Laparoscopic-Assisted Percutaneous Cryoablation of Abdominal Wall Desmoid Fibromatosis: Case Series and Local Experience

Abstract

Background: Desmoid tumors (DTs) are rare, non-metastatic but locally aggressive connective tissue neoplasms. While standard treatments include surgery, radiation, and ablation, current guidelines advocate active surveillance unless tumors progress or symptoms worsen. Cryotherapy has shown promise in treating DTs; however, its application in rectus abdominis DTs has been limited due to proximity to critical intra-abdominal structures. Methods: This case series describes a novel approach involving laparoscopic-assisted cryoablation in three patients with rectus abdominis DTs. Laparoscopic visualization was employed to improve tumor localization and procedural safety during percutaneous cryoablation. Results: The average tumor size was 7.4 cm, and a mean of 14 cryoprobes were used per case. All patients experienced complete symptom resolution. One patient developed a complication—injury to the inferior epigastric artery—requiring embolization. Follow-up imaging at three months showed significant tumor shrinkage and necrosis in two patients. The third patient had increased lesion volume due to post-procedural hematoma, although radiological markers of cryoablation efficacy were present. Conclusions: Laparoscopic-assisted cryoablation appears to be a feasible and effective technique for treating rectus abdominis DTs, providing symptom relief and favorable early tumor response. Further studies are warranted to evaluate long-term outcomes and validate this approach in broader clinical settings.

1. Introduction

Desmoid tumors (DTs) are rare neoplasms of connective tissue that, while lacking metastatic potential, can exhibit aggressive local invasion [1,2]. Most DTs arise sporadically and are associated with a mutation in exon 3 of the Catenin beta 1 (CTNNB1) gene, which can also arise because of trauma (e.g., surgery) or pregnancy or in individuals with a genetic predisposition, such as a mutation in the Adenomatous Polyposis Coli (APC) gene [1,3]. Managing DTs poses a significant challenge due to their unpredictable clinical course and potential impact on patients’ quality of life and daily activities [4,5]. Historically, DTs were treated with upfront surgical resection; however, patients who were deemed unresectable or refused surgery provided the initial evidence that a watch-and-wait approach could be feasible [6]. Several studies have provided evidence supporting an active surveillance-first approach, marking a significant shift in the management paradigm for DTs [7,8]. Hence, recent guidelines from the Desmoid Tumor Working Group recommend an active surveillance approach, with treatment deferred until there is clear evidence of tumor progression or a significant increase in symptom burden [7,9]. If active surveillance proves insufficient, management options expand to include both localized and systemic therapies. Localized treatment modalities for DTs include surgery, radiation therapy, and various ablative techniques.

Abdominal wall DTs present distinct clinical challenges, particularly due to their location and the complexities involved in treatment. Surgical resection is often considered the primary treatment modality following active surveillance or for patients presenting with symptoms, given the relatively low recurrence rates following surgery [10]. However, surgery is frequently associated with significant morbidity, including challenges related to abdominal wall reconstruction, which often necessitates the use of prosthetic mesh [11]. Achieving clear surgical margins can sometimes be difficult, based on the anatomical location of the DTs and their relationship to surrounding structures [12,13]. Radiation therapy is often used as an adjuvant therapy for positive surgical margins or in cases of tumor recurrence; however, its use is limited by associated morbidity, particularly in younger patients [14]. While systemic therapies have shown efficacy in certain instances, the side effect profile often leads to patients discontinuing or refusing treatment, further complicating the management of these tumors [15,16].

Cryotherapy—a minimally invasive technique involving repeated cycles of freezing and thawing to induce cellular necrosis—has emerged as a promising localized treatment for DTs. Reported outcomes vary, with symptom relief rates ranging from 20% to 100% and 3-year progression-free survival (PFS) rates between 68% and 82% [17,18,19]. However, the application of cryotherapy may be limited in cases where tumors are located near critical structures, such as the small bowel and peritoneal organs, particularly in cases involving the rectus abdominis muscle [18,20]. To mitigate these risks, laparoscopic-assisted cryoablation has been proposed as a novel approach, enabling direct visualization of the abdominal wall and adjacent structures. This technique employs carbon dioxide (CO₂) insufflation to displace and protect peritoneal organs, thereby enhancing both the safety and precision of the procedure [21].

