Negative-Pressure Wound Therapy: A Novel Approach for Terminal Ileum Anastomosis Success

Introduction

Intestinal anastomosis represents one of the fundamental pillars of digestive tract surgery [1]. The objective of this procedure is to restore intestinal transit in multiple clinical contexts, including mesenteric ischemia, abdominal trauma, tumors, and perforations [1]. However, intestinal anastomosis is associated with complications such as dehiscence, leakage, and stenosis, which confer high morbidity and mortality and increased costs of care [1]. Since Theodor Billroth performed the first successful anastomosis more than 100 years ago, advances in related devices and techniques have reduced complications as well as surgical durations [2,3]. Nevertheless, the development of complications in patients undergoing intestinal anastomosis remains a latent risk [2,3]. Starting from the premise that not all segments of the digestive tract behave identically and that the extremes of the tract are associated with a greater probability of complications, it would be worth exploring the particularities of the anastomoses performed in the terminal ileum (TI) [4].

When attempting a TI anastomosis, 3 dilemmas arise: 1) the anatomical characteristics of the segment do not provide adequate irrigation for ensuring a successful procedure; 2) the pressure at the ileocecal valve (ICV) increases the probability of fistula formation or dehiscence in the anastomosis; and 3) adjacent anatomical structures are an impediment to the performance of the procedure [5]. Additionally, the scientific evidence regarding the outcomes of this intervention is inconsistent, which reinforces the need to increase experience with anastomoses in the TI. The use of negative-pressure wound therapy (NPWT) for temporary abdominal closure following anastomosis is controversial but has shown promise in patients with inflammatory or vascular disease. This report presents 3 successful cases in which NPWT was used after TI anastomosis surgery.

Case Reports

CASE 1:

A 65-year-old woman with a history of smoking, chronic kidney disease, and paroxysmal atrial fibrillation (PAF), without adherence to treatment, presented to the emergency room for severe abdominal pain located in the hypochondrium and right flank, without signs of peritoneal irritation, accompanied by nausea. Abdominal computed tomography (CT) revealed a defect in the ileo-ceco-appendicular-colic branch of the superior mesenteric artery and in a proximal segment of the mesenteric vein, and edema in the walls of the corresponding intestinal segment was observed during exploratory laparotomy. Without macroscopic evidence of ischemic involvement, anticoagulation therapy was initiated due to a documented thrombotic phenomenon (Figure 1). During the postoperative period, abdominal pain, metabolic acidosis and increased leukocytosis persisted, highly suggestive of mesenteric ischemia. A second laparotomy revealed evidence of multiple ischemic patches and thickening of the distal ileum without macroscopic perforation, confirming the diagnosis of mesenteric ischemia which justified the resection of a segment of the jejunum and ileum between 80 cm from the angle of Treitz and up to 20 cm from the ICV. The remaining intestinal loops were sutured together, and the final size of the resected jejunum was 100 cm. The etiology of acute mesenteric ischemia was considered mixed due to arterial obstruction and non-occlusive ischemia due to low cardiac output.

A third laparotomy was performed 48 hours later, which revealed evidence of a leak in the ileum stump and a superficial ischemic patch; thus, a terminal jejunostomy and laparostomy were created. Intestinal anastomosis was not considered due to the high risk of leakage and the need for double hemodynamic support; instead, a fourth surgical intervention was planned for 48 hours later. The patient’s condition was favorable; she did not require hemodynamic support, showed adequate urinary output and production through the ileostomy. A new surgical procedure revealed evidence of necrosis at the distal edge of the jejunostomy, leading to an undoing of the jejunostomy and resection of the affected edge plus end-to-side anastomosis between the jejunum and ileum 10 cm from the ICV in 2 planes. Adequate patency of the anastomosis was determined by means of a pneumatic test without leakage. Primary closure of the abdominal wall at that time was not possible, so the team decided to use an NPWT system according to protocol as follows: The abdominal cavity was thoroughly washed and dried to ensure a sterile environment. A piece of black foam dressing was cut to fit the area of interest and placed over the wound. A white foam dressing was applied to protect the anastomosis site. The foam dressing was secured in place with adhesive strips, ensuring a tight seal around the wound edges.

