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Keywords:

  • kidney;
  • nephrectomy;
  • renal cell carcinoma;
  • haemostasis;
  • surgical equipment;
  • nephron-sparing surgery

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

OBJECTIVE

To describe a technical modification that facilitates nephron-sparing surgery (NSS) for renal tumours, without clamping the renal pedicle or promoting renal surface hypothermia.

PATIENTS AND METHODS

Seventeen patients with renal tumours had NSS using the selective renal-parenchymal clamping technique. In 11 patients the tumour was polar and in six it was central. The mean (range) size of the tumours was 3.6  (2–6) cm. The technique was performed using one or two large Satinsky vascular clamps. Time was not limited as there was no clamping of the renal pedicle, or renal hypothermia.

RESULTS

The mean (range) operative duration was 190 (120–300) min. Only one patient needed a blood transfusion. There were no complications in 13 patients after NSS. The mean (range) hospital stay was 5 (3–12) days. The pathological examination detected malignant tumours in 13 patients, and a microscopic examination showed adequate surgical margins in all. The mean (range) follow-up was 24.5 (4–60) months. No patients required haemodialysis immediately after surgery or later.

CONCLUSIONS

Selective renal parenchymal clamping is a simple and efficient technical manoeuvre that facilitates NSS without dissection or clamping of the renal pedicle. Time is not limited as the ischaemia is limited to the tissue surrounding the tumour. The operative duration and blood loss are acceptable and the complications similar to those with the conventional technique. The size and position of the tumour could be limiting factors to this technique.


Abbreviations
NSS

nephron-sparing surgery.

INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Nephron-sparing surgery (NSS) is classically used in patients with a solitary kidney with tumour, bilateral synchronous disease or when the opposite kidney is affected by a condition that may threaten future function [1–4]. A tumour of >4 cm is a questionable indication for partial nephrectomy [5–7]. Recent studies of tumour biology and the long-term follow-up of patients undergoing NSS show that a unilateral tumour of <4 cm (T1a) and a normal contralateral kidney [8,9] are also indications for NSS. The long-term follow-up of tumours of ≤ 4 cm (T1a) shows the same development as in patients treated by radical nephrectomy in complications after surgery [10,11] and tumour recurrence [1–4].

It was widely recommended to remove up to 10 mm of surgical margin around the tumour during NSS. Recent studies show that a minimal margin is enough to give a satisfactory resection [12–14], and this stimulates surgeons to undertake more partial nephrectomies.

NSS usually comprises a wide dissection of the renal pedicle, artery and vein clamping, renal cooling by ice placed on the kidney surface, tumour resection and closure of the renal defect. Renal-pedicle clamping can lead to a long period of ischaemia, with transitory or even definitive loss of renal function. In patients with a solitary kidney with tumour, the repercussions of the loss of renal function (even when transitory) could be important after surgery.

In the present study we describe a technical modification that facilitates NSS for renal tumours, without clamping the renal pedicle and not causing ischaemia in the remaining kidney.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

Seventeen patients with renal tumours had NSS using selective renal parenchymal clamping; 10 were men and seven women, with a mean (range) age of 49 (32–70) years; the indication was elective in all patients.

In nine patients the tumour was in the left kidney and in eight in the right; the tumour was polar in 11 (four superior and seven inferior pole) and central in six. The mean (range) size of the tumours was 3.6 (2–6) cm; only two patients had tumours of >4 cm, one with a solitary kidney and the other with bilateral disease who had had a right radical nephrectomy and left partial nephrectomy.

Kidney dissection is minimal, with only en bloc separation of perirenal fat and kidney from the surrounding structures. After Gerota's fascia is opened perirenal fat is dissected 2 cm from the tumour edges, without removing the tissue covering the tumour, and only exposing the area that will receive the clamps. The renal pedicle is not dissected. The renal parenchyma is clamped selectively using one or two large Satinsky vascular clamps, placed around and sufficiently far from the tumour to allow the excision with adequate surgical margins (Fig. 1). Clamping pressure is carefully controlled by the strength applied by a second surgeon's hands on the clamps, enough to stop the bleeding but not to crush the tissue (Fig. 2). The resection should be at a minimum margin from the tumour edges. Transected parenchyma and surgical specimens were analysed using frozen sections in all cases. Intrarenal vessels and the collecting system were closed with absorbable suture when necessary (Fig. 3). The resected surface was closed on itself using separated absorbable 2/0 or 0 sutures. Gerota's fascia and perirenal fat were applied over this suture when possible. Time was not limited as there was no clamping of the renal pedicle, or renal hypothermia. A Penrose drain was used in all cases and left in place for 36–72 h.

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Figure 1. Tumour dissection, without removing the fat tissue that covers the tumour.

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Figure 2. Positioning the two Satinsky clamps around and sufficiently far from the tumour to allow excision with adequate surgical margins.

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Figure 3. The intrarenal vessels and collecting system are sutured.

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RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

The mean (range) operative duration was 190 (120–300) and this decreased to 160 (120–240) min if the analysis included only patients with no previous renal surgery and a unilateral tumour. The estimated mean intraoperative blood loss was 300  (200–1000) mL. Only one patient, who had a simultaneous radical nephrectomy on one side and partial nephrectomy on the other, needed a blood transfusion. The patients’ characteristics are shown in Table 1.