This report describes three cases where laparoscopic assistance was used during percutaneous cryoablation of rectus abdominis desmoid tumors, assessing the technique’s efficacy and safety.

2. Case Presentation

Patients were selected and offered cryoablation following a case review by a soft tissue multidisciplinary tumor board, which included specialists in surgery, medical oncology, radiation oncology, orthopedics, pathology, and radiology, in accordance with institutional protocol. Eligibility required clinical or radiological progression on active surveillance or prior lines of therapy. All patients who underwent laparoscopic-assisted percutaneous cryoablation for desmoid tumors between January 2024 and July 2024 were included. While the institution had prior experience with open surgical cryoablation in patients with renal cell carcinoma, there had been no previous laparoscopic-assisted cases or use of surgical cryoablation in DTs. Written informed consent was obtained from all the patients during the clinic visit prior to treatment.

2.1. Patient Details

Case 1: A 32-year-old female initially presented with a progressively enlarging, painful mass on the left side of her abdomen. Ultrasound (US) and computed tomography (CT) imaging revealed a homogeneous, ovoid mass within the left rectus abdominis muscle, measuring 4.6 × 4.5 × 2.1 cm. A biopsy confirmed the diagnosis of desmoid fibromatosis with a CTNNB1 mutation. The case was reviewed at a multidisciplinary tumor board (MDT) meeting, where active surveillance was recommended. At the 3-month follow-up, the patient reported worsening pain. Repeat imaging showed tumor progression, with an increase in size to 7.5 × 5.0 × 3.2 cm. After further MDT discussion, a decision was made to proceed with laparoscopic-assisted cryoablation, considering the tumor’s location and the patient’s symptoms and young age.

Case 2: A 28-year-old female presented with an asymptomatic mass on the left side of her abdomen. US and magnetic resonance imaging (MRI) identified a well-defined mass within the left rectus abdominis, measuring 4.7 × 4.3 × 3.4 cm. A biopsy confirmed the diagnosis of desmoid fibromatosis with a CTNNB1 mutation. The case was reviewed in an MDT meeting, and active surveillance was recommended. At the 2-month follow-up, the patient reported worsening pain. Repeat imaging demonstrated tumor progression, with the mass increasing in size to 7.6 × 7.2 × 7.1 cm. After further discussion in an MDT meeting, she was referred for laparoscopic-assisted cryoablation as the next step in management, given the tumor’s location and the patient’s symptomatology and young age.

Case 3: A 26-year-old female presented with an asymptomatic lump in the right lower abdomen, first noticed after delivery, which progressively increased in size. US and CT revealed an intramuscular soft tissue mass within the right rectus abdominis, measuring 6.2 × 3.5 × 4.7 cm. A biopsy confirmed desmoid fibromatosis with a CTNNB1 mutation. After review by the MDT, she was placed on active surveillance. During her follow-up visit, she reported increasing mass size and worsening pain. Repeat imaging showed tumor progression, with the mass now measuring 7.1 × 4.6 × 6.8 cm. As a result, she was offered laparoscopic-assisted cryoablation, given the tumor’s anatomical location and the patient’s clinical symptoms and young age.

Figure 1 shows the preoperative imaging for all three patients, and

Table 1. Patient demographics with clinical and desmoid tumor characteristics.

Patient Number	Patient 1	Patient 2	Patient 3
Age (years)	32	28	26
Sex	Female	Female	Female
Tumor location	Rectus abdominis	Rectus abdominis	Rectus abdominis
Tumor size at diagnosis (cm) 1	5.5	4.7	6.2
Tumor size pre-cryotherapy (cm) 1	7.5	7.6	7.1
Tumor volume pre-cryotherapy (cm3)	60	194.2	111
Prior treatment	Active surveillance	Active surveillance	Active surveillance

¹ Largest diameter.

summarizes the patients’ demographics and desmoid characteristics.

