Use of a novel multi-purpose sponge for laparoscopic surgery: Does it have special relevance to robotically-assisted laparoscopic surgery?

BACKGROUND: The STAR System (Ekymed SpA) is a novel multipurpose sponge developed for conventional manual laparoscopic surgery.
MATERIALS AND METHODS: Between December 2012 and December 2014, we successfully used the sponge in ten robot-assisted and ten direct manual laparoscopic operations to achieve haemostasis, for blunt dissections, for atraumatic lifting of solid organs, to check for bile leaks, for cleaning the surgical field thus avoiding frequent use of suction or the application of haemostatic agents. The reason of the insertion (RI), the main use (MU) and any further use (FU), once inserted, were registered for each operation and compared between the two groups.
RESULTS: The principal RI was haemostasis for minor bleeding, without differences between the two groups (P = not significant). Regard to MU, in the robotic group cleaning the surgical field was utilised more than laparoscopic group (100% vs. 60%; P = 0.03). About FU, atraumatic solid organs lifting was more frequent during robotically assisted surgery than with laparoscopy (50% vs. 0%; P = 0.01). A statistically more frequent use of the sponge was registered during standard laparoscopy for the blunt dissection (30% vs. 80%; P = 0.03).
CONCLUSIONS: The STAR System was beneficial in both approaches, but it imparts added benefit during robotically-assisted laparoscopic surgery organs because of the lack of tactile feedback and because the operating surgeon is remote from the patient, and has to rely on the assisting surgeon in the sterile field for dealing with bleeding episodes, cleansing/mopping the operative field when necessary, who may not be experienced or completely proficient.

INTRODUCTION

Control of bleeding can be a challenging problem in laparoscopic surgery[1] and since the introduction of the laparoscopic approach, many techniques have been established to achieve safe and efficient haemostasis.[2] During laparoscopic surgery, visualisation of the bleeding point may prove difficult for several reasons including limited visualisation, contamination of the optic by blood, retraction of the bleeding vessel with the tissue, clot formation which absorb light and hence impair vision, etc.

A master-slave robotic manipulator, the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA), was introduced specifically to overcome the limitation of the degrees of freedoms (DoFs) imposed on the surgeon by the laparoscopic approach. More than a decade after its introduction, robotically-assisted laparoscopic surgery is still under evaluation in several surgical specialties, although randomised clinical trials have been few. Nonetheless, on a priori grounds, robotic-assisted laparoscopic surgery has several advantages over traditional direct manual laparoscopic surgery including increased DoFs with, easier instrument manipulation, motion scaling, stereoscopic three-dimensional vision, powerful magnification and improved ergonomics. The disadvantages of robotically-assisted laparoscopic surgery include high costs, longer operative times, total absence of tactile feedback, remote placement of the operating surgeon from the patient who operates from a console and has to rely on an assistant in the sterile field to undertake specific important tasks throughout the operation, for example, suction irrigation, haemostasis, cleansing/mopping of the operating field, stapling, etc.

The use of polyvinyl alcohol (PVA) sponges for control of bleeding, blunt dissection and other tasks is well established. In particular, they have been in routine clinical use in nasal surgery to prevent both post-operative haemorrhage and adhesion formation.[345] However, despite the established benefits of tampons/sponges especially in the control of bleeding, to date there have not been a sterile European Union (EU) labelled device for use in abdominal surgery. Such a device developed in Pisa is now marketed as the STAR System (Ekymed SpA, Peccioli, Italy), a single-use, disposable system which is CE marked specifically for use in laparoscopic surgery. For this study, a series of 20 unselected robotically-assisted and laparoscopic operations have been performed in which the use of the STAR System was evaluated.

MATERIALS AND METHODS

Between December 2012 and December 2014 in the Division of General Surgery of Cisanello Hospital (Pisa, Italy), STAR System (Ekymed SpA, Peccioli, Italy) has been serially used in 20 laparoscopic operations: 10 direct manual and 10 robotically-assisted.