The vacuum-assisted closure (VAC) therapy system was then configured and firmly attached to maintain proper suction; it was set at −75 mmHg. Adequate pressure was confirmed through a pneumatic test to ensure there were no leaks present. The system was activated, and continuous monitoring was initiated to assess the effectiveness of the VAC therapy. After 48 hours, the VAC system was withdrawn and primary closure of the abdominal wall was achieved. The patient presented with adequate healing and was discharged for outpatient follow-up with no evidence of complications.

Case 2

CASE 3:

A 69-year-old male patient presented with severe abdominal pain and abdominal distention following surgical treatment of an abdominal aortic aneurysm and myocardial revascularization. Physical examination revealed tachypnea, tachycardia, and signs of meteorism. Contrast-enhanced abdominal CT revealed evidence of changes suggestive of mesenteric ischemia. Exploratory laparotomy revealed edema of the small intestine and ischemic segments in the distal ileum, specifically from 15 cm from the ICV to the last 40 cm, associated with the hemoperitoneum, as seen on the CT scan (Figure 3). Given the severe hemodynamic compromise requiring a dual vasopressor and the presentation of signs of tissue hypoperfusion in the intestinal segments, mesenteric ischemia was confirmed, and damage control surgery was performed which included resection of the 40 cm of ischemic intestine, as well as suturing of the remnant ends and laparotomy. Then, 48 hours after the procedure, a second surgery revealed evidence of improvement in perfusion and restriction of the ischemia, at which point manual end-to-end anastomosis was performed in 2 planes 12 cm from the ICV. Adequate passage without evidence of leakage at the site of the anastomosis was verified; peritoneal fluid was collected for microbiological study, and an NPWT system was used due to the inability to achieve primary closure of the abdominal wall. The system was placed according to the protocol described in case 2, with a pressure of −50 mmHg. After another 48 hours, the anastomosis remained undamaged and patent, and the NPWT system was continued to achieve primary closure of the abdominal wall. On the fifth day following admission, the NPWT system was removed, and the abdominal wall was completely closed. However, the patient presented with sepsis of abdominal origin due to Klebsiella aerogenes, necessitating a long stay in the ICU with antibiotic treatment. After favorable progression of the infectious disease, the patient was discharged. During follow-up, no complications associated with the distal ileum anastomosis were reported.

Discussion

These cases create a platform for discussion on the anatomical and physiological implications of distal ileum anastomosis, current trends in intestinal preservation, and the management of open abdomen surgery using NPWT techniques, all framed within the necessity for individualized approaches and monitoring in high-risk scenarios. Anastomoses are fundamental pillars of digestive tract surgery since they restore intestinal transit in multiple clinical contexts [1]. However, these procedures carry significant risks, including dehiscence, leakage, fistula formation, and stenosis. Anastomotic leakage occurs in 0.5–30% of patients with intestinal anastomoses [6]; this variability in incidence is due to factors such as the anatomical site, vascular supply, tension to which the anastomosis is subjected, differences in bacterial load, and patient-intrinsic factors [7]. In terms of the anatomical site, the locations with the highest incidence of leakage are the esophagus (13.5%), pancreas (12.0%), and rectum (6%), followed by the colon and small intestine, with an incidence of 6% and 5.5%, respectively [8]. The locations with the lowest associated leakage are the stomach and bile duct (1.6% and 0%, respectively) [8]. Once a leak is established, local infection and hematogenous spread occur, with the potential to cause septic shock [2,3]. In the event of multiple organ failure, the mortality rate increases, reaching up to 90% [2,3]. Although the incidence of leakage is greater in the esophagus and pancreas than in the small intestine, similar 30-day mortality rates have been reported for these regions (16.7% for the esophagus and pancreas and 15% for the small intestine) [8]. The data available in Colombia, based on the observations of 2 fourth-level hospitals, indicate that 10.7% of patients present with anastomotic fistulas, with a mortality rate of 47.6% [2,3].

Likewise, complications can impact care costs. According to the American College of Surgeons registry, there is a significant difference in hospital costs among patients with an intact anastomosis without complications, patients with an intact anastomosis with complications, and patients with anastomotic leakage. The average costs are $944.64 USD, $1,456.77 USD and $1,694.28 USD, respectively [8].

