Noninvasive detection and mapping of intraabdominal adhesions: a review of the current literature

MR imaging for preoperative characterization of pelvic adhesions: role in diagnosis and surgical planning

Pelvic adhesions are nonanatomic connections between organs and normal peritoneal surfaces that develop secondary to a maladaptive inflammatory response to tissue insults. Comprised of fibrous tissue, adhesions can result in the distortion of operative dissection planes, which can complicate the establishment of abdominal access in patients undergoing surgery, prolong the length of surgery, and increase the risk of injury to bowel and other structures if involved by extensive adhesive disease. This can adversely impact patient outcomes by increasing the risk of surgical complications including bleeding, infection, and prolonging postoperative length of stay. Literature on the characterization of adhesions with imaging is limited and a systematic framework for evaluating adhesive disease on cross-sectional imaging of the pelvis does not currently exist. In this review, we discuss the MR imaging features of pelvic adhesions, highlighting unique teaching cases in which surgical exploration was significantly complicated by the presence of adhesive disease. We will also review the correlation between MR imaging and intraoperative findings in these cases. A proposed standardized framework for the detection and characterization of adhesions on pelvic MRI will be reviewed with multiple imaging examples. Identification and characterization of pelvic adhesive disease on preoperative imaging provides radiologists with an opportunity to inform the referring clinician of their presence, potentially improving outcomes and the quality of patient care.

Alternative to mesh repair for ventral hernias: Modified rectus muscle repair

BACKGROUND

Mesh utilization for ventral hernia repair is associated with potential complications such as mesh infections, adhesions, seromas, fistula formation and significant postoperative pain. The modified rectus muscle repair (RMR) is as an option to repair midline ventral hernias without mesh.

AIM

To evaluate the short term outcomes when the modified RMR was used to repair ventral hernias.

METHODS

This was a 5-year prospective study that examined the outcome of all consecutive patients with ventral abdominal wall hernias > 5 cm in maximal diameter who underwent repair using the modified RMR technique in a single surgeon unit. Patients were reviewed in an outpatient clinic at 3, 6 and 12 mo and evaluated for hernia recurrence on clinical examination. Each patient’s abdominal wall was also assessed with using ultrasonography at 24 mo to detect recurrences. All data were examined with SPSS ver 18.0.

RESULTS

Over the 5-year study period, there were 52 patients treated for ventral hernias at this institution. Four patients were excluded and there were 48 in the final study sample, at a mean age of 56 years (range 28-80). The mean maximal diameter of the hernia defect was 7 cm (range 5-12 cm). There were 5 (10.4%) seromas and 1 recurrence (2.1%) at a mean of 36 mo follow-up.

CONCLUSION

The authors recommend the modified RMR as an acceptable alternative to mesh repair of ventral hernias. The seroma rate can be further reduced with routine use of drains. The modified RMR also has the benefit of eliminating all mesh-specific complications.

Analgesia in patients with adhesion-related chronic abdominal and pelvic pain after surgery: a systematic review

BACKGROUND AND OBJECTIVE

Adhesions are the most common cause of chronic abdominal pain after surgery. Surgical adhesiolysis can relieve symptoms in selected patients, but many require other treatments. The aim of this study is to evaluate analgesic treatments other than abdominal surgery in chronic pain related to adhesions.

DATABASE AND DATA TREATMENT

A search was conducted in PubMed, Embase, and Central. Studies with patients suffering from chronic postoperative pain related to adhesions and undergoing all types' analgesic treatment were included. The primary outcome was the number of patients who improved in pain at long-term follow-up (at least 1 year). Secondary outcomes included improvement in pain at 3 months follow-up, quality of life, and physical functioning.

RESULTS

Searches identified 3022 citations. Four studies were included, one trial, one cohort study, and two case reports. The primary outcome was not reported. In a small trial (n = 18) pregabalin tended to have a benefit over placebo improving pain at 3 months. In the cohort study, 17 patients with chronic pelvic pain underwent a trial of sacral nerve stimulation. Eight patients who responded positively received an implanted device for continuous modulation, reporting sustainable improvement during follow-up (range: 6-36 months). One case report described improved pain at 6 months with trans-abdominis plane stimulation. The second report described improvement of physical function with manual therapy at long-term follow-up.

