Medical management of motility disorders in patients with intestinal failure: a focus on necrotizing enterocolitis, gastroschisis, and intestinal atresia

Background

Intestinal failure (IF) is the dependence upon parenteral nutrition to maintain minimal energy requirements for growth and development. It may occur secondary to a loss of bowel length, disorders of motility, or both. Short bowel syndrome (SBS) is a malabsorptive state resulting from surgical resection, congenital defect, or diseases associated with loss of absorptive surface area. A particularly vexing problem is associated with whole bowel and/or segmental intestinal dysmotility. Motility disorders within the context of SBS and IF may relate to rapid intestinal transit secondary to loss of intestinal length, dysmotility associated with loss or poor antegrade peristalsis, or gastroparesis. Therapy may be classified into medical (prokinetic and antidiarrheal agents) and surgical to deal with the overdistended poorly motile bowel.

Methods

We performed a systematic review of the literature pertaining to IF, SBS, and dysmotility in the pediatric population with gastroschisis, necrotizing enterocolitis, and intestinal atresia. In addition to the available treatment options, we have provided a review of the literature and a summary of the available evidence.

Conclusion

Despite relatively poor level of evidence regarding the application of promotility and antidiarrheal medications in patients with SBS and IF, these agents continue to be used. Herein, we provide a review of the physiology and pathophysiology of intestinal motility/dysmotility and available strategies for the use of promotility and antidiarrheal agents in patients with IF/SBS.     

Intestinal transplantation for short bowel syndrome secondary to gastroschisis

Background/Purpose

Gastroschisis is the most frequent cause of pediatric intestinal transplantation. This study reviews our experience of intestinal transplantation secondary to gastroschisis to elucidate those factors affecting the outcome of children with short bowel syndrome.

Methods

A retrospective review was performed for children who underwent intestinal transplantation for gastroschisis at the University of Miami between June 2003 and August 1994.

Results

Thirty-two transplants were performed in 28 children with gastroschisis during the study period. Associated intestinal anomalies were present in 22 infants (atresia [n = 14], volvulus [n = 3], and/or ischemia [n = 16]). Spontaneous prenatal closure of gastroschisis, a rare anomaly associated with bowel atresia and ischemia because of a very small abdominal defect, was seen in 9 patients. Most of the patients had a complicated course and required multiple abdominal surgeries before transplant. Fifteen (53.6%) patients are currently alive at a median follow-up of 23.5 months. Short-term survival rate has significantly improved in recent years.

Conclusions

Patients with complex gastroschisis and intestinal anomalies have a significant risk for progression to short bowel syndrome. Intestinal transplantation can be a lifesaving option and provides a satisfactory outcome for children with short bowel syndrome secondary to gastroschisis.     

Intestinal atresia with segmental musculature and neural defect

Background/Purpose

The aim of this study was to investigate the possible etiologic factors of small bowel atresia and to detect the prognostic role of adequate resection and tapering in postoperative morbidity and mortality.

Methods

Intestinal resection specimens were obtained from 10 patients with jejunoileal atresia and 3 control subjects without any gastrointestinal disease. Intestinal specimens taken from 2-cm and 4-cm proximal sides of atresia, atretic segment, and 1-cm and 2-cm distal sides of atresia were stained with Masson trichrome and H&E. Immunohistochemical staining of the biopsy specimens with synaptophysin was also performed to ascertain the number, the intensity, and the morphology of ganglia.

Results

At the blind proximal end, there was segmental absence of muscular layers, presence of neural defects, and replacement of the muscular layers with fibrous tissue beside the relatively intact mucosa.

Conclusions

Segmental defects in muscular and neural structures of the intestinal wall observed in both the antimesenteric and mesenteric sides of the atretic small bowel were considered to support the vascular insult theory as an etiologic factor. Adequate resection rather than tapering the dilated proximal atretic intestinal segment should be included in the surgical treatment of this pathology to avoid the intestinal dysmotility, which may result in gut-related sepsis and death in the postoperative period.     

