Laparoscopic Lysis of Adhesions for Closed Loop Small Bowel Obstruction

Abstract

Laparoscopic lysis of adhesions is a minimally-invasive approach to the resolution of a closed loop small bowel obstruction (SBO) due to adhesions. A patient with an SBO can present with nausea, vomiting, abdominal pain, and obstipation. History of prior abdominal surgeries serves as a significant risk factor for development of intra-abdominal adhesions. Imaging using either plain abdominal radiography or computed tomography (CT) can be diagnostic for closed loop SBOs. Conservative management with gastrografin can be considered in some SBOs, but closed loop SBOs are considered surgical emergencies. Utilization of specific signs (two transition points, pneumoperitoneum, signs of bowel ischemia) on imaging and patient presentation can facilitate earlier intervention. Laparoscopic lysis of adhesions can resolve symptoms through releasing the bowel from the adhesion to improve flow. Lysis of adhesions can be performed open, laparoscopically, or with robotic techniques. In this case, we present a laparoscopic lysis of adhesions in a patient with a closed loop small bowel obstruction.

Keywords

Laparoscopy; minimally-invasive surgery; adhesiolysis; intestinal obstruction; mechanical obstruction; small bowel obstruction.

Case Overview

Background

Small bowel obstructions account for 2–8% of total emergency department presentations.¹ Among those, a smaller portion will have a closed loop small bowel obstruction. Etiologies of small bowel obstructions and their incidence rates include: 60–75% due to postoperative adhesions, 3–20% due to malignancy in either the small bowel, mesentery, or retroperitoneum, up to 10% due to hernias, 10% due to inflammatory bowel disease, and 3–5% due to “other” causes (volvulus, infection, intussusception, radiation enteritis, mechanical obstruction, or gallstone ileus).² While approximately 60–85% of adhesion-related obstructions resolve without operative intervention, these patients did not have concerns for more severe bowel compromise, and did not include indications for needing immediate surgery such as free air on imaging, signs of intestinal ischemia, or signs of a closed-loop obstruction.³ Among operative interventions, a study conducted in 2019, 262 patients underwent adhesive small bowel obstruction surgery over the course of 9 years. 70% of the procedures were open and 30% were laparoscopic in approach with a 38.5% conversion from laparoscopic to open.⁴ While there is extensive research and knowledge surrounding small bowel obstructions, there still exists a need for clarity and standardization on the identification, management, and treatment of closed loop bowel obstructions. Proper understanding of closed loop small bowel obstructions will facilitate efficient and effective delivery of care and improve overall patient outcomes.

Focused History of the Patient

The patient is a 59-year-old, Spanish-speaking woman with a past medical history significant for hypothyroidism, anxiety, depression, esophagitis, hyperlipidemia, iron deficiency anemia, and cervical cancer treated with chemotherapy and radiation. She presented to the emergency department with a 2 day history of progressively worsening nausea, vomiting, obstipation, and worsening epigastric and periumbilical pain. Her surgical history include an open appendectomy as well as a laparoscopic lysis of adhesions a year prior for persistent small bowel obstruction. Home medications include acetaminophen, levothyroxine, and polyethylene glycol as needed. She does not drink alcohol or smoke tobacco. She does not have any known drug allergies. 

Physical Exam

Suspicion for a small bowel obstruction may be raised in a patient presenting with symptoms of abdominal distention, nausea and emesis, failure to pass flatus or bowel movements, and abdominal pain (may or may not be crampy or colicky in nature).^2, 3, 5 In patients with a closed-loop SBO, distention may be limited or negligible. Additional systemic signs found in acute SBO include findings of dehydration, tachycardia, and orthostatic hypotension. Visualization on abdominal inspection to identify scars from previous abdominal procedures is prudent as prior surgeries impose the risk of adhesion formation.

Findings on physical exam for a small bowel obstruction typically include tenderness to palpation with or without guarding.⁶ On auscultation, bowel sounds may be faint while an acute obstruction may be associated with high-pitched sounds. On percussion, a patient with distention will be hyperresonant to percussion while fluid-filled loops will be dull sounding.

In this case, the patient’s physical exam was significant for tachycardia, which was resolved with fluid resuscitation. Her abdomen was flat and soft, but tender to palpation in the epigastric and periumbilical areas. The patient’s BMI was 19.53. Her ASA score was 2. Nasogastric tube placement prior to surgery resolved symptoms of nausea and emesis.

