Prospective analysis of 164 fires of da Vinci SureForm SmartFire stapler in oncological cases: Indian cohort of 76 consecutive cases

Abstract

Background:

The application of robotic staplers in surgeries has increased in recent years. Robotic platform enhances ability of the surgeon to directly control and manoeuvre staplers to achieve required angulation and sealing within the confines of the thorax and pelvis. Hence, in this study, we intended to learn the effectiveness of the SureForm^™ SmartFire^™ technology stapling system in various oncological procedures.

Patients and Methods:

Prospective study of 76 patients who underwent robotic-assisted total oesophagectomy, gastrectomies, hemicolectomies, low anterior resection/abdominoperineal resection and lobectomies/metastasectomy for respective malignancies for 16 months. Internal data log of the da Vinci surgical system for reload colour, reloads used, clamp attempts and staple fires used during each procedure along with patient’s post-operative outcomes were recorded.

Results:

One hundred and sixty-four firings have been made in 76 cases, with the majority being green reloads (76.8%) and average reloads for radical cystectomy 3.5, lobectomies/metastasectomy 3.44 and oesophagectomy 2.55. None of the cases had incomplete firings and required force-fire activation. In forty per cent of cases, the robotic stapler had to pause for sequential compression and seal. Seventy per cent of anterior resection procedures had at least one firing >45° beyond the laparoscopy limit. Collectively 52% SureForm stapler fires in anterior resection with >45° angle of fire. None of the cases had bleed or leak.

Conclusion:

SureForm^™ SmartFire^™ robotic staplers can be used for various oncological surgeries with minimal peri-operative leak and bleeding and has better articulation in closed spaces. Further case-matched comparative studies with laparoscopic or handheld powered staplers would be required for useful operative decision-making and analyse the clinical outcomes.

INTRODUCTION

Robotic surgery has gained prominence in various surgical subspecialties. Compared to laparoscopy, the robotic platform enhances the ability of the surgeon to directly control and manoeuvre various challenges in the operating field due to its magnification, superior high-definition three-dimensional vision, camera and instrument stability, ergonomic positioning of the operating surgeon and endo wrist with 7° of freedom. All of these give a superior advantage for robotic-assisted procedures in confined spaces like that the thorax and pelvis. Stapling forms a critical step during many surgical procedures and involves anastomosis and the transection of vessels. Clean transection and integrity of the staple line are critical for adequate functioning of the anastomosis and achieving haemostasis.[1] Failure in achieving staple line integrity may end up in post-operative leaks and bleeding. Factors such as intrinsic mechanisms of the stapling system, tissue viscosity, staple height and anatomic location, influence the staple line formation.[2] In laparoscopy, the usage of manual or powered staplers to achieve required angulation and sealing within the confines of the thorax and pelvis forms a difficult task. Similarly, in most robotic surgical procedures, conventional endoscopic linear staplers were used by the bedside assistant. In mid-2018, Intuitive Surgical (Sunnyvale, CA, USA) received the United States Food and Drug Administration clearance for the SureForm^™ stapler with SmartFire^™ technology (referred to as the SureForm SmartFire Stapling System-SS) compatible with the da Vinci Xi^® Surgical System, which offers integrated stapling option for the da Vinci robotic system, thereby allowing for the entire procedure to be completed by the console surgeon. Hence, in this study, we intended to learn the effectiveness of the SS stapling system and its application in various oncological procedures performed at our institution.

PATIENTS AND METHODS

A prospective consecutive study of 76 patients who underwent thoracic, urinary bladder and gastrointestinal malignancy cases at our Manipal Comprehensive Cancer Centre, Bengaluru, were considered for the study from January 2021 to April 2022. Procedures considered in our study were robotic-assisted total oesophagectomy, robotic-assisted gastrectomies, robotic-assisted hemicolectomies, robotic-assisted low anterior resection, robotic-assisted abdominoperineal resection, robotic-assisted lobectomies/metastasectomy using the da Vinci X surgical system and SureForm 60/45^™ SmartFire^™ technology were included in the study. Tissues used for stapling were mainly bowel, lung and vessels. Inclusion criteria were patients of at least 18 years of age with a proven case of malignant thoracic, urinary bladder or GI malignancy. Patient demographics, medical history, pathology, tumour staging and procedural and stapler-specific details with clinical outcomes were documented.

