405 Radiological Analysis of Gentamicin Eluting Synthetic Bone Graft Substitute Used in The Management of Gustilo IIIB Open Fractures

Background

Management of traumatic bone void associated with Gustilo IIIB open fractures is challenging. Gentamicin eluting synthetic bone graft substitute (Cerament-G) had been recently utilised for the management of patients with these injuries. This study aims to assess radiological signs of Cerament-G remodelling.

Method

Retrospective data analysis of all patients admitted to our unit with IIIB open fractures who had Cerament-G applied as avoid filler. Postoperative radiographic images of the fracture site at 6-weeks, 3-months, 6-months and at the last follow-up were reviewed. The radiological signs of Cerament-G integration, percent of void healing, and bone cortical thickness at the final follow-up were assessed.

Results

34 patients met our inclusion criteria, mean age: 42 years. Mean follow-up time was 20 months. 59% of patients had excellent (>90%) void filling, 26.4% of patients had 50-90% void filling, and 14.6% had < 50% void filling. Normal bone cortical thickness was restored on AP and Lateral views in 55.8% of patients. No residual Cerement-G was seen on X-rays at the final follow-up in any of the patients.

Conclusions

Our results showed successful integration of Cerament-G with excellent void filling and normal cortical thickness achieved in more than half of the patients.

Subtypes of constipation predominant irritable bowel syndrome based on rectal perception

BACKGROUND

Patients who complain of constipation can be divided into those who have lost the natural call to stool, but develop abdominal discomfort after several days without a bowel movement (no urge); and those who experience a constant sensation of incomplete evacuation (urge).

AIMS

To determine whether the two groups differ in symptoms, colonic transit, and perceptual responses to controlled rectal distension.

METHODS

Forty four patients with constipation were evaluated with a bowel symptom questionnaire, colonic transit (radiopaque markers), and rectal balloon distension. Stool (S) and discomfort (D) thresholds to slow ramp (40 ml/min) and rapid phasic distension (870 ml/min) were determined with an electronic distension device. Fifteen healthy controls were also studied.

RESULTS

All patients had Rome positive irritable bowel syndrome (IBS); 17 were no urge and 27 urge. Mean D threshold to phasic rectal distensions was 28 (3) mm Hg in no urge, 27 (3) mm Hg in urge (NS), but higher in the control group (46 (2) mm Hg; p < 0.01). Sixty seven per cent of no urge and 69% of urge were hypersensitive for D. Slow ramp distension thresholds were higher in no urge (S: 26 (3); D: 45 (4) mm Hg) compared with urge (S: 16 (2); D: 31 (3) mm Hg; p < 0.01), or with controls (S: 15 (1); D: 30 (3); p < 0.01).

CONCLUSIONS

Hyposensitivity to slow rectal distension is found in patients with IBS who complain of constipation and have lost the call to stool even though their sensitivity to phasic distension is increased.

Characterization of afferent mechanisms in ileoanal pouches

OBJECTIVES

The afferent innervation of ileoanal pouches plays an important role in perception and in reflex regulation of pouch function. We aimed to characterize afferent nerve function in ileoanal pouches and thereby explain the clinical presentation of patients with such pouches.

METHODS

In eight patients who underwent surgery for active ulcerative colitis, perception of balloon distention of the pouch was measured using an electronic visceral distention device. In addition, pouch compliance and ileoanal reflex function were determined. Studies were performed during the initial stage of pouch creation (pouch without connection to proximal ileum, study 1) and a mean of 6.6 wk (range = 2-12 wk) after the second stage of the surgery (proximal ileum in continuity with the pouch, study 2). Nine normal volunteers made up the control group.

RESULTS

When expressed as intrapouch pressure, thresholds for stool and discomfort sensations were similar in patients with a pouch and controls. However, during ramp distention, patients with a pouch had a lower volume threshold for stool sensation (143 +/- 45 ml vs 300 +/- 30 ml, p = 0.009). The initial sensation of discomfort was experienced in the perineum at the S3 dermatome in all eight patients. At higher distention pressures, all patients with a pouch referred sensations to the abdomen, as opposed to only one of nine controls with such a referral pattern (p < 0.0001). Pouch compliance was markedly reduced during study 1 but normalized after continuity was established with the proximal ileum. Anal sphincter function in patients with a pouch was similar to that in controls.

CONCLUSIONS

Afferent pathways from both the ileum and rectum play a role in the mediation of sensations during mechanical distention of the ileoanal pouch and can explain a number of clinical features of patients with a pouch. The thresholds for activation of these pathways are not significantly altered by long-standing colorectal inflammation or by creation of the ileoanal pouch. Continuity with the proximal ileum significantly influences pouch compliance.

Rectal afferent function in patients with inflammatory and functional intestinal disorders

Chronic symptoms of abdominal pain and discomfort are reported by patients with inflammatory bowel disease (IBD) and functional disorders of the gut, such as Irritable Bowel Syndrome (IBS). It has recently been suggested that transient inflammatory mucosal events may result in long-lasting sensitization of visceral afferent pathways. To determine the effect of recurring intestinal tissue irritation on lumbosacral afferent pathways, and to identify a plausible mechanism that could account for the overlap in symptomatology between IBD and IBS, we compared rectal afferent mechanisms in patients with Crohn's disease (inflammation limited to the ileum) with those observed in patients with diarrhea-predominant IBS. Continuous volume ramp and phasic pressure step distension of a rectal balloon were performed in 9 healthy male control subjects, 12 male patients with isolated ileal Crohn's disease and 9 male patients with diarrhea-predominant IBS using an electronic visceral stimulation device. The response of rectal afferents to distension was evaluated by measuring thresholds for the perception of physiological (stool) and aversive (discomfort) sensations, viscerosomatic referral patterns, skin conductance responses, receptive relaxation, and rectoanal reflex responses. In response to slow ramp distension, thresholds for aversive sensations were significantly higher in Crohn's disease patients, but similar between the two other groups. In response to rapid phasic distension, IBS patients reported discomfort at lower distension pressures, while all other thresholds were similar between groups. Skin conductance responses to aversive distension were greatly reduced in Crohn's disease patients while IBS patients had greater responses when compared to normals. Changes in viscerosomatic referral patterns and receptive relaxation rate were similar in Crohn's disease and IBS patients. These findings demonstrate that chronic ileal inflammation is associated with increased thresholds for discomfort and greatly diminished systemic autonomic reflex responses. In contrast, IBS patients show lowered thresholds for discomfort associated with increased autonomic responses. The findings in Crohn's patients may result from descending bulbospinal inhibition of sacral dorsal horn neurons in response to chronic intestinal tissue irritation.