These factors may be dependent on the patient and his or her condition, technical factors, the site of anastomosis, and compliance with the criteria for high-risk anastomosis [9]. Among patient-intrinsic factors, diabetes mellitus, anemia, uremia, smoking, alcoholism, and prolonged use of steroids have been reported to increase the risk of anastomotic leakage [10,11]. It has also been reported that the loss of 5 kg prior to surgery is related to an increase in the incidence of anastomosis leakage; in the same way, preoperative albumin levels of at least 3.4 mg/dL can also affect the prognosis of the patient [9]. Studies based on the Colombian population have indicated that a history of abdominal surgery (OR 1.38, 95% CI 1.01–2.01) and the presence of intra-abdominal cancer (OR 1.46, 95% CI 1.30–1.77), peritonitis (OR 2.11, 95% CI 1.20–3.6), sepsis prior to surgery (OR 3.2 95%, CI 1.89–5.43) and hypoalbuminemia <3.5 g/dL (OR 9.07, 95% CI 4.01–20.5) are additional patient-intrinsic factors that are significantly associated with anastomotic leakage [12].

Conceptually, the key to a successful anastomosis is the precise union of 2 viable intestinal ends while completely avoiding tension. Additional important factors in the creation of an intestinal anastomosis are the use of a meticulous technique and adequate irrigation [13,14]. However, in practice, the choice of anastomosis technique is influenced by the diameter of the intestinal ends, the presence of edema, accessibility to the anatomical site, contamination, and the materials available [13,14]. The manual technique has been compared with staple anastomosis in multiple randomized and controlled studies, which have concluded that there are no significant differences in terms of morbidity, mortality, or incidence of failure in the anastomosis [13,14]. However, there are technical and intraoperative factors that impact the success of the intervention, including the urgency of the surgery (OR 1.55, 95% CI 1.02–2.35), the release of adhesions during surgery (OR 3.39, 95% CI 2.22–5.17), the use of manual suturing in a single plane (OR 2.32, 95% CI 1.17–4.6), the use of polypropylene as a suture material for manual anastomosis formation (OR 16.8, CI 2.1–129), and the need for 2 or more surgical reoperations (OR 4.93, 95% CI 1.95–12.4) [12]. Likewise, it has been reported that blood loss greater than 100 mL and/or multiple transfusions increase the incidence of leakage, as do surgical durations greater than 3 hours and fecal contamination [15]. In contrast, performing anastomosis (and not intestinal raffia) (OR 0.44, 95% CI 0.27–0.71) and providing nutritional support (OR 0.37, 95% CI 0.23–0.6) are protective factors against anastomosis failure [12].

Regarding the site of the anastomosis, it is important to note that the different segments of the digestive tract exhibit different behaviors [5]. In the TI, this is due to the fact that the anatomical characteristics of the segment may not provide adequate irrigation. As shown in Figure 4, the TI receives its blood supply mainly from the ileocolic artery, the terminal branch of the superior mesenteric artery, which is highly susceptible to thromboembolism and mesenteric ischemia [5]. The presence of the marginal artery of Drummond, a collateral pathway between the superior and inferior mesenteric arterial systems that runs close to the intestinal wall, may mitigate this risk [5]. However, less than half of the population has this fully developed collateral network around the splenic flexure, specifically at Griffith’s point [16]. This lack of collaterals from the left branch of the middle colic artery to the ascending left colic artery increases the risk of colonic ischemia and, therefore, hinders the success of this anastomosis [16].

When creating an anastomosis in the distal ileum, the anatomical and physiological characteristics of this segment should be considered. The last centimeters of the ileum wall, prior to the ICV, are known to have a thick circular muscle layer called the ileocecal sphincter [17]. This structure is usually slightly contracted, except during ingestion, since the gastroileal reflex intensifies peristalsis and allows emptying into the cecum [17]. Given the physiological importance of the ICV, its conservation during intestinal resection is important for the absorption of nutrients and the maintenance of the intestinal microbiota [18]. As a reference site for bacterial growth, the formation of necrotic tissue in the TI leads to an increase in gas and, therefore, an increase in intraluminal pressure, which can compromise the function of the ICV, leaving it dysfunctional [5,17]. This back pressure exerted by the ICV has been reported to increase the risk of fistula formation or dehiscence in the anastomosis [5,17].