Technical characteristics of the device

The STAR System is a disposable, EU CE marked device for laparoscopic surgery. It has two component parts [Figure 1]: The tampon (sponge), and the introducer/retriever. The dry tampon is made of hydroxylated polyvinyl acetyl tampon (slab shape 7.5 mm3 × 9 mm3 × 60 mm3), which can rapidly absorb a volume of 10 ml fluid (as it swells). It is connected to a buoy by means of a radiopaque wire. The white buoy remains clearly visible even in the presence of significant active haemorrhage, as is also radiopaque. The second component is a 26 mm long stainless steel tube with an ergonomic handle, in acrylonitrile butadiene styrene plastic, and an internal hook, which is used for retrieval of the tampon. The whole system is sterilised with ethylene dioxide gas and it is packaged in double-walled container.

Figure 1

STAR System, a device for haemostasis

Surgical technique

The STAR System device was introduced in various times during surgery, in accordance with the needs of the operation [Figure 2]. In all the manual laparoscopic operations, dissection was performed using harmonic scalpel, while both monopolar and bipolar coagulation were used in the robotically-assisted ones. The main tasks for which STAR System was inserted throughout the duration of both types of operations were: Haemostasis for minor bleeding, blunt dissection, atraumatic lifting of solid organs cleansing of surgical field, checks for bile leaks and application of haemostatic agents. Once introduced for a task, the STAR System was used also for others tasks if needed. At the end of operations, the sponge was removed using the own special retrieval system.

Figure 2

Introduction through a trocar inside the insufflated peritoneal cavity

For the purpose of this study, the reason of the insertion (RI), the main use (MU) and any further use (FU), once inserted, were registered for each operation and compared with the different surgical indications and between the two groups.

Statistical analysis was carried out with SPSS (Statistical Production and Service Solution for Windows, SPSS Inc., Chicago, IL, USA). Continuous variables were expressed as mean (range) and categorical variables as counts and percentages. Chi-square or Fisher's exact test were used for comparative study between the two approaches for single STAR System tasks. P <0.05 was considered statistically significant.

RESULTS

Surgical procedures included liver resection, anterior rectal resection, adrenalectomy, splenectomy and nephrectomy. The operations were performed successfully in all patients without intraoperative complications, with no conversion to open surgery or post-operative complications. The mean age was 60.7 years (range 37–79). The mean operative time was 231 min (range 150–340) and the mean intraoperative blood loss was 60.3 ml (range 35–130) [Table 1]. In both direct manual and robotically-assisted cases, the cleaning of the surgical field when needed, was performed using STAR System PVA tampon by placing the sponge between the tissues and the tip of the suction, thereby ensuing atraumatic suction/irrigation and avoiding accidental suction trauma to the tissues, which in not uncommon [Figure 3]. We also observed that the need for suction was reduced as a result of mopping with the sponge.

Table 1

Details of series used for study: Demographical, operations and post-operative outcome

Figure 3

Cleansing of the operative field by use of tampon interposed between tissue and suction device

In the robotic group, we noted that the principal RI of the sponge was the haemostasis for minor bleeding and in two cases the cleaning of the surgical field while in the laparoscopic group, in all cases, the sponge was inserted for haemostasis of minor bleeding [Table 2]. The RI was not statistically different between the two study groups, in all tasks (P = not significant).

Table 2

Use of STAR System table

As shown in Table 2, the MU of the sponge was the haemostasis of minor bleeding, the reason for which the sponge was designed, and the cleaning of the surgical field. However, in the robotic group cleaning the surgical field was more utilised than laparoscopic group (100% vs. 60%; P = 0.03). On the contrary, we did not note any differences in the other tasks considering the MU of the tampon.

About FU, atraumatic solid organs lifting was more frequent during robotically assisted surgery than with laparoscopy (50% vs. 0%; P = 0.01).

A statistically more frequent use of the sponge was registered during standard laparoscopy for the blunt dissection (30% vs. 80%; P = 0.03) [Table 3].