2.2. Procedure and Technique

All procedures were performed under general anesthesia in a hybrid surgical suite by an interventional radiologist experienced in cryoablation and a surgical oncologist. Following induction, a 10 mm trocar was inserted in the periumbilical region, and the abdomen was insufflated with CO₂ to a pressure of 20 mmHg. In the third patient, a cut-down access for pneumoperitoneum was performed in the left upper quadrant, as the tumor occupied the periumbilical region.

Cryoablation was conducted using a percutaneous, US, and CT-guided approach. Complete ablation was attempted in all cases, ensuring a 5–10 mm safety margin. Tumor puncture and probe advancement were performed under US guidance (Figure 2). Direct tumor puncture was achieved in all cases, and the CO₂ did not interfere with US probe placement visualization. The probe placement was confirmed laparoscopically (Figure 3) and using mobile non-contrast CT. A variety of IceSphere and IceForce cryoablation probes (Boston Scientific, MA, USA) were selected based on the tumor size and the manufacturer’s predicted ablation volumes, as assessed by the interventional radiologist, with a spacing of 1–1.5 cm between probes. Hydro-dissection was performed between the tumor and skin to protect the skin, as well as application of sterile heat packs, while CO₂ insufflation served as a barrier between the abdominal wall and intraperitoneal organs. Cryoablation was performed using a double-freeze protocol, consisting of two 10 min freezing cycles separated by a 5 min passive thaw. The first freezing cycle was performed using 100% freezing power, while the power in the second freezing cycle was adjusted to protect the skin. Ice ball formation and its extent were monitored laparoscopically (Figure 4), as well as by US and intermittent CT. Active thawing was initiated after the second freezing cycle to ensure resolution of the ice ball before the abdomen was desufflated, and ice spillage into the peritoneal cavity, if present, was suctioned using laparoscopic instruments. At the conclusion of the second freezing cycle, a final non-contrast CT scan was performed to delineate the maximum ablation zone, identify any untreated tumor areas, and confirm the absence of injury to adjacent structures. Following the procedure, the patients were transferred to the post-anesthesia care unit and admitted overnight for pain management and observation.

2.3. Follow-Up

The patients underwent follow-up imaging (CT or MRI) three months after cryoablation, in accordance with the institution’s protocol. The proposed follow-up schedule included imaging every 3 months during the first year, every 6 months up to year 3, and annually thereafter, completing a 5-year follow-up period based on the institutional criteria for DT. Imaging was performed prior to each follow-up clinic visit. Reports were generated at the discretion of the interpreting radiologist, as the institution does not currently use a standardized reporting template or criteria. Follow-up for these three patients remains ongoing.

2.4. Clinical Outcomes

All three patients underwent ultrasound- and CT-guided laparoscopic-assisted percutaneous cryoablation (Figure 5). At diagnosis, the average tumor size was 5.4 cm (range 4.7–6.2 cm), increasing to 7.4 cm (range 7.1–7.6 cm) preoperatively. The mean tumor volume (TV) prior to cryoablation was 121.7 cm³. TV was estimated using the formula V = 0.5  ×  L × W × D, where V is the tumor volume, L is the tumor length, W is the tumor width, and D is the depth of the tumor [22]. All the patients initially underwent a period of active surveillance, which was unsuccessful because of tumor progression and worsening symptoms. The average procedure duration, including anesthesia, was 159 min (range 103–202 min), with a mean of 14 probes used (range 10–19). All patients were admitted for overnight observation and pain management following the procedure. Cryoablation was attempted with curative intent in all cases.

Postoperative complications included skin blistering in one patient, which resolved with conservative management, and cellulitis in another patient, which required a short course of antibiotics. Both patients were discharged home the following day. The third patient experienced a fracture of a large portion of the ice ball intraoperatively, which detached and contacted the bowel. The area was irrigated and suctioned without evidence of bowel injury. The ice ball fracture was also believed to have fractured the ipsilateral inferior epigastric artery, leading to intraoperative bleeding. The bleeding was identified laparoscopically, and manual compression was performed, followed by angioembolization of the inferior epigastric and internal mammary arteries with coils and Gelfoam^® (Pfizer, New York, NY, USA) in the hybrid suite (Figure 6). This patient experienced a brief episode of hypotension, which was managed with fluid resuscitation. Hemostasis was confirmed both angiographically and laparoscopically. Because of pain, this patient had an extended postoperative hospital stay of 6 days.