While no specific studies have addressed the outcomes of distal ileum anastomosis in the adult population, research in neonates and Crohn’s disease offers relevant insights. Martos Rodríguez et al (2022) examined the safety of anastomosis near the ICV in neonates with focal intestinal perforation, emphasizing the long-term benefits of preserving the ICV [19]. Similarly, studies in Crohn’s disease highlight the importance of preserving the ICV due to its role in maintaining intestinal continuity and preventing complications such as bacterial overgrowth and diarrhea [20]. These studies suggest that anastomosis near the ICV can be performed safely with appropriate surgical techniques to mitigate pressure on the suture line. Although focused on different populations, these findings align with our cases and support the feasibility and safety of anastomosis near the ICV in adults. In our cases, the feasibility and safety of anastomosis near the ICV was supported despite concerns regarding vascularization and pressure near the ICV.

Two of the cases described above presented with acute mesenteric ischemia, as shown in Table 1. According to the guidelines of the World Society of Emergency Surgery, surgical intervention in this context should include the restoration of blood flow to the ischemic intestine, resection of all nonviable regions, and preservation of the entire viable intestine [21]. Therapeutic alternatives for patients with mesenteric ischemia range from conventional management to surgical resection [21]. It is important to bear in mind that intestinal segments presenting with irreversible ischemia and gangrene require immediate re-section; this can lead to an increased risk of a massive bowel resection (involving more than 200 cm of small intestine) that may result in short bowel syndrome (SBS), which has a 5-year mortality rate of 30% [22].

SBS is defined as a small intestine less than 100–120 cm in length without a preserved ileocecal junction or less than 60 cm in length with an intact ileocecal junction [23–25]. This syndrome poses several challenges for the nutritional autonomy of the patient; those with a shorter residual intestine have a greater probability of developing kidney and liver failure, which increases their likelihood of depending on parenteral nutrition [23–25]. The absorption of fats and carbohydrates has been shown to be significantly reduced; to 50–75% of what is ingested after intestinal resection with a residual intestine of 30 to 100 cm, while protein absorption is less affected (80% of intake) [23–25]. Although oral intake can meet the energy and nitrogen needs of the patient, parenteral nutrition is necessary for electrolytes, calcium, magnesium, zinc, and phosphorus [23–25]. The requirement of parenteral nutrition for preventing malnutrition is more likely for intestinal resections greater than 75%, while those less than 50% may not require such nutritional support [23–25]. The configuration of the intestinal remnant, regardless of continuity between the ileum and colon, influences the prognosis, as a shorter length of the residual jejunum or duodenostomy results in a greater risk of loss of nutritional autonomy [23–25]. Therefore, SBS not only affects the patient’s ability to absorb nutrients but can also compromise his or her nutritional independence, requiring specialized nutritional and medical care and increasing costs [23–25]. Given the above, the resection of long intestinal segments should be limited to patients for whom there are no treatment alternatives. Studies based on wound-control surgery for abdominal trauma have shown that the preservation of continuity, both in the small and large intestines, is a safe alternative and should be attempted whenever possible [26].

The cases presented here contribute to the growing evidence that a conservative approach to intestinal resection is both feasible and effective, particularly when mesenteric ischemia and intestinal complications are diagnosed promptly. Mesenteric ischemia is a common cause of SBS due to the frequent need for extensive resections; however, in our cases, such outcomes were avoided [27,28]. Early diagnosis and timely management allowed for the preservation of intestinal length, thereby reducing the risk of SBS and enhancing the patients’ nutritional autonomy.