CONCLUSIONS

Low level of evidence is available regarding analgesic treatments of chronic abdominal and pelvic pain related to adhesions. The benefit of pregabalin is doubtful; nerve modulation is promising in a selected group.HighlightsAdhesions are a frequent cause of chronic abdominal and pelvic pain after surgery.Many patients are not good candidates for surgery (Adhesiolysis) or have relapses of pain.There is an important knowledge gap regarding non-surgical analgesic treatment.Analgesia in adhesion-related chronic abdominal pain after surgery.

The technology of artificial pneumoperitoneum CT and its application in diagnosis of abdominal adhesion

To retrospectively analyze the use of artificial pneumoperitoneum in CT scans, to explore its operation methods and technical points, and to lay the foundation for the widespread application of artificial pneumoperitoneum in CT. A total of 331 patients who underwent artificial pneumoperitoneum with CT angiography from January 1, 2013, to November 1, 2019, were recruited. All patients underwent standardized artificial pneumoperitoneum in the horizontal, left and right lateral, and prone positions during CT thin-layer scans of the abdomen and 3D reconstruction. Taking the surgical results as the gold standard, and using kappa test to verify the consistency of surgical results and imaging results. In all 331 patients, 43 patients had a normal peritoneal space, and 288 patients had an abnormal peritoneal space. And only 22 patients developed complications of subcutaneous emphysema, accounting for 6.6% of all 331 patients. In terms of the postoperative results, 28 were normal, and 303 were abnormal. The sensitivity, specificity and accuracy of CT diagnosis of abdominal adhesions using artificial pneumoperitoneum were 100%, 95.04%, and 95.46%, respectively. According to the Kappa consistency test, the imaging diagnosis from the CT scan with artificial pneumoperitoneum had a high consistency with the surgical results (kappa = 0.796, P < 0.05). The technique of artificial pneumoperitoneum CT is safe, reliable, highly practical, and proficient for obtaining good imaging results. It provides a good imaging basis for the diagnosis of intra-abdominal diseases, especially intra-abdominal adhesions.

The role of non-invasive imaging techniques in detecting intra-abdominal adhesions: a systematic review

BACKGROUND

Intra-abdominal adhesions after surgery are highly prevalent. Adhesions implicate complications during subsequent surgery and can cause chronic abdominal pain. The objective of this review was to investigate the usefulness of non-invasive diagnostic methods for detection of adhesions.

METHODS

We searched the electronic databases: MEDLINE, Embase, and The Cochrane Central Register of Controlled Trials for studies investigating the use of non-invasive diagnostic imaging techniques for detecting adhesions. Main outcome was the sensitivity and specificity of each technique. We used the Quality Assessment of Diagnostic Accuracy studies tool to assess bias.

RESULTS

In total, 25 studies were included: 18 using ultrasound (US), 5 using magnetic resonance imaging (MRI), 1 using computed tomography (CT), and 1 using both US and MRI. A total of 2195 patients were included. Overall accuracy ranged between 76 and 100% for US studies and between 79 and 90% for MRI and was 66% for CT. Sensitivity ranged between 21 and 100% for US and between 22 and 93% for MRI and was 61% for CT. Specificity was 32-100% for US, 25-93% for MRI, and 63% for CT. Bias analysis revealed that in most studies, investigators were blinded to the reference standard but not to the index test and 11 of 25 studies had a high risk of selection bias.

CONCLUSIONS

Currently, abdominal US can be used to determine the presence of adhesions between bowel and the abdominal wall. MRI is also an accurate diagnostic modality and can in addition visualize adhesions between viscera, however, with a tendency to over diagnose adhesions. There is insufficient evidence to support CT as a diagnostic modality for adhesions.