Closing gastroschisis: diagnosis, management, and outcomes

Purpose

Gastroschisis (GS) is defined as a full-thickness abdominal wall defect (usually right-sided) with intestinal prolapse and occasionally other viscera. The defect itself may close around the viscera causing exit or entry level intestinal atresia and ischaemia or midgut infarction, previously described as closed GS. We now report the largest series of infants born with various stages of closing GS describing features, management, and outcome.

Methods

The study used a single-centre retrospective review of infants with GS and evidence of defect closure at birth.

Results

Nine infants (6 girls) with a median of 35 (range, 32-36) weeks of gestation fulfilled criteria for closing GS from a series of 146 (6%) infants born from August 1994 to December 2007. Delivery had been expedited in 6 based on increasing intraabdominal bowel dilatation and suspicion of closing GS on serial antenatal ultrasound. At delivery, 5 had compromised but viable bowel and required intestinal surgery.Three fetuses, all with midgut necrosis, had antenatal scans typical of GS with no additional features.After a variety of surgical procedures, 7 patients are now fully enterally fed, one is parenteral nutrition-dependent. One died of end-stage liver failure secondary to short bowel syndrome. The length of follow-up was 6 (range, 0.5-11) years.

Conclusions

Of infants with GS, 6% present with closing abdominal ring. Close antenatal monitoring may prevent severe bowel loss in some cases. After multiple surgical interventions, most have a favorable outcome.     

Surgical experimental jejunoileal atresia in rat embryo

Purpose

Jejunoileal atresia represents about 40% of intestinal atresia. After surgical repair, intestinal motility disorders are burdened with the postoperative outcome, and the origin of these troubles remains unclear. To specify the physiopathologic feature of jejunoileal atresia, we developed an experimental surgical model in fetal rat.

Methods

Time-dated pregnant rats were operated on at 18 days of gestational age. Hysterotomy was performed, followed by fetal wall incision. The exteriorization of the bowel loop was obtained by saline injection; the intestine was ligated and returned to the abdominal cavity before incisions were closed. Fetal intestine was excised at day 21, after cesarean delivery.

Results

Twenty-one pregnant rats underwent operation with 90% maternal survival rate. Among the 56 fetuses successfully operated on, 49 survived (87%). In fetuses with atresia, the mean birth weight (4.5 ± 0.6 g) and the mean intestinal length (12.8 ± 1.3 cm) were significantly lower compared to sham fetuses and controls.

Conclusion

The rat model offers the advantage of a low-expense mammal model with a wide panel of probes and reagents available for the study of the gut. This model of jejunoileal atresia could be used to study the consequences of prenatal intestinal obstruction on fetal gut.     

Closed gastroschisis: total parenteral nutrition-free survival with aggressive attempts at bowel preservation and intestinal adaptation

Background

In infants with gastroschisis antenatal closure of the umbilical defect results in a proximal atresia with ischemia and/or volvulus of the extracorporeal midgut. It has been described as “closed gastroschisis” or “vanishing midgut.”

Methods

A 10-year review of 219 gastroschisis patients identified 10 infants with this rare complication.

Results

In these 10 infants, the extracorporeal midgut was invariably matted and fibrosed. In 3 cases, the midgut had completely “vanished.” In the remaining 7 cases, the remnant midgut was surgically reduced into the abdominal cavity with care not to compromise the diminutive vascular pedicle. Abdominal exploration was performed several weeks later to reestablish bowel continuity; 4 required an ostomy and 2 underwent a serial transverse enteroplasty. Mean residual length of salvaged small bowel was 79 cm with retention of the distal half of the colon. Eight infants survived the initial hospitalization, with a mean length of stay of 121 days and mean hospital charge of $287,094. Six of the 7 long-term survivors have been completely weaned off total parenteral nutrition.