The other reported case involved a complicated incarcerated inguinal hernia that resulted in intestinal resection. Subsequently, dehiscence of the anastomosis occurred, which led to a second intervention to perform a second intestinal resection and side-to-side anastomosis of the TI. Intestinal obstruction caused by a hernia is a potentially risky surgical emergency associated with high rates of morbidity and mortality [29]. It also causes significant surgical adverse effects following hospital admission, and thereby adversely affects the lives of millions of people. According to a global 2015 WHO report, approximately 3.2 million people suffer from intestinal obstruction, with a reported mortality of 264 000 (8.25%) [29]. It is also important to recognize that the surgical approach for intestinal obstruction sometimes leads to a variety of postoperative complications depending on the specific procedure performed, such as surgical site infection, wound dehiscence, pneumonia, and/or sepsis [30]. A cohort of approximately 1001 patients who underwent surgery for intestinal obstruction was followed by Fevang et al, revealing a wide variety of complications, including pulmonary, cardiac, genitourinary, and neurological complications; thrombosis/embolism; major bleeding; wound infection/dehiscence; abdominal abscess; fistulas; and septicemia [31]. In that study, 23% (225 patients) of the patients presented with 1 or more complications, and multivariate regression analysis revealed that the factors associated with the incidence of complications were increased age, the presence of morbidities prior to surgery, a delay in treatment of more than 24 hours, and a history of 1 or more previous surgeries [31].

Open abdomen is a technique used in complex surgical situations, with mortality rates ranging from 21% to 55% according to the literature [32–34]. This approach is employed for the management of multiple conditions, although the most common causes are infectious peritonitis and damage control surgery for traumatic etiologies [35,36].

Given that this method is associated with increased patient mortality rates, it is essential to establish more promising approaches for temporary abdominal closure. In our cases, NPWT was used. NPWT is an innovative and adaptable method that enhances wound healing by applying negative pressure. This technique helps reduce intra-abdominal hypertension and facilitates tissue regeneration [37]. Among the most common NPWT systems are the Barker vacuum pack, VAC, the ABThera system, and the Suprasorb continuous negative pressure (CNP) system [38–42].

However, several complications can arise with the use of this therapy, such as anastomotic dehiscence. In a cohort of 97 patients, 47 anastomoses were performed, and 57% of them exhibited dehiscence, highlighting its relative frequency in hospital settings. Additionally, malnutrition characterized by albumin levels below 2.15 has been identified as a key factor in the occurrence of dehiscence due to its implications in the healing process [43]. Similarly, the use of vasopressors has been linked to impaired intestinal blood flow, increasing the likelihood of complications. Lastly, another factor to consider in preventing complications is the pressure level in NPWT systems, as pressures exceeding 110 mmHg are significantly associated with a higher risk of anastomotic dehiscence [43].

In an effort to prevent complications, the use of VAC has been shown to be effective and safe for closing defects and draining any present collections [44,45]. An important point with regard to the 3 cases described in this report is the use of VAC in postsurgical management. In this regard, its use was chosen because it can noninvasively and dynamically aid in promoting closure due to negative pressure, reduce excess fluids, and favor the stimulation of angiogenesis and primary closure of the abdominal wall [46].

The 3 patients described in this report were diagnosed with intra-abdominal infection, with peritonitis to different degrees. This complication, commonly caused by perforation or anastomotic leakage of the small intestine, is associated with a high mortality rate, reaching between 10% and 30% [47]. Intestinal resection and the creation of a proximal stoma have traditionally been the preferred surgical approach in severe cases of secondary peritonitis due to perforation or ischemia of the small intestine. However, the creation of a stoma, as previously described, carries nutritional risks and risks of SBS and long-term complications [48].

For this reason, other viable alternatives should be considered, such as primary anastomosis with an open abdomen or wound-control surgery with VAC, which was used for all the patients in this report in the postoperative period. VAC therapy has emerged as an alternative strategy for addressing complicated secondary peritonitis [47,49]. Originally created for the prevention and management of the lethal triad of hypothermia, acidosis and coagulopathy in traumatic settings, this technique has shown favorable results in the treatment of secondary peritonitis and has been used after the formation of intestinal anastomoses [47]. This technique facilitates the performance of programmed laparotomies, allowing abdominal lavage, intestinal inspection, and early detection of possible leaks, as well as the conduction of additional surgical procedures for preventing serious complications [47].

