymptomatic occult hernia was 42.3% and 65.4%, respectively. The sensitivity of USG according to the contralateral occult hernia type was 66.7%, 35.7%, 33.3%, and 50% for direct, indirect, femoral, and pantaloon hernias, respectively. The sensitivity of CT according to the contralateral occult hernia type was 0%, 57.1%, 100%, and 100% for direct, indirect, femoral, and pantaloon hernias, respectively.

CONCLUSIONS

The handicap created by the variability in the diagnostic sensitivity of imaging modalities can be overcome with the choice of transabdominal preperitoneal repair in the surgical technique.

Significance of routine preoperative prone computed tomography for predicting intractable cases of inguinal hernias treated by transabdominal preperitoneal repair

Physical examination is the standard diagnostic approach for adult inguinal hernias. We aimed to evaluate the clinical utility of routine preoperative computed tomography scans in the prone position for predicting intractable cases of inguinal hernias before performing transabdominal preperitoneal repairs. We retrospectively analyzed 56 lesions in 48 patients with inguinal hernias who underwent prone computed tomography scans prior to transabdominal preperitoneal repairs. To assess the ability of prone computed tomography to enable the accurate preoperative diagnosis of inguinal hernias, we compared preoperative hernia types as classified through hernia computed tomography and intraoperative diagnosis. We also analyzed the relationship between operation time and hernia type in unilateral cases (n = 40). The overall hernia computed tomography detection and classification accuracy rates were 81.0% and 83.9%, respectively, using the Japan Hernia Society classification system (2009 version) and 84.3% and 91.2%, respectively, using the European Hernia Society classification system. There were no differences in the hernia type frequencies between the shorter (n = 20) and longer (n = 20) operation time groups. Two patients had sliding inguinal hernias with prolapsing bladders, both of which were detectable using preoperative prone computed tomography. Although transabdominal preperitoneal repairs were completed in both cases, the operation times were exceptionally long (185 and 291 minute). Preoperative prone computed tomography is useful for predicting intractable cases of inguinal hernias. Prone computed tomography can play a significant role in not only typing and differentiating hernias from other diseases, but also in helping surgeons appropriately treat unexpected intractable cases with laparoscopic surgery.

Unnecessary use of radiology studies in the diagnosis of inguinal hernias: a retrospective cohort study

BACKGROUND

The diagnosis of inguinal hernias is predominantly based on physical exam, although imaging may be used in select cases. The objective of this study was to determine the frequency of unnecessary imaging used in the diagnosis of inguinal hernias.

METHODS

Patients who underwent elective inguinal hernia repair at a large academic health system in the U.S. from 2010 to 2017 were included. Within this cohort, we identified patients who received imaging 6 months prior to surgery. Through chart review of physical exam findings and imaging indications, we categorized patients into four imaging categories: unrelated, necessary, unnecessary, and borderline. Multivariable logistic regression analysis was used to identify factors associated with receipt of unnecessary imaging.

RESULTS

Of 2162 patients who underwent inguinal hernia surgery, 249 patients had related imaging studies 6 months prior to surgery. 47.0% of patients received unnecessary imaging. 66.9% and 33.1% of unnecessary studies were ultrasounds and CT scans, respectively. 24.5% of patients had necessary studies, while 28.5% had studies with borderline indications. On multivariable analysis, having a BMI between 25.0 and 29.9 kg/m2 was associated with receipt of unnecessary studies. Primary care providers and ED physicians were more likely to order unnecessary imaging.

CONCLUSIONS

Nearly 50% of all patients who receive any related imaging prior to surgery had potentially unnecessary diagnostic radiology studies. This not only exposes patients to avoidable risks, but also places a significant economic burden on patients and our already-strained health system.

A Case of bilateral concomitant inguinal and femoral hernias treated with transabdominal preperitoneal repair

Synchronous bilateral hernias are very rare, and subclinical hernias as this case are very difficult to diagnose preoperatively. Laparoscopic surgery, which can accurately confirm and reinforce the weakened bilateral inguinal region, was very useful.

Development of Upright Computed Tomography With Area Detector for Whole-Body Scans: Phantom Study, Efficacy on Workflow, Effect of Gravity on Human Body, and Potential Clinical Impact

OBJECTIVES

Multiple human systems are greatly affected by gravity, and many disease symptoms are altered by posture. However, the overall anatomical structure and pathophysiology of the human body while standing has not been thoroughly analyzed due to the limitations of various upright imaging modalities, such as low spatial resolution, low contrast resolution, limited scan range, or long examination time. Recently, we developed an upright computed tomography (CT), which enables whole-torso cross-sectional scanning with 3-dimensional acquisition within 15 seconds. The purpose of this study was to evaluate the performance, workflow efficacy, effects of gravity on a large circulation system and the pelvic floor, and potential clinical impact of upright CT.