Conclusion

A nihilistic attitude toward infants with closed gastroschisis may not be uniformly supported because in the majority of these infants' long-term independence from total parenteral nutrition was achieved.     

Cholestasis associated with small bowel atresia: do we always need to investigate?

Background/Purpose

Cholestasis occurs frequently in patients with small bowel atresia (SBA) and is often attributed to prolonged parental nutrition. When severe or prolonged, patients may undergo unnecessary intensive or invasive investigation. We characterized cholestasis and analyzed the pertinence of investigating this patient population.

Methods

With Research Ethics Board approval, patients with SBA between 1996 and 2005 were retrospectively reviewed. Demographics, location of atresia, operative findings, complications, investigations, resumption of feeding, duration of prolonged parental nutrition, and follow-up information were examined. Cholestasis was evaluated for incidence, severity, and evolution.

Results

Fifty-five patients (29 male, 26 female), with a median gestational age and birth weight of 36 weeks and 2025 g, respectively, were reviewed. Care was withdrawn for 2 patients before repair. For the remaining 53 patients, SBA were duodenal atresia in 18, jejunoileal atresia in 32, and multiple atresia in 3. Of 53, 24 (45%) patients developed cholestasis postoperatively (direct/total bilirubin >20%). All patients with short bowel (4) and 60% (6/10) of patients with a delay of enteral feeding more than 14 days postoperatively had cholestasis. Ten patients (36%) proceeded with in-depth evaluations for cholestasis, with 8 (28%) undergoing liver biopsy. No patient had biliary atresia. No deaths were related to isolated cholestasis/cirrhosis. Cholestasis resolved spontaneously in all the survivors.

Conclusions

Small bowel atresia is frequently associated with postoperative cholestasis that will resolve with time. We recommend a more selective and expectant approach to SBA-associated cholestasis to minimize unnecessary investigations.     

The 2 STEP: an approach to repeating a serial transverse enteroplasty

Purpose

The serial transverse enteroplasty procedure (STEP) procedure is a successful and safe approach to lengthen small bowel in patients with short bowel syndrome (SBS). However, postlengthening dilatation may occur, which can lead to bacterial overgrowth and malabsorption. We addressed this problem by reperforming the STEP in 2 patients.

Methods

Two infants underwent the STEP procedure at 3 days and at 4 months of life for SBS secondary to intestinal atresia and gastroschisis. The patients' small bowel lengths were 20 and 32 cm before and 25 and 52 cm after the initial STEP. Nine and 8.5 months afterward, the patients developed dilatation of the small bowel and feeding intolerance. A second STEP procedure was undertaken with additional transverse firings of staplers between previously lengthened segments and tapering of redundant blind-ending portions of bowel.

Results

At operation, the bowel lengths were 45 and 62 cm. The second STEP left the patients with 61 and 73 cm of small bowel with a normalization of intestinal diameter. The first patient is doing well 5 months after surgery, and the second child tolerated increased enteral intake but died 1 year later from total parenteral nutrition-related liver failure.

Conclusions

This is the first report of a successful application of a second STEP procedure to further lengthen small bowel in SBS patients. Reapplication of the procedure requires careful stapling and a removal of small blind-ending segments to avoid further stasis.     

In utero repair of gastroschisis in the sheep (Ovis aries) model

Objective

Gastroschisis is associated with inflammatory changes in the exposed bowel which leads to intestinal dysmotility after postnatal repair. The insult is a combined effect of amniotic fluid exposure and mechanical constriction. We hypothesized that in utero anatomic repair is possible in a sheep model, and that it may halt the inflammatory damage caused by both mechanisms.

Methods

Gastroschisis was surgically created in mid-gestation (day 75) in 8 sheep fetuses. On gestational day 100, 2 fetuses underwent open fetal gastroschisis repair, where the eviscerated bowel was returned to the peritoneal cavity, and the abdominal wall was primarily closed. All fetuses were harvested at 135 days of gestation.