Adhesion awareness in 2016: An update of the national survey of surgeons

BACKGROUND AND AIMS

Adhesions, that form in 60-80% of all abdominal operations, can cause complications such as chronic abdominal pain, small-bowel obstruction, female infertility, and the need for adhesiolysis in future surgeries. Our 2010 Adhesion Awareness survey demonstrated that despite the huge clinical impact of adhesions; adhesion-related complications were seldom mentioned in the informed consent. Six years later, a follow-up survey was conducted to assess the progress on awareness on adhesion-related complications in the Netherlands.

MATERIAL AND METHODS

The 2010 Adhesion Awareness survey was repeated after a literature update. The knowledge regarding adhesions; the use of anti-adhesive agents and involvement in the informed consent process were assessed. Surgeons and surgical trainees were contacted by e-mail. The data was analysed using a Chi-square or Mann-Whitney U test and corrected for multiple testing.

RESULTS

The response rate was 32.6%, similar to the survey in 2010 (34.4%). 88.1% agreed with the clinical relevance of adhesions, comparable to 2010 (89.8%). The score on the knowledge test was 38.8% (2010: 37.2%). Involvement of adhesion-related complications in the informed consent process increased, although 32.5% almost never mentions adhesions. In 2016, 42.4% reported a correct occurrence of bowel lesions during adhesiolysis, higher than in 2010 (P<0.001).

CONCLUSIONS

The adhesion awareness did not increase in six years, despite the efforts made. However, an increased awareness regarding adhesiolysis related complications was detected. Improvement of knowledge and behavior is essential to narrowing the gap between the impact of adhesions as a major complication of abdominal surgery and the limited adhesion awareness.

A Shared Decision Approach to Chronic Abdominal Pain Based on Cine-MRI: A Prospective Cohort Study

OBJECTIVES

Chronic abdominal pain develops in 11-20% of patients undergoing abdominal surgery, partly owing to post-operative adhesions. In this study we evaluate results of a novel diagnostic and therapeutic approach for pain associated with adhesions.

METHODS

Prospective cohort study including patients with a history of abdominal surgery referred to the outpatient clinic of a tertiary referral center for the evaluation of chronic abdominal pain. Subgroups were made based on outcome of adhesion mapping with cine-MRI and shared decision making. In operatively managed cases, anti-adhesion barriers were applied after adhesiolysis. Long-term results for pain were evaluated by a questionnaire.

RESULTS

A total of 106 patients were recruited. Seventy-nine patients had adhesions on cine-MRI, 45 of whom underwent an operation. Response rate to follow-up questionnaire was 86.8%. In the operative group (Group 1), the number of negative laparoscopies was 3 (6%). After a median of 19 (range 6-47) months follow-up, 80.0% of patients in group 1 reported improvement of pain, compared with 42.9% in patients with adhesions on cine-MRI who declined surgery (group 2), and 26.3% in patients with no adhesions on cine-MRI (group 3), P = 0.002. Consultation of medical specialists was significantly lower in group 1 compared with groups 2 and 3 (35.7 vs. 65.2 vs. 58.8%; P = 0.023).

CONCLUSION

We demonstrate long-term pain relief in two-thirds of patients with chronic pain likely caused by adhesions, using cine-MRI and a shared decision-making process. Long-term improvement of pain was achieved in 80% of patients who underwent surgery with concurrent application of an anti-adhesion barrier.

The feasibility and efficacy of pure laparoscopic repeat hepatectomy

BACKGROUND

Repeat hepatectomy is often required for hepatocellular carcinoma and metastatic tumors. However, this procedure is technically challenging, so laparoscopic repeat hepatectomy (LRH) has not been widely adopted. The aim of this study was to evaluate the feasibility and efficacy of LRH compared with open repeat hepatectomy (ORH) and laparoscopic primary hepatectomy (LPH).

METHODS

We introduced laparoscopic hepatectomy at our institution in April 2014. We performed 127 LPH (LPH group) and 33 LRH procedures (LRH group) from April 2014 to April 2017; 37 patients underwent ORH from January 2010 to April 2017 (ORH group). This study retrospectively compared the patient characteristics and short-term outcomes of the LRH and ORH groups as well as the LRH and LPH groups.