MATERIALS AND METHODS

We compared noise characteristics, spatial resolution, and CT numbers in a phantom between supine and upright CT. Thirty-two asymptomatic volunteers (48.4 ± 11.5 years) prospectively underwent both CT examinations with the same scanning protocols on the same day. We conducted a questionnaire survey among these volunteers who underwent the upright CT examination to determine their opinions regarding the stability of using the pole throughout the acquisition (closed question), as well as safety and comfortability throughout each examination (both used 5-point scales). The total access time (sum of entry time and exit time) and gravity effects on a large circulation system and the pelvic floor were evaluated using the Wilcoxon signed-rank test and the Mann-Whitney U test. For a large circulation system, the areas of the vena cava and aorta were evaluated at 3 points (superior vena cava or ascending aorta, at the level of the diaphragm, and inferior vena cava or abdominal aorta). For the pelvic floor, distances were evaluated from the bladder neck to the pubococcygeal line and the anorectal junction to the pubococcygeal line. We also examined the usefulness of the upright CT in patients with functional diseases of spondylolisthesis, pelvic floor prolapse, and inguinal hernia.

RESULTS

Noise characteristics, spatial resolution, and CT numbers on upright CT were comparable to those of supine CT. In the volunteer study, all volunteers answered yes regarding the stability of using the pole, and most reported feeling safe (average rating of 4.2) and comfortable (average rating of 3.8) throughout the upright CT examination. The total access time for the upright CT was significantly reduced by 56% in comparison with that of supine CT (upright: 41 ± 9 seconds vs supine: 91 ± 15 seconds, P < 0.001). In the upright position, the area of superior vena cava was 80% smaller than that of the supine position (upright: 39.9 ± 17.4 mm vs supine: 195.4 ± 52.2 mm, P < 0.001), the area at the level of the diaphragm was similar (upright: 428.3 ± 87.9 mm vs supine: 426.1 ± 82.0 mm, P = 0.866), and the area of inferior vena cava was 37% larger (upright: 346.6 ± 96.9 mm vs supine: 252.5 ± 93.1 mm, P < 0.001), whereas the areas of aortas did not significantly differ among the 3 levels. The bladder neck and anorectal junction significantly descended (9.4 ± 6.0 mm and 8.0 ± 5.6 mm, respectively, both P < 0.001) in the standing position, relative to their levels in the supine position. This tendency of the bladder neck to descend was more prominent in women than in men (12.2 ± 5.2 mm in women vs 6.7 ± 5.6 mm in men, P = 0.006). In 3 patients, upright CT revealed lumbar foraminal stenosis, bladder prolapse, and inguinal hernia; moreover, it clarified the grade or clinical significance of the disease in a manner that was not apparent on conventional CT.

CONCLUSIONS

Upright CT was comparable to supine CT in physical characteristics, and it significantly reduced the access time for examination. Upright CT was useful in clarifying the effect of gravity on the human body: gravity differentially affected the volume and shape of the vena cava, depending on body position. The pelvic floor descended significantly in the standing position, compared with its location in the supine position, and the descent of the bladder neck was more prominent in women than in men. Upright CT could potentially aid in objective diagnosis and determination of the grade or clinical significance of common functional diseases.

Imaging modalities for inguinal hernia diagnosis: a systematic review

PURPOSE

The aim of the study was to determine which diagnostic modality [Computerized Tomography (CT), Magnetic Resonance Imaging (MRI), or ultrasound (US)] is more precise in terms of sensitivity and specificity in diagnosing inguinal hernia and sub-type of inguinal hernia (direct or indirect).

METHODS

This systematic review was reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), and a search for relevant articles was undertaken in PubMed, Embase, and the Cochrane Library. Inclusion criteria were original studies that preoperatively diagnosed patients suspected of inguinal hernia by either CT, MRI, or US and compared diagnostic findings with operative findings or definitive follow-up. The main outcomes were the diagnostic certainty of inguinal hernia and type of hernia by sensitivity and specificity. All eligible studies were searched in the Retraction Watch database to ensure that all included studies were suitable for inclusion.

RESULTS

Bubble charts depicting the size of each patient cohort and percentual range for both sensitivity and specificity showed that US was better than CT and MRI in diagnosing inguinal hernia. Bubble charts for US and CT depicted high values within the studies that reported sensitivity and specificity in diagnosing type of hernia.

CONCLUSIONS

We found that US had the highest sensitivity and specificity. However, it must be taken into consideration that performance is highly dependent on the operator's level of expertise. Based on this systematic review, ultrasound may be the preferred imaging modality when physical examination is inconclusive, given that local expertise in performing US examination for hernia disease is adequate.

Management of Occult Contralateral Inguinal Hernia: Diagnosis and Treatment With Laparoscopic Totally Extra Peritoneal Repair

BACKGROUND

Up to 33% risk of occult contralateral inguinal hernia has been reported. This study aims to evaluate diagnostic and treatment modalities in the case of occult contralateral hernia and the role of ultrasonography (USG).

MATERIALS AND METHODS

Patients who had undergone inguinal hernia repair between 2009 and 2018 were studied retrospectively. The detection rate of occult inguinal hernia by USG and results of laparoscopic totally extra peritoneal repair (TEP) were evaluated.

RESULTS

Of 295 patients, USG was performed to the contralateral site in 80 with clinically unilateral hernia and occult hernia was detected in 44 (55%). Bilateral TEP was performed for these patients. There was no recurrence and no significant complication.

CONCLUSIONS

As it is noninvasive, easily accessible and has high sensitivity, USG is recommended in diagnosis. In the case of occult contralateral inguinal hernia, bilateral TEP is considered as a safe procedure. Thus, the need for a second operation and related complications can be prevented. We recommend routine USG to detect whether contralateral occult inguinal hernia is present.