Single-Port Hybrid Open and Laparoscopic Approach for Pediatric Appendectomy for Acute Appendicitis

Acute appendicitis is one of the most common surgical conditions in pediatric patients, and laparoscopic appendectomy is widely accepted as the standard treatment. However, conventional multi-port laparoscopic techniques and intracorporeal single-port approaches can be technically demanding in children due to the limited intra-abdominal working space and instrument interference.

This case involved a 4-year 9-month-old girl presenting with acute abdominal pain and vomiting. Ultrasonography demonstrated appendiceal enlargement with suspected appendicolith, supporting the diagnosis of acute appendicitis and indicating a potential risk of progression and recurrence.

To address both anatomical and technical considerations, we adopted a hybrid laparoscopic–open appendectomy using a single umbilical incision. A small longitudinal incision was made at the umbilicus, and a wound protector with a multiport cap was applied. Adequate exposure was confirmed when the surgeon could insert an index finger into the abdominal cavity. The laparoscopic component was limited to identifying and grasping the appendix, which was then retracted and exteriorized through the umbilical incision. Appendectomy was performed extracorporeally under direct visualization, thereby avoiding technically demanding intracorporeal maneuvers. In this case, the degree of inflammation was mild, allowing smooth mobilization and uncomplicated extracorporeal removal.

This hybrid approach simplifies the procedure while preserving the advantages of minimally invasive surgery, including reduced operative complexity and improved cosmetic outcomes, and represents a practical option for pediatric appendicitis. 

Pediatric surgery; acute appendicitis; laparoscopic appendectomy; transumbilical single-port surgery.

Acute appendicitis is one of the most common surgical conditions in the pediatric population, with a lifetime risk of 7–8% and a peak incidence in the teenage years. Laparoscopic appendectomy has emerged as the widely accepted standard for the treatment of appendicitis in children, although several laparoscopic approaches have been described. The most common approach in both adults and children is 3-port laparoscopic appendectomy, which remains a reliable technique using an umbilical port and 2 additional ports placed in the right flank, left flank, or suprapubic region. Another approach is transumbilical two-port laparoscopic appendectomy, which requires single-handed manipulation when cauterizing mesoappendix and ligating the base of the appendix.¹

Indeed, the three-port approach allows easier manipulation of tissues around the appendix. However, it requires additional port-site incisions other than a port at the umbilicus. This inevitably results in visible postoperative scars that should be avoided especially in children as such scars, even tiny at the time of surgery, become larger as they grow. In contrast, the transumbilical approach offers superior cosmetic outcomes, but the narrow space at the umbilicus often leads to significant interference between the laparoscope and working instruments, thereby increasing procedural complexity. On the other hand, conventional open appendectomy, which is no longer considered a first-line approach, provides a wider operative field just above the appendix, making subsequent manipulation much easier.

This case involves a 4-year 9-month-old girl who presented with severe abdominal pain and vomiting that began the day before the first visit to a local medical center. Laboratory tests revealed mildly elevated inflammatory markers, including the white blood cell count, 9.1 × 10³/μL, and C-reactive protein, 0.31 mg/dL.

Based on the presenting symptoms, laboratory findings, and subsequent physical examination, the Alvarado score² was 5 (migration of pain, 1; anorexia, 1; nausea, 1; tenderness, 2). The Pediatric Appendicitis Score³ was 5 (right lower quadrant tenderness, 2; anorexia, 1; nausea, 1; migration of pain, 1). Acute appendicitis could not be excluded, and ultrasonography was therefore performed.

The patient presented with acute abdominal pain that began one day prior to her initial emergency visit to a local medical center. The pain was intermittent, occurring approximately every 10 minutes, and was accompanied by nausea and vomiting.

On physical examination, the abdomen was soft and flat, with diffuse tenderness. The pain had migrated from the epigastric region to the lower abdomen.

At our institution, the diagnosis of acute appendicitis is primarily established using ultrasonography, with contrast-enhanced computed tomography reserved for cases in which ultrasound findings are inconclusive.
In this case, ultrasonography revealed edema at the tip of the appendix, with a diameter exceeding 6 mm. A suspected appendicolith was also identified at the appendiceal tip, suggesting a potential risk for recurrence. Plain abdominal radiography demonstrated no significant abnormalities.

Acute appendicitis is an inflammatory condition of the appendix, most commonly caused by luminal obstruction due to fecaliths, infection, or less frequently tumors. The disease typically begins with vague periumbilical pain, which subsequently localizes to the right lower quadrant as inflammation progresses. Associated symptoms often include anorexia, nausea, vomiting, and low-grade fever. Appendicitis can be broadly classified into uncomplicated and complicated forms. Uncomplicated appendicitis is defined by the absence of perforation, whereas complicated appendicitis involves perforation, abscess formation, or generalized peritonitis. If left untreated, the inflammatory process may progress from mucosal inflammation to transmural necrosis and eventual perforation, leading to intra-abdominal infection.⁴

