Systematic review of internal hernia formation following laparoscopic left nephrectomy.

This is the first identifiable description where internal herniation following laparoscopic left nephrectomy necessitated gangrenous small intestinal resection; similar cases and prevention are discussed.

Endoscopic transanal rectal mucosal ablation in the surgical treatment of ulcerative colitis: preliminary results of a novel technique.

PURPOSE: We describe a new technique that endoscopically eradicates rectal stump mucosa after total colectomy for ulcerative colitis. METHODS: Seven patients (5 males; median age, 56 (range, 36-72) years) underwent attempted endoscopic transanal rectal mucosal ablation using the 28-French-gauge urologic resectoscope, either at the time of total colectomy and ileostomy for failed medical therapy (5 patients) or as an alternative to completion proctectomy (2 patients) with rectal stump discharge. All had declined restorative proctocolectomy. Clinical, endoscopic, and histologic follow-up was undertaken during a mean of 15 (range, 3-28) months. RESULTS: The operative technique evolved during these cases; mucosal ablation was successfully performed leaving a denuded muscular rectal tube in situ in six patients. Mean operative time was 45 minutes. Postoperative endoscopic surveillance has not demonstrated any viable rectal mucosa in these six patients, with only granulation tissue detected histologically. Narrowing of the rectal tube has occurred in two patients. Although all patients report insignificant rectal discharge, urinary and sexual function have remained unchanged. CONCLUSIONS: Diathermy ablation of the rectal mucosa via endoscopic transanal rectal mucosal ablation avoids the complications of pelvic dissection and might offer an effective alternative to proctectomy for ulcerative colitis.

Pilot study: fibrin sealant in anal fistula model.

PURPOSE: The aim of this study was to investigate the failure of fibrin sealant treatment for fistula-in-ano in an experimental porcine model and to determine histologic changes associated with the sealant and setons. METHODS: Three surgically created fistulas were treated by seton drainage in each of eight male pigs. After 26 days, magnetic resonance imaging was performed and setons were removed. Two pigs were killed as controls for stereologic histologic fistula track assessment. In six, fistulas were curetted, and in four the fistulas were treated with fibrin sealant. In these four sealant and two seton pigs, magnetic resonance imaging was repeated a median of 47.5 days after fistula formation. The pigs were killed and stereologic histologic fistula track examination was performed to determine granulation tissue and fistula lumen volumes. These values were compared among control, seton, and sealant groups over time, and related to fistula volumes derived from magnetic resonance imaging. RESULTS: Sealant was not visible microscopically within tracks, although some sections revealed a foreign body-type reaction. On stereologic assessment, granulation tissue volumes were smaller in sealant and seton groups than in controls (median, 88 vs. 187 vs. 453 mm3, respectively; P = 0.002) and decreased over time (median, 408 and 152 mm3 (Day 42) vs. 88 and 75 (Day 53), respectively; P = 0.002). Fistula lumen (P < 0.001), and granulation tissue combined with fistula lumen volumes (P = 0.002) were similarly smaller. Magnetic resonance imaging of fistula intensity was less in the sealant group than in the seton group and controls (mean, 777 vs. 978 vs. 1214 units/mm2, P = 0.003). Magnetic resonance imaging fistula volumes were least in sealant and seton groups vs. controls (P = 0.024), decreasing significantly in the sealant group over time (P = 0.018). No direct relationship was found between imaging and histologic volumes. CONCLUSIONS: In an experimental porcine model of anal fistula, granulation tissue was still present, albeit diminished, following track curettage combined with seton or sealant therapy, and was minimal in the sealant group, confirming some benefit from this procedure. Eradication of all longstanding granulation tissue may ensure complete success of fibrin sealant therapy.

Experimental model of fistula-in-ano.