Table 3

Statistical analysis between the robotic and laparoscopic group for single task tampon usage

Furthermore, as can be seen from Table 2, the sponge was successively used for different tasks also depending on the type of surgical operation.

In particular, in the hepatic resections, the device was successfully employed during isolation of vessels at hepatic ilium where is absorbing proprieties proved very useful. The STAR System was also particularly useful in control bleeding during the parenchymal transection, in addition to its procoagulant activity. In fact, leaving the sponge on the cut surface during transection of parenchyma encouraged spontaneous haemostasis, such that the surgeon was able on lifting the sponge, to continue the dissection in a clear field. Moreover, the white buoy allowed easy optical recognition of the tampon in case of significant bleeding. At the end of the transection the use of STAR System in combination with FloSeal (Baxter Healthcare Corporation, Deerfield, IL, USA) on the cut surface resulted in excellent haemostasis. Finally, at the end of the liver resections, the stump was checked with STAR System to identify any bile leaks, in much the same way as is practiced in open hepatic resections with use of with gauze swabs.

In the two left robotic adrenalectomies, the sponge was useful for retraction of the spleen just to avoid damage caused by robotic instruments while in the left laparoscopic adrenalectomy the sponge was useful for blunt dissection. In one case of robotic adrenalectmomy, the sponge was used to achieve haemostasis in one major bleeding episode, consisting of significant haemorrhage from a large collateral vessel arising from splenic vein, which was accidentally damaged during dissection. In this instance, the combined use of FloSeal and STAR System tampon resulted in successful haemostasis [Figure 4a and b].

Figure 4

Application of FloSeal combined with the STAR system surgical tampon (a); haemostatic plug few minutes after application (b)

In laparoscopic nephrectomies, the blunt dissection of mesocolon from Gerota fascia was greatly aided by STAR System. Moreover, in these cases, the sponge was successfully used to keep the operative field clean from small bleeding points and lymphatic leakages during one of the most careful steps of nephrectomy, i.e., dissection of renal vessels from the surrounding lymphatic tissue.

In rectal surgery, the sponge was useful mainly to keep the operative field clean, especially during the total mesorectal excision, by helping the blunt dissection of the posterior avascular plane of mesocolon, which is mandatory to identify and preserve the ureter and the iliac vessels. In the narrow space of the pelvis, the effective cleansing of the surgical field allowed the identification and preservation of the pelvic splanchnic nerves, which is essential in these operations.[6] In one case of robotic rectal resection, a small capsular laceration of the spleen was inflicted inadvertently during splenic flexure mobilisation, and it was successfully controlled by application of FloSeal and compression with the sponge leaved under the fourth robotic arm until the haemostasis was achieved. Furthermore, in the robotic splenectomy, the STAR System sponge was useful to aid the retraction of colonic flexure and the exposure of spleen without direct manipulation by tips of robotic instruments directly on the organ. In another case, a small bleeding from a small branch during the isolation of the splenic vein was easily controlled by placing the sponge of the STAR System between the source of bleeding and the laparoscopic suction. The compression together with the initiation of the physiological coagulant cascade resulted in cessation of bleeding. The splenectomy then proceeded without any further complication. At the end of the interventions, the tampon was removed by the assistant in robotic-assisted operations and by the operative surgeon in the direct manual laparoscopic procedures, using its dedicated retrieval system [Figure 5a–c] without any mishaps.