Results

Six fetuses survived the initial operation, and both fetuses that underwent gastroschisis repair survived to term. At 100 and 135 days of gestation, the eviscerated bowel showed progressive signs of inflammation and peel development. The gross and microscopic inflammatory changes in the gastroschisis bowel at 100 days of gestation were completely resolved at term following in utero repair.

Conclusion

In utero anatomic repair of gastroschisis is possible in mid-gestation in the fetal lamb model, and it appears to ameliorate the inflammatory process.     

Evaluation of intestinal absorption after longitudinal intestinal lengthening for short bowel syndrome

Purpose

The aim of this study was to answer if the longitudinal intestinal lengthening and tailoring (LILT) by Bianchi, modified by Aigrain, can allow the child to be weaned from parenteral nutrition (PN) and if the length of the bowel after the procedure can influence the results of the absorption test such as Schilling or d-xylose test.

Patients and Methods

We reviewed the files of 7 children who have had LILT from 1980 to 2003. We performed to explore 2 intestinal function tests: the d-xylose and the Schilling tests. Both were performed early (during the first year after the procedure) and late (during the second year) after the LILT. We used the χ² and Bartlett's correlation tests for statistical analysis.

Results

There were 6 boys and 1 girl. The surgical indication was short bowel syndrome with parenteral nutrition owing to multiple intestinal atresia (2 cases), severe necrotizing enterocolitis with volvulus (1 case), necrotizing enterocolitis (1 case), intestinal atresia with gastroschisis (2 cases), and volvulus owing to malrotation (1 case). The length of the bowel was significantly different before and after LILT (P < .0001). After LILT, the length of the bowel was significantly correlated with the percentage of PN on energy at 6 months (P = .02) and at 12 months (P = .001). Moreover, the length of the bowel after the procedure was significantly correlated with the results of the d-xylose test during the first year (P = .002) but not with the results after the second year. The length after lengthening influenced neither the results of the Schilling test during the first nor those of the second year after. Four patients were weaned from the PN 21 months in average after the LILT (57%); 1 was not because we had only a 2-month follow-up. The average follow-up was 111 (5 months; range, 4- 206).

Conclusion

Longitudinal intestinal lengthening and tailoring for short bowel syndrome is a good option to allow children to be weaned from the PN. The length of the bowel after the procedure can influence the absorption test such as d-xylose during the first postoperative year but not during the second and does not influence the Schilling test. We think it is not necessary to perform these tests during the follow-up of these patients.     

Antenatal diagnosis of bowel dilatation in gastroschisis is predictive of poor postnatal outcome

Purpose

Although gastroschisis infants usually have a good outcome, there remains a cohort of babies who fare poorly. We inquired whether the presence of bowel dilatation in utero is predictive of postnatal course in infants with gastroschisis.

Methods

We compared the clinical course of infants who had bowel dilatation with those who did not. Bowel dilatation was defined as more than 20 mm in cross-sectional diameter on ultrasound at any gestational age. Outcome measures used were length of time of parenteral nutrition, death, and surgery for intestinal failure.

Results

A review of 170 infants with gastroschisis identified 74 who had dilatation of more than 20 mm (43.5%). There was no significant difference in the incidence of intestinal atresia in those with bowel dilatation and those without (P = .07). Those with bowel dilatation spent a longer period on parenteral nutrition. There were significantly more deaths in the group with bowel dilatation (P = .01). There was no significant difference in the number of infants requiring surgery for intestinal failure between the 2 groups (P = .47).

Conclusions

We found that sonographically detected bowel dilatation more than 20 mm in utero in fetuses with gastroschisis may have value in predicting clinically significant adverse postnatal outcomes.     

Preservation of extracorporeal tissue in closing gastroschisis augments intestinal length

Background

Prenatal closure of the umbilical ring in gastroschisis may result in an amorphous, nonviable appearing extracorporeal tissue that is resected during the repair. However, it is unclear whether such remnant intestine is truly nonviable.