Table 2. Laparoscopic-assisted desmoid cryoablation procedure and post-procedure details.

Patient Number	Patient 1	Patient 2	Patient 3
Indication	Pain, growth	Pain, growth	Pain, growth
Procedure duration (minutes)	202	103	173
Number of probes	10	19	13
Length of stay (days)	1	1	6
Complications	Skin blistering	Cellulitis	Bleeding

summarizes the periprocedural details.

The mean follow-up duration for the first clinic visit was 92 ± 7.1 days. In the first patient, follow-up imaging revealed a 20% reduction in tumor size and a 51.7% reduction in TV, with hypo-enhancement and central necrosis. The second patient’s tumor size remained unchanged (7.6 cm), but there was an 18.7% reduction in TV, with MRI showing hypo-enhancement of the entire tumor. The third patient exhibited a 94.4% increase in tumor size and a 107.8% increase in TV due to hematoma formation following the inferior epigastric artery injury. However, MRI also demonstrated hypo-enhancement in the tumor, a radiologic finding indicative of non-viable tissue and consistent with effective cryoablation. Hence, although the vascular injury led to increases in lesion size due to hemorrhage, it did not necessarily compromise the overall success of the ablation procedure. All the patients experienced complete pain resolution in their follow-up visits, which was subjectively assessed without the use of a pain scale. Follow-up is still ongoing, and long-term outcomes will be reported in the future.

Table 3. Outcomes and tumor response.

Patient Number	Patient 1	Patient 2	Patient 3 *
Follow-up (days)	82	96	98
Mass size on follow-up (cm) 1	6.0	7.6	13.8
Total volume on follow-up (cm3)	28.9	157.8	230.7
Size change	−20%	0%	+94.4%
Volume change	−51.7%	−18.74%	+107.8%
Characteristics change	Hypo-enhancement with central necrosis	Hypo-enhancement	Hypo-enhancement
Symptom change	Resolution of pain	Resolution of pain	Resolution of pain

¹ Largest diameter. * The observed increase in tumor size and volume was attributed to hematoma formation, as determined by radiological assessment.

summarizes the outcomes at follow-up.

3. Discussion

In this limited institutional experience, we report three cases of laparoscopic-assisted cryoablation of DTs of the rectus abdominis, utilizing a collaborative approach between interventional radiology and surgical oncology. At the 3-month follow-up, imaging demonstrated radiological evidence of a treatment response, with changes in tumor size, volume, and enhancement characteristics. Clinically, all three patients reported complete resolution of pain. The first two cases proceeded without significant complications, with only a grade 1 Clavien–Dindo event observed. However, one case was complicated by intraoperative bleeding resulting from an injury to the inferior epigastric artery, requiring angioembolization to control the hemorrhage and leading to an extended hospital stay. Despite this complication, the current technique offers a major advantage over traditional surgical resection by minimizing the morbidity associated with wide local excisions and complex abdominal wall reconstructions, which often require prosthetic mesh placement and carry a risk of postoperative complications. By integrating laparoscopic assistance with percutaneous cryoablation, this approach aims to preserve the therapeutic efficacy of cryoablation while enhancing procedural safety through improved visualization and organ protection.

Cryoablation offers distinct advantages over other minimally invasive techniques, such as radiofrequency ablation (RFA) and high-intensity focused ultrasound (HIFU), in the management of DTs. While RFA has been used in the treatment of both abdominal wall and extra-abdominal DTs with reasonable outcomes, its use has been limited to small case series and is associated with notable complications, including wound issues, soft tissue infections, and tissue necrosis [23,24]. In contrast, HIFU is a non-invasive, non-thermal ablation modality that utilizes focused ultrasound waves to induce coagulative necrosis. This technique can be guided either by ultrasound or magnetic resonance imaging [23,25]. Although several case series have reported the use of HIFU in DTs, the reported reduction in tumor size has ranged from only 35% to 63% [23], which is comparatively lower than the size reductions typically achieved with cryoablation. Additionally, cryoablation provides the added advantage of precise targeting under image guidance, as well as real-time monitoring of the ablation zone, which may contribute to its superior efficacy and safety profile.