RESULTS

There were no conversions to open surgery in the LRH group. In comparing the LRH and ORH groups, there were no significant differences in patient characteristics except for the type of approach to the previous hepatectomy (p = 0.004) and indocyanine green retention rate at 15 min (median 12.5 vs. 8.75%, p = 0.026). The LRH group had less blood loss (median 30 mL vs. 652 mL; p < 0.001), less intraoperative transfusion (6.1 vs. 32.4%; p = 0.006), and shorter postoperative hospital stays (median 6.5 days vs. 9.0 days; p < 0.001). There were no differences with regard to operation time, severe postoperative complications, and mortality. In comparing the LRH and LPH groups, there was a significant difference only in past history of abdominal surgery (100 vs. 61.4%; p < 0.001). In the short-term outcomes, the postoperative hospital stay was significantly shorter in the LRH group (median 6.5 days vs. 7 days; p = 0.033), and the other results were comparable between the two groups.

CONCLUSIONS

LRH is feasible and useful for repeat hepatectomy, achieving good short-term outcomes.

Role of Minimally Invasive Surgery in the Reoperative Abdomen or Pelvis

Laparoscopy has become widely accepted as the preferred surgical approach in the management of benign and malignant colorectal diseases. Once considered a relative contraindication in patients with prior abdominal surgery (PAS), as surgeons have continued to gain expertise in advanced laparoscopy, minimally invasive approaches have been increasingly incorporated in the reoperative abdomen and pelvis. Although earlier studies have described conversion rates, most contemporary series evaluating the impact of PAS in laparoscopic colorectal resection have reported equivalent conversion and morbidity rates between reoperative and non-reoperative cases, and series evaluating the impact of laparoscopy in reoperative cases have demonstrated improved short-term outcomes with laparoscopy. The data overall highlight the importance of case selection, careful preoperative preparation and planning, and the critical role of surgeons' expertise in advanced laparoscopic techniques. Challenges to the widespread adoption of minimally invasive techniques in reoperative colorectal cases include the longer learning curve and longer operative time. However, with the steady increase in adoption of minimally invasive techniques worldwide, minimally invasive surgery (MIS) is likely to continue to be applied in the management of increasingly complex reoperative colorectal cases in an effort to improve patient outcomes. In the hands of experienced MIS surgeons and in carefully selected cases, laparoscopy is both safe and efficacious for reoperative procedures in the abdomen and pelvis, with measurable short-term benefits.

Adhesions to Mesh after Ventral Hernia Mesh Repair Are Detected by MRI but Are Not a Cause of Long Term Chronic Abdominal Pain

Aim. The aim of the present study was to perform MRI in patients after ventral hernia mesh repair, in order to evaluate MRI's ability to detect intra-abdominal adhesions. Materials and Methods. Single-center long term follow-up study of 155 patients operated for ventral hernia with laparoscopic (LVHR) or open mesh repair (OVHR), including analyzing medical records, clinical investigation with patient-reported pain (VAS-scale), and MRI. MRI was performed in 124 patients: 114 patients (74%) after follow-up, and 10 patients referred for late complaints after ventral mesh repair. To verify the MRI-diagnosis of adhesions, laparoscopy was performed after MRI in a cohort of 20 patients. Results. MRI detected adhesions between bowel and abdominal wall/mesh in 60% of the patients and mesh shrinkage in 20-50%. Adhesions were demonstrated to all types of meshes after both LVHR and OVHR with a sensitivity of 70%, specificity of 75%, positive predictive value of 78%, and negative predictive value of 67%. Independent predictors for formation of adhesions were mesh area as determined by MRI and Charlson index. The presence of adhesions was not associated with more pain. Conclusion. MRI can detect adhesions between bowel and abdominal wall in a fair reliable way. Adhesions are formed both after open and laparoscopic hernia mesh repair and are not associated with chronic pain.