Table 1.  The patients’ characteristics
No.Age, years/ genderTumour size, cmPathologyFollow-up, monthsComplications
 142/M3.5RCC60New tumour in solitary kidney (different location from first resection)
 238/F4.0Mesoblastic nephroma50No complications
 355/M3.5RCC44No complications
 457/M6.0RCC36No complications
 550/M3.0RCC36Persistent haematuria (resolved spontaneously in 5 days)
 632/F4.0Multicystic nephroma30No complications
 762/M4.5Simple cyst27Persistent haematuria (resolved spontaneously in 6 days)
 843/M2.5Simple cyst24Incisional hernia
 932/F2.5Angiomyolipoma22No complications
1048/M4.0RCC16No complications
1161/F2.0RCC15No complications
1270/F4.0RCC14No complications
1348/M4.0RCC13No complications
1439/M3.0Simple cyst12Pneumonia
1565/F4.0RCC 8No complications
1650/M3.5RCC 7No complications
1751/F2.5RCC 4No complications

There were no major complications after NSS in any patient; four had minor complications, i.e. two had persistent haematuria (treated conservatively), one had pneumonia, and the other had an infected surgical incision. The mean hospital stay, including before surgery, was 5 (3–12) days and 12 patients left the hospital <3 days after surgery. The pathological examination detected malignant tumours in 13 patients; in 11 the diagnosis was RCC, in one it was mesoblastic nephroma, and in one it was multicystic nephroma. Of the four benign tumours three were simple cysts and one an angiomyolipoma.

A macroscopic surgical margin was respected in all patients, and microscopic examination showed adequate surgical margins in all. The mean follow-up was 24.5 (4–60) months. One patient, with von Hippel-Lindau disease, developed a new tumour in the same excised kidney; this patient had had a previous resection of the superior pole and developed a new tumour in the inferior pole. The mean serum creatinine level before surgery was 1.04 (0.61–2.0) mg/dL and that after surgery 1.26 (0.61–3.5) mg/dL. No patient needed haemodialysis immediately or later after surgery.

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES

NSS usually comprises a wide dissection of the renal pedicle and artery, and vein clamping and renal cooling, giving better bleeding control. Otherwise, pedicle dissection is time-consuming and leads to the risk of vascular injury with profuse bleeding. Renal pedicle clamping limits the resection time to 30–60 min, in which the tumour should be removed, prominent vessels sutured, the collecting system closed and tissue removed for frozen-section analysis. The most important complications of the conventional technique are urinary fistulae (8–10%) and acute renal failure in 20–25% of patients with a solitary kidney. In these cases haemodialysis is necessary, until kidney function recovers sufficiently. Vascular thrombosis with kidney loss is a rare complication, occurring in <1% of patients [10,11].

With selective renal parenchymal clamping the ischaemia is restricted to renal tissue close to the tumour. The remaining parenchyma is unaffected by ischaemia or cooling, and there is no risk of transitory or permanent loss of renal function, as with the conventional technique. The period after surgery is not affected by this technique, mainly in patients with a solitary kidney, as many complications of haemodialysis can be avoided.

Other surgeons use fingers to circumscribe the tumour and control bleeding during surgery; with this method, not only is one of surgeon's hands restricted, but also the tumour is not completely surrounded, leading to inaccurate control of the bleeding.

Selective renal parenchymal clamping uses one or two large Satinsky clamps, completely surrounding the tumour, and maintains exposure of all of the resection area with minimal bleeding. The renal pedicle is not dissected and the surgery is faster. Renal cooling is unnecessary and the surgical incision can be smaller. Renal ischaemia is localized and does not affect the remaining parenchyma. Prominent vessels and the collecting system can be sutured easily and rigorously, because the resection time is not limited, as there is no parenchymal ischaemia other than the resection area. The surgeon can easily adjust the clamp position at any time during surgery, with no loss of time, or important bleeding. By reducing the clamp pressure, the second surgeon allows the visualization of all bleeding vessels that should be sutured, facilitating complete control of bleeding before removing the clamps. The surgical specimen and tissue samples of the resection surface can then be assessed by frozen-section analysis of the surgical margins.

Similar techniques were described previously by other authors [15]. Gill et al.[16] described a technique using a tourniquet to control the bleeding, and Cariou and Cussenot [17] a technique using two small vascular clamps. However, these techniques were essentially useful for small polar lesions and not applicable for central tumours. Recently, Mejean et al.[18] described a new technique that uses one large aortic DeBakey clamp to surround the tumour and control the bleeding during resection. This technique is similar to the present, but they used a surgical loop around the clamp, tied by Kocher forceps, to control clamping pressure during surgery. A second surgeon's hands were kept free, but it was impossible to intermittently reduce the clamping pressure during surgery, to facilitate intrarenal suturing of open vessels. The adjustment of the clamp position is much more difficult with the other techniques than with the present method. Other studies do not refer to the use of two clamps simultaneously, which makes it possible to remove larger and central tumours with perfect control of bleeding. The follow-up was only 3 months and there was no reference to pathological examination of the surgical margins or about the malignancy of resected tumours in the recent report [18]. There were no major complications in the present patients and all had a satisfactory course during the follow-up.

The tumour size and location could be limiting factors for the present technique. If tumours are >7 cm then positioning the clamp could be very difficult, and in most cases we would use two clamps simultaneously. Tumours close to renal pedicle do not allow the clamp to be placed and would probably need the classical technique of pedicle clamping and kidney hypothermia, or the parenchymal suture technique, surrounding the tumour with haemostatic suture, enough to allow the resection.

In conclusion, selective renal parenchymal clamping is a simple and efficient technical manoeuvre that facilitates NSS with no dissection and clamping of the renal pedicle. Time is not limited as the ischaemia is restricted to the tissue surrounding the tumour. The operative duration and blood loss are acceptable and complications similar to those with the conventional technique. There is no need for any specific investment in surgical material or equipment for this technique, as it uses conventional vascular clamps. The size and position of the tumour could be limiting factors to this technique.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. CONFLICT OF INTEREST
  8. REFERENCES