Symptom management remains a key factor in DT treatment, with initial cryoablation experiences showing varied subjective symptom relief, ranging from 20% to 100% (19–21). The degree of pain relief also varies. A systematic review by Vora et al. [26] reported partial or complete responses in 37.5% to 96.9% of cases. This improvement typically occurs gradually over a 6-month period post-procedure [18,27]. In this study, all patients experienced full symptom resolution within 3 months after treatment. Although follow-up was insufficient to assess disease progression or disease-free survival, post-cryoablation PFS rates have been reported to range from 85.1% at 1 year to 77.1% at 5 years [20,28].

Preoperative surgical and radiological planning is crucial for the successful ablation of DTs, as risk stratification and technical feasibility depend on evaluating tumor characteristics such as size, location, and proximity to skin and adjacent organs [29]. MRI is widely regarded as the gold standard diagnostic tool for DTs and is frequently used in preoperative planning [30]. During cryoablation, US and CT scans are used to guide probe placement and determine the number of probes required for complete or partial cryoablation. In laparoscopic-assisted cryoablation, this is enhanced by direct visualization of the deeper margin, particularly the peritoneum, and to avoid injury to intraperitoneal structures (i.e., bowel) with the use of pneumoperitoneum. The success of cryoablation procedures is generally closely tied to precise intraoperative image guidance, predominantly CT-based. However, CT’s inability to reliably differentiate between tumor and healthy tissue limits its capacity to directly assess the success of cryoablation procedures [31,32].

As with all new procedures, intraoperative risks must be considered, anticipated, and mitigated. During the second thaw cycle for patient 3, the ice ball split apart, ultimately falling onto the exposed bowel. At that time, only a camera port was in place; two additional 5 mm ports were inserted as working ports to clear the ice ball using warm irrigation. No bowel injuries were identified intraoperatively. The pneumoperitoneum is integral to the procedure to protect the intra-abdominal contents; however, additional safety measures for situations where the ice ball might fall had not been previously considered. For future procedures, the team plans to consider placing additional ports at the start and possibly introducing a protective barrier—such as a sponge or plastic cover—between the intra-abdominal contents and the ice ball to mitigate similar risks. Another issue was the inferior epigastric injury caused by the ice ball fracturing the vessel. All procedures were planned in the hybrid suite with interventional radiology capabilities, ensuring immediate access for angioembolization if needed. It is essential that these procedures are performed with the appropriate technology and equipment in a specialized center to ensure patient safety.

This patient series evaluates the potential feasibility and safety of an innovative, minimally invasive approach for treating extra-abdominal DTs, particularly those involving the rectus abdominis, where concerns about deep margins and proximity to intra-abdominal organs are significant. This technique may offer an alternative for patients experiencing disease progression during active surveillance or other lines of therapy. The observed efficacy aligns with the existing literature, and the safety profile appears comparable. However, the conclusions regarding safety and feasibility should be interpreted with caution because of the small sample size, limited follow-up duration, and the occurrence of a major complication in one of the three cases, which limits the generalizability of these findings. As such, long-term efficacy remains uncertain. Successful implementation of this technique depends on close multidisciplinary collaboration—particularly between interventional radiology and surgical oncology, as well as discussion at MDT—highlighting the importance of its use within specialized centers with the necessary expertise.

4. Conclusions

As this is a novel procedure at the author’s institution, variability in outcomes due to the learning curve and technical nuances is anticipated. Given the exploratory nature of this technique, further research is essential to validate these initial findings. Future studies should focus on evaluating the reproducibility of these results and assessing the long-term efficacy and clinical outcomes. Such studies will be critical in defining the clinical utility of this technique, determining its place within the standard of care, and providing the necessary evidence to support the development of clinical practice guidelines.