PURPOSE: This study was designed to create and evaluate an experimental porcine model of fistula-in-ano. METHODS: Initial cadaveric dissection enabled refinement of the technique for fistula formation and histoanatomical study of the porcine anal canal. Subsequently, three surgically created fistulas were treated by seton drainage in each of eight male pigs (weight, 38-41 kg). After 26 days, magnetic resonance imaging at 1.5 Tesla was performed and setons removed under general anesthesia, enabling clinical and microbiologic track assessment. Two pigs were killed for histologic fistula track assessment. RESULTS: Histoanatomical assessment noted a rudimentary internal anal sphincter, together with structures resembling anal glands. Artificial fistulas persisted during seton drainage and were more often associated with fecal than skin-derived organisms compared with both perineal and anal canal swabs (P = 0.002). All six fistulas assessed histologically had a lumen, and abundant surrounding granulation tissue similar to that seen in human fistula-in-ano. Epithelialization was not evident in any track. Fistulas were visualized as high signal tracks using magnetic resonance imaging. CONCLUSIONS: Porcine anal anatomy resembles that of humans, and an experimental model proved suitable when assessed by magnetic resonance imaging, microbiology, and histologically, which demonstrated abundant granulation tissue. This model could be further used to investigate fistula treatments.

Value of hydrogen peroxide enhancement of three-dimensional endoanal ultrasound in fistula-in-ano.

PURPOSE: The aim of this prospective study was to compare the accuracy of three-dimensional endoanal ultrasound with that of hydrogen peroxide enhanced three-dimensional endoanal ultrasound in diagnosing recurrent or complex fistula-in-ano. METHODS: Three-dimensional endoanal ultrasound reconstructions were performed before and after hydrogen peroxide enhancement in 19 patients with suspected recurrent or complex fistula-in-ano. Two experienced observers derived a consensus fistula classification after a blinded random review of the data sets. The accuracy of three-dimensional endoanal ultrasound and that of hydrogen peroxide-enhanced three-dimensional endoanal ultrasound were compared with a reference standard derived from surgical findings and magnetic resonance imaging and modified by outcome over a median follow-up of 13 months. RESULTS: Patients had previously undergone a median of three fistula operations. Four had Crohn's disease. There were 21 internal openings and primary tracks in 19 patients: 1 superficial, 1 intersphincteric, 18 transsphincteric, and 1 extrasphincteric. Fourteen patients had 19 secondary tracks. Both techniques detected fistula tracks in 19 of 21 (90 percent) patients. There was no significant difference between three-dimensional endoanal ultrasound and hydrogen peroxide-enhanced three-dimensional endoanal ultrasound in classifying internal openings (19/21 (90 percent) vs. 18/21 (86 percent)), primary tracks (17/21 (81 percent) vs. 15/21 (71 percent)), or secondary tracks (13/19 (68 percent) vs. 12/19 (63 percent)). Where three-dimensional endoanal ultrasound correctly detected an internal opening, gas from hydrogen peroxide enhancement was present in 8 of 18 (44 percent) studies. Similarly, gas made primary tracks more conspicuous in 6 of 19 (32 percent) and secondary tracks in 6 of 13 (46 percent) of those detected. CONCLUSIONS: In recurrent or complex fistula-in-ano, endoanal ultrasound proved more accurate for detecting primary tracks and internal openings than for detecting extensions. Hydrogen peroxide improved conspicuity of some tracks and internal openings and so may be helpful in difficult cases, although no overall diagnostic benefit was demonstrated.

Clinical examination, endosonography, and MR imaging in preoperative assessment of fistula in ano: comparison with outcome-based reference standard.

PURPOSE: To prospectively evaluate the relative accuracy of digital examination, anal endosonography, and magnetic resonance (MR) imaging for preoperative assessment of fistula in ano by comparison to an outcome-derived reference standard. MATERIALS AND METHODS: Ethical committee approval and informed consent were obtained. A total of 104 patients who were suspected of having fistula in ano underwent preoperative digital examination, 10-MHz anal endosonography, and body-coil MR imaging. Fistula classification was determined with each modality, with reviewers blinded to findings of other assessments. For fistula classification, an outcome-derived reference standard was based on a combination of subsequent surgical and MR imaging findings and clinical outcome after surgery. The proportion of patients correctly classified and agreement between the preoperative assessment and reference standard were determined with trend tests and kappa statistics, respectively. RESULTS: There was a significant linear trend (P < .001) in the proportion of fistula tracks (n = 108) correctly classified with each modality, as follows: clinical examination, 66 (61%) patients; endosonography, 87 (81%) patients; MR imaging, 97 (90%) patients. Similar trends were found for the correct anatomic classification of abscesses (P < .001), horseshoe extensions (P = .003), and internal openings (n = 99, P < .001); endosonography was used to correctly identify the internal opening in 90 (91%) patients versus 96 (97%) patients with MR imaging. Agreement between the outcome-derived reference standard and digital examination, endosonography, and MR imaging for classification of the primary track was fair (kappa = 0.38), good (kappa = 0.68), and very good (kappa = 0.84), respectively, and fair (kappa = 0.29), good (kappa = 0.64), and very good (kappa = 0.88), respectively, for classification of abscesses and horseshoe extensions combined. CONCLUSION: Endosonography with a high-frequency transducer is superior to digital examination for the preoperative classification of fistula in ano. While MR imaging remains superior in all respects, endosonography is a viable alternative for identification of the internal opening.