The internal data log which is integral to the da Vinci surgical system captures the data with regard to reload selection by the colour, reloads used, clamp attempts and staple fires used during each procedure.

Definitions of specific terms notified during the usage of SureForm™ SmartFire™ stapler during the procedure were as follows

Clamp: post-dissection, the concerned tissue is navigated through the jaws of the stapler, and on depressing blue foot pedal for 3 s of the concerned arm, uniform compression is applied to the tissue concerned. Once successful, feedback is displayed to fire. Clamp completion: At the clamp completion, stapler jaws are adequately closed to enable the firing function. It is based on cantilever mechanism, where initially SmartFire™ technology gets activated by using software-based multiple algorithms and activates the fire option once the tissue thickness is adequate enough for iBeam mechanism to get activated during firing of staplers. Fire: The firing function gets activated when the clamp-based algorithm finds tissue thickness sufficient to be stapled. The firing sequence is activated once the yellow pedal of the concerned arm is depressed for 3 s resulting in simultaneous stapling and cutting of tissue. Clamp attempts: The total count of clamping attempts made to the tissue whether it is successful or unsuccessful to be fired. The attempts may vary based on the surgeon, if he finds the angulation is not sufficient even though it is clamped and ready to fire or it could be algorithm-based feedback mentioning, ‘Tissue too thick. Reposition or consider changing reload colour. Tap the blue pedal to unclamp’. Thus for a single procedure, the number of clamps can be equal to the number of fires done or more. Incomplete fires: It can occur when the stapler stops the firing sequence and may display a feedback message, ‘Tissue too thick to continue. Tap the blue pedal to unclamp and consider changing reload colour’. The surgeon can then unclamp and change to a higher reload colour or activate force fire if a black reload is being used at the time of the feedback message being displayed. Descriptive statistics were used to assess the data collected from the study using IBM SPSS Statistics for Windows, version 1.0.0.1406 (IBM Corp., Armonk, N. Y., USA). Categorical variables were summarised as frequencies and proportions while continuous data were expressed as mean ± standard deviation.

RESULTS

One hundred and sixty-four firings were done in 76 consecutive cases with robotic-assisted surgical oncology procedures at our institute over 15 months using SureForm 60/45^™ SmartFire^™ technology. Cases included in this study were varied into different regional specialties such as oesophagectomies (9), gastrectomy (13), hemicolectomies (9), anterior resection/abdominoperineal resection (34), lung resection (9) and radical cystectomies (2). The demographic, procedural details and clinical outcomes have been outlined in Table 1. The mean age of our cohort was 48.2 ± 6.9 years with the range being the youngest of 29 years and the oldest being 72 years. The mean body mass index was 26.3 ± 4.3 kg/m². The mean operative time for all the procedures was 179.7 ± 19.9 min with none of the cases required to be converted to open surgery and mean blood loss was 53.6 ± 21.8 ml. None of our patients had stapler-related complications and the mean length of stay was 7.18 ± 1.5 days [Table 1].

Table 1.

Demographic, intraoperative and postoperative details

	Overall	Esophagectomies	Gastrectomy	Hemicolectomies	Anterior Resection/Apr	Lung Resections	Bladder Resection
Number	76	9	13	9	34	9	2
Mean age (yr)	48.2 +/- 6.9	62.2 +/- 9.3	36.4 +/- 8.1	43.7 +/- 5.9	52.7 +/- 7.2	47.6 +/- 6.3	46.6
Gender
Male	52	6	9	ā5	23	7	2
Female	24	3	4	4	11	2	0
Mean bmi	26.3 +/- 4.3	23.4 +/- 2.3	24.6 +/- 4.7	27.6 +/- 4.3	28.3 +/- 3.7	26.7 +/- 5.2	27.3
Mean operative time (min)	179.7 +/- 19.9	182.5 +/- 32.1	131.4 +/- 21.2	147.4 +/- 16.4	210.8 +/- 8.2	165.4 +/- 17.5	240.7
Conversion to open	0	0	0	0	0	0	0
Mean blood loss	53.6 +/- 21.8	57.5 +/- 24.7	62.7 +/- 10.2	56. 3 +/- 29.3	42.1 +/- 23.3	44.5 +/- 19.2	58.8 +/-24.5
Mean length of stay (days)	7.18 +/- 1.5	8.6 +/- 2.1	7.1 +/- 1.8	5.2 +/- 1.9	8.52 +/- 1.08	4.2 +/- 0.9	9.5
Stapler related complications	0	0	0	0	0	0	0