The use of the VAC system after intestinal anastomosis is controversial. Although VAC therapy has been recognized as safe, numerous studies have indicated that it is associated with potential complications, such as anastomotic dehiscence and intestinal fistula formation [47,50]. One example is a 2023 retrospective study by Rajabaleyan et al, in which 20 patients with fecal peritonitis treated with intestinal resection and primary anastomosis were evaluated, followed by open abdominal surgery with VAC, which showed a higher rate of leakage and formation of entero-atmospheric fistulas, especially in patients with severe peritonitis [47]. However, a systematic review by Bruhin et al provided contrasting evidence, suggesting that in vulnerable patients, such as those with intestinal anastomosis or loop edema, a VAC pressure of 80 mmHg or less is recommended to avoid complications. This approach is based on the assumption that increased pressure could reduce blood flow to the anastomosis area, which could increase the risk of anastomotic dehiscence [51].

Similarly, additional research has highlighted the challenges associated with prolonged VAC use in patients with secondary peritonitis. Mintziras et al demonstrated that prolonged treatment with VAC, regardless of the formation of a primary anastomosis or presentation with an open abdomen due to secondary peritonitis, results in a relatively low rate of fascial closure and a high risk of fistula formation. They established that, ideally, to reduce the incidence of fistulas, the duration of VAC treatment should not exceed 13 days, and a negative pressure of −100 mmHg should be maintained [50]. In all of the presented cases, VAC therapy was administered for a short duration and under the recommended pressure settings, aligning with these guidelines.

These findings underscore the importance of a periodic reevaluation of the treatment method to avoid complications, prioritizing early closure when possible [50]. It is important to note the need to identify both modifiable and nonmodifiable risk factors associated with VAC-related anastomotic dehiscence to prevent possible complications in the future. These factors include coronary heart disease, severe peritonitis, and fistula development. Recognizing both modifiable and nonmodifiable factors is essential for preventing these complications [50,52].

It is important to emphasize that in our patients, VAC treatment following intestinal anastomosis was carried out without significant complications. However, it is important to recognize that each patient and each situation must be considered individually so that the efficacy and safety of the treatment may vary according to the circumstances of each patient and the experience of the treating group. Therefore, it is essential to perform a thorough evaluation of each patient and closely monitor his or her progress during treatment with VAC to identify and address any potential complications in a timely manner.

Conclusions

In conclusion, the presented cases highlight the feasibility and safety of TI anastomosis for the management of patients with mesenteric ischemia and intestinal complications, along with the use of NPWT as an adjuvant technique that supports recovery and the management of intestinal complications. These case reports are of particular interest as they challenge conventional surgical practices regarding TI anastomosis near the ICV and the use of NPWT. Traditionally, performing anastomoses close to the ICV is considered a risky procedure due to concerns about inadequate vascularization, increased pressure, and the potential for complications like anastomotic dehiscence or fistula formation. Similarly, NPWT, while widely used for wound management, is often approached with caution in patients undergoing intestinal surgery due to the risk of anastomotic dehiscence and fistula formation. However, the reports presented here demonstrate that, with a careful patient approach and close monitoring, both practices – performing anastomosis near the ICV and utilizing NPWT – can be carried out successfully without adverse outcomes. In all 3 cases, the patients recovered without complications, highlighting that these techniques, though considered high-risk in some studies, can be viable alternatives when performed in well-controlled settings.

These cases represent a challenge for surgeons due to several factors that can affect postoperative complications, including the vascularization of this anatomical area and the pressure exerted near the ICV, as well as other individual factors specific to the patient. Although the evidence supporting this technique is limited and most recommendations suggest avoiding anastomosis at this level to prevent anastomotic dehiscence and other complications, these cases challenge this notion by demonstrating that it is possible to perform the anastomosis without the need to generate a short bowel or other associated complications. This case report encourages the surgical community to control modifiable risk factors and identify nonmodifiable risk factors in patients who are undergoing intestinal resection and who may be capable of achieving continuity of the gastrointestinal tract in a safe manner. It is necessary to guide and strengthen this experience with analytical, descriptive, observational studies that support reliable and safe behaviors for patients receiving evidence-based medical treatment.