Methods and Results

We examined the outcomes of patients when this tissue is preserved. We identified 8 patients who presented with a closing gastroschisis and a mass of tissue connected by a vascular pedicle. Four patients underwent abdominal exploration with resection of the mass and gastroschisis closure. Histologic examination revealed normal intestinal wall architecture. All patients in this group developed short bowel syndrome, requiring long-term parenteral nutrition. Conversely, 4 patients underwent abdominal exploration with internalization of the remnant tissue, a maneuver referred to as “parking,” along with either silo placement, or primary closure of the gastroschisis. At re-exploration, 3 of 4 patients were found to have viable intestine, and bowel continuity was reestablished. The mean parenteral nutrition requirement for this group was significantly shorter than the resected group.

Conclusion

In this series, we show that this amorphous tissue, when preserved, may exhibit normal intestinal architecture and absorptive function. Therefore, such remnant tissue should be preserved as it may significantly increase bowel length and minimize parenteral nutrition requirement.     

Intestinal atresias: factors affecting clinical outcomes

Background

Despite improvements in care, intestinal atresias are associated with prolonged hospitalization and occasionally mortality. Although each type of atresia is distinct, it is unclear which factors impact clinical course. This study seeks to identify predictors of untoward outcome.

Methods

Neonates with duodenal, jejunal/ileal, and colonic atresia, treated at 1 institution from 1982 to 2005 were reviewed. Data were evaluated using nonparametric analysis of variance and logistic regression. Nonparametric data were expressed as medians with interquartile range (IQR).

Results

A total of 132 infants were evaluated including 63 with duodenal, 60 with jejunal/ileal, and 9 with colonic atresias. Overall mortality was 7% with associated congenital anomalies identified as an independent risk factor (P = .01). Infants with associated anomalies were more likely to have low birth weight (2.3 ± 0.8 vs 3.0 ± 0.8 kg, P = .01), which further increased mortality risk. Atresia location did not affect mortality or length of stay; however it did impact the time to full enteral nutrition with jejunal atresia requiring longer than duodenal (17 [IQR, 9-40 days] vs 10 [IQR, 7-70 days]; P = .01).

Conclusion

Overall mortality from intestinal atresia is low and is not dependent on the location of obstruction. Infants with birth weight less than 2 kg and associated anomalies are at an increased risk for prolonged hospital stay and mortality.     

Complex gastroschisis: Clinical spectrum and neonatal outcomes at a referral center

Aim of the study

To evaluate the outcomes of neonates with complex gastroschisis (GC), and correlate outcomes with each type of complication.

Neonatal outcomes associated with intestinal abnormalities diagnosed by fetal ultrasound

Purpose

Intestinal abnormalities are sometimes seen during antenatal testing; however, the postnatal importance of these findings has not been well established. We evaluated whether abnormal intestinal appearance on fetal ultrasound (US) was ultimately related to neonatal outcome.

Methods

Fetal US examinations from 2003 to 2006 were evaluated. Hyperechogenic bowel was defined as having the echogenicity comparable to bone, and dilated bowel was identified based on the sonographer's assessment. Persistence or resolution of US findings on subsequent US examinations and eventual outcomes were assessed. Cases were categorized as hyperechogenic or dilated and then subgrouped based on whether the US finding resolved.

Results

Sixty-eight fetuses had either hyperechogenic (n = 48) or dilated bowel (n = 20) on antenatal US. In 56 cases, complete data were available for analysis. Of 44 liveborn infants, 11 (25.0%) had an abdominal abnormality, and 33 (75.0%) were normal at birth. Compared to those with dilated bowel, fetuses with hyperechogenic bowel had a higher rate of prenatal demise (20.8% vs 10%) but a lower rate of abnormality at birth (10.3% vs 53.3%). Hyperechogenic bowel resolved on subsequent US more frequently than dilated bowel (65.5% vs 20.0%). In both groups, all fetuses with sonographic resolution were normal at birth. Of 9 fetuses that had persistently hyperechogenic bowel, 3 (33.3%) were born with an abnormality, and all were found to have meconium peritonitis or meconium ileus. In the 12 cases where dilated bowel did not resolve, 8 (66.7%) were eventually born with an abnormality, most commonly intestinal atresia.