Figure 5

Three retrieval steps a, b, c of tampon

DISCUSSION

The STAR System is the first hydroxylated polyvinyl acetyl sponge EU-labelled for laparoscopic surgery. Previously, Boni et al.[78] had described the efficacy of nasal tampons for control of minor bleeding, mopping fluid and tissue dissection during laparoscopic operations. Two problems regarding the use of nasal tampons are that they are not EU approved for abdominal surgery use and the possibility of surgical site seeding of tampon material during extraction through the trocar. Another important consideration is the risk of loss of the tampon in the peritoneal cavity without any means of radiological localisation as these nasal tampons do not contain radiopaque markers. The tampon-wire-buoy of STAR System avoids all these issues as the tampon incorporates a radiopaque maker which makes it easy to locate by X-ray.[9] Moreover, the compact PVA tampon structure obviates the problem of dispersion of component fibres. In addition, the white buoy ensures easy optical recognition of the tampon in the event of haemorrhage. The STAR System is inserted into the insufflated peritoneal cavity, following insertion of ports the beginning of operation. Once dropped and within <1 min of deployment, the STAR System sponge becomes bigger and softer, due to the contact with humidity/peritoneal fluid, which it absorbs, and is then ready for use. The STAR System tampon, with its buoy, is readily identifiable within the operative field and remains so even in the presence of severe bleeding. At the end of the procedure, removal is easy with the use of the dedicated retrieval system.

In both robotically-assisted and direct manual laparoscopic surgery, we have found use of tampon extremely useful to avoid suction-induced trauma when the sponge is placed between the tissue/organ and the tip of the suction device. In addition, the STAR System sponge reduces overall the need for suction/irrigation, thereby reducing the overall operating time.[10] The sponge is also useful for atraumatic lifting/displacement of tissue/organs due to its soft compressible consistency and thickness (15 mm when wet). At the end of the procedure, the tube of the STAR System allows safe retrieval and the squeezing of the tampon away from the abdominal wound; minimizing risk of any possible contamination. Moreover, during active bleeding, the need for use of thermal energy and suction is reduced thus avoiding instrument traffic associated with increased operative time and of CO2 losses.[11] One of the most important benefits from the use of the STAR System tampon is in achieving quick and effective haemostasis, not just by safe compression but also because of the promotion of the procoagulant cascade. Together with the combined use with suction and haemostatic agents (FloSeal) even major bleeding in hepatic and splenic surgery can be achieved. The hydrophilic capacity of the PVA sponge enables extraction of fluid from the blood during compression, resulting in a concentration of coagulation factors, which support haemostasis. Moreover, the smooth contact surface layer of PVA foam together with affinity to fibrin enhances polymerisation of fibrinogen polymerisation, hence achieving sealing of the bleeding site. In case of major bleeding such as that described from collateral of the splenic vein, the STAR System facilitated the placement of fibrin sealant haemostatic agents such as FloSeal. Similar applications of this have been reported previously.[12131415] The device is very useful to activate haemostatic effect of FloSeal in laparoscopic and robotic surgery as FloSeal needs a humid gauze for activation. However, in laparoscopic surgery use of gauze swabs is not recommended for safety reasons.[16] The STAR System tampon overcomes this issue.

The results of this study suggest that that the STAR System is a useful adjunct to laparoscopic surgery, but is particularly useful in robotically-assisted laparoscopic surgery; as the operative surgeon operates remotely from the patient and is not in immediate direct control of the operative field, and for this reason, has to delegate the execution of important tasks to an assistant surgeon standing in the sterile area at the operative table, who may not be very experienced especially for crucial tasks such as safe efficient control of minor haemorrhage and maintaining surgical field clean. In fact, while in the laparoscopic surgery the suction device is used by the first operator, in the robotic surgery it is used by the assistant and for this reason the first operator can exploit the sponge to maintain surgical field cleaned. In addition, the complete loss of tactile feedback in robotically assisted laparoscopic surgery is mitigated by interposition of the sponge between the tissue and potentially damaging maneuvers such lifting. Instead, mostly during standard laparoscopy, the sponge was used for blunt dissection. In fact, a limit of laparoscopic surgery in respect to the robotic surgery is the absence of wrist-like movements and magnified three-dimensional vision that can make blunt dissection and the dissection around hilar pedicles more difficult. For these reasons, the sponge could be used to gently dissect the structures and thus facilitate the identification and isolation of the structures.

CONCLUSIONS

This multi-purpose, EU CE marked device, is useful for many tasks during laparoscopic especially when robotically assisted. However, this promising initial report requires confirmation with larger prospective studies.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.