Notably, the natural history of appendicitis differs between pediatric and adult populations. In children, particularly in younger age groups, disease progression tends to be more rapid, with a higher risk of early perforation even after a relatively short duration of symptoms. In contrast, adults generally exhibit a more gradual disease course with more typical symptom progression. These differences are thought to be related to variations in pathophysiology, such as a higher prevalence of lymphoid hyperplasia and less well-developed omental containment in children, as well as differences in clinical presentation that may delay diagnosis.^5–7

Surgical Management

Laparoscopic appendectomy is the standard surgical treatment for acute appendicitis in children, offering minimal invasiveness, reduced postoperative pain, and improved cosmetic outcomes.¹

Conventional three-port laparoscopic appendectomy remains the well-accepted standard, while alternative approaches such as transumbilical techniques have been developed to further reduce surgical trauma. These minimally invasive approaches demonstrate comparable clinical outcomes to the conventional laparoscopic approach, including similar complication rates and length of hospital stay, although they are often associated with longer operative times and greater technical complexity.⁸

While cosmetic benefits are observed in both adults and children, port-site scars in pediatric patients may become more prominent with growth; thus, transumbilical approaches offer an additional cosmetic advantage.¹

Nonoperative Management

Nonoperative management with antibiotics may be considered in selected patients with uncomplicated appendicitis. Recent randomized trials, including the APPAC trial, have demonstrated that antibiotic therapy can be an effective initial treatment in a subset of patients, although the study population was limited to adults aged 18 years and older.⁹ However, recurrence rates remain substantial, with approximately 15–41% of patients experiencing recurrent appendicitis within one year.⁴ Furthermore, the cumulative appendectomy rate has been reported to exceed 40%.⁹

In the pediatric population, an international multicenter randomized trial and a systematic review with meta-analysis reported that treatment failure following antibiotic therapy occurred in approximately one-third of patients, and the relative risk of mild-to-moderate adverse events was higher compared with appendectomy.^10,11 These findings suggest that nonoperative management for non-perforated appendicitis is inferior to surgical treatment in children.

The success of nonoperative management depends on careful patient selection. Factors associated with treatment failure include the presence of an appendicolith, marked appendiceal dilation, and advanced inflammatory changes on imaging. In addition, patient condition and preference should be considered when determining the treatment strategy.⁹

Although nonoperative management may avoid surgery in the short term, the risk of recurrence and subsequent intervention remains a significant limitation. Therefore, while this approach may be appropriate in selected cases, surgical treatment remains the standard of care, particularly in pediatric patients.

Given the rapid progression and increased risk of early perforation in pediatric appendicitis, prompt definitive treatment is warranted. Although nonoperative management may be considered in selected cases, it is associated with a substantial risk of treatment failure and recurrence, particularly in the presence of an appendicolith, as in this case. Therefore, laparoscopic appendectomy was selected as a definitive and reliable treatment to prevent disease progression and recurrence while achieving favorable postoperative outcomes.

Considering the limited working space in pediatric patients and the relatively short distance between the umbilicus and the appendix, we selected a hybrid laparoscopic–open approach through a single umbilical incision rather than a conventional multi-port or purely intracorporeal single-port technique. This approach allows extracorporeal appendectomy under direct visualization, thereby simplifying the procedure while maintaining the advantages of minimally invasive surgery.

In pediatric patients, the intra-abdominal cavity is smaller than in adults, which makes laparoscopic manipulation more technically demanding due to the limited working space. However, this smaller body size also results in a relatively shorter distance between the umbilicus and the appendix compared with adults. In addition, the pediatric abdominal wall is generally soft and compliant, and the appendix itself is also relatively flexible. These characteristics allow both the umbilical incision and the appendix to be readily mobilized and approximated, thereby facilitating extracorporeal delivery of the appendix.

Based on these anatomical and technical considerations, we perform a hybrid laparoscopic–open appendectomy for acute appendicitis. In this approach, a small longitudinal incision is made at the umbilicus, typically extending from the cranial to the caudal margin when the umbilicus is fully retracted anteriorly. A wound protector is then applied, onto which a specialized cap with two or three ports is mounted (Figure 1). Although a wound protector and a dedicated single-incision device were used in this case, a similar approach can also be performed using an infraumbilical incision with placement of two conventional ports, without specialized equipment. A key technical step in this procedure is the establishment of a minimally invasive yet sufficiently wide operative field at the umbilicus. As a practical intraoperative indicator, adequate exposure can be confirmed when the surgeon is able to insert an index finger through the umbilical incision into the abdominal cavity. Once this condition is achieved, the subsequent steps can generally be performed without difficulty. This approach allows the procedure to be performed in a reproducible manner without requiring advanced intracorporeal laparoscopic skills.

A)

B)

Figure 1. A, LAP PROTECTOR; B, E·Z ACCESS Photograph courtesy of Hakko Medical Co., Ltd., Japan.).