Conclusions

Hyperechogenic and dilated bowel are associated with a significant rate of fetal demise. Hyperechogenicity is more common than dilation and is more likely to be transient. Dilated bowel is more often associated with neonatal abnormality than hyperechogenic bowel. Persistence of fetal US findings predicts a higher likelihood of abnormality in the neonate.     

Preserving bowel length with a transluminal stent in neonates with multiple intestinal anastomoses: a case series and review of the literature

Background/purpose

In neonatal surgery, preserving small bowel length is important to avoid short bowel syndrome. Our aim was to assess the outcomes of intraluminal stenting of neonatal multiple intestinal anastomoses.

Methods

We conducted a retrospective review of 9 patients (5, single institution; 4, published literature) who received multiple anastomoses stented by a silicon tube. Demographics, surgical anatomy and complications, nutritional outcomes, and follow-up were reviewed.

Results

Diagnosis was multiple intestinal atresias in 8 patients and necrotizing enterocolitis in 1. A silicon catheter entered either the mucous fistula (5 patients received a jejunostomy/mucous fistula) or a proximal opening on the dilated bowel and was threaded through viable segments of the bowel. The bowel ends were approximated. Stent was externalized in 7 patients. Final mean small bowel length was 63.9 cm. All complications (3 patients, leak/stricture) required surgery. Mean time to stent removal, feeds initiation, and parenteral nutrition (PN) discontinuation was 31.2 days, 17.3 days, and 159 days, respectively. Only 1 patient remains on PN (mean follow-up, 25.4 months).

Conclusions

Multiple intestinal anastomoses stenting is an excellent technique to avoid short bowel syndrome in the setting of multiple viable segments of gut, such as type IV intestinal atresia or necrotizing enterocolitis. Both our experience and the published literature show no mortality and PN-free survival.     

Gastroschisis: the cost of an epidemic

Background

The rising incidence of gastroschisis has been highlighted by the Department of Health as a growing concern. As well as the health implications for the increasing number of affected infants, this increase in incidence will have an impact of the costs of health care. This study was undertaken to estimate the financial cost of treating this condition in one tertiary neonatal surgical center.

Methods

A retrospective analysis was performed of all patients admitted to a tertiary neonatal surgical center with gastroschisis from January 1996 to December 2005. The main outcome measures were incidence, length of hospital stay, and total cost for all patients each year.

Results

The incidence of gastroschisis has risen 3-fold in 10 years. The median cost per patient is relatively constant. A few patients with severe intestinal dysmotility require prolonged hospital stay. As the condition becomes more common, there are an increasing number of complex patients and thus an increase in annual costs, which is disproportionate to the increase in numbers of cases. We estimate that the annual cost to the National Health Service (NHS) of this condition in England and Wales has risen from £3.6 million in 1996 to in excess of £15 million in 2005.

Conclusions

Urgent research is required into the etiology of gastroschisis and into the severe intestinal dysmotility that occurs in some complex patients.     

Anastomotic stricture after surgical repair of esophageal atresia: frequency, risk factors, and efficacy of esophageal bougie dilatations

Aims

The aim of this study was to evaluate the frequency and risk factors of postoperative anastomotic stricture, and the efficacy and complications of esophageal bougie dilatations for symptomatic anastomotic stricture in a population of children with esophageal atresia.

Patients and Methods

The medical records of 62 children operated on for esophageal atresia type III (Ladd and Gross) over a 5-year period were retrospectively reviewed.