Imaging

Upon suspicion of an SBO, imaging can facilitate making a diagnosis. In a patient with significant abdominal distention, nausea, and/or emesis, decompression via nasogastric (NG) tube may be necessary. Traditional radiographic images can be rapidly administered. Findings on plain radiography can guide clinical management, but a computed tomography (CT) scan of the abdomen and pelvis with IV contrast is most useful. Free air on plain abdominal radiograph imaging is highly indicative of acute SBOs that requires immediate surgical intervention.³ A closed loop obstruction has been noted to be more difficult to identify on radiologic studies.⁷ A closed loop obstruction on imaging will appear as either dilated that is fluid-filled or with air-fluid levels, and may have a “whirl sign” or appear with a C or U-shaped bowel segment.^3, 8 A whirl sign indicates twisting of the mesentery. While closed loop SBOs due to adhesions is often a diagnosis of exclusion, identification of two transition points can facilitate distinguishing closed loop SBOs due to adhesions.^7, 8, 9

This patient underwent a CT scan of her abdomen and pelvis with contrast. Imaging revealed multiple dilated loops of bowel with air-fluid levels throughout the abdomen and two transition points in the mid-abdomen. Findings were concerning for a closed loop obstruction indicating need for immediate operative treatment. 

Natural History

The small bowel is composed of the duodenum, jejunum, and the ileum, each with their own unique histological markers. The proximal half of the duodenum arises from the foregut, while the distal half of the duodenum through the proximal ⅔ of the transverse colon arises from the midgut. The layers of the small bowel include the mucosa (containing villi and crypts), submucosa, muscularis propria, and the serosa. Overlaying these structures is the greater omentum.

There are three greater categories for the etiology of an SBO: intrinsic lesion (neoplasm, congenital malformations, strictures), extrinsic lesion (adhesions, hernias, volvulus, SMA syndrome), or an intraluminal obstruction (intussusception, gallstones, feces or meconium, foreign body, etc.). Closed loop SBO, while an uncommon type of SBO, is often from internal herniation (twisting), congenital bands, adhesions (both postoperative and spontaneous), and malrotation.¹⁰ Adhesions are the leading cause of a closed loop SBO. In a literature review on acute abdominal pain, researchers found that 75% of cases of SBO are a result of postoperative adhesive bands.⁵ In closed loop SBO, there are two points of obstruction resulting in a proximal and distal occlusion of a segment of bowel. Among patients who have an abdominal surgical history, studies have found that up to 15–20% of cases will experience SBO recurrence.¹¹ Research findings vary in terms of frequency of closed loop SBO among all SBOs with estimates ranging from 5–42% of individuals with an SBO will have a closed loop SBO.¹² Additionally, patients who have received pelvic and/or abdominal radiation are at greater risk for developing SBO due to adhesions, bowel wall fibrosis, and dysmotility.¹³

Closed loop obstructions prevent forward movement of abdominal contents and strangulation of bowel poses risks for ischemia, necrosis, and perforation.³ Most common findings for closed loop SBOs include the aforementioned nausea and emesis, failure to pass flatus or bowel movements, and abdominal pain. Typically, patients experiencing an acute exacerbation reduce dietary intake due to nausea and vomiting.

Options for Treatment

Treatment for an SBO may be managed either conservatively or via surgical intervention. Approximately 60–85% of adhesion-related SBOs resolve without surgery, but determining who will or will not fail a priori is difficult to ascertain.³ Conservative management can include diet intake restriction, intravenous hydration, nasogastric decompression.¹⁴ Rapid identification of etiology of the obstruction should inform next steps. For example, distinction between a closed loop and a simple or partial bowel obstruction is imperative, as a closed loop obstruction is considered a surgical emergency due to low probability of self-resolution and substantial risk of complication if left untreated.¹⁵ Gastrografin does not serve a purpose for closed loop obstructions, thus a CT scan is necessary prior to administration.¹⁶ Surgical options include laparoscopy or laparotomy. While surgery poses risks for introducing opportunities for development of adhesions, the adverse risks associated with abstaining from intervention are greater.

Rationale for Treatment

This patient displayed symptoms and signs of an SBO, and given her past history with SBOs and surgical abdominal history, she met the criterion for concern for an SBO. Following confirmatory imaging, CT results indicated the need for emergent surgery to resolve the closed loop SBO. The surgeon utilized a minimally-invasive approach.

