Single-port retroperitoneoscopic partial nephrectomy: Initial description and standardisation of technique

Abstract

Introduction:

Minimally invasive surgery has been established as the gold standard for the treatment of localised renal tumours. A retroperitoneal approach is a feasible option with advantages in posterior tumours and patients with previous abdominal surgeries. In this context, single-port retroperitoneoscopic partial nephrectomy (SPOR-PN) has not been widely explored and developed. We present this technique’s description and our first results.

Methods:

We present a case series of nine patients undergoing SPOR-PN in a single institution. We used a multi-channel single-port access dispositive through a 35 mm incision below the 12^th rib, a 30° two-dimensional laparoscope, curved graspers and needle drivers on the left hand and standard rigid material in the right hand. In all surgeries, we performed a complete renorrhaphy with the sliding-clip technique. The pain was evaluated through visual analogue scale (VAS) the day after surgery.

Results:

Patients’ age ranged from 44 to 78 years. The median RENAL score was 5p, and the mean surgical time was 134 min. We performed an ‘off-clamp’ procedure on three patients. Among the patients who had renal artery clamped, the median ischaemia time was 18 min. The median in-hospital stay time was 48 h. Median VAS the day after surgery was 2. None of the anatomical pieces had positive borders. Only one complication was reported (Clavien IIIa).

Conclusions:

SPOR-PN is a feasible minimally invasive and nephron-sparing technique. The advantages of this procedure may not be only a better cosmetic appearance but also less post-operative pain. Further development and larger studies are needed.

INTRODUCTION

Nephron-sparing surgery has gained widespread attention in recent years and constitutes the preferred option for T1 tumours when an intervention is indicated.[1-3] Moreover, it can be considered an option in T2 for patients with an anatomically or functionally single kidney, pre-existing chronic kidney disease or a known familiar renal cell carcinoma.[3]

Minimally invasive procedures, such as laparoscopic and robotic-assisted surgeries, are continuously being developed with new techniques and advances. These techniques pursue the ‘Trifecta’ concept:[4] preservation of healthy tissue, oncologic control and absence of complications.[4]

Single-port (SP) laparoscopy was first introduced by general surgeons in the late 90s, but it was first used in urology much later.[5] The objective was not only to achieve excellent cosmesis but also to decrease post-operative morbidity.[6] Unfortunately, in urology, SP surgery was not widely adopted, probably due to difficult technical aspects and a steep learning curve.[5,6]

Conventionally, laparoscopic partial nephrectomy (PN) has been done through a transperitoneal approach.[7] A retroperitoneal approach is a valid option and presents technical advantages over the transperitoneal approach in posterior renal tumours and patients with previous abdominal surgeries.[8] Furthermore, it is associated with less operative time, less blood loss and shorter hospital stays. It has also been suggested to have fewer intra-operative complications, mainly because of avoiding the need to move bowel structures and faster access to the renal artery.[8,9]

SP retroperitoneoscopic (SPOR) surgery was recently introduced as a novel method that combines the potential benefits of both minimal invasiveness and a retroperitoneal approach.[10,11] The technique has been reported several times for adrenalectomies and radical nephrectomies;[11-14] however, only anecdotal case reports were found in the literature for PN.[13,14] In this article, we describe the techniques and outcomes of what, to our knowledge, represents the first SPOR-PN case series in Europe.

METHODS

This study was done in accordance with the Declaration of Helsinki, was approved by the Regional Ethics Committee and included within the Urology Department line of investigation (code 2022/32). Informed consent was obtained from all enrolled patients. All data are available for review.

We describe nine cases of SPOR-PN. All surgeries were performed by the same surgeon, with previous experience in minimally invasive retroperitoneal surgery. All patients’ computed tomographies (CTs) were evaluated according to the RENAL score system by a single radiologist [Figure 1a and b].[15] Pain was assessed through visual analogue scale (VAS) the day after surgery. We collected information on ischaemia time, intra-operative bleeding, hospital stay duration and whether the tumour borders were compromised in the pathology report. Intra-operative bleeding was measured according to the amount of blood aspirated in the surgical field.

Figure 1.

(a and b) Kidney tumours on computed tomography scan. (c) External renorrhaphy. (d) Excision of kidney tumour

Surgical technique

We first placed the patients in lateral decubitus position with a light flex, delimited the anatomic references and then made a 30–40 mm incision below the 12^th rib cartilage [Figure 2b]. We created a retroperitoneal space through a balloon dilator[16] then, we collocated a multichannel SP device (Lapsingle^®, Sejong Medical, Paju, South Korea) and started insufflation with CO₂ with 12–15 mmHg of pressure [Figure 2c].

Figure 2.

(a) Curved graspers and needle holder. (b) Anatomical references and point of incision (dots). (c) Multi-channel device: we observe the introduction of the video laparoscope below, curved graspers in the left hand and conventional straight devices in the surgeon’s right hand. (d) Final result after placement of drain tube

We utilised a rigid two-dimensional 30° video laparoscope. In the surgeon’s left hand, a pre-bent articulated laparoscopic grasper and a pre-bent needle driver were used (Karl Storz SE and Co., Tuttlingen, Germany), and a standard laparoscopic devices was used in the right hand [Figure 2a].