Altered rectal perception is a biological marker of patients with irritable bowel syndrome

BACKGROUND & AIMS

Lowered visceral perception thresholds have been suggested as a biological marker of irritable bowel syndrome (IBS). The current study sought to determine the prevalence of altered rectal visceral perception in patients with IBS and the correlation of altered perception thresholds with subjective symptoms.

METHODS

Anorectal manometry and rectal perception thresholds to balloon distention were determined in 100 patients with IBS and 15 control subjects. Gastrointestinal and psychological symptoms were assessed by questionnaire. Perception thresholds and symptoms were reassessed after 3 months in 15 patients with IBS.

RESULTS

Ninety-four percent of patients showed altered rectal perception in the form of lowered thresholds for aversive sensations (discomfort), increased intensity of sensations, or altered viscerosomatic referral. Hypersensitivity was found only for aversive sensations in response to rapid phasic distention; stool thresholds and thresholds in response to slow ramp distention were normal. Cluster analysis by physiological parameters identified three IBS subgroups with predominant patterns of symptoms. Longitudinal evaluation indicated a correlation between changes in perception thresholds and symptom severity.

CONCLUSIONS

Because altered rectal perception is present in almost all patients with IBS and perception thresholds correlate with temporal changes in retrospective symptom severity, altered rectal perception represents a reliable biological marker of IBS.

Evidence for the hypersensitivity of lumbar splanchnic afferents in irritable bowel syndrome

BACKGROUND/AIMS

The pathways underlying rectal hypersensitivity to balloon distention in patients with irritable bowel syndrome (IBS) are not known. The aim of this study was to characterize the involvement of sacral and thoracolumbar afferents in the perception of rectal distention.

METHODS

Rectal balloon distention was performed in 15 normal control subjects, 6 patients with spinal cord injury, and 50 patients with IBS using a slow-volume ramp (40 mL/min) or rapid phasic step distension. Additional studies were performed in the presence of 2% intrarectal lidocaine.

RESULTS

Patients with spinal cord injury with lesions below T7 reported sensations only during phasic distention. Sixty percent of patients with IBS (n = 50) were hypersensitive for discomfort during phasic distention, whereas only 4% were hypersensitive during ramp distention. Less than 15% of patients were hypersensitive for the sensation of stool. In normal patients, lidocaine increased thresholds in response to slow ramp distention by 40%-70% but had no effect on perception in response to other types of distention. Lidocaine had no effect on (1) thresholds in response to either ramp or phasic distention in normosensitive or hypersensitive patients with IBS or (2) the rate of receptive relaxation or rectal compliance in any group.

CONCLUSIONS

Rapid phasic distention preferentially stimulates splanchnic afferents. Hypersensitivity of these afferents in patients with IBS is unaffected by mucosally applied lidocaine.

Sleep and duodenal motor activity in patients with severe non-ulcer dyspepsia

The prevalence of sleep disturbances was studied in patients with severe non-ulcer dyspepsia. It was also considered if the change in sleep pattern was associated with changes in the rhythmic fasting motor activity of the gastrointestinal tract, and if motor events correlate with the patient's symptoms. Motor activity in the duodenum was monitored over a 24 hour period under freely ambulatory conditions in 10 healthy controls and in 10 patients with severe non-ulcer dyspepsia using a transnasally placed catheter with six solid state pressure transducers connected to a digital data logging device. Symptoms and sleep disturbance were assessed by questionnaire and diary. Based on their symptoms, the patients were separated into two groups: those with dyspepsia symptoms only (non-ulcer dyspepsia; n = 5) and those with dyspepsia and additional functional symptoms thought to arise from the lower gastrointestinal tract (non-ulcer dyspepsia+irritable bowel syndrome; n = 5). When compared with either the control or the non-ulcer dyspepsia+irritable bowel syndrome group, non-ulcer dyspepsia patients had a considerably decreased number of migrating motor complexes during the nocturnal period (0.7 v 4.6), a decreased percentage of nocturnal phase I (5.2% v 78.0%), and an increased percentage of the nocturnal period in phase II (94% v 15.4%). Patients with non-ulcer dyspepsia+irritable bowel syndrome were not different from normal controls. Four of the non-ulcer dyspepsia patients and all of the non-ulcer dyspepsia+irritable bowel syndrome patients reported difficulties with sleep. Clusters of high amplitude tonic and phasic activity, not accompanied by subjective reports of discomfort were noted in several patients in both groups during the study. In eight of 10 patients, abdominal pain was reported during normal motor activity, while in one patient, pain correlated with phase III of the migrating motor complex. In contrast with previous reports in patients with irritable bowel syndrome, our findings suggest an abnormality of diurnal rhythmicity--shown in changed sleep and changed rhythmic duodenal motor activity--in patients with chronic abdominal pain thought to arise from the upper gastrointestinal tract.