The laparoscopic component of the procedure only involves grasping the base of the appendix, retracting it toward the umbilical incision, and exteriorizing the diseased appendix. Appendectomy is subsequently performed extracorporeally under direct visualization. This hybrid technique avoids the most technically demanding steps of conventional laparoscopic appendectomy, such as intracorporeal dissection of the mesoappendix and ligation of the appendiceal base. In cases with severe inflammation or dense adhesions, complete exteriorization of the appendix toward the umbilicus may be difficult. Nevertheless, careful blunt or sharp dissection through the umbilical ports generally allows sufficient mobilization to enable extracorporeal delivery of at least a portion of the appendix. In some cases, additional blunt laparoscopic mobilization of the cecum may be required to facilitate delivery of the appendix to the umbilicus. Once a portion of the appendix is exteriorized, the remaining segment can, in most cases, be delivered extracorporeally by further dissection under direct vision. In addition, mobilization may occasionally be challenging when using a single working port, particularly when the inflamed appendix is densely adherent to surrounding tissues. In such cases, an additional port for a second working instrument can be incorporated into the wound protector cap; however, this may limit instrument maneuverability. Alternatively, an additional port can be placed at another site, such as the right or left flank or the suprapubic region. Although this approach technically constitutes a three-port procedure, it may still be considered a reduced-port technique from a cosmetic standpoint and a simpler method, as the laparoscopic component is largely limited to exteriorization of the appendix.

We generally adopt this hybrid approach as the first-line technique for appendectomy; however, several factors should be considered. First, in older children, the distance between the umbilicus and the appendix is greater, and the tissues tend to be less compliant, making extracorporeal delivery of the appendix more challenging. Based on our experience, most patients younger than 15 years are suitable candidates for this technique. In contrast, in patients aged 15 years or older—particularly patients with obesity, in whom a deep umbilical pit may limit adequate visualization and instrument maneuverability—this approach may be technically more demanding. Therefore, careful patient selection is required. Second, in patients with suspected perforated appendicitis based on imaging findings, in whom mobilization of the cecum and appendix is expected to be difficult, interval appendectomy may be considered. At our institution, this strategy is typically selected when the appendiceal base is located within an abscess and the duration of symptoms exceeds 48 hours prior to admission. In our practice, we preferentially begin with a single-incision approach and escalate stepwise by adding ports as needed. Specifically, additional ports are first placed at the umbilicus, followed by placement at another site if necessary, and ultimately conversion to a conventional multi-port configuration when required. This strategy allows the procedure to be successfully completed in the majority of cases, including those with the aforementioned challenges, while maintaining flexibility based on intraoperative findings.

The degree of inflammation was mild in this case, and the operation proceeded without difficulty. Although the appendix appeared macroscopically normal on intraoperative video, the combination of clinical presentation and imaging findings supported the diagnosis of acute appendicitis. Whether a macroscopically normal appendix should be removed remains controversial, particularly in pediatric patients, where the reliability of macroscopic assessment is limited and the risk of disease progression supports a more proactive surgical approach. A recent study supports appendectomy in pediatric patients undergoing laparoscopy for suspected appendicitis when no alternative pathology is identified, even if the appendix appears normal, with low morbidity and favorable clinical outcomes.¹² In the present case, histopathological examination ultimately confirmed the diagnosis of acute appendicitis.

Regarding the inversion of the appendiceal stump, it also remains controversial. In our practice, stump inversion is not routinely performed. Recent evidence supports this approach, demonstrating that simple ligation does not compromise treatment efficacy or increase postoperative complications or length of hospital stay.¹³

Although there is a potential risk of postoperative surgical site infection with this technique—given that the inflamed appendix is primarily manipulated through a small umbilical incision—our experience suggests that such infections are uncommon, likely due to effective isolation of the incision site by the wound protector. In addition, thorough pressurized irrigation of the wound at the end of the procedure may further reduce the risk of infection. Nevertheless, further studies are required to validate these observations. In the present case, no postoperative complications were observed.

In conclusion, this hybrid laparoscopic–open appendectomy represents a practical refinement that leverages pediatric anatomical characteristics to simplify the procedure. It combines the advantages of both laparoscopic and open techniques, including improved cosmetic outcomes and facilitation of tissue handling. Given the high prevalence of appendicitis in pediatric practice, this approach may serve as a useful and effective option for pediatric surgeons.

• LAP PROTECTOR Mini for 2–4-cm skin incisions (Hakko Co., Ltd., Japan) (Figure 1).
• E·Z ACCESS device compatible with the LAP PROTECTOR Mini (Hakko Co., Ltd., Japan) (Figure 1).
• Two or three 5-mm ports
• 5-mm, 30-degree laparoscope.
• 5-mm laparoscopic forceps.
• 3-0 absorbable suture (e.g., Vicryl).
• 5-0 absorbable monofilament (e.g., PDS).
• General instruments for open surgery.

Nothing to disclose.

Informed consent for filming and online publication of the images and clinical information was obtained from the patient’s parents and documented in the medical record.

The authors express sincere gratitude to Medical Engineer Akihito Inoue for his invaluable assistance and cooperation throughout the filming process. The authors are also deeply grateful to Operating Room Nurse Miki Hachitani for her dedicated support during the surgical procedure.