Efficacy of laparoscopic liver resection in colorectal liver metastases and the influence of preoperative chemotherapy

Background

Since 1993, we have performed minimally invasive laparoscopic liver resection (LLR) to treat malignant liver cancer, including colorectal liver metastases (CLM). However, further studies are needed to accumulate sufficient evidence on the oncological outcome of LLR for CLM.

Methods

To elucidate the efficacy of LLR for CLM, this study comparatively analyzed the invasiveness and short-term prognosis of LLR (n = 43 cases) and open liver resection (OR) (n = 62 cases) performed for CLM after 2006 and also investigated the safety of LLR following chemotherapy.

Results

Compared with the OR group, the LLR group had significantly less blood loss (P < 0.001) and a shorter hospital stay (P < 0.001). The E-PASS scoring system was used to compare surgical invasiveness, and although the preoperative risk score did not differ between the groups, the surgical stress score and comprehensive risk score were significantly lower in the LLR group (P < 0.001). Concerning the survival rate and disease-free survival rate, there were no significant differences between procedures. However, more clinical cases and longer follow-up periods are needed to reach a definitive conclusion.

Preoperative hemanalysis, intraoperative bleeding, complications, and postoperative length of stay did not differ significantly between LLR patients with preoperative chemotherapy and those with surgery alone, indicating no adverse effects of chemotherapy.

Conclusions

LLR can be an effective minimally invasive surgery in CLM patients receiving both perioperative chemotherapy and surgery. Because LLR is comparable with OR with regard to short-term oncological outcome, LLR may be a valuable option for CLM.

Imaging visceral adhesion to polymeric mesh using pneumoperitoneal-MRI in an experimental rat model

BACKGROUND

Intraperitoneal mesh implantation is often associated with formation of adhesion to the mesh. This experimental study examines the potential of minimally invasive pneumoperitoneal-MRI to assess these adhesions in a preclinical context.

METHODS

Uncoated polyethylene terephthalate meshes were placed intraperitoneally in rats, in regard to the caecum previously scraped to promote petechial bleeding and subsequent adhesions. Examinations were performed 2-weeks post mesh implantation using a rodent dedicated high field MRI. Respiratory-triggered T2-weighted images were acquired prior to and after intraperitoneal injection of ~8-10 mL gas to induce a mechanical stress on the abdominal wall.

RESULTS

Adhesions are occasionally seen in sham-operated rats as opposed to rats receiving polyethylene terephthalate meshes. On high-resolution images, meshes can be detected due to their characteristic net shape. However, evidence of adherence is only found if intraperitoneal gas injection is performed, when a ~1-cm elevation of the abdominal wall is observed. When adherence occurs between the mesh and the caecum, the latter remains in contact with the wall. Looser adherences between visceral tissue and meshes are also observed.

CONCLUSIONS

T2-weighted pneumoperitoneal-MRI is a powerful tool for assessing adherence after intraperitoneal mesh implantation. According to the mini-invasive procedure adopted here, this approach may allow a temporal follow-up of adherence fate.

Preoperative nomogram to predict risk of bowel injury during adhesiolysis

BACKGROUND

Inadvertent bowel injury during adhesiolysis is a major cause of increased morbidity and mortality following abdominal surgery. Identification of risk factors predicting this complication would guide preoperative counselling and surgical decision-making. The aim of this study was to identify predictive preoperative factors for inadvertent bowel injury occurring during adhesiolysis.

METHODS

All patients undergoing elective abdominal surgery between June 2008 and June 2010 were evaluated prospectively as part of the LAPAD study. Data on adhesiolysis and inadvertent organ injury were gathered by direct observation during operation. Univariable logistic regression was used to investigate factors that increased the risk of inadvertent bowel injury. Independent predictors of bowel injury were identified using multivariable logistic regression and used to create a clinical nomogram.