One hundred and sixty-four firings have been made over 76 cases with the majority being used were green reloads (126, 76.8%) with average reloads used in carcinoma bladder resections 3.5, lung resection 3.44 and 2.55 in oesophagectomy. Maximum was used in bladder resection as it required to create a conduit, whereas, in lung resections, staplers were used for non-anatomic resections in metastasectomy cases as well as for vascular and bronchial stapling in the lobectomy cases. None of the cases had incomplete firings and also force fire option was never required to be activated. In 40% of cases, the robotic stapler had to pause for sequential compression and sealing once the firing pedal was activated [Figure 1]. In anterior resection, 70% of procedures were with at least one firing with the angle of fire >45°. Collectively, 52% times SureForm stapler fires in anterior resection with the angle of fire >45° [Figure 2]. None of the stapler lines had an air leak in lung resection cases or a bleed or leak in bowel anastomosis [Table 2].

Figure 1.

SureForm StaplerFire sequence after being activated

Figure 2.

Articulation angles achieved in rectal cancer surgeries

Table 2.

Stapler details

	Overall (n=76 )		Esophagectomies (n=9)		Gastrectomy (n=13)		Hemicolectomies (n=9)		Anterior Resection/Apr (n=34)		Lung Resections (n=9)		Bladder Resection (n=2)
	Total	Average	Total	Average	Total	Average	Total	Average	Total	Average	Total	Average	Total	Average
Fires	164	2.15	23	2.55	31	2.38	17	1.88	55	1.61	31	3.44	7	3.5
White reloads	9	0.11	0	0	0	0	0	0	0	0	6	0.66	3	1.5
Blue reloads	23	0.3	0	0	4	0.12	4	0.44	1	0.02	10	1.11	4	2
Green reloads	126	1.65	23	2.55	27	2.07	13	1.44	53	1.55	10	1.11	0	0
Black reloads	6	0.07	0	0	0	0	0	0	1	0.02	5	0.55	0	0
Incomplete	0	0	0	0	0	0	0	0	0	0	0	0	0	0

DISCUSSION

SureForm, a single-patient use stapling device with 12 reload applications is an industry first product with allows 120° of fully wristed articulation connected to the surgeon console. It helps surgeons to synchronously coordinate between clinical decision-making and instrument action. SureForm’s tip stability together with da Vinci’s tremor filtration and 120° of articulation in all directions may help provide surgeons with precise stapler manipulation and placement. SureForm uses SmartFire technology, an integrated software that optimises stapler and staple line performance.[3] Generally, stapling devices follow two principles either cantilever mechanism or iBeam mechanism. In cantilever mechanism, there is immediate application of force during clamping which enables tissue compression for haemostasis and reduces tissue oedema which is maintained during firing and tissue division/anastomosis. This mechanism is usually ineffective in larger staplers beyond 45 mm as it relies on the stiffness of the anvil and high tissue load can deflect the anvil. While iBeam mechanism, there is a slow application of force during clamping which increase during stapling as a spot on compression and firing. SmartFire technology measures tissue compression before and during staple firing, making automatic adjustments to the firing process as staples are formed and the transaction is made. Hence, it follows both the cantilever and iBeam mechanisms to form a B staple line. SmartFire follows an algorithm which makes >1000 measurements, helping to ensure a more consistent staple line, while helping prevent tissue damage, across a range of tissue thicknesses.[3] This makes it unique out of the previous generation endowrist staplers which would follow only cantilever mechanism.