Results

Anastomotic stricture developed in 23 (37%) of patients. Anastomotic tension during primary repair of esophageal atresia was associated with subsequent stricture formation (P < .05). Patients required esophageal dilation at a mean age of 149 days (range, 30-600 days). Stricture resolution occurred after a mean of 3.2 dilatations per patient (range, 1-7). Dilation was successful in 87% of patients. Three patients continued to present mild (n = 1) to severe (n = 2) dysphagia, mainly related to esophageal dysmotility. No complications were observed during or after the dilatation sessions.

Conclusions

Anastomotic stricture, secondary to the surgical treatment of esophageal atresia, remains a frequent complication in patients with esophageal atresia. Esophageal dilation with Savary-Gilliard bougies is a safe and effective procedure in the management of strictures.     

An alternative management option for colonic atresia preventing loss of the ileocecal valve

Purpose

Management of colonic atresia is contentious, with primary anastomosis having a notable risk of anastomotic leak. In addition, resection of the terminal ileum and ileocecal (i-c) valve is frequently performed, risking side effects such as diarrhea, vitamin B₁₂ deficiency, and gall stone formation.

Methods

The hospital coding system was searched for all patients with a diagnosis of colonic atresia between July 2005 and July 2008. Four term neonates were managed by formation of an ileostomy, a “blow hole” stoma just proximal to the atresia, and a mucus fistula distal to the atresia.

Results

Average time to full feeds was 7.5 days (range, 3-12 days), and average length of stay was 23 days (range, 13-47 days). Stoma management, problematic in 2 infants, was individualized by a specialist stoma nurse. Ileostomy output was refed into the mucus fistula. Complications included 3 episodes of prolapse of the blow hole stoma in infant 2. All of the infants returned to the operating theater at 1 to 3 months of age for restoration of bowel continuity and closure of the ileostomy. The atretic segment was resected, and an end-to-end anastomosis was performed. Recovery was straightforward in all cases.

Conclusion

A procedure that retains the i-c valve and most of the colon through creation of a blow hole stoma in the distended proximal colon with a diverting ileostomy and mucus fistula is described. The technique is recommended in selected infants as bowel length and anatomy can be preserved, despite the use of multiple stomas.     

Fetal gastrointestinal motility in a rabbit model of gastroschisis

Purpose

Gastrointestinal (GI) dysmotility occurs frequently in full-term infants with gastroschisis (GS). Although controversial, preterm delivery of infants with GS has been advocated to prevent the development of GI dysmotility, and understanding the etiology of gestational-related bowel injury may lead to prenatal therapies. Using a fetal rabbit model, the authors assessed in vivo and in vitro GI motility in preterm GS fetuses.

Methods

On gestation day 24 (term, 31), surgery was performed in maternal rabbits and GS induced in fetuses, whereas control fetuses underwent sham procedures. On gestation day 29, both groups of fetuses received ultrasound-guided intragastric injection of fluorescein and colored microspheres. Two hours after injection, fetuses were delivered by cesarean section and stomach and small intestine harvested intact. “GI motility” was calculated as the distance traveled by fluorescein divided by total length. In vitro studies of fetal gastric muscle strips contractility responses to bethanechol, a cholinergic agonist, were assessed in an organ bath system. Data were analyzed as paired and unpaired t tests and expressed as means ± SEM.

Results

GS reduced fetal body weight and intestinal length compared with controls (28.4 ± 1.4 v. 33.5 ± 1.5 g, 36.9 ± 1.8 v. 25.9 ± 1.2 cm; P < .05, respectively). Fetuses with GS showed markedly reduced in vivo GI motility (51.4 ± 2.9 v 24.8 ± 2.7%; P < .05) and in vitro gastric contractile tension (769 ± 53 v 396 ± 26 mNcm²; P < .05).

Conclusions

GI exposure to amniotic fluid reduces intestinal motility and gastric contractility functions in the preterm rabbit fetus. The results suggest that GS-associated impairment of GI neuromuscular functions occurs in utero, before term, and may be responsive to manipulation of amniotic fluid content or other therapeutic interventions.