RESULTS

Of 715 patients eligible for analysis, 48 (6.7 per cent) had inadvertent bowel injuries. In 42 patients the defect was detected during operation and in nine at a later time (3 patients had both). Bowel resection was required for almost two-thirds of the enterotomies. The number of previous laparotomies, anatomical site of the operation, presence of bowel fistula and laparotomy via a pre-existing median scar were independent predictors of bowel injury. A clinical scoring system was constructed using a nomogram incorporating these risk factors; this had a predictive discrimination, measured as the area under the receiver operating characteristic curve, of 0.85.

CONCLUSION

A nomogram based on four independent factors predicted the risk of inadvertent bowel injury.

REGISTRATION NUMBER

NCT01236625 (http://www.clinicaltrials.gov).

Malpractice claims and avoidance of complications in endoscopic surgery

Laparoscopy has become a valuable tool for the gynaecologist in the diagnosis and treatment of a variety of gynecological disorders. Its quicker recovery time and other advantages has benefitted countless women. Laparoscopic procedures, however, have their own associated risks and complications, and the surgeon must become thoroughly familiar with these. This awareness will help reduce patient morbidity and mortality, and potentially avoid the stress and burden of litigation, which has been increasing in recent years. Complications of gynaecologic laparoscopy include entry-related problems, and injuries to bowel, urinary tract, blood vessels, and nerves. Although some of these complications have been well described, some have emerged recently in relation to new technology and techniques. In this chapter, we discuss some of the complications of endoscopic surgery, including their incidence, prevention, and medico-legal implications, and provide a brief overview of their management.

Accuracy of transthoracic ultrasound for the detection of pleural adhesions

OBJECTIVES

In the era of minimally invasive surgery, preoperative detection of pleural adhesions can be very useful for the assessment of surgical approach, because pleural adhesions are the main contraindication to video-assisted thoracoscopy. The aim of this study was to assess the sensitivity and specificity of transthoracic ultrasound in the detection of pleural adhesions prior to thoracic surgery.

METHODS

From February 2010 to January 2011, 142 consecutive patients (male, 98; female, 44; age range, 36-83 years, mean age, 63.4 years) undergoing surgical thoracic intervention (except for pneumothorax) were preoperatively scanned by two different surgeons. According to thoracic wall projections of lung segments, we created a nine-region topographic map, in which every pulmonary area was scanned to assess the presence or the absence of 'gliding sign' (lesion-by-lesion analysis). During operations the surgeon, blinded to the prediction, confirmed or excluded each suspected adhesion or documented other adhesions not previously identified.

RESULTS

A total of 1192 predictions were made. Ultrasound predictions were confirmed 1124 times and refuted 68 times. Sensitivity was 80.6% (95% confidence interval, 0.740-0.872) and specificity 96.1% (95% confidence interval, 0.949-0.973). The positive predictive value was 73.2% and the negative predictive value was 97.4%.

CONCLUSIONS

Transthoracic ultrasound is an effective method for predicting pleural adhesions before thoracic surgery in experienced hands. Its safety, feasibility and low cost make it a useful method for the planning of minimally invasive surgical interventions.

[Postoperative abdominal adhesions and their prevention in gynaecological surgery: II. How can they be prevented?]

This paper is the second of a two-part publication. The initial paper provided a comprehensive overview of the evidence on adhesions to allow gynaecological surgeons to be best informed on adhesions, their development, impact on patients, health systems and surgical outcomes. There is rising evidence that surgeons can take important steps to reduce the burden of adhesions. In this second paper, we review the various strategies to reduce the impact of adhesions, improve surgical outcomes and provide some practical proposals for action on adhesions. As well as improvements in surgical technique, developments in adhesion-reduction strategies and new agents offer a realistic possibility of reducing adhesion formation and improving outcomes for patients. They should be considered for use particularly in high-risk surgery and in patients with adhesiogenic conditions. Further research into new strategies to prevent adhesions more effectively through an improved surgical environment, new and combination devices and pharmacological agents should be encouraged. Formal recommendations would ensure better prioritisation of adhesion-reduction within the French health system. Patients should also be better informed of the risks of adhesions.