This study is probably the first of its kind to provide a scientific and technological evaluation of SureForm 60/45^™ SmartFire^™ robotic staplers. It is controlled from the surgeon’s console with 60° articulation all around giving in total of 120° in both horizontal and vertical axes. SmartFire + technology runs algorithms while being clamped and provides an objective feedback if the required tissue is clamped successfully or requires further skeletonisation/upgradation of reloads by giving a message that, ‘Tissue too thick’.[3,4] If the tissue is successfully clamped then the firing sequence is enabled. It runs algorithms and by iBeam mechanism, it sequentially compresses and prepares the tissue for the optimal B staple lining and divides the tissue concerned sequentially after forming a secure staple line. This compensates the loss of tactile feedback which is being used in the laparoscopic staplers for effective stapling. Furthermore, due to the iBeam mechanism and simultaneous running of algorithms, if the tissue is not able to be sealed successfully that’s when it runs a command, ‘Tissue too thick’ where the reload can be changed or ‘force fire’ option could be activated if it’s the black reload being used [Figure 3]. Thus, it fulfils the criteria of optimal stapling, where there is adequate tissue compression, sequentially decreases tissue fluid, elongates the tissue to be stapled with smooth firing and consistent staple line formation balancing with excessive tensile strength and tissue fragmentation.[5] The reloads comes in four colours: white, blue, green and black colour based on ascending order for tissue thickness usage. Individual reload comes with the information which is relayed to the console on application to the stapler arm.[3,4]

Figure 3.

Intraoperative workflow for SureForm SmartFire stapler

In our study, we found that the robotic staplers are more effective in terms of tissue sealing, leak rates and articulation. In closed spaces like that of the pelvis, we could achieve with the angle of fire >45° with at least one firing in 70% procedures. Collectively, 52% times SureForm stapler fires in anterior resection with the angle of fire >45°, making it easy to manoeuvre in closed space and achieve tissue seal [Figures 2 and 4]. While most powered stapler angulates only up to 45°, which proves that robotic stapler has got a wide range of motion[6] [Figure 5]. A study by Holzmacher et al. compared laparoscopic stapler versus robotic stapler performance in robotic-assisted colorectal procedures and reported that there was no difference in complication rates and laparoscopic arm had more stapler fires per patient than the robotic group incurring higher direct stapler costs.[7] These findings were similar to our study where we had used an average of 1.88 fires and 1.61 fires in hemicolectomies and anterior resection, respectively. Although Hagen et al. reported unsuccessful stapler clamping in 20% of all attempts, with more reload and intraoperative complications of staplers for bariatric procedures, Holzmacher et al. and Atasoy et al. had contrary results of lesser stapler clamping failures similar to our findings.[7-9] In bladder resection and conduit formation, non-comparative studies by Mass et al. and Simone et al. found robotic staplers to be safe and efficient in creation in orthotopic neobladder with favourable peri-operative and functional outcomes similar to findings in our work. As for non-anatomic lung resections or lobectomies, there were varied outcomes with previous generation staplers. Some comparative studies reported that ultilisation of robotic staplers was associated with significant lower risks of peri-operative bleeding, air leak and conversion when compared to hand-held staplers, while some suggested that there was no difference in rates of complications between the two groups.[10,11] Our study is the first study to the best of our knowledge after the introduction of the SureForm 60/45^™ SmartFire^™ robotic staplers. The comparative studies and review articles of the robotic staplers concerns with the previous generation staplers. The limitation of our study was the absence of the comparative case-matched arm with laparoscopic powered staplers. More comparative and case-matched studies would provide better insight and open possibilities for the future research and analysis.

Figure 4.

Intraoperative images of SureForm staplers for rectal surgeries. (a) Distal transection for APR, (b) Distal transection in ultralow anterior resection, (c) Post-transaction stump close to the pelvic diaphragm, (d-f) Distal transection in low anterior resection showing angulation, clamping and remainder stump, post-transection. APR: Abdomino-perineal resection

Figure 5.

Intraoperative images of SureForm staplers. (a and b) Gastric conduit formation, (c) Oesophageal transaction in total gastrectomy procedure, (d-f) Lung resection

CONCLUSION

The study data demonstrate the efficiency of SureForm 60/45^™ SmartFire^™ technology robotic staplers in various oncological surgeries with minimal peri-operative leak, bleeding and better articulation in closed spaces with the detailed functional application of the staplers full controlled by the operating surgeon at surgeons console. The SmartFire algorithm paused in 40% of cases to achieve sequential compression once the fire pedal was activated. In LAR, 52% SureForm SmartFires stapling was able to be done beyond the laparoscopic powered stapler limit of 45°. Further, case-matched comparative studies with laparoscopic or handheld powered staplers would be required for useful operative decision-making and analyse of the clinical outcomes.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.