MRI of fistula in ano: inter- and intraobserver agreement and effects of directed education.

OBJECTIVE: Preoperative MRI of fistula in ano is becoming more common. This prospective study aimed to determine if a significant difference occurred in interpretation between one expert and one novice observer and to assess inter- and intraobserver agreement after both observers underwent a period of directed education. SUBJECTS AND METHODS. An outcome-derived reference standard was defined in 100 patients with suspected fistula in ano via a combination of preoperative MRI, surgical findings, and clinical outcome. The performances of a single expert and a single novice interpreter were compared with this reference standard both before and after a period of directed education, and inter- and intraobserver agreement was determined. RESULTS: Initially the expert correctly classified significantly more fistulas than the novice (85% vs 63%, p = 0.024), but after directed education there was no significant difference, with good agreement for both the classification of the primary track (kappa = 0.71) and identification of extensions (k = 0.61). Intraobserver agreement was very good for the expert (kappa = 0.92) and novice (kappa = 0.88) for classification of the primary track and good (kappa = 0.64 and 0.74, respectively) for identification of extensions. CONCLUSION: The diagnostic accuracy for fistula in ano classification using MRI was significantly higher for one expert than for one novice, though this was rectified by a short period of directed education.

Efficacy of fibrin sealant in the management of complex anal fistula: a prospective trial.

PURPOSE: A prospective trial was conducted to establish long-term healing of complex idiopathic anorectal fistula, without extension, after fibrin glue treatment, with clinical assessment and magnetic resonance imaging to determine tract healing. METHODS: Twenty-two patients undergoing glue instillation after fistula curettage and irrigation were followed up for a median of 14 months. Clinical assessment, short tau inversion recovery sequence magnetic resonance imaging, and combined short tau inversion recovery and dynamic contrast-enhanced magnetic resonance imaging were performed at a median of three months postoperatively, and their ability to predict outcome in the presence of early skin healing was determined. RESULTS: Of 22 patients, 19 (86.5 percent) had transsphincteric fistulas, 1 (4.5 percent) had a suprasphincteric fistula, 1 (4.5 percent) had an extrasphincteric fistula, and 1 (4.5 percent) had a rectovaginal fistula. None had clinical or radiologic evidence of secondary extension. Despite skin healing in 17 (77 percent) of 22 patients at a median of 14 days after treatment, only 3 (14 percent) remained healed at 16 months. Magnetic resonance imaging with short tau inversion recovery sequences in combination with dynamic contrast-enhanced magnetic resonance imaging predicted outcome in all 10 assessments (100 percent), compared with short tau inversion recovery sequence alone in 16 (94 percent) of 17 assessments or clinical examination in 12 (71 percent) of 17 (P = 0.02). CONCLUSIONS: The success rate of fibrin glue application for complex anorectal fistulas without extension is 14 percent. Magnetic resonance imaging predicts outcome at an earlier stage than clinical examination.

Diverticulitis.

Although diverticular disease is common in the Western world, few patients who develop diverticulitis require surgery. The use of appropriate broad-spectrum antibiotics in uncomplicated diverticulitis can be an effective treatment, avoiding the need for acute surgical intervention. In the event of surgery the choice of procedure is dictated by the degree of contamination and the expertise of the operating surgeon. This chapter will outline the modern management of diverticulitis, from steps in diagnosis to different surgical options in each clinical scenario, thus aiding clinicians on a practical level.