After the access and creation of the retroperitoneal space retroperitoneal space, we localise first the renal artery. We then identify the tumour and score the capsule with monopolar scissors around it [Figure 1d]. In six cases, we clamped the renal artery with a vascular laparoscopic bulldog; then, we excise the tumour using cold scissors with the assistance of a grasper to provide counter traction. In the other three cases, we used ‘off-clamp’ technique since tumours were small and mostly exophytic.

We then proceeded to make a renorrhaphy in two planes: internally with a barbed 3/0 suture and externally with a multifilament 2/0 suture according to the sliding technique described by Benway et al. [Figure 1c].[17,18]

For safety reasons, we left a drain in all cases that was promptly removed in the first 24–48 h after surgery [Figure 2d].

RESULTS

Table 1 summarizes the patients’ characteristics and main results. The mean age was 53.89 (44–78) years. Right kidney tumours were present in 44% of patients, whereas 55.6% were on the other side. All tumours were posterior, and the median RENAL score was 5p (4–5). The mean surgical time was 134.4 min (70–190). Median ischaemia time, excluding off-clamp cases, was 18 min (5–23). Intra-operative blood loss was minimal, ranging from 10 to 180 ml. The median hospital stay was 48 h (24–96). All patients were managed only with oral analgesia and VAS media was 2 the day after surgery. Notably, all specimens had negative margins. We did not find any remarkable difference between right-sided versus left-sided tumours.

Table 1.

Patients’ characteristics and main results

Variables	Values
Patients	9
Age, mean±SD (range)	53.89±12.54 (44–78)
RENAL score, mean (range)	5 (4–5)
Tumour size (cm), mean±SD, (range)	1.7±0.48 (0.9–2.5)
Surgical time (min), mean (range)	134.4±34.5 (70-190)
Side (%)
Right	44.4
Left	55.6
Warm ischaemia time (min), mean±SD (range)	18±6.94 (5–23)
Off clamp (%)	33.3
Intra-operative bleeding (ml), mean±SD (range)	80±56.8 (10–180)
In-hospital stay (h), mean±SD (range)	48±20 (24–96)
Post-operative pain (VAS), mean (range)	2 (1–4)
Positive margins (%)	0

SD: Standard deviation, VAS: Visual analogue scale

We should remark the case in which ischaemia time was 5 min: It was a 2 cm exophytic tumour; after excising it, we observed a small and clean base, with no bleeding, so we decided to unclamp early.

We only had one remarkable surgical complication, Clavien–Dindo IIIa, as one patient experienced important bleeding after the intervention. The drain output after the first 2 post-operative hours was 180 cc, and an urgent CT showed surgical bed bleeding. The patient was managed by an endovascular intervention and remained stable with no further bleeding.

DISCUSSION

The basis for minimal invasion and miniaturisation procedures is settled in the reduction of tissue damage, less inflammation and blood loss and a faster post-operative recovery. In this sense, SP laparoscopy initial reports appeared in the literature almost 20 years ago.[19,20] Unfortunately, because of limitations regarding technological instrumentation, technical difficulty and troublesome reproducibility, broad development and use in urology were hindered. This paradigm is shifting nowadays as flexible tip laparoscopes and articulated operating instruments are becoming more widely available,[5] and new SP robotic platforms were recently launched.[21]

There are many reports on the feasibility of SP surgery in kidney surgery, and most of them have focused exclusively on the transperitoneal approach through the umbilicus.[19,22] A retroperitoneal approach shows superiority when dissecting the posterior axis of the kidney and allows faster access to the renal artery. In our experience and as per a previous meta-analysis, it is related to less post-operative pain, surgery time and blood loss.[8] Furthermore, it avoids damaging the bowel and the possibility of intraperitoneal contamination owing to urine leaks.[8] Even though SPOR had been reported in radical nephrectomy and adrenalectomy,[2,11] SPOR-PN was only reported in two previous case reports; however, no clear description of the technique was stated.[13,14]

We have shown that SPOR-PN is a feasible and reproducible procedure; our results show, most importantly, negative margins in the surgical pieces and minimal post-operative pain. We have several limitations, including a small patient sample and a lack of long-term oncologic results. In addition, SP retroperitoneoscopy requires many training hours and has a steep learning curve, especially when adapting flexible instruments to suturing, so future reproducibility studies should address these issues. The widespread adoption of this technique will need stronger evidence and long follow-up studies.

The advent of new SP robotic-assisted laparoscopic platforms has determined a revival of SP procedures.[21] We need to rely on more studies for stating if these procedures will become a new gold standard in the near future. We must carefully look if any of the aforementioned benefits – pain, cosmesis and technical advantages – mean better outcomes for patients compared to traditional approaches. We need better evidence if we want to encourage SP surgeries and justify funds for new robotic platforms. Studies such as ours help better understand the potential benefits of SP surgery and continue to push the boundaries of urology.

CONCLUSION

SPOR-PN is a feasible minimally invasive and nephron-sparing technique. The advantages of this procedure may not be only a better cosmetic appearance but also less post-operative pain. Further development and larger studies are needed

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.