Special Considerations

A laparoscopic lysis of adhesions may be contraindicated in patients who have perforated bowel, evidence of severe intra-abdominal sepsis, extensive abdominal distention, and those who have a high probability of diffuse and tangled adhesions.¹⁶

Discussion

The case in focus pertains to a 59-year-old woman with a closed loop SBO with continued and worsening symptoms of nausea, emesis, and obstipation. Given the findings of dilated loops of bowel with air fluid levels and two transition points on imaging, suspicion for a closed loop SBO was raised indicating need for operative management. The patient underwent a laparoscopic approach, and lysis of adhesions was performed. The point of transition was identified. There was no evidence of bowel ischemia or necrosis; therefore, no enterectomy was performed. On postoperative day one, the NG tube was removed and the patient was started on a clear liquid diet, which she tolerated well. Her diet was advanced as tolerated on postoperative day two, and she was subsequently discharged home without services needed.

This case is particularly noteworthy given the patient's prior history of abdominal radiation and history of abdominal surgeries including an open appendectomy and a prior lysis of adhesions along with persistent SBOs. All of these are associated with increased risks of developing adhesions. Similarly, the innovative minimally-invasive techniques showcased in this video demonstrate valuable contributions to the field in understanding the treatment for such conditions. The procedural insights presented therein are instrumental in enhancing the efficacy of medical interventions.

Laparoscopic lysis of adhesions, in particular for a closed loop SBO, is typically carried out utilizing an evidence-based distal-to-proximal running of the bowel technique with minimized manipulation of the obstructed loop of bowel.¹⁷ This approach starts with identifying the cecum and working up the distal ileal loop towards the transition point and was the approach taken in this case. Release of the adhesion may be done utilizing a laparoscopic scissor or a laparoscopic energy device. Techniques utilized are largely based on surgeon experience and preference.

While lysis of adhesions may be performed open, standard practice today opts towards the more minimally-invasive approach. Patient positioning and port placement were both taken under consideration to ensure proper and maximal access and visualization of anatomy. The patient was placed in a supine position with the left arm tucked. A Veress needle was used to obtain pneumoperitoneum by being placed in the left upper abdomen at Palmer’s point. Once adequate pneumoperitoneum was achieved, a 5-mm trocar was placed at the Veress needle site. Three additional 5-mm ports were placed: one in the right upper abdomen, one in the left lower abdomen, and one slightly-off midline in the epigastric region. The patient was positioned in Trendelenburg position to identify the cecum and terminal ileum, and the bowel was examined distal-to-proximal until the transition point was identified. An adhesive band was identified causing the bowel obstruction with obvious proximal bowel dilation and distally decompressed bowel loops. Adhesiolysis was performed to release the adhesion using a laparoscopic energy device. The remainder of the bowel was evaluated—no other transition points were identified. Bowel viability was assessed and all appeared viable without evidence of ischemia or necrosis.

While the first documented laparoscopic adhesiolysis was performed in 1933 by Carl Fervers, open surgery was the standard practice for such processes prior to the late 1980s.¹⁸ Laparoscopic procedures revolutionized in 1986 following the advent of video computer chips that allowed for on screen monitor relaying of graphics.¹⁹ Surgical practices have begun to shift from open towards minimally invasive where possible because of the reduction in their associated morbidities; for example, laparoscopic compared to open surgery carries a reduced risk of complications, reduced risk of new adhesion formation in abdominal surgery, improved recovery length, and reduced length of hospital stay.

Approximately 65–75% of SBOs are due to peritoneal adhesions and accounts for nearly $2.3 billion in medical expenses annually in the United States.²⁰ Future research should continue to explore techniques that reduce associated known morbidities such as adhesion cause-effect patterns, standardization of protocols for diagnosing and managing SBOs, and techniques for early identification of closed loop SBOs. Current advancements include robotic assisted laparoscopic  adhesiolysis and single-incision laparoscopic lysis of adhesions.²¹ A systematic review found that compared to laparoscopic procedures, overall, robotic surgery had a lower rate of unplanned conversions to open surgery.²² Laparoscopic lysis of adhesions, especially for a closed loop SBO remains the standard practice today. This is evidenced in the efficient time spent in this case (26 minutes) as well as the reduction in perioperative and postoperative morbidities.

Equipment

Laparoscopic lysis of adhesions was performed using Olympus laparoscopic tools including laparoscopic grasping forceps. The surgical field was visualized by an Olympus high-resolution video endoscopy system including two high-resolution color monitors. Energy device used was Ethicon Laparoscopic Harmonic ACE+ Shears.

Disclosures

Nothing to disclose.